bluuebunny/crossref_metadata_2025 huggingface dataset:
Ring A Modifications of Podocarpic Acid: Towards the Synthesis of Quassinoids
Authors: Cambie RC , Hay MP , Larsen L , Rickard CEF , Rutledge PS , Woodgate PD
Published: September 2010

Efficient methods for the formation of the hydroxy enone moieties in (17), (18), (45) and (46) from podocarpic acid (1) have been developed. The exocyclic alkene (13) has been converted into the α-hydroxy enones (17) and (18) in six steps and high overall yield. Oxidation of the enones (7) and (44) with manganese(III) acetate gave high yields of the α-acetoxy enones (10) and (47) and (48), respectively. Hydrolysis of (10), (47) and (48) afforded the α-hydroxy enones (11), (45) and (46), respectively. Hydroboration-oxidation of the alkene mixture (38) and (41) provided the alcohol (53) (53%) which was readily oxidized to the ketone (21) (92%). This ketone (21) was converted in three steps into the hydroxy enone (57) in 39% overall yield. Hydroxylation of the enone (44) via the silyl dienol ether (58) gave the α- hydroxy enones (45) (16%) and (46) (33%). The stereochemistry of 12-methoxy-19-nor-5β-podocarpa-3,8,11,13-tetraen-2-one (44) was established by X-ray crystallography.
Efficient Syntheses of cis-6-Bromo- and cis-7-Bromo-2,2-dimethyl-3a,4,5,7a-tetrahydro-1,3-benzodioxole
Authors: Banwell MG , Lambert JN , Richards SL
Published: September 2010

Regio- and stereo-controlled syntheses of the title compounds (1) and (2), starting from cyclohexane-1,3-dione (10) and cyclohexa-1,3-diene (17) respectively, are reported.
Solvent Effect on the Dissociation Constants of Aliphatic Carboxylic Acids
Authors: Bartnicka H , Bojanowska I , Kalinowski MK
Published: September 2010

Dissociation constants of 10 aliphatic carboxylic acids, of general formula R-COOH, were measured by potentiometric titration in acetonitrile, propylene carbonate, acetone, N,N- dimethylformamide and dimethyl sulfoxide. The p* reaction constants of the Taft equation were found to depend on the solvent
polarity, whereas the influence of the Lewis basicity and acidity is negligible. The p* values determined earlier in water, methanol and nitromethane also fulfil this rule.
Intramolecular Oxidative Coupling of Aromatic Compounds. II. The Synthesis of (2RS,3SR)- and (2RS,3RS)-2,3-Dimethyl-1,4-bis(3,4,5-trimethoxyphenyl)butan-1-one and the Determination of Stereochemistry
Authors: Krauss AS , Taylor WC
Published: September 2010

The C- methylation of 3-methyl-1,4-bis(3,4,5-trimethoxyphenyl)butan-1-one (9) gave in a ratio of 4:1 the diastereoisomers, (2RS,3SR)- and (2RS,3RS)-2,3-dimethyl-1,4-bis(3,4,5-trimethoxyphenyl) butan-1-one, (7) and (8) respectively. The stereochemistry of each isomer was determined by conversion into an aryltetralin of known stereochemistry.
Pigments of Fungi. XXI. Synthesis of (±)-6-Demethoxyaustrocortirubin
Authors: Burns CJ , Gill M , Saubern S
Published: September 2010

6-Demethoxyaustrocortirubin (6) is synthesized via the epoxide (21) which is available in 73% yield over four steps from naphthazarin (10). Hydrolysis of the epoxide (21) yields the diol (25) which on hydrogenolysis affords 6-demethoxy-1-deoxyaustrocortirubin (7). Stereoselective benzylic hydroxylation of (7) gives (6). Cleavage of the epoxide (21) with sodium acetate in acetic acid affords a mixture of the esters (22)-(24), while methanolysis yields the isomeric ethers (29) and (30). Hydrogenolysis of (22), (23) and (29) gives high yields of (7). Potentially more direct routes to the alcohol (7) involving oxymercuration, epoxidation and bromohydrin formation from the alkene (8) are not viable.
The Effects of Single- and Twin-Tailed Ionic Surfactants on the Hydroxydehalogenation of Charged Substrates
Authors: Cipiciani A , Primieri S
Published: September 2010

Reactions of OH- with 4-chloro-3,5-dinitrobenzoic and 2-chloro-3,5-dinitrobenzoic acids have been examined in solutions of cetyltrimethylammonium chloride, bromide and hydroxide, bis ( dodecyl ) dimethylammonium chloride, and bis(tetradecyl) dimethylammonium chloride. Rate effects were analysed quantitatively in terms of the distribution of reactants between water and the colloidal particles. It has been found that twin-tailed ionic surfactants better distinguish between favourable and unfavourable orientations of substrate molecules within micellar aggregates than do single-tailed ionic surfactants.
On the Reaction of Vinyl Isocyanates With Enamines
Authors: Prager RH , Were ST
Published: September 2010

Vinyl isocyanate reacts with enamines to give N-vinyl carboxamides which, unlike the more highly substituted analogues, do not cyclize readily to 2-pyridones.
Metal-Betaine Interactions.XIV. Silver(I) 3-Carboxylato-1-pyridinioacetate Monohydrate, [Ag{C5H4(COO)NCH2.COO}]n.nH2O
Authors: Chen XM , Mak TCW
Published: September 2010

The complex silver(I) 3-carboxylato-1-pyridinioacetate monohydrate, [Ag{C5H4(COO)NCH2.COO}]n.nH2O, crystallizes in space group P21/c (No. 14), with Z-4, a 12.233(6), b 5.049(1), c 14.418(7)Ǻ, and β 94.96(4)°; the structure was refined to RF -0.057 for 1721 observed [I ≥ 3σ(I)] Mo Kα data. The silver(I) atom is coordinated by four carboxylato oxygen atoms in a distorted tetrahedral environment [Ag-O 2.284(5)-2.570(5)Ǻ]. The tridentate acetato group bridges the Ag1 atoms into a zigzag chain featuring an uncommon [Ag2( carboxylato -O,O′)(carboxylato-μ-1,1-O)] six- membered ring, and the coordination sphere about each metal centre is completed by the unidentate aromatic carboxylato group, resulting in a two-dimensional network in the solid. The lattice water molecule forms hydrogen bonds with the uncoordinated oxygen atom of the aromatic carboxylato group [2.755(9)Ǻ] and the coordinated oxygen atom of the acetato group [2.936(9)Ǻ].
The Synthesis of Optically Pure β-Cyclopiazonic Acid, an Indolic Fungal Metabolite
Authors: Holzapfel CW , Kruger FWH
Published: September 2010

The chiral synthesis of the fungal metabolite β- cyclopiazonic acid is described. The key step involves the use of the tricarbonylchromium complex of an N-protected L- tryptophan methyl ester as a substrate for the addition/oxidation method of substitution of its indole ring system.
Acetylene Stacking: a New Concept for the Synthesis of Cyclic Polyenes. Application to the Preparation of a 1,6-Bridged Bicyclo[4.2.0]octa-2,4,7-triene and Some Novel Oxepins
Authors: Warrener RN , Pitt IG , Weerasuria KDV , Russell RA
Published: September 2010

A new protocol for a general synthesis of cyclic polyenes is presented; in this protocol two new concepts are introduced. The first, acetylene stacking, is the generic term covering both the synthesis of a target molecule and the specific retrosynthesis upon which it is based. This retrosynthetic analysis involves conversion of the target molecule, through a series of transannular [ π2s+π2s] valence isomerizations , into a key polycyclobutanoid intermediate (24). This intermediate is cleaved, in turn, through a similar number of [ σ2s+ σ2s] electrocyclic fragmentations, to yield a set of acetylene synthons . The synthetic phase is based on the recombination of the corresponding acetylene synthetic equivalents in a stacking mode which leads to the target molecule by way of the same polycyclobutanoid intermediate (24). To achieve the ordered assembly of the acteylene synthons, in the required stacking mode, it has been necessary to develop the second concept, namely transfer technology. This involves the use of special transfer reagents, to act as synthetic equivalents and provide the molecular equivalent of acetylenes without ever producing acetylenes per se. Similar transfer reagents are described for cyclobutadienes which serves to demonstrate the wider implications of this new concept in organic synthesis. The bridged bicyclic polyene 8-oxatricyclo [4.3.2.01,6]undeca-2,4,10-triene (73), and the heterocycle 2,4,5,7,8-pentamethyl-1H-oxepino[4,5-c]pyrrole-1,3(2H)- dione (91) are used as the target molecules to illustrate this new synthesis protocol involving sets of stacked acetylenes (or cyclobutadienes ) as the synthetic base. The conversion of the oxepin (91) into isomeric oxepins, and the role of their tautomeric benzene oxides, present as equilibrium partners, is discussed.
The Nitration of Tetrachlorocatechol and 3,4,6-Trichloro-5-methylcatechol. The Formation of 1-Hydroxycyclopent-3-enecarboxylic Acids
Authors: Calvert JL , Gordon JLM , Hartshorn MP , Robinson WT , Wright GJ
Published: September 2010

Reaction of tetrachlorocatechol (la) with nitric acid (d 1.48) gives the ring-contracted hydroxy dinitro acid (4), which was isolated as its ether solvate. Similar nitration of 3,4,6-trichloro-5-methylcatechol (lb) gives a mixture of stereoisomeric hydroxy dinitro acids (5), from which the methoxy methyl ester (8) can be isolated after methylation of the mixture with diazomethane. X-Ray crystal structure determinations are reported for the etherate of hydroxy dinitro acid (4) and the methoxy methyl ester (8).
Structural Aspects of V2( µ;-S2)2(S2CNR2)4 Complexes: the X-Ray Crystal Structure of V2( µ;-S2)2(S2CNEt2)4.2CHBr3
Authors: Tiekink ERT , Yan XF , Young CG
Published: September 2010

Brown V2(p-S2)2(S2CNEt2)4 is produced upon reaction of [vs4]3- with (Et2NCS2)2, in a synthesis similar to that described for V2( �-S2)2(S2CNBui2)4 ( Halbert , T. R., Hutchings, L. L., Rhodes, R., and Stiefel , E. I., J. Am. Chem. Soc., 1986, 108, 6437). Crystals of V2( �;-S2)2(S2CNEt2)4.2CHBr3 are orthorhombic and belong to space group Pbca , with a 10.909(2), b 20.492(2), c 20.471(2) � , V 4576.2 �3, and Z 4 dimers . The structure was solved by Patterson and Fourier methods and refined by using 1189 reflections to final R 0.061 ( Rw 0.059). The vanadium(IV) atoms in the dimeric complex are bridged by two �-k2S,S′: k2S,S′-S22- ligands [S(1)-S(2) 2.00(1) �] and a metal-metal single bond [V-V 2.900(6) �]. Each vanadium atom is further coordinated by two bidentate dithiocarbamate ligands whose arrangement defines a meso isomer with Λ and Δ configurations at the vanadium centres. This Λ Δ diastereomer differs from the Λ Λ -ΔΔ racemate structurally characterized in the case of V2(�-S2)2(S2CNBui2)4 but is the same as that found for the molybdenum(v) dication in [Mo2( �S2)2(S2CNEt2)4] (BF4)2.2CHBr3 ( Kocaba, T., Young, C. G., and Tiekink , E. R. T., Inorg. Chim. Acta, 1990, 174, 143).
Imidazo[1,2-b]pyridazines. XIII. Syntheses and Central Nervous System Activities of Some 2-Benzyl(phenethyl, biphenyl-4'-yl, 6'-methylnaphthalen-2'-yl, t-Butyl and cyclohexyl)-3-methoxy(acylaminomethyl and dimethylaminomethyl)-6-(variously substituted)imidazo[1,2-b]pyridazines
Authors: Barlin GB , Davies LP , Ireland SJ , Zhang JK
Published: September 2010

6-(Variously substituted)-3-methoxy(unsubstituted, dimethylaminomethyl, acetamidomethyl and benzamidomethy1)-2-benzyl(phenethyl, biphenyl-4'-yl, 6'-methylnaphthalen-2'-yl, t-butyl and cyclohexyl)imidazo[1,2-b] pyridazines have been prepared and examined for activity in the central nervous system. Of these, 2-benzyl-3-methoxy-6-(3'-methoxybenzylamino) imidazo[1,2-b]pyridazine (IC50 88nM) bound most strongly to rat brain membrane. In general, the order of activity for groups at the 2-position was Ph > PhCH2 > PhCH2CH2 > C6H4Ph-p, 6'-methylnaphthalen-2'-yl, c-C6H11 or But.
Crystal Structure Determination of Ag3CuS2 From Powder X-Ray Diffraction Data
Authors: Baker CL , Lincoln FJ , Johnson AWS
Published: September 2010

The crystal structure of Ag3CuS2 has been determined by using X-ray powder diffraction data. The unit cell is tetragonal, a = 8.6705(10), c = 11.7573(18) � , and the space group is I41/amd (141) with Z = 8. A starting model for the structure was derived by using direct methods and difference Fourier cycling from 93 unambiguously indexed integrated intensities, and then refined by the Rietveld method. Both diffractometer and Guinier-Hagg data were utilized. Corroborative evidence for the correctness of the resulting structure was obtained by comparison of experimental and calculated single-crystal electron diffraction intensities. The Ag3CuS2 structure is based on distorted bcc sulfur packing. There are two distinct silver sites. In one the silver atom is surrounded by six sulfur atoms forming a [2+4] distorted octahedral environment. In the other site the silver atom is in a distorted tetrahedral environment with two sulfur atoms nearby and two more, somewhat farther away. Copper is linearly coordinated by two sulfur atoms.
2-Hydroxyindole Compounds. Alkylation of 3-Acetyl-1-benzyl-2-hydroxy-5-,ethoxyindole Under Basic Conditions
Authors: Hugel HM , Greenwood RJ , Mackay MF
Published: September 2010

Alkylation of 3-acetyl-1-benzyl-2-hydroxy-5-methoxyindole with benzyl bromide in the presence of base resulted in isolation of the C- alkylated product which has been shown by X-ray crystallographic analysis to be 3-acetyl-1,3-dibenzyl-5-methoxy-1,3-dihydro-2H-indol-2-one (5c) in accord with the spectroscopic data. Triclinic crystals of (5c) belong to the space group P1 with a 10.649(3), b 13.736(3), c 14.555(2) Ǻ, α: 86-73(2), β 85.98(2), γ 78-01(2)° and Z 4. Least-squares refinement with 1996 observed data converged at R 0.061. Molecular mechanics was used to calculate the minimum-energy structure of (5c) which is compared with the X-ray results.
Ozonolysis of Amino Alkenes Derived From Labda-8(17),14-dien-13-ol
Authors: Grant PK , Lynch GP
Published: September 2010

A series of amino alkenes was synthesized from manool [labda-8(17),14-dien-13-ol] as substrates for an investigation of the ability of an amino group to act as an internal nucleophile during ozonolysis. A 10-membered ring keto lactam (20) was produced from amino. alkene (4) but the C8-C9 bond remained intact during the ozonolysis of amino alkene (18). Substrates with an unfavourable relationship of the amino group to the olefin, (7), (10) and (16), gave no products resulting from intramolecular participation.
Guidelines for the Presentation of Quantum Mechanical Computational Data in Organic Chemistry
Authors: Albright TA , Halevi EA
Published: September 2010

The primary objective of this document is to offer a set of guidelines concerning what information should be reported in the primary chemical literature relating to the techniques and results of quantum mechanical calculations. This information should be comprehensive to the point that an informed reader can reproduce the results and make an objective evaluation of the quality of the work.
The Action of Trifluoromethanesulfonic Acid on Naphthalene
Authors: Launikonis A , Sasse WHF , Willing IR
Published: September 2010

Trifluoromethanesulfonic ( triflic ) acid reacts with naphthalene at room temperature to give a complex mixture from which five products have been isolated and identified as follows: (E)-3-benzylidene-2,3-dihydro-1H-benz[e]indene (2) (yield 15-20%), 1,2,3,4-tetrahydroanthracene (7) (c. 0.5%), 4-phenyl-1,2-dihydroanthracene (8), 3,4-dihydro-1,2′-binaphthyl (9a′), 4-(2-naphthyl)-1,2-dihydroanthracene (10) [yields of (8), (9a′) and (10) each less than 0.1%]. Also formed is (Z)-2-benzylidene-1,3-dihydro-1H-benz[e]indene (6) which is formed reversibly from (2) by the action of triflic acid. Mechanisms are proposed for the formation of these products.
7-Hydroxy-1,8-cineole and 7-Cineolic Acid. Two New Possum Urinary Metabolites
Authors: Bull SD , Carman RM , Carrick FN , Klika KD
Published: September 2010

7-Hydroxy-1,8-cineole (3a) and the corresponding carboxylic acid (3b) have been isolated from the urine of brushtail possums ( Trichosurus vulpecula: Marsupialia ) fed a diet enhanced with 1,8-cineole. Chemical syntheses of these two novel metabolites are described.
Synthesis and Properties of 6A-Amino-6A-deoxy-α and β-cyclodextrin
Authors: Brown SE , Coates JH , Coghlan DR , Easton CJ , Vaneyk SJ , Janowski W , Lepore A , Lincoln SF , Luo Y , May BL , Schiesser DS , Wang P , Williams ML
Published: September 2010

The monotosylates obtained by treatment of α- and β- cyclodextrin with p- methylbenzenesulfonyl chloride reacted with ammonia to give the title compounds. These amines are of unusually low basicity , with pKa values of 8.70 and 8.72, respectively. In water at 25°, the hydrochloride salt of the amine derived from β- cyclodextrin is approximately 40 times more soluble than β-cyclodextrin and, through complexation, the salt increases the solubility of Nabumetone over 800 times.
A Theoretical Study of the Stevens Rearrangement of Methylammonium Methylide and Methylammonium Formylmethylide
Authors: Heard GL , Frankcombe KE , Yates BF
Published: September 2010

Ab initio and semi-empirical molecular orbital theory has been used to study the reaction pathways of the Stevens rearrangement of the prototype methylammonium methylide and methylammonium formylmethylide . For both reactions, the stepwise (free radical) process is predicted to require less energy than the concerted rearrangement (in accordance with experimental suggestions). With inclusion of electron correlation, the energy difference between these pathways is reduced; however, for the smaller system at the CCSD/6-31G(d) level of theory, the free radical process is still favoured by over 180 kJ mol-1. For both systems, the concerted transition structures for the pericyclic mechanisms reveal that some amount of bonding is retained in these formally symmetry-forbidden processes.
Synthesis and Amino Acid Chain Extension of 1-Acylated Hydroxymethylpyrroles
Authors: Abell AD , Litten JC
Published: September 2010

Acylation of pyrrole-2-carbaldehyde (3) with an N-phthaloyl amino acid chloride, N,N-diisopropylethylamine and 4-dimethylaminopyridine (dmap) gave the 1-acylpyrrole-2-carbalde-hydes (4a-c). The 1-acylated pyrroles (4d-i), (8) and (9) were similarly prepared in good yields from the relevant pyrrole derivative using dmap and either an acid chloride/N,N- diisopropylethylamine or an anhydride/triethylamine. Reduction of (4a-f) with zinc borohydride gave the 1-acylated hydroxymethylpyrroles (5a-f). A coupling of (5a) with N-Cbz-L-Val-L-Val-OH under Mitsunobu conditions gave the tetrapeptide analogue (11).
Potential Antimalarials. XIX. Syntheses and Testing of α-(Piperidin-2-yl)-α-(7′-trifluoromethylquinolin-4′-yl)methanol and α-(7-Bromo-1,5-naphthyridin-4-yl)-α-(piperidin-2′-yl)methanol
Authors: Barlin GB , Ireland SJ , Jiravinyu C , Nguyen TMT , Kotecka B , Rieckmann KH
Published: September 2010

The synthesis of the mefloquine analogue α-(piperidin-2-yl)-α-(7′-trifluoromethylquinolin-4′-yl)methanol (1) from 4-bromo-7-trifluoromethylquinoline and N-(hex-5-enyl) phthalimide through N-{4-[3′-(7″-trifluoromethylquinolin-4″-yl)oxiran-2′-yl]butyl} phthalimide 1′-oxide is reported. α-(7-Bromo-1,5-naphthyridin-4-yl)-α-(piperidin-2′-yl)methanol (2) was prepared by similar procedures. In tests against the K-1 isolate of Plasmodium falciparum, compound (1) proved the more active (IC50 99 nM ).
Structural and Spectroscopic Studies on the Dimeric Complexes of Tris(2-methylphenyl)phosphine With Copper(I) Halides
Authors: Bowmaker GA , Hanna JV , Hart RD , Healy PC , White AH
Published: September 2010

1:1 adducts of the copper(I) halides, CuX (X = Cl, Br, I), with the sterically hindered ligand tris (2-methylphenyl) phospine [P(o- tol )3] have been synthesized as crystalline dihalo -bridged centrosymmetric binuclear species; six compounds have been characterized by solid-state CP-MAS n.m.r. and far-infrared spectroscopy and by room-temperature single-crystal X-ray structure determination. For X = Cl , the dimeric complex. [P(o- tol )3CuCl]2, with three-coordinate copper atoms has been obtained from acetonitrile solution. Similar dimeric complexes for X = Br and I were obtained from toluene solution, the iodide adduct incorporating cocrystallized toluene. The X = Br and I complexes crystallized from acetonitrile solution yield mixed- ligand four-coordinate copper(I) dimers, [( MeCN )P(o- tol )3CuX]2, the iodide as a 2MeCN solvate. An additional crystalline phase incorporating crystallographically independent molecules of both the three-coordinate dimer and the four-coordinate mixed- ligand dimer has also been characterized for X = Br. Solid-state 31P CP-MAS n.m.r. spectra of the complexes at B = 7.05 T show well resolved asymmetric quartets with a ∆v3/∆v1 of 1.4 for the PcuX2 complexes and 1.1-1.2 for the PcuX2N complexes; these results reflect the geometric and bonding changes in the copper coordination sphere. Far-infrared spectra of the complexes show two strong halogen-sensitive bands, with a wavenumber separation of 30-40 cm-1, which have been assigned to copper-halogen stretching modes v( CuX ), this assignment being supported by a normal coordinate analysis on the Cu2X2 core.
Coscinoquinol, a New Cytotoxic Sesterterpene From a Dictyoceratid Sponge, Coscinoderma sp.
Authors: Alea GV , Carroll AR , Bowden BF
Published: September 2010

A marine sponge, Coscinoderma sp., from the Great Barrier Reef, Australia, contained a new sesterterpene hydroquinone, coscinoquinol (1). The structure was elucidated by one-dimensional and two-dimensional n.m.r. techniques. Cytotoxicity and other biological activities are reported for (1).
Photochemical Electron Transfer Between Methylene Blue and Quinones
Authors: Misran M , Matthews D , Valente P , Hope A
Published: September 2010

Methylene Blue is a well known photochemical oxidant. In this paper we present results of cyclic voltammetry and laser flash photolysis experiments which demonstrate that Methylene Blue may function also as a photochemical reductant. Laser flash photolysis studies of Methylene Blue were carried out in aqueous solution at pH 10, in ethanol and in aqueous dispersions of lipid vesicles in the presence of benzoquinol , benzoquinone and the long-chain naphthoquinone Vitamin K1. Both the quinones and the quinol affected the transient of the decay of triplet Methylene Blue to its ground electronic state. The transients were biphasic and characteristic of an initial electron transfer reaction between triplet Methylene Blue and the quinone or quinol , followed by back electron transfer between the products. For Vitamin K1 and Methylene Blue in ethanol the back electron transfer was very slow (lifetime about 4 ms). This slow back electron transfer is favourable to the use of this system for energy storage via photosynthetic solar energy conversion.
Structural Systematics of Rare Earth Complexes. III. Structural Characterization of Lanthanoid(III) Picrate Hydrates: Gadolinium Picrate Dodecahydrate—an X-Ray-Induced Phase Modification?—and Some General Aspects of the Structural Chemistry of Lanthanoid Picrates
Authors: Harrowfield JM , Lu WM , Skelton BW , White AH
Published: September 2010

In the course of the studies described in Parts I and II, an unusual result was observed in the case of the structure determination of hydrated gadolinium(III) picrate. Midway through data collection, the monoclinic P 21/c phase underwent a phase modification (X-ray-induced?) to a similar cell more nearly resembling that of the La → Pr structure type recorded previously, with no loss of crystal integrity, and with useful data sets being obtained on both forms. Redetermination of the structure with a fresh sample yielded no reproduction of the anomaly. These results are recorded and discussed, together with an overview of the consequences of the data of Parts I-III in relation to those of other literature in the field.
Formation of 4-Nitro-2-phenylquinoline on Attempted Diazotization of 3-Amino-2-phenylquinoline-4-carboxylic Acid
Authors: Brown RFC , Coulston KJ , Eastwood FW , Jurss CJ
Published: September 2010

Treatment of 3-amino-2-phenylquinoline-4-carboxylic acid with isoamyl nitrite in acidic dimethylformamide gave 4-nitro-2-phenylquinoline.
Constituents of Some Species of Beilschmiedia and Endiandra (Lauraceae): New Endiandric Acid and Benzopyran Derivatives Isolated From B. oligandra
Authors: Banfield JE , Black DS , Collins DJ , Hyland BPM , Lee JJ , Pranowo SR
Published: September 2010

On the basis of a preliminary u.v. assay of the dried leaf of nine species of Beilschmiedia and 26 species of Endiandra, several were selected for closer examination. Magnolol (9) was found in B.volckii and (+)-sesamin (10) was isolated from E. xanthocarpa. Endiandric acid B (2) and endiandric acid C (3) were obtained from both E. jonesii and B. tooram, and endiandric acid A (1) was found in B. obtusifolia. The new endiandric acid derivative (1′RS,3′RS,6′SR,7′SR,10′SR,11′ RS,12′RS,13′RS)-2-[6′-(3″,4″-methylenedioxyphenyl) tetracyclo [5.4.2.03,13.010,12]trideca-4′,8′-dien-11′ -yl ]acetic acid (3″,4″-methylenedioxyendiandric acid A) (4) was extracted from B. oligandra which also yielded the new phenolic benzopyran derivative (-)-(E)-2-(4′,8′-dimethylnona-3′,7′-dienyl)-2,8-dimethyl-3,4-dihydro-2H-1-benzopyran-6-ol ( oligandrol ) (12a). Several known hydrocarbon derivatives and terpenoids were isolated from the leaf of E. palmerstonii and E. baillonii, both of which were devoid of endiandric acids.
Structural Revision and Synthesis of Sinharine and Methylsinharine
Authors: Johnson WM , Littler SW , Strauss CR
Published: September 2010

An unambiguous synthesis of the published structure for the natural product sinharine (1) showed that the assignment was incorrect. (E)-3-( Methylthio )-N-(2-phenylethyl) propenamide (4) was proposed as an alternative structure and this was confirmed by synthesis. Similarly the literature proposal for the structure of methylsinharine was reviewed and the natural product tentatively reassigned as (E)-N-methyl-3-( methylthio )-N-(2-phenylethyl) propenamide.
Preparation of Cyclohexane-1,3-dione Herbicide Precursors by Birch Reduction of 3,5-Dimethoxyphenyl-Substituted Silane Derivatives
Authors: Ali AS , Liepa AJ , Thomas MD , Wilkie JS , Winzenberg KN
Published: September 2010

Birch reduction of the silane derivatives (3a-d), prepared from Grignard cross-coupling reactions, afforded the cyclohexane-1,3-dione derivatives (5a-d) after acid hydrolysis. Compounds (5a-d) are precursors to silicon-containing herbicides of the general structure (8).
Synthesis of Diastereoisomeric 2-Benzyl-1,2-diphenylindans
Authors: Alesso EN , Bianchi DE , Iglesias GYM , Sierra MG , Aguirre JM
Published: September 2010

The diastereoisomeric 2-benzyl-1,2-diphenylindan-1-ols were prepared and subjected to deoxygenation reactions under a variety of conditions to obtain 2-benzyl-1,2-diphenylindan. The stereochemistry of these compounds has been characterized on the basis of chemical and spectroscopic evidence.
Further New Depsones From the Lichen Pertusaria truncata
Authors: Elix JA , Elix JA , Venables DA , Venables DA , Archer AW , Archer AW
Published: September 2010

The new depsones, hyperpicrolichenic acid (4), isohyperpicrolichenic acid (5), megapicrolichenic acid (6) isomegapicrolichenic acid (7) and isosubpicrolichenic acid (8) have been shown to co-occur with picrolichenic acid (1) in the lichen Pertusaria truncata. The assigned structures were confirmed by unambiguous synthesis.
Conversion of 5-(4',7'-Dimethyl-1',3'-dihydro-1',3'-ethano-2'H-inden-2'-ylidene)-2,2-dimethyl-1,3-dioxan-4,6-dione Into 3-Methylacenaphthylene in a Flash Vacuum Pyrolytic Experiment
Authors: Bell SEV , Brown RFC , Coulston KJ , Eastwood FW
Published: September 2010

Flash vacuum pyrolysis of 5-(4′,7′-dimethyl-1′,3′-dihydro-1′,3′-ethano-2′ H-inden-2′-ylidene)-2,2-dimethyl-1,3-dioxan-4,6-dione (13) at temperatures in the range 600-750°p led to complex mixtures, but at higher temperatures (850°) it was converted into 3-methylacenaphthylene (major) and 1,4-dimethylnaphthalene (minor). 5-Ethenyl-1,4-dimethylnaphthalene on f.v.p. at 850° gave 5-methylacenaphthylene together with other compounds and was not on the reaction pathway.
Verification of the Chemical Weapons Convention: Mass Spectrometry of Alkyl Methylphosphonofluoridates
Authors: Borrett VT , Mathews RJ , Mattsson ER
Published: September 2010

Under the provisions of the United Nations Chemical Weapons Convention (CWC), certain parts of chemical industry will be monitored to verify compliance with the Convention. This will include analysis of samples from industrial sites to check for the presence or absence of chemical warfare related compounds. One of the problems in screening the chemicals to be monitored under the CWC is that certain classes of chemical warfare agents are represented as families of chemicals, with many of the individual chemicals having no analytical data available. One example is the alkyl methylphosphonofluoridate family with an alkyl ester substituent from CH3 to C10H21. In this work, the mass spectra of 60 alkyl methylphosphonofluoridate family members have been studied to enable the development of rapid on-site screening methods for this family of chemicals.
A genetic mosaic approach for neural circuit mapping in
Drosophila
Authors: Bohm Rudolf A. , Welch William P. , Goodnight Lindsey K. , Cox Logan W. , Henry Leah G. , Gunter Tyler C. , Bao Hong , Zhang Bing
Published: September 2010

Transgenic manipulation of subsets of brain cells is increasingly used for studying behaviors and their underlying neural circuits. In
Drosophila
, the GAL4–
u
pstream
a
ctivating
s
equence (UAS) binary system is powerful for gene manipulation, but GAL4 expression is often too broad for fine mapping of neural circuits. Here, we describe the development of unique molecular genetic tools to restrict GAL4 expression patterns. Building on the GAL4-UAS system, our method adds two components: a collection of
e
nhancer-
t
rap recombinase,
Fl
i
p
pase (ET-FLP), transgenic lines that provide inheritable, reproducible, and tissue-specific FLP and an FRT-dependent GAL80 “flip-in” construct that converts FLP expression into tissue-specific repression of GAL4 by GAL80. By including a UAS-encoded fluorescent protein, circuit morphology can be simultaneously marked while the circuit function is assessed using another UAS transgene. In a proof-of-principle analysis, we applied this ET-
F
LP-induced
in
tersectional
G
AL80/GAL4
r
epression (FINGR) method to map the neural circuitry underlying fly wing inflation. The FINGR system is versatile and powerful in combination with the vast collection of GAL4 lines for neural circuit mapping as well as for clonal analysis based on the infusion of the yeast-derived FRT/FLP system of mitotic recombination into
Drosophila.
The strategies and tactics underlying our FINGR system are also applicable to other genetically amenable organisms in which transgenes including the GAL4, UAS, GAL80, and FLP factors can be applied.
Real-time mapping of electronic structure with single-shot two-dimensional electronic spectroscopy
Authors: Harel Elad , Fidler Andrew F. , Engel Gregory S.
Published: September 2010

Electronic structure and dynamics determine material properties and behavior. Important time scales for electronic dynamics range from attoseconds to milliseconds. Two-dimensional optical spectroscopy has proven an incisive tool to probe fast spatiotemporal electronic dynamics in complex multichromophoric systems. However, acquiring these spectra requires long point-by-point acquisitions that preclude observations on the millisecond and microsecond time scales. Here we demonstrate that imaging temporally encoded information within a homogeneous sample allows mapping of the evolution of the electronic Hamiltonian with femtosecond temporal resolution in a single-laser-shot, providing real-time maps of electronic coupling. This method, which we call GRadient-Assisted Photon Echo spectroscopy (GRAPE), eliminates phase errors deleterious to Fourier spectroscopies while reducing the acquisition time by orders of magnitude using only conventional optical components. In analogy to MRI in which magnetic field gradients are used to create spatial correlation maps, GRAPE spectroscopy takes advantage of a similar type of spatial encoding to construct electronic correlation maps. Unlike magnetic resonance, however, this spatial encoding of the nonlinear polarization along the excitation frequency axis of the two-dimensional spectrum results in no loss in signal while simultaneously reducing overall noise. Correlating the energy transfer events and electronic coupling occurring in tens of femtoseconds with slow dynamics on the subsecond time scale is fundamentally important in photobiology, solar energy research, nonlinear spectroscopy, and optoelectronic device characterization.
Glucocorticoids in the prefrontal cortex enhance memory consolidation and impair working memory by a common neural mechanism
Authors: Barsegyan Areg , Mackenzie Scott M. , Kurose Brian D. , McGaugh James L. , Roozendaal Benno
Published: September 2010

It is well established that acute administration of adrenocortical hormones enhances the consolidation of memories of emotional experiences and, concurrently, impairs working memory. These different glucocorticoid effects on these two memory functions have generally been considered to be independently regulated processes. Here we report that a glucocorticoid receptor agonist administered into the medial prefrontal cortex (mPFC) of male Sprague-Dawley rats both enhances memory consolidation and impairs working memory. Both memory effects are mediated by activation of a membrane-bound steroid receptor and depend on noradrenergic activity within the mPFC to increase levels of cAMP-dependent protein kinase. These findings provide direct evidence that glucocorticoid effects on both memory consolidation and working memory share a common neural influence within the mPFC.
Revenue Risk‐Reduction Impacts of Crop Insurance in a Multicrop Framework
Authors: Woodard Joshua D. , Sherrick Bruce J. , Schnitkey Gary D.
Published: September 2010

The authors develop a multicrop insurance model to evaluate crop insurance decisions when several crops are produced. The results suggest that the diversification effects derived from producing multiple crops can substantially alter the risk‐reduction impacts of crop insurance versus if the decision is viewed from the perspective of a single crop. Further, the relatedness of crop production and price responses among crops differs considerably across insurance products and strategies. As a result, insurance strategies that might provide the maximum risk reduction for an individual crop do not necessarily carry over to the multicrop case.
CoGAPS: an R/C++ package to identify patterns and biological process activity in transcriptomic data
Authors: Fertig Elana J. , Ding Jie , Favorov Alexander V. , Parmigiani Giovanni , Ochs Michael F.
Published: September 2010

Summary: Coordinated Gene Activity in Pattern Sets (CoGAPS) provides an integrated package for isolating gene expression driven by a biological process, enhancing inference of biological processes from transcriptomic data. CoGAPS improves on other enrichment measurement methods by combining a Markov chain Monte Carlo (MCMC) matrix factorization algorithm (GAPS) with a threshold-independent statistic inferring activity on gene sets. The software is provided as open source C++ code built on top of JAGS software with an R interface.

Availability: The R package CoGAPS and the C++ package GAPS-JAGS are provided open source under the GNU Lesser Public License (GLPL) with a users manual containing installation and operating instructions. CoGAPS is available through Bioconductor and depends on the rjags package available through CRAN to interface CoGAPS with GAPS-JAGS.

URL:  http://www.cancerbiostats.onc.jhmi.edu/cogaps.cfm

Contact:  ejfertig@jhmi.edu; mfo@jhu.edu

Supplementary Information:  Supplementary data is available at Bioinformatics online.
Parenteral administration of recombinant human neuregulin‐1 to patients with stable chronic heart failure produces favourable acute and chronic haemodynamic responses
Authors: Jabbour Andrew , Hayward Christopher S. , Keogh Anne M. , Kotlyar Eugene , McCrohon Jane A. , England John F. , Amor Raul , Liu Xifu , Li Xin Yan , Zhou Ming Dong , Graham Robert M. , Macdonald Peter S.
Published: September 2010

Aims

Neuregulin‐1 (NRG‐1) plays a critical role in the adaptation of the heart to injury, inhibiting apoptosis and inducing cardiomyocyte proliferation. We have shown previously that rhNRG‐1 improves cardiac function and survival in animal models of cardiomyopathy. Here we report the first human study aimed at exploring the acute and chronic haemodynamic responses to recombinant human NRG‐1 (beta2a isoform; rhNRG‐1) in patients with stable chronic heart failure (CHF).

Methods and results

Fifteen patients (age, 60 ± 2; NYHA II:III, 9:6; left ventricular ejection fraction (LVEF) <40%) on optimal medical therapy for CHF, received a rhNRG‐1 infusion daily for 11 days. Acute and chronic haemodynamic, structural and biochemical effects were determined by serial right heart catheterization, cardiac magnetic resonance (CMR), echocardiography and measurement of neurohumoral indices. Acutely, cardiac output increased by 30% during a 6 h rhNRG‐1 infusion (P < 0.01). Pulmonary artery wedge pressure and systemic vascular resistance decreased 30 and 20%, respectively, at 2 h (P < 0.01). A 47% reduction in serum noradrenaline, a 55% reduction in serum aldosterone and a 3.6‐fold increase in N‐terminal prohormone brain natriuretic peptide levels were concurrently observed (P < 0.001). These acute haemodynamic effects were sustained, as demonstrated by the 12% increase in LVEF from 32.2 ± 2.0% (baseline) to 36.1 ± 2.3% (mean ± SE, P < 0.001) at 12 weeks. The therapy was well tolerated.

Conclusion

rhNRG‐1 appears to produce favourable acute and chronic haemodynamic effects in patients with stable CHF on optimal medical therapy. Randomized controlled trials of rhNRG‐1 in cardiac disease are thus warranted.

Clinical Trial Registration Information

The trial was registered with the Australian New Zealand Clinical Trials Registry, anzctr.org.au Identifier: ACTRN12607000330448.
Positive selection on the killer whale mitogenome
Authors: Foote Andrew D. , Morin Phillip A. , Durban John W. , Pitman Robert L. , Wade Paul , Willerslev Eske , Gilbert M. Thomas P. , da Fonseca Rute R.
Published: September 2010

Mitochondria produce up to 95 per cent of the eukaryotic cell's energy. The coding genes of the mitochondrial DNA may therefore evolve under selection owing to metabolic requirements. The killer whale,Orcinus orca, is polymorphic, has a global distribution and occupies a range of ecological niches. It is therefore a suitable organism for testing this hypothesis. We compared a global dataset of the complete mitochondrial genomes of 139 individuals for amino acid changes that were associated with radical physico-chemical property changes and were influenced by positive selection. Two such selected non-synonymous amino acid changes were found; one in each of two ecotypes that inhabit the Antarctic pack ice. Both substitutions were associated with changes in local polarity, increased steric constraints and α-helical tendencies that could influence overall metabolic performance, suggesting a functional change.
On optimal hierarchy of load-bearing biological materials
Authors: Zhang Zuoqi , Zhang Yong-Wei , Gao Huajian
Published: September 2010

Load-bearing biological materials such as shell, mineralized tendon and bone exhibit two to seven levels of structural hierarchy based on constituent materials (biominerals and proteins) of relatively poor mechanical properties. A key question that remains unanswered is what determines the number of hierarchical levels in these materials. Here we develop a quasi-self-similar hierarchical model to show that, depending on the mineral content, there exists an optimal level of structural hierarchy for maximal toughness of biocomposites. The predicted optimal levels of hierarchy and cooperative deformation across multiple structural levels are in excellent agreement with experimental observations.
Individual-learning ability predicts social-foraging strategy in house sparrows
Authors: Katsnelson Edith , Motro Uzi , Feldman Marcus W. , Lotem Arnon
Published: September 2010

Social foragers can use either a ‘producer’ strategy, which involves searching for food, or a ‘scrounger’ strategy, which involves joining others' food discoveries. While producers rely on personal information and past experience, we may ask whether the tendency to forage as a producer is related to being a better learner. To answer this question, we hand-raised house sparrow (
Passer domesticus
) nestlings that upon independence were given an individual-learning task that required them to associate colour signal and food presence. Following the testing phase, all fledglings were released into a shared aviary, and their social-foraging tendencies were measured. We found a significant positive correlation between individual's performance in the individual-learning task and subsequent tendency to use searching (producing) behaviour. Individual-learning score was negatively correlated with initial fear of the test apparatus and with body weight. However, the correlation between individual learning and searching remained significant after controlling for these variables. Since it was measured before the birds entered a social group, individual-learning ability could not be the outcome of being a producer. However, the two traits may be initially associated, or individual learning could facilitate producing behaviour. To our knowledge, this is the first evidence that associates individual-learning abilities with social-foraging strategies in animal groups.
How resource quality differentially affects motivation and ability to fight in hermit crabs
Authors: Doake S. , Elwood R. W.
Published: September 2010

Contesting animals typically gather information about the resource value and that information affects fight motivation. However, it is possible that particular resource characteristics alter the ability to fight independently of the motivation. Using hermit crabs, we investigate how the resource in terms of shell quality affects both motivation and ability to fight. These crabs fight for shells, but those shells have to be carried and may impose physiological costs that impede fight vigour. We find that the shell has different effects on motivation and ability. Potential attackers in very small shells were highly motivated to attack but, rather than having enhanced ability, unexpectedly quickly fatigued and subsequently were not more successful in the fights than were crabs in larger shells. We also examined whether defending crabs could gather information about the attacker's shell from the vigour of the attack. Defending crabs gave up quickly when a potential gain had been assessed, indicating that such information had been gathered. However, there was no indication that this could be owing to the activity of the attacker and the information is probably gathered via visual assessment of the shell.
How to run far: multiple solutions and sex-specific responses to selective breeding for high voluntary activity levels
Authors: Garland Theodore , Kelly Scott A. , Malisch Jessica L. , Kolb Erik M. , Hannon Robert M. , Keeney Brooke K. , Van Cleave Shana L. , Middleton Kevin M.
Published: September 2010

The response to uniform selection may occur in alternate ways that result in similar performance. We tested for multiple adaptive solutions during artificial selection for high voluntary wheel running in laboratory mice. At generation 43, the four replicate high runner (HR) lines averaged 2.85-fold more revolutions per day as compared with four non-selected control (C) lines, and females ran 1.11-fold more than males, with no sex-by-linetype interaction. Analysis of variance indicated significant differences among C lines but not among HR for revolutions per day. By contrast, average speed varied significantly among HR lines, but not among C, and showed a sex-by-linetype interaction, with the HR/C ratio being 2.02 for males and 2.45 for females. Time spent running varied among both HR and C lines, and showed a sex-by-linetype interaction, with the HR/C ratio being 1.52 for males but only 1.17 for females. Thus, females (speed) and males (speed, but also time) evolved differently, as did the replicate selected lines. Speed and time showed a trade-off among HR but not among C lines. These results demonstrate that uniform selection on a complex trait can cause consistent responses in the trait under direct selection while promoting divergence in the lower-level components of that trait.
Founder population-specific HapMap panel increases power in GWA studies through improved imputation accuracy and CNV tagging
Authors: Surakka Ida , Kristiansson Kati , Anttila Verneri , Inouye Michael , Barnes Chris , Moutsianas Loukas , Salomaa Veikko , Daly Mark , Palotie Aarno , Peltonen Leena , Ripatti Samuli
Published: September 2010

The combining of genome-wide association (GWA) data across populations represents a major challenge for massive global meta-analyses. Genotype imputation using densely genotyped reference samples facilitates the combination of data across different genotyping platforms. HapMap data is typically used as a reference for single nucleotide polymorphism (SNP) imputation and tagging copy number polymorphisms (CNPs). However, the advantage of having population-specific reference panels for founder populations has not been evaluated. We looked at the properties and impact of adding 81 individuals from a founder population to HapMap3 reference data on imputation quality, CNP tagging, and power to detect association in simulations and in an independent cohort of 2138 individuals. The gain in SNP imputation accuracy was highest among low-frequency markers (minor allele frequency [MAF] < 5%), for which adding the population-specific samples to the reference set increased the median R2 between imputed and genotyped SNPs from 0.90 to 0.94. Accuracy also increased in regions with high recombination rates. Similarly, a reference set with population-specific extension facilitated the identification of better tag-SNPs for a subset of CNPs; for 4% of CNPs the R2 between SNP genotypes and CNP intensity in the independent population cohort was at least twice as high as without the extension. We conclude that even a relatively small population-specific reference set yields considerable benefits in SNP imputation, CNP tagging accuracy, and the power to detect associations in founder populations and population isolates in particular.
Comprehensive annotation of the transcriptome of the human fungal pathogen Candida albicans using RNA-seq
Authors: Bruno Vincent M. , Wang Zhong , Marjani Sadie L. , Euskirchen Ghia M. , Martin Jeffrey , Sherlock Gavin , Snyder Michael
Published: September 2010

Candida albicans is the major invasive fungal pathogen of humans, causing diseases ranging from superficial mucosal infections to disseminated, systemic infections that are often lifethreatening. We have used massively parallel high-throughput sequencing of cDNA (RNA-seq) to generate a high-resolution map of the C. albicans transcriptome under several different environmental conditions. We have quantitatively determined all of the regions that are transcribed under these different conditions, and have identified 602 novel transcriptionally active regions (TARs) and numerous novel introns that are not represented in the current genome annotation. Interestingly, the expression of many of these TARs is regulated in a condition-specific manner. This comprehensive transcriptome analysis significantly enhances the current genome annotation of C. albicans, a necessary framework for a complete understanding of the molecular mechanisms of pathogenesis for this important eukaryotic pathogen.