bluuebunny/crossref_metadata_2025 huggingface dataset:
Connections of the bullfrog striatum: Efferent projections
Authors: Wilczynski Walter , Northcutt R. Glenn
Published: December 2004

Autoradiographic and degeneration techniques were used to describe striatal efferents in the bullfrog (Rana catesbeiana). Horseradish peroxidase (HRP) was then placed in the major terminal fields to reveal the striatal cells responsible for these projections. Except for the small ventral eminence of the lateral pallium immediately adjacent to the dorsal striatum, no pallial region receives a striatal projection. Most striatal efferents descend in the lateral forebrain bundle (LFB), passing through the anterior entopedun‐cular nucleus, where one large fascicle decussates in the anterior commissure and innervates the contralateral anterior entopeduncular nucleus and caudal ventral striatum. A smaller fascicle exits the LFB to terminate in the ipsilateral lateral amygdala. The remaining efferents continue caudal in the LFB through the posterior entopeduncular nucleus, with sparse projections to the ventral thalamus, the adjacent preoptic areas, and the posterior tuberculum leaving the bundle at various points. At pretectal levels, some efferents leave the LFB to run dorsally, through the caudal pole of the central thalamic nucleus and into the posterior division of the lateral nucleus and the lateral portion of the posterior thalamic nucleus. Efferents also continue caudal, through the superficial tegmental cell groups (nucleus profundus mesencephali and superficial isthmal reticular nucleus) before turning dorsomedially into the ventral anterodorsal, lateral anteroventral, and rostral pole of the posterodorsal tegmental fields. A small superficial projection continues to isthmal levels but cannot be traced beyond. Tegmental HRP injections retrogradely fill cells in the dorsal and ventral striatum as well as nucleus accumbens and the anterior entopeduncular nucleus. Pretectal HRP injections fill cells only in the caudal ventral striatum and anterior entopeduncular nucleus. Anterior entopeduncular nucleus HRP injections fill numerous cells in all striatal divisions, but some of this filling may be due to interrupted fibers of passage. Thus the anuran striatum, which receives its major input from thalamic nuclei relaying tectal and toral input, can in turn influence the midbrain roof via several disynaptic pathways: through the anterior entopeduncular nucleus, pretectum, and tegmentum, all of which project directly to the tectum and torus (Wilczynski and Northcutt, ′77; Wilczynski, ′81). Additional trisynaptic routes through the anterior entopeduncular nucleus and its pretectal and tegmental connections parallel the striatal routes.
Rapid fiber reorganization after early olfactory tract section and bulbectomy in the hamster
Authors: Small Rochelle K. , Leonard Christiana M.
Published: December 2004

Details of neuronal reorganization were investigated in golden hamster pups 10 days after neonatal olfactory lesions. Pups sustained unilateral olfactory tract section (ULOT) or unilateral olfactory bulbectomy (UOB) on postnatal day 5 (P5) and were then behaviorally tested through P15. UOBs were sacrificed after P15 to assess the extent of lesions. ULOTs were processed with degeneration techniques to demonstrate the terminal distribution of bulb fibers whose path had been either deflected or severed by the early tract section.

Ten days after complete tract section, extensive sprouting of bulb fibers had occurred rostral to the cut in olfactory as well as adjacent nonolfactory (e.g., neocortical) regions. The pattern of rostral sprouting was similar to, and in some cases exceeded, that described in adults subjected to neonatal tract sections (Devor, 76b). Fibers grew caudally past the cut following aberrant paths to reinnervate limited regions of the olfactory tubercle and less frequently, the piriform cortex. Unlike the continuous band of terminals soon in the caudal field of adults given neonatal tract sections, at this early stage of regrowth, fibers were organized in small discontinuous fascicles that tended to cluster at the islands of Calleja of the tubercle. Although these fibers innervated a relatively restricted region in comparison with normal innervation, their connections were apparently functional, as measured by a thermotaxis behavioral assay for the effects of UOB. The ther‐motaxis behavior of most pups showing tubercle reinnervation returned to normal, while the behavior of pups without tubercle reinnervation remained similar to UOBs (Small and Leonard, ′82). Excessive rostral sprouting and invasion of neocortex were seen in all tract‐sectioned pups and were, therefore, apparently not sufficient to sustain normal behavior on this assay.

Regrowth of sensory olfactory fibers and extensive formation of glo‐meruli in the anterior olfactory nucleus and, occasionally, in prefrontal neocortex were found following olfactory bulbectomy. There was no correlation between the extent of glomerulization and the behavioral performance, however.

The olfactory system provides an appropriate system for investigating the parameters governing age‐dependent axonal sprouting and functional recovery following early brain damage.
Postnatal development of auditory callosal connections in the kitten
Authors: Feng Jia Zhen , Brugge John F.
Published: December 2004

Tritiatedproline or horseradish peroxidase (HRP) was injected into the middle ectosylvian auditory cortex (AI) of one hemisphere in kittens during the first few weeks postpartum. Survival time was 24–96 hours. The tetra‐methylbenzidine (TMB) (Mesulam '78) method was used to process the HRP material. By the first postnatal day (PND 1) most neurons retrogradely filled in the contralateral auditory cortex form a densely packed, continuous band that presumably represents mainly layer III. This continuous pattern is in contrast to that seen in the adult cat where callosal neurons tend to aggregate in clusters. Other retrogradely labelled cells are more sparsely distributed in deeper layers with the greatest accumulation being in layer VI. At this time callosal neurons are elongated, with their long axes parallel to radial cell columns. In autoradiographs on PND 2, silver grains are seen throughout the thickness of the cortex, indicating that callosal axons have reached the upper layers of the gray matter. Neither the alternating vertical columns nor the laminar bands of callosal afferents that characterize this projection in the adult are clearly seen in kittens of this age. By PND 8–12 the segregation of callosal afferents into vertical bands is evident in the gray matter; by PND 18 this pattern is well developed. On the other hand, the somata of callosal neurons of layer III retain their juvenile distribution well into the seventh postnatal week and show adultlike aggregations sometime around the 14th week after birth. Projections to the medial geniculate body, inferior colliculus, putamen, caudate nucleus, and pons are clearly evident early in the first postnatal week.
The use of kainic acid for tracing neuroanatomical connections in the septohabenvilointerpeduncular system of the rat
Authors: Contestabile A. , Villani L.
Published: December 2004

Intracerebral injections of the neuron‐destroying agent, kainic acid, and electron microscopic examination of the injected and the target areas, have been used in order to confirm some controversial anatomical connections in the Septohabenulointerpeduncular system. Kainic acid injections in the lateral habenula (LHb) caused the selective degeneration of several LHb neurons, sparing the neurons of the medial habenula (MHb). Degenerating terminals were found in well‐known target areas of the LHb (dorsal and median raphe nuclei) and, in addition, in the interpeduncular nucleus (IPN), thus confirming the existence of a small LHb‐IPN projection. Kainic acid injections in the nucleus of the diagonal band of Broca (NDBB) resulted in severe ncuronal degeneration in the nucleus itself and in terminal degeneration in the LHb and MHb as well as, to a lesser extent, in the IPN. No evidence of distant neuronal damage was apparent by light (conventional and cupric‐silver stain) and electron microscopic examination, in nuclei receiving afferent inputs from the injected areas and projecting in turn to the target areas. Furthermore, terminal degeneration was not observed in the Hb and IPN after injections of kainic acid in areas not projecting toward these nuclei (hippocampus and striatum). In the present study, therefore, problems of interpretation due to the possible occurrence of distant neuronal damage could be overcome by control tests.

On the basis of the selectivity and sensitivity of its action, kainic acid seems particularly useful in the study of small projections and in attempts to discriminate between differential connections of adjacent neuronal populations.
Cortical and thalamic afferent connections of the insular and adjacent cortex of the rat
Authors: Guldin W. O. , Markowitsch H. J.
Published: December 2004

Thalamic and cortical afferents to the insular and perirhinal cortex of the rat were investigated, Unilateral injections of horseradish peroxidase (HRP) were made iontophoretically along the rhinal sulcus. HRP injections covered or invaded areas along the rhinal fissure from about the level of the middle cerebral artery to the posterior end of the fissure. The most anterior injection labeled a few cells in the mediodorsal nucleus. More posterior injections labeled neurons in the basal portion of the nucleus ventralis medialis, thus suggesting that this cortical region constitutes the rat's gustatory (insular) cortex. We consider the cortex situated posterior to the gustatory cortex in and above the rhinal sulcus as the core region of the rat's (associative) insular cortex, as this cortex receives afferents from the regions of and between the nuclei suprageniculatus and geniculatus medialis, pars magnocellularis. It includes parts of the cortex termed perirhinal in other studies. The cortex dorsal and posterior to the insular cortex we consider auditory cortex, as it receives afferents from the principal part of the medial geniculate nucleus, and the cortex ventral to the insular cortex (below the fundus of the rhinal sulcus) we consider to constitute the pre‐piriform cortex, which is athalamic. The posterior part of the perirhinal cortex (area 35) receives afferents from nonspecific thalamic nuclei (midline nuclei).

Cortical afferents to the injection loci arise from a number of regions, above all from regions of the medial and sulcal prefrontal cortex. Those injections confined to the projection cortex of the suprageniculate‐magno‐cellular medial geniculate nuclear complex also led to labeling in contra‐lateral prefrontal regions, particularly in area 25 (infralimbic region).

A comparison of our results with those on the insular cortex of cats and monkeys suggests that on the basis of thalamocortical connections, topographical relations, and involvements of neurons in information processing and overt behavior, the insular cortex has to be regarded as a heterogeneous region which may be separated into prefrontal insular, gustatory (somato‐sensory) insular, and associative insularportions.
A light and electron microscopic study of premotor neurons for the trigeminal motor nucleus
Authors: Mizuno Noboru , Yasui Yukihiko , Nomura Sakashi , Itoh Kazuo , Konishi Akira , Takada Masahiko , Kudo Motoi
Published: December 2004

Premotor neurons sending their axons to the trigeminal motor nucleus were observed in the cat by light and electron microscopy after labeling the neurons retrogradely or anterogradely with horseradish peroxidase (HRP).

After HRP injection into the trigeminal motor nucleus, retrogradely labeled neurons were seen most frequently in the parvocellular reticular formation bilaterally. Many labeled neurons were also seen contralaterally in the intermediate zone at the rostralmost levels of the cervical cord and its rostral extension into the caudalmost levels of the medulla oblongata. Additionally, some neurons were labeled ipsilaterally in the mesencephalic tri‐geminal nucleus, contralaterally in the main sensory trigeminal nucleus and the trigeminal motor nucleus, and bilaterally in the oral and interpolar sub‐nuclei of the spinal trigeminal nucleus. Only a few labeled neurons were seen in the confines of the gigantocellular reticular formation. All labeled neurons were small or of medium size; no large neurons were labeled.

After HRP injection into the regions around the trigeminal motor nucleus or the parvocellular reticular formation, axodendritic terminals containing HRP granules were found contralaterally within the trigeminal motor nucleus. Some of these labeled terminals were filled with round synap‐tic vesicles and others contained pleomorphic synaptic vesicles. The varied morphology of labeled axon terminals was considered to reflect the functional heterogeneity of the premotor neurons for the trigeminal motor nucleus.
Characterization of the peripheral‐type benzodiazepine receptors in cultured astrocytes: Evidence for multiplicity
Authors: Itzhak Yossef , Baker Linnell , Norenberg Michael D.
Published: December 2004

In mammalian brain peripheral benzodiazepine (PBZD) receptors are predominantly localized on astroglial cells. Previous studies utilizing whole membrane preparations from brain and peripheral organs of various species have indicated several distinctions between the drug‐receptor interactions of the two prototypic PBZD receptor ligands, PK 11195 and Ro5‐4864. The present study was undertaken to determine whether putative differences in the binding of PBZD receptor ligands in homogenates of primary astrocyte cultures can be interpreted as the labeling of PBZD receptor subtypes. Equilib‐rium competition and saturation binding experiments in homogenate preparations of primary astrocytes from cerebral cortex of new born rats revealed that [3H]PK 11195 labels twice the number of [3H]Ro5‐4864 binding sites. Unlabeled Ro5‐4864 competes for [3H]PK 11195 binding in a manner suggesting the existence of multiple PK 11195 bind‐ing sites. The competition binding experiments, using various benzodiazepines, indicate that one binding component of PK 11195 corresponds to Ro5‐4864 binding sites, whereas the second is different. The latter binding site does not correspond to the central BZD receptor but displays the pharmacological properties of the PBZD receptor. Further differences between the binding of PK 11195 and Ro5‐4864 in astrocytes were detected in the presence of ethanol which was more effective in inhibiting the binding of the latter. Subcellular distribution studies indicated, however, that the binding of both [3H]PK 11195 and [3H]Ro5‐4864 is associated primarily with the mitochondrial fraction of astro‐cytes. Taken together, the present study indicates the existence of non‐overlapping PBZD binding sites in astrocytes and thus suggests the existence of PBZD receptor subtypes. It appears, however, that there is no distinction in the subcellular localization of the putative subtypes of the PBZD receptor. © 1993 Wiley‐Liss, Inc.
Binding of atrial and brain natriuretic peptides to cultured mouse astrocytes from different brain regions and effect on cyclic GMP production
Authors: Yeung V. T. F. , Ho S. K. S. , Leung D. H. Y. , Stadlin A. , Nicholls M. G. , Cockram C. S.
Published: December 2004

We prepared primary cultures of mouse astrocytes from the cerebral cortex, hypothalamus, and cerebellum to examine the possibility of regional disparity in binding of human atrial and porcine brain natriuretic peptides (hANP, pBNP) and their effect on cyclic guanosine monophosphate (cGMP) production. 125I‐hANP and 125I‐pBNP bound in a specific and saturable manner to all three regions. For both peptides, Scatchard analysis suggested a single population of binding sites on astrocytes from all three regions. No significant differences were observed in the maximal binding capacities (Bmax) or binding dissociation constants (KD) between the two peptides in the astrocyte preparations from different regions. ANP and BNP also evoked cGMP stimulation in a similar, dose‐dependent fashion in astrocytes from all three regions, with maximal responses to both peptides reached at a concentration above 1 μM. While BNP elicited a greater maximal cGMP accumulation than ANP, no difference could be demonstrated in the cGMP responses to either peptide between brain regions. Thus we have been unable to demonstrate regional heterogeneity in the responsiveness of astrocytes to ANP and BNP. © 1993 Wiley‐Liss, Inc.
Cytokine receptors on glial cells
Authors: Otero Glen C. , Merrill Jean E.
Published: December 2004

Given what evidence there is for the molecular and functional nature of cytokines and their cognate binding proteins in the immune system and the emerging similarities or even identities for these ligands and receptors in the nervous system, two general models may be relevant. The first emerging pattern is that receptors for related but distinct trophic factors in the CNS are in many instances multichain complexes with one or more shared components. The shared components of the receptor complex may be either signal‐ or nonsignal‐transducing chains. A second emerging motif is that related ligands and related receptors fall into gene families. Undoubtedly, these models will facilitate the cloning of novel members of these families whose function is quite specific to the nervous system and in particular to glial cells. This article will review the function of the receptors for cytokines and families of differentiation/survival/growth factors as they operate on astrocytes, microglia, and oligodendrocytes in development, health, and disease. © 1994 Wiley‐Liss, Inc.
Beitrag zur Emissionsspektralanalyse von Molekeldämpfen
Authors: Handelsmann M.
Published: December 2004

Es wird der minimale Sättigungsdruck bestimmt, bei dem sich die Salzdämpfe der Halogenide von Quecksilber, Cadmium und Zink auf Grund ihrer charakteristischen Bandenspektren in einem mit Aussenelektroden versehenen Entladungsrohre noch nachweisen lassen. Der mittlere Wert der minimalen Sättigungsdrucke beträgt 0,01 mm. Die untere Grenze für die absolute Nachweisbarkeit liegt im Falle von HgCl2 bei ca. 3 γ.
Der Abbau der Behensäure im Tierkörper
Authors: Bernhard Karl , Vischer Ernst
Published: December 2004

1. Wir hydrierten aus Rapsöl gewonnene Erucasäure mit schwerem Wasserstoff und fütterten Ratten, einem normalen Futter beigemischt, Deuteriobehensäure‐äthylester. Die Resorption betrug bei Zulagen von 5 und 10% Ester zur Nahrung berechnet auf Behensäure rund 40%.
Synthèse de la 6‐ et de la 8‐trifluorométhyl‐quinoléine
Authors: Pouterman E. , Girardet A.
Published: December 2004

Au cours de ce travail nous avons amélioré la préparation du trifluorotoluéne et avons montré que la décomposition du phénylchloroforme observée par Swarts doit être imputée aux impuretés contenues dans ce produit. Nous avons également montré, que lors de la chloruration du p‐nitrotoluéne à température élevée en présence de pentachlorure de phosphore ou d'anhydride phosphorique, il y a substitution du groupe nitro par le chlore, avec formation du chlorure de l'acide p‐chlorobenzoïque.
Sur la présence d'ionones dans les produits végétaux
Authors: Naves Y.‐R.
Published: December 2004

La β‐ionone, identifiée précédemment dans l'essence de Boronia megastigma, l'est aussi dans l'essence obtenue des marcs de framboise.
Zum Mechanismus der Photochemie von 2‐Alkylindazolen in wässerigen Lösungen
Authors: Heinzelmann Willy , Märky Michael , Gilgen Paul
Published: December 2004

Mechanistic studies on the photochemistry of 2‐alkylindazoles in aqueous solutions.

The photochemistry of 2‐alkylindazoles 1 in aqueous solutions is rather complex, the relative yields of different products being dependent on the pH‐value of the irradiated solution: In neutral or basic solutions (pH > 7) as well as in most of the organic solvents isomerization to 1‐alkyl‐benzimidazoles 2 takes place. In dilute sulfuric acid (pH 2–4) this reaction is suppressed and the dihydro‐azepinones 3 and 4 are formed. Irradiation in strongly acid solutions (pH < 1) yields the o‐amino‐acetophenones 5 (Scheme 1).

The relative quantum yields of the photoproducts 2–5 have been measured as a function of the pH‐value of the irradiated solution (Fig. 1). A comparison of these yields with the protonation equilibrium of the indazole in its first excited singlet state (pK = 2.8) suggests that 2 and 3 are both photoproducts of the neutral indazole molecule, whereas 4 as well as 5 are formed from the protonated indazole.

The rearrangement of the indazole 1 to the benzimidazole 2 proceeds via an intermediate 6, which can be produced in high concentrations by monochromatic irradiation of 1 at low temperatures. The thermal reactivity of this intermediate in dilute sulfuric acid could be investigated: At pH 8 the only product is the benzimidazole 2. With decreasing pH‐value increasing amounts of 3 are formed and at pH < 4 the formation of 2 is completely suppressed, the only product being the azepinone 3. Thus, 3 is a solvolysis product of the intermediate 6 (Scheme 2).

The most probable primary product of singlet indazolium is the nitrenium ion 7. From this intermediate the formation of 5 can proceed in well‐known thermal reactions. The formation of 4 is possibly due to a further protonation equilibrium nitrenium‐nitrene. The nitrene 7 can be converted into the azepinone 4 via the azirine 8 (Scheme 3). The pK‐values of different indazoles and intermediates are listed in the Table.
Heterotricyclodecane XX (+)‐(1S, 3S, 6S, 8S)‐ und (−)‐(1R, 3R, 6R, 8R)‐2, 7‐Dioxa‐twista‐4,9‐dien
Authors: Ackermann Peter , Ganter Camille
Published: December 2004

(+)‐(1S, 3S, 6S, 8S)‐ and (−)‐(1R, 3R, 6R, 8R)‐2,7‐dioxa‐twista‐4,9‐diene.

A synthesis and the determination of the sense of chirality of (+)‐(1S, 3S, 6S, 8S)‐ and (−)‐(1R, 3R, 6R, 8R)‐2,7‐dioxa‐twista‐4,9‐diene ((+)‐5 and (−)‐5, respectively) is described.
Flash Pyrolysis of 4‐Arylmethylidene‐oxazolones and ‐isoxazolones. A Versatile Synthesis of Arylacetylenes. Preliminary communication
Authors: Wentrup Curt , Reichen Werner
Published: December 2004

Flash pyrolysis of 4‐benzylidene‐2‐phenyl‐5(4H)‐oxazolone (1) yields carbonmonoxide, benzene, biphenyl, diphenylacetonitrile, and 2,3‐diphenylsuccinonitrile; N‐benzoylphenylketenimine is implicated as the primary intermediate. The flash pyrolysis of 4‐arylmethylidene‐3‐methyl‐5(4H)‐isoxazolones (3) yields carbon dioxide, acetonitrile, and phenylacetylenes substituted by alkoxy, chloro, dimethylamino, and hydroxy groups, in yields of 45–95%. Arylmethylidenecarbenes are implicated as intermediates.
Linear‐reactor‐infrared‐matrix and microwave spectroscopy of the cis‐2‐butene gas‐phase ozonolysis
Authors: Kühne Heinz , Forster Martin , Hulliger Jürg , Ruprecht Heidi , Bauder Alfred , Günthard Hans‐Heinrich
Published: December 2004

Investigation of the formation of complex products in the gas‐phase ozonolysis of cis,‐2‐butene by linear‐reactor‐infrared‐matrix and linear‐reactor‐microwave spectroscopy is reported. The following species have been unequivocally detected: secondary 2‐butene ozonide, acetic acid, peracetic acid, glycolaldehyde, dimethyl ketene, the simple and mixed anhydrides of formic and acetic acid, 2,3‐epoxybutane and 2‐butanone, besides polyatomic products already known. In contrast, the primary ozonide has been detectable neither by LR.‐MW. nor by LR.‐IR. Observation of both stereoisomeric epoxides and kinetic modelling are used to support the intermediate formation of the O'Neal‐Blumstein radical CH3CH(O2)CH(O)CH3 and the existence of a reaction channel in which the two carbon atoms of the C, C double bond of the olefin remain connected. As the dominant reaction path a mechanism with a Criegee type split into methyldioxirane (ethylidene peroxide) and acetaldehyde is considered and subsequently proposed to explain formation of many complex products by either unimolecular or bimolecular processes of the peroxide. For the reactions considered, thermochemical estimates of reaction enthalpies and activation data are included. Kinetic modelling for a partial reaction mechanism involving at least two different paths of decay of the O'Neal‐Blumstein biradical into Criegee‐type intermediates and the 2, 3‐epoxybutanes is discussed.
A Model for Nicotinamide‐Trytophane Charge‐Transfer Interactions: The complexation of nicotinamide‐ammonium salts by a macrocyclic receptor molecule bearing tryptophane side chains
Authors: Behr Jean‐Paul , Lehn Jean‐Marie
Published: December 2004

The complexation of primary ammonium salt substrates by macrocyclic polyether receptor molecules provides a general method for studying the nature and stereochemistry of intermolecular interactions. The substrates and receptors are fitted each with one of the interacting units and the resulting effects in the complex are analyzed. The method is used to study the biologically important indole‐pyridinium donor‐acceptor interaction. The complexes between macrocycles, bearing an indole group in side chains, and pyridinium‐ammonium salts display a characteristic charge‐transfer band. The absorption coefficients and stability constants have been determined. Competition experiments also provide a new method for measuring the stability constants of macrocycle‐ammonium complexes in organic solvents.
New Iridoid Glucosides and a Lignan Diglucoside from Globularia alypumL
Authors: Chaudhuri Ratan K. , Sticher Otto
Published: December 2004

The four new iridoid glucosides globularicisin (2), globularidin (5), globularimin (9), and globularinin (13), the lignan diglucoside liriodendrin (18), and syringin (20) have been isolated from Globularia alypum L. along with the previously reported glucosides globularin (1) and catalpol (4). Compound 2 is the first report of any cinnamoyl iridoid with a cis‐configuration at the acyl double bond. Compound 5 is another novel iridoid which lacks the characteristic C(3), C(4) double bond in the aglucone part. Compounds 9 and 13 are diastereomeric and contain highly oxygenated aglucone structures. The isolation of liriodendrin, from Globularia alypum is the first demonstration of the occurrence of a lignan in the family Globulariaceae.

The structures have been elucidated by 1H‐ and 13C‐NMR. spectroscopy as well as by chemical transformations. Taxonomical significance of the cooccurrence of iridoid and lignan glycosides as well as the antileukemic potentiality of the latter are also appraised.
Ladroside (= 6′‐Caffeoyl‐mussaenoside), a New Iridoid Glucoside from Veronica officinalis L. (Scrophulariaceae) and the elucidation of the absolute configuration at C(8) of mussaenoside
Authors: Afifi‐Yazar Fatmaüu , Sticher Otto , Uesato Shinichi , Nagajima Kimiko , Inouye Hiroyuki
Published: December 2004

A new iridoid glucoside, named ladroside, together with mussaenoside (1) [2], has been isolated from Veronica officinalis L. The structure of ladroside (4) and the identity of mussaenoside have been established by spectral analysis. Additionally, the absolute configuration at C(8) carrying the tertiary hydroxyl group has been established by chemical evidence.
Metallic Conductivity in Metal Tetraaza [14]Annulene Iodides: The Crystal Structures of Dihydrodibenzo‐[b, i]‐1, 4, 8, 11‐tetraazacyclotetradecinenickel and ‐palladium Iodides
Authors: Hunziker Max , Hilti Bruno , Rihs Grety
Published: December 2004

Single crystals of dihydrodibenzo[b, i]‐1, 4, 8, 11‐tetraazacyclotetradecinenickel iodide show metallic conductivity between room temperature and approx. 110 K. The crystals are orthorhombic, space group Ibam with four formula units per cell of the following dimensions: a = 20.245, b = 13.416, c = 6.418 Å. The analogous palladium complex is isomorphous, the cell constants being a = 20.452, b = 13.430 and c = 6.499 Å. A number of other partially oxidized metal tetraaza [14]annulenes also show electrical conductivity.
Reactions of Disulfides Derived from Penicillin Sulfoxides with Tertiary Phosphines in Presence of Carboxylic Acids
Authors: Prasad Kapa , Hamberger Helmut , Stüutz Peter , Schulz Gerhard
Published: December 2004

A novel method for the preparation of thioesters starting from Iso‐Fujisawa disulfides is reported. The presence of an acylamino group cis to the disulfide function on the β‐lactam nucleus seems to be an essential requirement for this reaction. In the absence of such a cis‐acylamino group, desulfurization, is the preferred course.
Isolation and Structure of Pseurotin A, a Microbial Metabolite of Pseudeurotium ovalis STOLK with an Unusual Heterospirocyclic System
Authors: Bloch Peter , Tamm Christoph
Published: December 2004

The structure and absolute configuration of pseurotin A, a new metabolite, isolated from culture filtrates of Pseudeurotium ovalis STOLK (Ascomycetes) has been shown to be (1′S, 2′S, 5S, 8S, 9R, 3′Z)‐8‐benzoyl‐2 (1′,2‐dihydroxy‐3′‐hexenyl)‐9‐hydroxy‐8‐methoxy‐3‐methyl‐1‐oxa‐7‐azaspiro [4,4]non‐2‐ene‐4,6‐dione (1).
Visible Light Induced Water Cleavage in CdS Dispersions Loaded with Pt and RuO2, Hole Scavenging by RuO2
Authors: Kalyanasundaram Kuppuswamy , Borgarello Enrico , Gráutzel Michael
Published: December 2004

Illumination of aqueous CdS dispersions loaded with Pt and RuO2 by visible light produces hydrogen and oxygen in stoichiometric proportion. No degradation of the photocatalyst is noted after 60 h of irradiation time. The RuO2 deposit on the particle surface greatly accelerates the transfer of holes from the semiconductor valence band to the aqueous solution thus inhibiting photocorrosion.
Über Pterinchemie. 77. Mitteilung)Das (6R,S)‐5‐Formyl‐6‐methyl‐5,6,7,8‐tetrahydropterin: Synthese, chemische und physikalisch‐chemische Eigenschaften
Authors: Ganguly Abhoy N. , Bieri Jost H. , Viscontini M.
Published: December 2004

(6R,S)‐5‐Formyl‐6‐methyl‐5,6,7,8‐tetrahydropterine: Synthesis, Chemical and Physico‐chemical Properties

(6R, S)‐5‐Formyl‐6‐methyl‐5,6,7,8‐tetrahydropterine (III), a model substance for the biologically important 6‐substituted 5‐formyl‐5,6,7,8‐tetrahydropterines, was obtained for the first time by formylation of the corresponding tetrahydropterine with formic acid. Compound III, analogously to the other known 5‐acyltetrahydropterines, exists in solution (except in DMSO) as a mixture of two rotamers IIIa and IIIb. The two H‐C(7) in III have the same chemical shift and the same coupling constant to H‐C(6), giving rise to a A,A',X,C‐system. Conformational analysis of III, based on its 1H‐NMR,‐spectrum, shows that the methyl group is pseudo‐axial and the formyl group pseudo‐equatorial. Moreover, the H(X)‐C(6) bond lies nearly in the plane bisecting the C(6)‐C(7)‐H(A), C(6)‐C(7)‐H(A') dihedral angle; the C(6) and C(7) lie outside the N(5)‐C(4a)‐C(8a) plane and the tetrahydropyrazine cycle must be extremely strained, according to Dreiding models.
Natural Occurrence of Enantiomeric and meso‐Astaxanthin. 5. Ex wild salmon (Salmo salar and Oncorhynchus)
Authors: Schiedt Katharina , Leuenberger Franz J. , Vecchi Max
Published: December 2004

The configurational isomers of astaxanthin (3,3′‐dihydroxy‐β,β‐carotene‐4,4′‐dione) from the flesh of salmon (Salmo salar and Oncorhynchus) caught at different places in Europe and Canada were isolated and analyzed as (−)‐camphanic acid diesters by means of HPLC. The biological variation in the composition of the configurational isomers in seven fish was surprisingly similar: 78 to 85% of (3S, 3′S)‐astaxanthin, 12 to 17% (3R, 3′R)‐astaxanthin and 2 to 6% meso‐astaxanthin.
Selektive Umfunktionalisierung der terminalen Amidgruppe offenkettiger Polyamide via 2‐Oxazolin‐5‐one als Zwischenstufen. Vorläufige Mitteilung
Authors: Obrecht Daniel , Heimgartner Heinz
Published: December 2004

Selective Modification of the Terminal Amide Group of Linear Polyamides via 2‐Oxazolin‐5‐ones as Intermediates

Treatment of aqueous or alcoholic solutions of diamides of type 2 with HCl leads to the formation of amide‐acids and amide‐esters of type 3 (Scheme 1 and Table). It has been shown, that 2‐oxazolin‐5‐ones of type 4 are intermediates of this selective transformation of the disubstituted terminal amide group. The selectivity of the transformation is demonstrated by the reaction sequence shown in Scheme 3. No selectivity has been observed in the acid‐catalyzed hydrolysis of triamide 9 with a monosubstituted terminal amide group (Scheme 4). Hydrolysis of the optically active dipeptide derivatives (+)‐(L)‐13 and (+)‐(L)‐15 with HBr in nitromethane at 60–80° yields the pure enantiomer (+)‐(L)‐14 and (+)‐(L)‐16, respectively (Scheme 5), i.e., no racemization takes place under the reaction conditions.

These results show the usefulness of the dimethylamide group as a protecting group for carboxylic acids for example in the peptide synthesis.
Complexes of Lanthanoid Nitrates with 15‐Crown‐5 and 18‐Crown‐6 Ethers
Authors: Bünzli Jean‐Claude G. , Wessner Denis
Published: December 2004

Complexes between the heavier lanthanoid nitrates Ln(NO3)3 and 15‐crown‐5 (1) and 18‐crown‐6 (2) ethers were isolated and characterized. Both 1:1 and 4:3 complexes are formed with each Ln(III) ion, except in the case of Gd and 2. The thermal transformation of the 1:1 complexes into the corresponding 4:3 complexes was studied by thermogravimetry and by DSC, X‐ray and vibrational data provide information about the structure of these complexes. The interaction between Ln(III) ions and ligands 1 and 2 in non‐aqueous solutions is discussed on the basis of conductometric, fluorescence, UV./VIS. and 1H‐NMR. data. Only 1:1 complexes of 2 formed in solution and their formation constants range from logKf = 4.4 (Ln = La) to 2.4 (Ln = Yb); for Eu, Kf of the 15‐crown‐5 and 18‐crown‐6 ether complexes are of the same order of magnitude. For La, Pr, Nd, Eu, Yb, a variable temperature NMR. study gave some indications about the chemical exchanges in solution.

The factors which determine the stoichiometry of the complexes are discussed.
Synthese und Charakterisierung der 8 isomeren, im Ring B mono‐ bzw. dihydroxylierten Royleanone
Authors: Meier Heidi , Rüedi Peter , Eugster Conrad Hans
Published: December 2004

Synthesis and Characterization of the 8 Stereoisomeric Royleanones with One or Two Hydroxy Groups in Ring B

The partial syntheses of 6α, 7α‐dihydroxyroyleanone (6a), 6α, 7β‐dihydroxyroyleanone (7a) and 6β, 7β‐dihydroxyroyleanone (9a) are described. Thus, all in ring B mono‐ and dihydroxylated royleanones are now known (see [2–11]), being fully characterized by extensive spectroscopic, chiroptic and chromatographic (HPLC.) methods. An opening of the epoxyroyleanone 11a yields cis‐ and trans‐diols together with their corresponding mono‐ and di‐O‐acetyl derivatives. We postulate a reversible addition of the acetate ion at C(8) of the quinone system, followed by a neighbouring group participation of this O‐acetyl group.
Aromatization of 1‐Benzyltetrahydroisoquinolines: Racemization of (−)‐(S)‐(N‐nor)‐Reticuline
Authors: Buchs Peter , Brossi Arnold
Published: December 2004

Aromatization in the series of optically active 1‐benzyltetrahydroisoquinolines has been accomplished with (—)‐(S)−(N‐nor)‐reticuline (1b) and analogs. Direct catalytic or chemical reduction of the isoquinoline 4 obtained could not be achieved in a practical way but 4 was converted into 1 in three steps (4 → 8 → 9 → 1), in 55% overall yield. Partial O‐methylation of the isoquinoline 4 gave the isoquinoline alkaloid palaudine (5), before papaverine (6) was formed.
Stereoselektive Hydrid‐Reduktion von Tetronsäurederivaten. Synthese verzweigtkettiger Tetrofuranosen
Authors: Wyss Heinz , Vögeli Ulrich , Scheffold Rolf
Published: December 2004

Stereoselective Hydride Reduction of Tetronic Acid Derivatives, Synthesis of Branched‐Chain Tetrofuranoses

The 3‐methoxymethyl derivatives of 2‐methyl‐D, L‐threofuranose (10a) and 2‐deoxy‐2‐methyl‐D,L‐erythrofuranose (11a) are prepared starting from 2‐methyl‐tetronic acid (1). The key step is the stereoselective reduction of the 3‐oxo‐function of 2‐chloro‐2‐methyl‐3‐oxo‐γ‐butyrolacton (2) by sodiumborohydride, which proceeds predominantly anti with respect to the C,Cl‐bond. The configuration of the reduction products has been established by 1H‐ and 13C‐NMR.‐spectroscopy.
1‐Amino‐2‐phthalimido‐diazen‐1‐oxide: Bildung, Eigenschaften und Fragmentierungen in Imido‐ und Amino‐nitrene
Authors: Hoesch Lienhard
Published: December 2004

1‐Amino‐2‐phthalimido‐diazene‐1‐oxides: Formation, Properties and Fragmentation Reactions into Imido‐ and Amino‐nitrenes1)

Oxidatively generated phthalimido‐nitrene (1) reacts with the nitrosoamines 2a‐d (see Scheme 1) to give the corresponding (Z)‐1‐amino‐2‐phthalimido‐diazene‐1‐oxides 3a‐d in good yields. With the O‐nitroso compound 2e, no addition of the nitrene 1 took place.

The constitution the adducts 3 (R = NR′2) is deduced from their spectroscopic properties (UV., IR., 1H‐NMR. and MS.) as compared to those of (Z)‐1‐aryl‐ and (Z)‐1‐alkyl‐2‐phthalimido‐diazene‐1‐oxides 3 (R = aryl and alkyl, resp.). The (Z)‐configuration of 3 (R = NR′2) follows from an X‐ray analysis which is reported separately.

Compounds 3 (R = NR′2) are cleaved photolytically as well as by acid to the corresponding nitrosoamines 2 (R = NR′2) and the nitrene 1, which could be trapped by cyclohexene to give 40% of 7‐phthalimido‐7‐azabicyclo [4.1.0]heptane (8) and by dimethylsulfoxide to yield 96% of S, S‐dimethyl‐N‐phthalimido‐sulfoximide (13).

Nucleophilic attack leads to fragmentation of 3 (R = NR′2) into derivatives of phthalic acid and degradation products of intermediate aminonitrenes 24 corresponding to the respective nitrosoamines 2 (R = NR′2) with loss of oxygen. A general rationalization for the formation of 24 includes as a key step of N‐ to C‐migration of the O‐atom (see Scheme 6). The final fate of 24 is depending on the type of the nucleophile used. Thus, hydrazinolysis of 3b and of 3c generates besides N, N′‐phthaloylhydrazine (15), morpholine (14) from 3b and 1, 3‐dihydroisoindole (16) together with 6′‐methylidene‐1, 2, 3, 4‐tetrahydronaphthalene‐2‐spiro‐1′‐cyclohexa‐2′, 4′‐diene (17) from 3c (see Scheme 5). Treatment of 3b and of 3c with sodium methylate leads in both reactions to monomethyl phthalate (33) and, with 3b, to 1, 2‐dimorpholinodiazene (31) and, with 3c, to 17 (see Scheme 7). Finally, the reaction of 3b with diethylamine generates N, N‐diethylphthalamic acid (36), morpholine (14), 1,1,4,4‐tetraethyl‐2‐tetrazene(34) and l,l‐diethyl‐4,4‐(3‐oxapentamethylene)‐2‐tetrazene (35) (see Scheme 8).
The Influence of Molecular Host Lattices on Electronic Properties of Orbitally (Near‐) Degenerate Transition Metal Complexes
Authors: Ammeter John H. , Zoller Linus , Bachmann Jürg , Baltzer Philippe , Gamp Eduard , Bucher René , Deiss Erich
Published: December 2004

Transition metal complexes often have low‐lying excited electronic states and, as a consequence, tend to beelectronically labile, i.e., their electronic properties exhibit pronounced sensitivity to external perturbations. Often drastic changes in various spectroscopic properties indicating substantial electronic rearrangements can be induced be relatively weak intermolecular forces as provided by nonpolar solvents or solid molecular host lattices. This behaviour can be explained by crossing of potential surfaces in the vicinity of the absolute minimum. Many physical properties of a given orbitally (near‐) degenerate system depend strongly on the relative magnitude of some characteristic parameters determining the shape of the groundBorn‐Oppenheimerpotential surface(s),e.g.barrier heightversuszero‐point energy, distance between minimaversuszero‐point amplitude, energy difference between minima,etc.Typical examples are systems exhibitingJahn‐Telleractivity, spin‐crossover, mixed valence, exchange coupling and other types of electronic near‐degeneracies. In paramagnetic systems changes in the electronic wavefunction can be most conveniently detected and analyzed by using EPR. spectroscopy.

In paramagnetic sandwich complexes we studied two types of orbital degeneracies:Jahn‐Tellerdegeneracies (d7‐systems such as Co (cp)2, Ni(cp)and Fe (cp) (bz), low‐spin d5‐systems such as Mn (cp)2) andlow‐spin/high‐spin equilibria(d5‐systems such as Mn (cp)2). By diluting these complexes and ring‐substituted derivatives in a large variety of diamagnetic host systems we have been able to control the6A/2E equilibrium of Mn (cp)2by influencing the metal‐to‐ring distance and by changing the degree of ring alkylation; similarly we have been able to vary the relative weights of the two electronic states contributing to the two‐fold degenerate electronic ground state of d5‐ and d7‐systems to a large degree by variation of the local asymmetric fields offered by the lattice sites of the host systems.

For comparison the electronic ground state properties of octahedral Cu(II) complexes with CuN6CuO6chromophores, of V (CO)6and tetrahedral VCl4were also studied by EPR. between 4K and room temperature in several host systems. Characteristic differences in the details of the temperature and host dependence of the EPR. spectra in all these electronically labile systems can be explained in terms of differences in the vibronic coupling type (E⊗ evs.T ⊗ e, t), the strength of linear and/or quadraticJT‐coupling and the effects produced by spin‐orbit coupling.
Reaktionen von 2‐ und 3‐phenylsubstituierten Alkylakyliden‐iminium‐Ionen in der Gasphase. 5. Mitteilung über stossinduzierte Fragmentierungen von felddesorbierten Kationen
Authors: Fischer Matthias , Veith Hans Jürgen
Published: December 2004

Reactions of 2‐ and 3‐Phenyl Substituted Alkylalkylidene Iminium Ions in the Gas Phase

The collision‐induced fragmentations of 2‐ and 3‐phenyl substituted alkylalkylidene iminium ions are reported. Besides the homolytic cleavage of the azaallyl bond a nucleophilic attack of the unsubstituted phenyl group at the iminium function is observed in the gas phase, yielding carbonium ions such as cyclopropanspirobenzenium (3), indanylium (10) and indenylium ions (11).
A Stereocontrolled Access to (±)‐, (−)‐, and (+)‐Patchouli Alcohol
Authors: Näf Ferdinand , Decorzant René , Giersch Wolfgang , Ohloff Günther
Published: December 2004

The racemate and both enantiomers of patchouli alcohol have been synthesized by stereocontrolled routes. The olfactive properties of the patchouli alcohols prepared are reported.
Cyclizations of the C10 Fatty Acids from the Mandibulary Glands of the Honeybee Apis mellificaL.: Queen substance and royal jelly acid
Authors: Barbier Michel
Published: December 2004

Series of assays have been performed to cyclize the two main C10 aliphatic acids, (E)‐9‐oxo‐dec‐2‐enoic acid (3) (queen substance) and (E)‐10‐hydroxy‐dec‐2‐enoic acid (7) (royal jelly acid) produced by the mandibulary glands of the honeybee Apis mellifica L. Queen substance 3, resistant to thermocyclization, was cyclized by the action of polyphosphoric acid to the fulvene ketone 5. Triphenylphosphinediethyl azodicarboxylate treatment of royal jelly acid 7 mainly furnished the dilactide 6 together with a series of cyclic oligomers up to the pentamer. Attempts to favour the formation of the lactone 11 through other conditions failed, and thus the reaction does not seem suitable for the preparation of lactones using α, β‐unsaturated hydroxy acids.

Substances 3,7,12,13,14,15, were submitted to in vitro antibacterial as well as growth inhibition tests but all results were negative at the concentrations reported.
New Irregular Monoterpenes in Artemisia vulgaris
Authors: Näf‐Müller Regula , Pickenhagen Wilhelm , Willhalm Bruno
Published: December 2004

A gas chromatographic investigation of the steam distilled oil of the herb of Artemisia vulgaris led to the identification of 21 irregular monoterpenes of non‐head‐to‐tail isoprenoid skeleton. The spectral data of some of these compounds are discussed. The structures of eight new irregular monoterpenes are given.
Cyclometalation of Arylazo Compounds. Part 1 synthesis and cyclopalladation of some substituted 1‐arylazonaphthalenes. 1st Communication on compounds with a metal‐arene σ‐bond
Authors: Klaus Alfred J. , Rys Paul
Published: December 2004

The syntheses of 1‐phenylazonaphthalene (1a) and its [3′‐methyl‐ (1b), 4′‐methoxy‐ (1c), 3′‐methoxy‐ (1d)] derivatives are described. Cyclopalladation of these azo ligands with Pd(II) acetate or Na2PdCl4 leads to complexes with Pd(II) coordinated on the azo Nβ‐atom and a PdC σ‐bond at C(2) in the naphthalene moiety. The preference of Pd(II) for this type of metalation at C(2) over the palladation at the ortho positions of the phenyl ring or at the peri position of the naphthyl ring is believed to be largely due to steric effects and the different reactivities of the two arene moieties. Substitution of the acetato‐bridge with bromide or iodide allows the syntheses of the corresponding bromo‐ and iodo‐bridged complexes, and a chloro‐bridged dimer complex can be converted to a monomeric ethylenediamino‐Pd(II)‐azo species with ethylenediamine. Cyclopalladation of sulfonated azo ligands leads to water‐soluble Pd(II) complexes with a Pd‐C σ‐bond at C(2).
Doppelt und dreifach funktionalisierte, enantiomerenreine C4‐Synthesebausteine aus β‐Hydroxybuttersäure, Äpfelsäure und Weinsäure
Authors: Hungerbühler Ernst , Seebach Dieter , Wasmuth Daniel
Published: December 2004

Enantiomerically Pure Synthetic Building Blocks with Four C‐Atoms and Two or Three Functional Groups from β‐Hydroxy‐butanoic, Malic, and Tartaric Acid

The pool of chiral, non‐racemic electrophilic building blocks, which are available from simple natural products in both enantiomeric forms is enlarged by the epoxides 3, 5, and 10, by the tosylate 12a, and by the aldehydes 18 (cf. symbols A‐D, 14, and Scheme 1). Key steps of the conversions leading from hydroxyacids to the building blocks are: epoxide‐opening by triethylborohydride (1 → 2a) and tosylate reduction (12a → 12b); the Mitsunobu inversion (2a → 4a); the reduction of (R, R)‐tartaric ester to (R)‐malic ester by NBS (N‐bromosuccinimide) opening of the benzaldehyde acetal 8 and tin hydride reduction (6c → 7c); the enantiomer enrichment of optically active ethyl β‐hydroxy‐butanoate through the crystalline dinitrobenzoate 21b. Detailed procedures are given for large scale preparations of the key intermediates. The enantiomeric purities of the building blocks are secured by correlations.
Alkyl‐, Aryl‐, Vinyl‐, and Heterosubstituted Organozirconium Compounds. ‐Selective nucleophiles of low basicity. Preliminary communication
Authors: Weidmann Beat , Maycock Christopher D. , Seebach Dieter
Published: December 2004

Solutions of the title compounds are accessible from organolithium reagents and trialkoxyzirconium chloride (equation 2). In contrast to their titanium analogues, vinylzirconium reagents are stable enough to be employed. Generally, organozirconium reagents are highly selective aldehyde and ketone carbonylophiles of exceedingly low basicity (Tables 1, 2, 3 and typical procedure).
A New Base‐induced Rearrangement of Hexopyranuronic Acid Derivatives with Solvent Participation. Preliminary communication
Authors: Kiss Joseph , Arnold Wolf
Published: December 2004

Uronates (as pyranosides or furanosides) bearing good leaving groups (mesylates, tosylates, phosphates, etc.) in β‐ and γ‐position to the alkoxycarbonyl group (e.g. 1) give the epimeric β,γ‐unsaturated α‐alkoxy‐β,γ‐dideoxy‐uronates 4 by treatment with organic or inorganic bases in alcoholic solution.

This new rearrangement of carbohydrates was exemplified with a D‐glucosamine derivative: an alcoholic solution of methyl [O (1)‐benzyl‐2‐C‐benzyloxyformamido]‐2‐deoxy‐3,4‐bis [O (methylsulfonyl)]‐α‐D‐glucopyranosiduronate 1 in the presence of KOH, DBU, or strong alkaline anion exchange resins gave the C(5)‐epimeric mixture of methyl [benzyl‐2‐[C‐(benzyloxy)formamido]‐2,3,4‐trideoxy‐5‐alkoxy‐α‐D‐glycero‐hex‐3‐enopyranosid]uronates (4a–e). The reaction took place with stoichiometric solvent participation using primary, secondary or tertiary alcohols. Other polyfunctional compounds having an alcoholic hydroxyl group can also participate in this reaction. Compounds obtained have been characterized in the form of their crystalline amides.