bluuebunny/crossref_metadata_2025 huggingface dataset:
The fine structure of laminae IV, V, and VI of the macaque spinal cord
Authors: Ralston Henry J.
Published: December 2004

The normal fine structure of the deep dorsal horn (laminae IV, V, and VI) of the lumbosacral spinal cords of adult Macaque monkeys was examined. Axonal profiles with rounded synaptic vesicles (R) constitute about one‐fourth of the total synaptic population in lamina IV and gradually increase in number to comprise more than a third of the synaptic population in lamina VI. Conversely, profiles with flattened vesicles (F) make up two‐thirds of the synaptic population in lamina IV and slightly more than half in lamina VI. Axons which form the central profile (C) of synaptic glomeruli are more common in laminae IV and V than in lamina VI, and constitute about 5% of the total synaptic population. Profiles with large granular vesicles (LGV) are relatively uncommon in all the deep laminae.

The vast majority of synaptic contacts are axodendritic. Axoaxonal synapses are formed between F, and R or C profiles, the F profile being the presynaptic component.

It is concluded that there are both light and electron microscopic morphological differences among the deep laminae, as well as between the deep laminae and the superficial laminae of the spinal cord. Therefore, it appears that Rexed's original schema for laminar organization of the dorsal horn in the cat is also applicable to that of the monkey. In view of the relative paucity of LGV profiles in the deep dorsal horn, it is suggested that synapses in these laminae which contain monoamines or peptides are more likely to be associated with clear synaptic vesicles than granular synaptic vesicles.
Development of retinal amacrine cells in the mouse embryo: Evidence for two modes of formation
Authors: Hinds James W. , Hinds Patricia L.
Published: December 2004

Developing amacrine and ganglion cells have been graphically reconstructed from a series of 567 consecutive thin sections of the E17 mouse retina on the first day when an obvious inner plexiform layer (IPL) is present and 2 days later than for our previous study of amacrine cell formation at E15 (Hinds and Hinds ('78). At E17 amacrine cells of the neuroblastic layer (normally placed amacrine cells), unlike those at E15, appear to develop directly from ventricular cells; intermediate elements are bipolar‐shaped cells with terminal arborization in the IPL. On the other hand, the development of displaced amacrine cells and some normally placed amacrine cells at E17 appears to closely resembles that described for all amacrine cells at E15: derivation from “ganglion cells” by loss of the axon and transformation of the cell. Three lines of evidence support this conclusion. (1) Cells have been found that resemble ganglion cells except that they have only an apparent axon remnant and have somata restricted to the IPL and the immediately adjacent portion of the ganglion cell layer (GCL); amacrine cells transitional between these cells and the smaller and darker, normally placed amacrine cells also occur in the IPL. (2) Axons of two ganglion cells have been found which appeared to be in the process of breaking up and degenerating. (3) The fraction of anaxonic cells with somata in the GCL (two out of 79, or 3%) or in the GCL plus IPL (ten out of 88 or 11%) is too small to account easily for the large fraction (probably at least 45%) of displaced amacrine cells found in the adult, even with conservative assumptions (P < 0.05). A mathematical model suggests that approximately 40% of the ganglion cells present at E17 will lose their axon, and of these around half will migrate to the neuroblastic layer, while the other half will become displaced amacrine cells. The results suggest a natural explanation for the recent finding that wide field amacrine cells are found with somata on both sides of the IPL, while narrow field amacrine cells are never displaced: the former may be derived from ganglion cells by loss of the axon, while the latter may be formed directly from ventricular cells.
Location and distribution of tracheosyringeal motorneuron somata in the fowl
Authors: Youngren Orlan M. , Philips Richard E.
Published: December 2004

Injection of horseradish peroxidase solution (HRP) into the tracheosyringeal musculature and tongue of the domestic chick labeled their motorneuron somata inthe medulla. Those of tracheosyringeal motor neurons occupied the caudal portions of the nucleus nervi hypoglossi (n. XII), whereas those for motor neurons supplying the tongue occupied the rostral part. The rostrocaudal representations of tracheolateralis, sternotrachealis, and ypsilotrachealis muscles were roughly mapped by the rostrocaudal distribution of labeled somata in n. XII. Except for sparse labeling found in the caudal part of the dorsal vagal nucleus of a few animals, no labeled cells were found outside of n XII. Most tracheosyringeal injections labeled contralateral n. XII, but section of the contralteral tracheosyringeal nerve high on the neck prior to HRP injection abolished this labeling.
Structure of the piriform cortex of the opossum. I. Description of neuron types with golgi methods
Authors: Haberly Lewis B.
Published: December 2004

The piriform cortex was studied in the adult opossum with rapid Golgi and Golgi‐Cox techniques.

Most pyramidal cells in the deep part of layer II and layer III resemble those in other parts of the cerebral cortex by virtue of a single apical dendritic trunk, multiple basal dendrites, a large number of small to medium dendritic spines, and a deeply directed axon. Pyramidal cells in the superficial part of layer II are similar with the exception that “secondary” apical dendrites often emerge directly from the cell body rather than from a single primary trunk.

With conservative criteria for categorization, nine different types of nonpyramidal cells were distinguished, four of which have not been previously described. Layer I contains a small number of neurons with both smooth and spiny dendrites including distinctive fusiform cells with large somatic appendages. As in other species, the most common type of nonpyramidal neuron in layer II is the semilunar cell which has only apically directed dendrites. These cells have distinctive large spines confined to their distal dendritic segments. The mid to deep portion of layer III contains multipolar neurons with smooth dendrites that resemble the well‐known large stellate cells in neocortex. In addition, layer III contains three non‐pyramidal neuron types with spiny dendrites: (1) fusiform and multipolar cells with complex, branched dendritic appendages and somatic spines, (2) very large multipolar cells (up to 35 μm mean diameter) with large‐diameter dendrites that give rise to abruptly tapering side branches and filiform spines, and (3) multipolar cells with profusely spiny dendrites. In all three layers, small neurons have been found with spherical cell bodies and “axoniform” dendrites that resemble the so called neurogliaform neurons described in a variety of brain areas. A striking feature of the organization of the piriform cortex is that, with the exception of the neurogliaform neurons, the different types of nonpyramidal cells tend to be segregated in individual layers or sublayers.

Physiological implications of the results are discussed. Remarks are also made concerning the potential of the piriform cortex as a model cortical system.
Structure and innervation of the inner ear of the bowfin, Amia calva
Authors: Popper Arthur N. , Northcutt R. Glenn
Published: December 2004

The hair cell orientation patterns and the number of innervating nerve cells was determined for the ear of the holostean fish Amia calva. Scanning electron microscopy was used to analyze the sensory cells of the three otolith organs: the saccule, the lagena, and the utricle. The utricular hair cell orientation pattern is similar to that found in most vertebrates, while the lagenar hair cell pattern is similar to that in ostariophysine fishes. The saccule has both horizontally and vertically oriented hair cells, although in the living animal many of the horizontally oriented cells are really oriented lateromedially. The transition region between cells oriented horizontally and vertically suggests that the horizontal cells are ontogenetically derived from vertically oriented cells. The lagenar macula has the largest sensory region, with over 216,000 cells in its main sensory part. The utricular macula contains over 56,400 cells in the main sensory region, and the saccular macula over 8,600 cells. The otic nerve divides into anterior and posterior rami, and ganglion cell counts totaled 2,021 in the anterior ramus and 1,619 in the posterior ramus. There are three populations of ganglion cells in each ramus, on the basis of differences in cell diameter. By a rough estimate, the ratio of sensory to ganglion cells is at least 90:1. By comparing SEM data from Amia, other nonteleosts, and various teleost species, we suggest that the ontogenetic derivations of the horizontal cells in the teleosts and nonteleosts are substantially different and apparently unrelated to each other and that the most primitive ray‐finned fishes had only vertically oriented sensory cells while the horizontally oriented cells subsequently evolved at least twice, once in Amia and other nonteleosts, and once in the ancestors of the teleosts.
Morphology of normal and deafferented neurons in the chick ectomamillary nucleus
Authors: Peduzzi J. D. , Crossland W. J.
Published: December 2004

Neurons in the ectomamillary nucleus (EMN) undergo both atrophy and cell death following eye removal at hatching. It is not known whether all EMN neurons are affected uniformly by transneuronal atrophy or whether cell loss is an artifact due to misidentification of atrophied neurons as glia.

In a preliminary morphological study, four types of neurons were found in the EMN by using the rapid Golgi method: A large multipolar neuron (type I); two medium‐sized spindle‐shaped neurons, one possessing many dendritic branches (type II) and the other possessing few dendritic branches (type III); and a small round neuron (type IV). Horseradish peroxidase (HRP) was then injected into two of the EMN projection fields in enucleated chicks in order to label retrogradely as many EMN neurons as possible. Types, I, II, and III neurons were identified both in the control and experimental EMN. The three types of backfilled neurons showed different degrees of transneuronal atrophy ranging from 12 to 47%. The type IV neuron, which could not be backfilled, was inferred to atrophy by 33%. Substantial differences in transneuronal atrophy, therefore, exist among the different types of neurons within the same nucleus.

Since no glialike neurons could be retrogradely labeled it was concluded that there is a true neuron loss in the EMN following eye removal rather than mistaken identification of neurons as glia.
The development of the Purkinje cell in the cerebellar cortex of the opossum
Authors: Laxson L. C. , King J. S.
Published: December 2004

The development of the Purkinje cell in the cerebellar cortex of the opossum, Didelphis virginiana, was analyzed by using Golgi preparations and electron microscopy. The maturation process of the Purkinje cell was observed to occur in five stages: the immature stage, the perisomatic den‐drite stage, the perisomatic spine stage, the main dendrite stage, and the adult stage. These stages were first defined by Hendelman and Aggerwal (′80), using Golgi preparations of immature mouse cerebellum.

Each of the five stages of Purkinje cell development, as observed in electron micrographs, is characterized by distinct synaptic relationships and cytological features. During the first or immature stage (postnatal (PN) 19‐32), the Purkinje cells have long apical processes which may be involved in the early migration of these neurons. Few boutons make synaptic contacts with Purkinje cells during the early part of this first stage; synapses are more frequent by the end of the immature stage. The second or perisomatic dendrite stage (PN 33‐44) is characterized by numerous somatic processes which have the cytological characteristics of dendrites. All synaptic contacts present during this stage form asymmetric contacts and contain round vesicles. The shape of the terminals and their postsynaptic location were used to tentatively distinguish different types of terminals. During the third or perisomatic spine stage (PN 45‐60) the Purkinje cell has numerous somatic spines and the dendritic tree is achieving its mature form. Most synaptic terminals observed during this period have asymmetric junctions and contain spherical vesicles; both the perisomatic spines and the dendritic shafts and spines are the postsynaptic sites of these terminals. Another type of bouton has pleomorphic vesicles and forms indistinct symmetric junctions directly on the cell body. The fourth stage, the main dendrite stage (PN 61‐77), is characterized by the loss of the perisomatic spines. Terminals on the soma contain pleomorphic vesicles and form symmetric synapses. The thorns of the primary and secondary dendrites and the more distal dendritic spines are postsynaptic to boutons with spherical vesicles and asymmetric junctions. The adult stage or the mature stage (PN 78‐adult) is characterized by the appearance of adult synaptic relationships.

These data suggest that although olivary axons are present in the cerebellum by PN 14 (King et al., ′82), synaptogenesis does not ensue until the latter part of the immature stage (PN 26‐32). During the subsequent stages of Purkinje cell development, synaptic formation and remodeling proceeds until the adult structure and synaptic relationships are achieved about PN 78–80.
Astrocytes and neurons regulate the expression of the neural recognition molecule janusin by cultured oligodendrocytes
Authors: Jung Marion , Pesheva Penka , Schachner Melitta , Trotter Jacqueline
Published: December 2004

Janusin (formerly designated J1–160/180) is an extracellular matrix glycoprotein highly homologous to tenascin, consisting of two major molecular forms of 160 and 180 kD expressed by oligodendrocytes and in myelin. Janusin expression is upregulated during myelination and in the adult it remains expressed at lower levels. It is also present at the node of Ranvier, where myelin, axon, and astrocytic process are in close contact. To gain an understanding of the regulatory mechanisms which may under‐lie expression of janusin, the differentiation stage‐dependent expression of janusin was studied in cultures enriched in mouse oligodendrocytes and their precursor cells. Expression of janusin by these cells was highest on both A2B5+ and O4+/O1− oligodendroglial precursor cells and a subset of myelin associated glycoprotein‐positive (MAG+) oligodendrocytes. Hardly any of the more differentiated O1+ or O10+ oligodendrocytes expressed janusin. Expression of janusin was influenced by co‐culture with astrocytes or neurons. Astrocytes or astrocytic‐conditioned culture supernatants elevated the expression of janusin by the more differentiated oligodendrocytes (O1+ or MAG+ cells), while its expression by oligodendroglial precursor cells was relatively unchanged. Platelet‐derived growth factor, but not basic fibroblast growth factor, also elevated the expression of janusin by O1+ or O10+ oligodendrocytes. In contrast, co‐culture with neurons originating from dorsal root ganglia or spinal cord decreased the expression of cell‐bound janusin by oligodendrocytes and their precursor cells. These observations indicate that expression of janusin on these cells in culture is susceptible to opposing regulatory influences from astrocytes and neurons. Such influences may modulate the temporal and spatial distribution of janusin in the developing and adult central nervous system. © 1993 Wiley‐Liss, Inc.
Transient presence of GABA in astrocytes of the developing optic nerve
Authors: Ochi Satoko , Lim Jae Y. , Rand Mark N. , During Matthew J. , Sakatani Kaoru , Kocsis Jeffery D.
Published: December 2004

Immunostaining and high‐pressure liquid chromatography (HPLC) were used to study the developmental time course of astrocytic γ‐aminobutyric acid (GABA) expression in rat optic nerve. GABA immunostaining was carried out on cultured astrocytes, and on whole optic nerve. Confocal scanning laser microscopy was used to obtain optical sections in excised whole tissue in order to localize the cellular origins of GABA within the relatively intact optic nerve. GABA immunoreactivity was localized in astrocytes identified by GFAP staining; GABA staining was most intense in early neonatal optic nerve and attenuated over 3 weeks of postnatal development. The staining was pronounced in the astrocyte cell bodies and processes but not in the nucleus. There was a paucity of GABA immunoreactivity by postnatal day 20, both in culture and in whole optic nerve. A biochemical assay for optic nerve GABA using HPLC indicated a relatively high concentration of GABA in the neonate, which rapidly attenuated over the first 3 postnatal weeks. Immunoreactivity for the GABA synthesis enzyme glutamic acid decarboxylase (GAD) was pronounced in neonates but also attenuated with development. These results indicate that GABA and the GABA synthesis enzyme GAD are localized in astrocytes of optic nerve, and that their expression is transient during postnatal development. © 1993 Wiley‐Liss, Inc.
Single ion channel currents in neuropile glial cells of the leech central nervous system
Authors: Müller Michael , Hanke Wolfgang , Schlue Wolf‐R.
Published: December 2004

The patch‐clamp technique was used to investigate the activity of single ion channels in neuropile glial (NG) cells in the central nervous system (CNS) of the medicinal leech, Hirudo medicinalis. We found evidence for two distinct Cl− channels that could be distinguished by their basic electrical properties and their responses to different inhibitors on single ion channels currents. In the Inside‐out configuration in symmetrical Cl solutions, these channels showed current‐voltage relationships with slight outward rectification, mean conductances of 70 and 80 pS, and reversal potentials near 0 mV. Significant permeability to Na+, K+, or SO42− could not be detected. The open‐state probability of the 70 pS Cl− channel increased with membrane depolarization, whereas the open‐state probability of the 80 pS Cl− channel was voltage‐independent. The application of the stilbene derivative DIDS (100 μM) to the cytoplasmic side of the glial cell membrane blocked both Cl− channels. The activity of the 70 pS channel was blocked irreversibly by DIDS, whereas the activity of the 80 pS channel reappeared after wash‐out of DIDS. Both channels were blocked reversibly by 1 mM Zn2+. K+ channels could only be observed occasionally in the soma membrane of the NG cells. We have characterized a 60 pS K+ channel with a high selectivity for K+ over Na+. The low density of K+ channels in the soma membrane may indicate a non‐uniform distribution of this channel type in NG cells. © 1993 Wiley‐Liss, Inc.
Peptide receptors in astroglia: Focus on angiotensin II and atrial natriuretic peptide
Authors: Sumners Colin , Tang Wei , Paulding Waltke , Raizada Mohan K.
Published: December 2004

Astroglial cells derived from the mammalian central nervous system contain a wide variety of peptide receptors, including specific sites for angiotensin II (AII) and atrial natriuretic peptide (ANP). The AII receptors present in these cells are primarily of the AT1 subtype. The ANP receptors present in these cells consist of a mix of ANP‐A and ANP‐B sites (“biological receptors”) and also ANP‐C sites (“clearance receptors”). Available evidence indicates that activation of AII receptors results in a stimulation of astroglial proliferation, whereas ANP has an antiproliferative effect in these cells. Intracellular pathways which may mediate these effects of AII and ANP on cell proliferation are discussed, including the presentation of novel data on the activation of protein kinase C and of glucose uptake by AII. We also consider the possibility that the opposing actions of AII and ANP on astroglial proliferation may represent another facet of the mutual antagonism between these two peptides, which has been observed throughout mammalian systems. © 1994 Wiley‐Liss, Inc.
Voltage‐dependent ion channels in glial cells
Authors: Sontheimer Harald
Published: December 2004

Glial cells, although non‐excitable, express a wealth of voltage‐activated ion channels that are typically characteristic of excitable cells. Since these channels are also observed in acutely isolated cells and in brain slices, they have to be considered functional in the intact brain. Numerous studies over the past 10 years have yielded detailed characterizations of glial channels permitting comparison of their properties to those of their neuronal counterparts. While for the most part such comparisons have demonstrated a high degree of similarity, they also provide evidence for the expression of some uniquely glial ion channels. An increasing number of studies indicate that the expression of “glial” channels is influenced by the cells' microenvironment. For example, the presence of neurons can induce or inhibit (depending on the preparation and type of channel studied) the expression of glial ion channels. Like ion channels in excitable cells, glial channels can be functionally regulated by activation of second‐messenger pathways, allowing for short‐term modulation of their membrane properties. Although the extent to which most of the characterized ion channels are involved in glial function is presently unclear, a growing body of data suggests that certain channels play an active role in glial function. Thus inwardly rectifying K+ channels in concert with delayed rectifying K+ channels are thought to be involved in the removal and redistribution of excess K+ in the brain, a process referred to as “spatial buffering.” Glial K+ channels may also be crucial in modulating glial proliferation. Cl− channels and stretch‐activated cation channels are believed to be involved in volume regulation. Na+ channels appear to be important in fueling the glial Na+/K+ ‐pump, and Ca2+ channels are likely involved in numerous cellular events in which intracellular Ca2+ is a critical second messenger. © 1994 Wiley‐Liss, Inc.
Glutamate‐induced calcium signaling in astrocytes
Authors: Kim Warren T. , Rioult Marika G. , Cornell‐Bell Ann H.
Published: December 2004

Astrocytes respond to the excitatory neurotransmitter glutamate with dynamic spatio‐temporal changes in intracellular calcium [Ca2+]i. Although they share a common wave‐like appearance, the different [Ca2+]i changes‐‐an initial spike, sustained elevation, oscillatory intracellular waves, and regenerative intercellular waves‐‐are actually separate and distinct phenomena. These separate components of the astrocytic Ca2+ response appear to be generated by two different signal transduction pathways. The metabotropic response evokes an initial spatial Ca2+ spike that can propagate rapidly from cell to cell and appears to involve IP3. The metabotropic response can also produce oscillatory intracellular waves of various amplitudes and frequencies that propagate within cells and are sustained only in the presence of external Ca2+. The ionotropic response, however, evokes a sustained elevation in [Ca2+]i associated with receptor‐mediated Na+ and Ca2+ influx, depolarization, and voltage‐dependent Ca2+ influx. In addition, the ionotropic response can lead to regenerative intercellular waves that propagate smoothly and nondecrementally from cell to cell, possibly involving Na+/Ca2+ exchange. All these astrocytic [Ca2+]i changes tend to appear wave‐like, traveling from region to region as a transient rise in [Ca2+]i. Nevertheless, as our understanding of the cellular events that underlie these [Ca2+]i changes grows, it becomes increasingly clear that glutamate‐induced Ca2+ signaling is a composite of separate and distinct phenomena, which may be distinguished not based on appearance alone, but rather on their underlying mechanisms. © 1994 Wiley‐Liss, Inc.
Über zwei isomere Formen des 5‐(2,4‐Dinitroanilino)‐2‐methyl‐benzimidazols
Authors: Stäuble Max
Published: December 2004

1. 5‐(2,4‐Dinitroanilino)‐2‐methyl‐benzimidazo1 besitzt Dipolcharakter und zeigt normalerweise den Smp. 156° (I). Die Verbindung krystallisiert aus Wasser oder wässrigem Alkohol ohne Krystallwasser.
Über die katalytische Herstellung von 1,4‐Naphthochinon aus Naphthalin
Authors: Fierz‐David H. E. , Blangey L. , v. Krannichfeldt W.
Published: December 2004

1. Bei der katalytischen Oxydation von Naphthalin über einem mit Kaliumsulfat stabilisierten Vanadiumpentoxyd‐Katalysator wurde bei einer Reaktionstemperatur von 430° und einem Naphthalin‐Luftverhältnis von 1 : 40 1,4‐Naphthochinon in einer Ausbeute von 15% der Theorie erhalten.
Sur l'arôme de viande de boeuf grillée II. Dihydro‐6,7‐5H‐cyclopenta[b]pyrazines, identification et mode de formation
Authors: Flament Ivon , Kohler Margrit , Aschiero Roland
Published: December 2004

Identification of alkyl‐5H‐6,7‐dihydrococyclopenta[b]pyrazines in roasted meat flavor. Model reaction used as basis for natural product formation and new synthesis.

Seven alkyl‐5H‐6,7‐dihydrocyclopenta[b]pyrazines have been identified in a roasted meat aroma obtained by thermolysis of the hydrosoluble flavor precursors of raw meat. Formation of these heterocyclics by condensation of hydroxycyclopentenones with aliphatic α‐dicarbonyl compounds in the presence of ammonia has been confirmed by a model reaction.

Alkyl‐5H‐cyclopenta[b]pyrazines and dicyclopenta [b,e]pyrazines are also obtained from this reaction, but have not yet been identified in roasted flavors. Preparation of the intermediates of the model reaction enabled development of an economical synthesis of 2,3,5‐trimethyl‐5H‐6,7‐dihydrocyclopenta[b]pyrazine.
13C‐Kernresonanzspektroskopische Untersuchungen an ionenselektiven Flüssigmembranen
Authors: Büchi Rolf , Presch Ernö , Simon Wilhelm
Published: December 2004

13C‐NMR. Studies on Ion‐Selective Liquid Membranes.

A method for the 13C‐NMR. study of solvent polymeric membranes in equilibrium with aqueous salt solutions is described. Neutral ion carriers incorporated in these membranes maintain a high degree of rotational mobility. The complexation by group IA and IIA cations of macrotetrolide antibiotics as well as of carriers of the type 3,6‐dioxa‐octanedioic diamides in the membrane phase was followed by 13C‐NMR. chemical shift and spin‐lattice relaxation studies.
Conformational Analysis and Chromic Acid Oxidation. Oxidation Rates and Equilibrium Constants of Epimeric Alcohols
Authors: Müller Paul , Perlberger Jean‐Claude
Published: December 2004

The linear free energy relationship of Sicher for relative reactivity towards chromic acid oxidation (ΔΔG) as a function of thermodynamic stability (ΔG) has been reexamined with 23 pairs of epimeric alcohols. The plot of ΔG vs. ΔG has a slope of 0.8, a correlation coefficient of 0.97 and a standard deviation of 0.23 kcal/mol on ΔΔGOx. The limitations of the relationship and the exceptions are discussed.
The Reaction of Difluorocarbene with Bicyclo[2.2.2]octadiene
Authors: Jefford Charles W. , Delay Arlette , Wallace Timothy W. , Burger Ulrich
Published: December 2004

The addition of difluorocarbene to bicyclo[2.2.2]octa‐2,5‐diene gave the exo and endo 1:1 cyclopropane adducts. In contrast to norbornadiene, no homo‐1,4 adduct was formed. The adducts were thermally stable under the conditions of their formation and separation (<170°). However, smooth equilibration was achieved on heating at 250° for 36 h. The same mixture resulted from either isomer. At 250° ΔΔG = 1.83 kcal/mol; the endo isomer being the more stable. Heating to higher temperatures caused decomposition, rather than further reaction to the intramolecular [2+2]cyclization products. The kinetic and thermodynamic product compositions were essentially the same on extrapolating to the same temperature, viz. endo/exo = 19–22 at 25°. The mechanisms by which the cyclo‐addition and the stereomutation of the cis‐fused cyclopropane moiety occur are discussed.
Isolement et identification de deux β‐carbolines dans la racine de chicorée torréfiée
Authors: Proliac Arlette , Blanc Maurice
Published: December 2004

Isolation and identification of two β‐carbolins in roasted chicory roet.

Two β‐carbolines, harman and norharman, have been isolated from roasted chicory roots by solvent extraction and chromatography on alumina. They have been identified by chromatographic and spectroscopic techniques in comparison with reference compounds.
Heterotricyclodecane XIX. Umlagerungen von 4,8‐disubstituierten 2,6‐Dioxa‐ und 2‐Oxa‐6‐aza‐adamantanen zu 4,10‐disubstituierten 2,7‐Dioxa‐ und 2‐Oxa‐7‐aza‐isotwistanen sowie ‐twistanen
Authors: Ackermann Peter , Portmann Robert Ernst , Ganter Camille
Published: December 2004

Rearrangements of 4,8‐disubstituted 2,6‐dioxa‐ and 2‐oxa‐6‐aza‐adamantanes to 4,10‐disubstituted 2,7‐dioxa‐ and 2‐oxa‐7‐aza‐isotwistanes as well as ‐twistanes.

Substitutions and rearrangements involving neighboring group participation starting from 4,8‐diiodo‐2,6‐dioxa‐ and 4,8‐diiodo‐2‐oxa‐6‐aza‐adamantanes (5 and 6, 12 and 48, resp.) were studied, yielding 4,8‐disubstituted 2,6‐dioxa‐ and 2‐oxa‐6‐aza‐adamantanes (7, 9, 39, 42 and 13, 15, 50, 52, resp.), 4,10‐disubstituted 2,7‐dioxa‐ and 2‐oxa‐7‐aza‐isotwistanes (8, 10, 41, 43 and 14, 16, 51, 53, resp.) and corresponding‐twistanes (11 and 17, resp.).
Reactions in the Acridone‐Fields.
Authors: Manukian Badrig K.
Published: December 2004

1‐Chlor‐ und 1,7‐Dichlor‐4‐nitro‐acridon wurden mit einigen Phenolen und Bisphenolen zu Farbstoffen umgesetzt, die Polyvinylchlorid grünlichgelb färben. Im Xenotest 800 Std. belichtet, zeigten die einfachen Acridone IX bis XIII eine ungewöhnlich hohe Lichtechtheit; sie sind aber migrationsunecht. Eine Verdoppelung der Molekel (lineare Bisacridone) bewirkte eine bedeutende Verminderung der Löslichkeit, jedoch begleitet vom Verlust der hohen Lichtechtheit.
Über Pterinchemie 75. Mitteilung Synthese von 7‐Aminoxanthopterin
Authors: Baumgartner Konrad , Bieri Jost H.
Published: December 2004

Synthesis of 7‐Aminoxanthopterin

7‐Aminoxanthopterin (II) is obtained in good yield and purity by the transformation of isomer‐free xanthopterin‐7‐carboxylic acid (I) with NH3 followed by oxidation with MnO2. The Frontier Orbital Theory contributes to a better understanding of the reaction pathway.
Synthesis of 1‐Bicyclo [3.2.2]nonene and 1 (7)‐Bicyclo [3.2.2]nonene by Intramolecular Wittig Reaction
Authors: Becker Konrad B. , Chappuis Jacques L.
Published: December 2004

The synthesis of 1‐bicyclo[3.2.2]nonene (2) and of 1 (7)‐bicyclo [3.2.2]nonene (3), two isomeric bridged (E)‐cycloheptenes, by intramolecular Wittig reaction is described. These ‘Bredt olefins’ could not be isolated, but dimerized rapidly. In both cases, the main product was shown to be a head‐to‐tail dimer with a cyclobutane ring. The ‘Bredt olefins’ were also trapped in situ with furan or 2,5‐diphenylbenzo [c]furan.
Alkaloid Production in Catharanthusroseus Cell Cultures. IV. Characterization of the 953 Cell Line
Authors: Kurz Wolfgang G. W. , Chatson Kenneth B. , Constabel Friedrich , Kutney James P. , Choi Lewis S. L. , Kolodziejczyk Pawel , Sleigh Stephen K. , Stuart Kenneth L. , Worth Brian R.
Published: December 2004

The 953 cell line, one of the cell lines from Catharanthus roseus, has been investigated in terms of its ability to produce indole alkaloids. Various parameters (mitotic index, pH, cell dry weight, growth period) were evaluated in the fermentation process and their relative importance for alkaloid production was determined. The alkaloids isolated and identified are ajmalicine, yohimbine, isositsirikine, vallesiachotamine, strictosidine lactam, lochnericine, hörhammericine, hörhammerinine, vindolinine, 19‐epivindolinine, 19‐acetoxy‐11‐methoxytabersonine, 19‐hydroxy‐11‐methoxytabersonine and dimethyltryptamine.
Laser Induced Excitation Spectra of the Cations of Some Fluoro‐substituted Phenols (B̃2 A″ ↔ X̃2 A″) in the Gaseous Phase
Authors: Maier J. P. , Misev L. , Shiley R. H.
Published: December 2004

Excitation spectra of the cations of pentafluorophenol, 2,3,4‐trifluorophenol, 2,4,5‐trifluorophenol, 2,5‐difluorophenol and 3,5‐difluorophenol have been obtained by pumping the B̃2 A″ ← X̃2A″ transition with a dye laser. The cations were first produced in their ground states by Penning ionisation using argon metastables. Vibrational frequencies of some of the fundamentals have been inferred for these cations in the B̃2 A″ state from the excitation spectra, and in the X̃2 A″ state from the emission spectra. Possible applications of the reported results are suggested.
Heterodiamantanes and Structurally Related Compounds. Part II: The Pentacyclic C10‐Diethers 5,12‐Dioxapentacyclo [6.4.0.02,6.03,11.04,9]dodecane and 4,12‐Dioxapentacyclo[6.3.1.02,7.03,10.05,9]dodecane
Authors: Ammann Willi , Jäggi Franz Josef , Ganter Camille
Published: December 2004

In connection with studies on heterodiamantanes and structurally related compounds the two novel pentacyclic diethers 9 and 10 were prepared starting from the photo‐dimer 8 of cyclopentadienone. All three compounds have as common features a central carbocyclic 6membered ring with four axial alkyl substituents and two oxygen function in 1,4‐position. The diether 9 was obtained on the one hand from the intermediate tetracyclic unsaturated alcohol 23 by intramolecular addition, catalyzed either by acid or base (scheme 3), and on the other hand from the tetracyclic diol 32 or the dibromoketones 34 (via 38) and 35 (via 39) by intramolecular substitution (schemes 4 and 5). The synthesis of the isomeric diether 10 was achieved by intramolecular substitution of the tetracyclic diol 33 (scheme 4). Diether 9 is thermodynamically more stable than 10. The latter was easily isomerized to the former on treatment with concentrated sulfuric acid in benzene.
Tricyclo [3.3.2.03,7]decan (9‐Homo‐nor‐adamantan) Synthese und Umwandlungen
Authors: Jäggi Franz Josef , Ganter Camille
Published: December 2004

Tricyclo[3.3.2.03,7]decane (9‐Homo‐nor‐adamantane). Synthesis and Transformations

A synthesis of tricyclo [3.3.2.03,7]decane (=9‐homo‐nor‐adamantane; 1), which belongs to the adamantaneland, a family of nineteen isomeric C10H16 hydrocarbons, is described, as well as derivatives thereof. Treatment of protoadamantan‐5endo‐ol (11) with either thionyl chloride or phosphorus pentachloride yielded under rearrangement the chloride 18, and solvolysis of the 5endo‐chloro‐protoadamantane (16) led to the acetate 26, 18 and 26 having both the tricyclo [3.3.2.03,7]decane skeleton. Subsequent transformations gave the title compound 1 as well as the corresponding olefin 8.
Aristoserratin, ein neues Indolalkaloid aus Aristotelia serrata W.R.B. OLIVER und A. peduncularis (LABILL.) HOOK. F. 178. Mitteilung über organische Naturstoffe
Authors: Hai Mohammad A. , Preston Nigel W. , Kyburz Rolf , Schöpp Emanuel , Bick I. Ralph C. , Hesse Manfred
Published: December 2004

Aristoserratine, a New Indole Alkaloid from Aristotelia serrata W.R.B. OLIVER and from A. peduncularis (LABILL.) HOOK. F.

The new indole alkaloid aristoserratine (2) has been isolated from Aristotelia. Its structure and absolute configuration were elucidated on the basis of spectroscopic data.
Azimine IV. Kinetik und Mechanismus der thermischen Stereoisomerisierung von 2,3‐Diaryl‐1‐phthalimido‐aziminen
Authors: Hoesch Lienhard
Published: December 2004

Azimines IV. Kinetics and Mechanism of the Thermal Stereoisomerization of 2,3‐Diaryl‐1‐phthalimido‐azimines1)

Mixtures of (1E, 2Z)‐ and (1Z, 2E)‐2‐phenyl‐1‐phthalimido‐3‐p‐tolyl‐azimine (3a and 3b, resp.) and (1E, 2Z)‐ and (1Z, 2E)‐3‐phenyl‐1‐phthalimido‐2‐p‐tolylazimine (4a and 4b, resp.) were obtained by the addition of oxidatively generated phthalimido‐nitrene (6) to (E)‐ and (Z)‐4‐methyl‐azobenzene (7a and 7b, resp.). Whereas complete separation of the 4 isomers 3a, 3b, 4a and 4b was not possible, partial separation by chromatography and crystallization led to 5 differently composed mixtures of azimine isomers. The spectroscopic properties of these mixtures (UV., 1H‐NMR.) were used to determine the ratios of isomers in the mixtures, and served as a tool for the assignment of constitution and configuration to those isomers which were dominant in each of these mixtures, respectively.

Investigation of the isomerization of the azimines 3a, 3b, 4a and 4b within the 5 mixtures at various concentrations by 1H‐NMR.‐spectroscopy at room temperature revealed that only stereoisomers are interconverted (3a ⇄ 3b; 4a ⇄ 4b) and that the (1E, 2Z) ⇄ (1Z, 2E) stereoisomerization is a unimolecular reaction. These observations exclude an isomerization mechanism via an intermediate 1‐phthalimido‐triaziridine (2) or via dimerization of 1‐phthalimido‐azimines (1), respectively. The 3‐p‐tolyl substituted stereoisomers 3a and 3b isomerized slightly slower than the 3‐phenyl substituted ones 4a and 4b, an effect which is consistent with the assumption that the rate determining step of the interconversion of (1E, 2Z)‐ and (1Z, 2E)‐1‐phthalimido‐azimines (1a ⇄ 1b) is the stereoisomerization of the stereogenic center at N(2), N(3), either by inversion of N(3) or by rotation around the N(2), N(3) bond. The total isomerization process is assumed to occur via the thermodynamically less stable (1Z, 2Z)‐ and (1E, 2E)‐isomers 1c and 1d, respectively, as intermediates in undetectably low concentrations which stay in rapidly established equilibria with the observed, thermodynamically more stable (1E, 2Z)‐ and (1Z, 2E)‐isomers 1a and 1b, respectively.

At higher temperatures, the azimines 3 and 4 are transformed into N‐phenyl‐N,N′‐phthaloyl‐N′‐p‐tolyl‐hydrazine (8) with loss of nitrogen.
Physico‐Chemical Properties of Deuterated Compounds. 5th Communication. The isotope partition coefficient in cyclohexane hydrogen and cycloheptane/hydrogen mixtures
Authors: Dessauges Gëarald , Gäumann Tino
Published: December 2004

The isotope partition coefficient α between cyclohexane, cycloheptane and hydrogen has been determined between 80 and 180° and pressures around 1 atm. The values decrease with increasing deuterium content y of the hydrogen and can be expressed by the simple equation Ina = Δ S/R + (ΔH + δ · y)/RT with an error of ±1%. However it was not possible to achieve good agreement with theoretical calculations using a unique average value for the partition function of the hydrocarbon.
New Dienophiles: 1‐Acetylvinyl Arenecarboxylates. Reactivity toward cyclopentadiene and exocyclic dienes
Authors: Tamariz Joaquin , Vogel Pierre
Published: December 2004

The preparations of 1‐acetylvinyl arenecarboxylates H2C=C(COCH3)OCOR with R = phenyl,p‐nitrophenyl, 2,4‐dinitrophenyl, α‐ and β‐naphthyl are described(3). TheDiels‐Alderreactivity of these dienophiles toward cyclopentadiene is evaluated and compared with that of methyl vinylketone, 3‐trimethylsilyloxy‐, 3‐ethoxy‐ and 3‐acetoxy‐3‐buten‐2‐ones. The stereoselectivity of the cycloadditions of these dienophiles with 2,3,5,6‐tetramethylidene‐7‐oxanorbornane(1)and 5,8‐dimethoxy‐1,4‐epoxy‐2,3‐dimethylidene‐1,2,3,4‐tetrahydroanthracene(2)is studied. In principle, the dienophiles3allow direct functionalization of the position C(9) of the A‐ring of daunomycinone analogs byDiels‐Alderadditions to exocyclic dienes such as1and2.
Partial Synthesis of 3′‐Hydroxy‐2′‐deoxy‐2″,3″,4″,5″‐tetrahydroverrucarin A. Verrucarins and roridins, 38th Communication [1]
Authors: Notegen Eric‐Andréa , Tori Motoo , Tamm Christoph
Published: December 2004

The macrocyclic trichothecene triester 3′‐hydroxy‐2′‐deoxy‐2",3",4",5"‐tetrahydroverrucarin A (37), has been synthesized starting from the sesquiterpene alcohol verrucarol (3), adipic acid and a derivative of mevalonic acid (14). The latter has been prepared from 4‐(tetrahydro‐2‐pyranyloxy)‐2‐butanone (9).
The Synthesis of Some 7, 8‐Dimethoxy‐5‐phenyl‐2H‐3‐benzazepin‐2‐one Derivatives
Authors: Berney Daniel , Schuh Karlheinz
Published: December 2004

The benzazepin‐2‐ones 7 and 9 were prepared from homoveratroyl chloride (4) and phenacylamine. Compounds 7 and 9 were used for the preparation of the benzazepin‐2‐amines 3, 11, 13 and 14. A synthesis of the benzazepine‐1,2‐dione 17 and the benzazepine‐2,4‐dione 20 is also described.
Crystal Structures of 8‐Methoxy‐ and 8‐Nitronaphthonitrile; Intramolecular Nucleophile‐electrophile Interactions
Authors: Procter Garry , Britton Doyle , Dunitz Jack D.
Published: December 2004

The crystal structures of 8‐methoxy‐1‐naphthonitrile and 8‐nitro‐1‐naphthonitrile have been determined by X‐ray analysis. The methoxynitrile molecule shows a distortion pattern that is essentially similar to that found previously in other 1,8‐disubstituted naphthalenes with Nu…CO interactions; instead of non‐planarity at the carbonyl C‐atom there is bending at the the cyano C‐atom. Crystals of the nitronitrile contain two symmetry‐independent molecules that differ in structure; both show bent cyano groups, short O…CN distances, and asymmetric nitro groups, but in different degree. There is no clear correlation between the amount of any given distortion and the strength of the nucleophile‐electrophile interaction.
On the Relation between One‐Bond Coupling Constants and the s‐Electron Density at the Nucleus
Authors: Mitchell Terence N. , El‐Behairy Mostafa
Published: December 2004

A comparison of Mössbauer isomer shifts and direct Sn, Sn‐coupling constants for a series of di‐ and polytin compounds indicates that the s‐electron density at the Sn‐atom has little influence on this coupling.
Nucleophilic Addition to C, C‐Double Bonds. IV. Ether formation by intramolecular addition to unsymmetrically alkyl‐substituted C, C‐double bonds
Authors: Ramos Tombo Gerardo M. , Pfund Rolland A. , Ganter Camille
Published: December 2004

Tricyclic olefinic alcohols containing an unsymmetrically alkyl‐substituted C, C‐double bond were cyclized intramolecularly to their corresponding ethers under basic conditions: 9 → 12, 10 → 17 + 18, and 11 → 12 (Scheme 3, Table 1). The reactivity is mainly due to relieve of ground state strain.

Alcohol 9 (endocyclic double bond) isomerized under intramolecular assistance by the hydroxyl group to 11 (exocyclic double bond) before cyclization to 12 occurred (Scheme 5). The latter step being the faster one, no isomerization 11 → 9 was observed.
Loss of H2O from M + t‐Butyl Complex Ions of Benzyl Alcohol in Isobutane Chemical Ionization Mass Spectrometry
Authors: Liehr Joachim G. , Brenton Gareth A. , Beynon John H. , McCloskey James A. , Blum Wolfgang , Richter Wilhelm J.
Published: December 2004

In isobutane chemical ionization mass spectrometry benzyl alcohol exhibits ions at m/z 147 (‘M + 39’) that arise by a loss of H2O from [M + C4H9]+, i.e. ‘M + 57’ complex ions. Electrophilic aromatic substitution of a proton at an ortho‐position of neutral C6H5CH2OH with [t‐C4H9]+ and, alternatively, nucleophilic substitution of H2O at the benzylic carbon in \documentclass{article}\pagestyle{empty}\begin{document}$ {\rm C_6 H_5 CH_2}\mathop {\rm O}\limits^+ {\rm H}_2 $\end{document} with CH2C (CH3)2 are discussed as possible pathways. Evidence in favor of the latter is derived from the analysis of C6D5CH2OH and C6H5CD2OH for the origin of the H‐atoms lost in H2O. The inferred ion structure of m/z 147 is verified by mass‐analyzed ion kinetic energy (MIKE.) measurements of its collision‐activated (CA.) decomposition. MIKE./CA. spectra of mass‐selected m/z 147 ions, once generated by (CI(i‐C4H10) from benzyl alcohol and, once, from 2‐methyl‐4‐phenyl‐2‐butanol match closely and, thus, reflect identical ion structures. With reference to the simple genesis of this ion from the latter precursor, the structure in question can be concluded to be \documentclass{article}\pagestyle{empty}\begin{document}$ {\rm C_6 H_5 CH_2 CH_2}\mathop {\rm C}\limits^+ ({\rm CH}_3)_2 $\end{document}
.
Conformational Dependence of One‐Bond Cα,H Spin Coupling in Cyclic Peptides
Authors: Egli Huldrych , Von Philipsborn Wolfgang
Published: December 2004

Conformational effects on the one‐bond Cα, H coupling constant have been studied in cyclic oligopeptides containing glycine, alanine, sarcosine and proline. The conformational contribution to 1J (Cα, H) can be described as being composed of a positive hyperconjugative term from the neighbouring N‐pz orbital and a negative one from the carbonyl π‐system. For glycyl units, a quantitative relation between 1J (Cα,H) and the vicinal interorbital angles Φ′ and Ψ′ is derived with maximum values ΔJ (Ψ′) = + 14.0 Hz and ΔJ (Ψ′) = −4.9 Hz. Applications to conformational analysis of cyclo (L‐Pro‐Gly)3, cyclo (D‐Ala‐D‐Ala‐L‐Ala‐D‐Ala‐L‐Ala‐L‐Ala) and cyclo (Sar)8 are presented.
Some Observations Concerning 1H‐NMR. Spectra of 5‐hydroxy‐ and 5‐acetoxy‐steroid compounds
Authors: Mihailović Mihailo Lj. , Lorenc Ljubinka , Pavlović Vladimir , Fuhrer Hermann
Published: December 2004

It was found that analysis of the 1H‐NMR. signals (at 360 (preferably) and/or 100 MHz) of the protons at C (4) and of the equatorial α‐proton at C (6), particularly when these are located in the 2–3 ppm region and therefore convenient for detection and identification, may be of valuable aid in the structural and configurational characterization of 5‐hydroxy‐ and 5‐acetoxy‐steroids (unsubstituted or containing a hydroxy or acyloxy substituent at C (3)).
Cryptates Sphériques. Synthèse et Complexes d'Inclusion de Ligands Macrotricycliques Sphériques
Authors: Graf Ernest , Lehn Jean‐Marie
Published: December 2004

Spherical Cryptates. Synthesis and Inclusion‐Complexes of Spherical Macrotricyclic Ligands

A general strategy for the synthesis of spherical macrotricyclic ligands has been developed. Four spherical cryptands, SC‐24, SC‐25, SC‐26 and SC‐27 have been obtained by this route. The synthesis and cation‐complexing properties of these compounds are described in detail. Stability constants and cation exchange rates of the spherical cryptates obtained with alkali and alkaline‐earth cations have been determined. Highly stable complexes are formed by SC‐24; the Rb+ and Cs+ cryptates of SC‐24 are the most stable complexes of these cations known to date. The size of the intramolecular cavity affects the complexation selectivity. The cation exchange rates are very slow, and the corresponding free energies of activation are even larger than, for macrobicyclic cryptates of similar stability. Both the high complex stabilities and the high activation energies required for cation exchange indicate a marked ‘spherical cryptate effect’ resulting from the highly connected nature of the molecular architecture of spherical macrotricyclic ligands.
119Sn‐ and 31P‐NMR. Spectroscopy of the 5‐coordinate complexes [Rh (SnClnBr(3−n)) (norbornadiene) (tertiary phosphine)2]
Authors: Garrlda Maria , Garcia Victoria , Kretschmer Matthias , Pregosin Paul S. , Ruegger Heinz
Published: December 2004

The products of the reaction of [RhCl (NBD)]2 (NBD = norbornadiene), with four equivalents tertiary phosphine and two equivalents of tin (II) bromide have been studied by 119Sn‐ and 31P‐NMR. spectroscopy. The solution data suggest that halogen scrambling occurs during the preparation and results in a mixture of complexes containing SnBr3, SnClBr2, and SnCl2Br and SnCl3 ligands, and this is confirmed by independent synthesis of the SnCl3 and SnBr3 complexes. The metalmetal coupling constants, 1J (119Sn, 103Rh), vary from 452 to 580 Hz and are linearly related to: (a) δ(119Sn) in the complexes [Rh (SnClnBr(3‐n))NBD (PEtPh2)2] and (b) the sum of the Pauling electronegativities for the halogens on tin.