Two new xanthones from the stems of Garcinia cowa

Two new xanthones, 1,5,6-trihydroxy-3-methoxy-4-(3-hydroxyl-3-methylbutyl)xanthone (1) and 1,5-dihydroxy-3-methoxy-6',6'-dimethyl-2H-pyrano(2',3':6,7)-4-(3-methylbut-2-enyl)xanthone (2), have been isolated together with six known xanthones: 1,3,5-trihydroxy-6',6'-dimethyl-2H-pyrano(2',3':6,7)xanthone (3), dulxanthone A (4), 1,5,6-trihydroxy-3,7-dimethoxyxanthone (5), 1,7-dihydroxyxanthone (6), 1,3,5-trihydroxy-6-methoxyxanthone (7), 1,3,6,7-tetrahydroxyxanthone (8), from the stems of Garcinia cowa (Guttiferae).     

Studies on the constituents of Anaxagorea luzonensis A. GRAY

Five new xanthones, 1,3,6-trihydroxy-5-methoxy-4-prenylxanthone (1), 1,3,5-trihydroxy-6-methoxy-2-prenylxanthone (2), 1,3,5-trihydroxy-4-(3-hydroxy-3-methylbutyl) xanthone (3), 1,3,6-trihydroxy-4-prenylxanthone (4), 3,6-dihydroxy-1,5-dimethoxyxanthone (5) and one new flavonoid, 3,5,7,4'-tetrahydroxy-2'-methoxyflavone (6) along with seven known xanthones and seven known flavonoids were isolated from the bark of Anaxagorea luzonensis A. GRAY and their chemical structures were determined by means of chemical and spectral studies. Almost all flavonoids and one xanthone (13) showed antioxidant activity.     

A spiro[chroman-3,7'-isochromene]-4,6'(8'H)-dione from the Cordyceps-colonizing fungus Fimetariella sp

Fimetarone A (1), a metabolite with the new spiro[chroman-3,7'-isochromene]-4,6'(8'H)-dione skeleton, was isolated from cultures of the Cordyceps-colonizing fungus Fimetariella sp. Compound 1 was a 1:1 atropdiastereomeric mixture in NMR data, and aS,9S and aR,9R enantiomers were found and confirmed by X-ray crystallography. Compound 1 could be derived from the hypothetical precursors 3,4,5-trihydroxy-2-(2-methylene-3,5-dioxohexanoyl)benzoic acid (5) and lapidosin (6).     

Synthesis of acrimarins from 1,3,5‐trioxygenated‐9‐acridone derivatives

1,3,5‐Trihydroxy‐9(10H)‐acridinone (1) was prepared from 3‐hydroxyanthranillic acid with phloroglucinol. 1,3‐Dihydroxy‐5‐methoxy‐9(10H)‐acridinone (2) was prepared from 3‐methoxyanthranillic acid and phloroglucinol. Methylation of 1 under different conditions gave 1‐hydroxy‐3,5‐dimethoxy (3), 1‐hydroxy‐3,5‐dimethoxy‐10‐methyl (4), 1‐hydroxy‐3,5‐dimethoxy‐4‐methyl (5), 1,3,5‐trimethoxy‐10‐methyl (6) and 1,3,5‐trimethoxy‐4,10‐dimethyl (7) analogues. Demethylation of 4 afforded the 1,3,5‐trihydroxy‐10‐methyl analogue 8. Condensation of acridones 1, 2, 3 and 4 individually with E‐suberenol (9) gave four novel acrimarins (acridone‐coumarin dimers) 10, 11, 12 and 13 respectively, while the acridone 8 gave previously reported acrimarin‐G (14).     

Three new fatty acids from the roots of Boehmeria nivea (L.) Gaudich and their antifungal activities

Three new unsaturated fatty acids, (Z)-9,10,11-trihydroxy-12-octadecenoic acid (1), (Z)-7,8,9-trihydroxy-10-hexadecenoic acid (2) and (Z)-12-keto-7,8,9-trihydroxy-10-hexadecenoic acid (3) were isolated from the roots of Boehmeria nivea (L.) Gaudich, along with a known unsaturated fatty acid, (E)-8,11,12-trihydroxy-9-octadecenoic acid (4). The structures of the new compounds were established by HR ESI-MS, (1)H, (13)C, 2D ((1)H-(1)H COSY, HSQC, HMBC) NMR experiments. The known compound was identified by a comparison of its spectral data with published references. The three new compounds showed some antifungal activities by agar assay.     

Triterpenes from the spores of Ganoderma lucidum and their cytotoxicity against meth-A and LLC tumor cells

Six new highly oxygenated lanostane-type triterpenes, called ganoderic acid gamma (1), ganoderic acid delta (2), ganoderic acid epsilon (3), ganoderic acid zeta (4), ganoderic acid eta (5) and ganoderic acid theta (6), were isolated from the spores of Ganoderma lucidum, together with known ganolucidic acid D (7) and ganoderic acid C2 (8). Their structures of the new triterpenes were determined as (23S)-7beta,15alpha,23-trihydroxy-3,11-dioxolanosta-8, 24(E)-diene-26-oic acid (1), (23S)-7alpha,15alpha23-trihydroxy-3,11-dioxolanosta-8, 24(E)-diene-26-oic acid (2), (23S)-3beta3,7beta, 23-trihydroxy-11,15-dioxolanosta-8,24(E)-diene-26-oic acid (3), (23S)-3beta,23-dihydroxy-7,11,15-trioxolanosta-8, 24(E)-diene-26-oic acid (4), (23S)-3beta,7beta,12beta,23-tetrahydroxy-11,15-dioxolanos ta-8,24(E)-diene-26-oic acid (5) and (23S)-3beta,12beta23-trihydroxy-7,11,15-trioxolanosta-8,24(E )-diene-26-oic acid (6), respectively, by chemical and spectroscopic means, which included the determination of a chiral center in the side chain by a modification of Mosher's method. The cytotoxicity of the compounds isolated from the Ganoderma spores was carried out in vitro against Meth-A and LLC tumor cell lines.     

Studies on naphthyridines. Part 2 . Synthesis of 4-substituted and 6-substituted 1,6-naphthyridin-5(6H)-ones

Ethyl 4-substituted 2-methyl-5-oxo-5,6-dihydro-1,6-naphthyridine-3-carboxylates 3a-h were synthetized in a one-step reaction from diethyl 2,6-diraethylpyridine-3,5-dicarboxylates 1a-h by aminomethinylation with 1,3,5-triazine (2). The 6-substitued derivatives 6a-z,aa-ff could be obtained from diethyl 2-[2-(dimethylamino)-vinyl]-6-methylpyridine-3,5-dicarboxylate ( 4 ) either directly or via the isolated intermediate 2-[2-(arylamino)-vinyl]pyridine compounds 5a-i.     

In vitro cytotoxicity activity on several cancer cell lines of acridone alkaloids and N-phenylethyl-benzamide derivatives from Swinglea glutinosa (Bl.) Merr

The methanol extract from the stems and fruits of Swinglea glutinosa (Rutaceae) afforded 11 known acridone alkaloids and three N-phenylethyl-benzamide derivatives, glycocitrine-IV, 1,3,5-trihydroxy-4-methoxy-10-methyl-2,8-bis(3-methylbut-2-enyl)acridin-9(10H)-one, 1,3,5- trihydroxy-2,8-bis(3-methylbut-2-enyl)-10-methyl-9-acridone, citbrasine, citrusinine-II, citrusinine-I, 5-dihydroxyacronycine, pyranofoline, 3,4-dihydro-3,5,8-trihydroxy-6-methoxy-2,2,7-trimethyl-2H-pyrano[2,3-a]acridin-12(7H)-one, 2,3-dihydro-4,9-dihydroxy-2-(2-hydroxy-propan-2-yl)-11-methoxy-10-methylfuro[3,2-b]acridin-5(10H)-one, bis-5-hydroxyacronycine, N-(2-{4-[(3,7-dimethylocta-2,6-dien-1-yl)oxy]phenyl}ethyl)benzamide, N-(2-{4-[(3,7-dimethyl-4-acethyl-octa-2,6-dien-1-yl)oxy]phenyl}ethyl)benzamide, and severine acetate. All compounds isolated were examined for their activity against three cancer cell lines: human lung carcinoma (COR-L23), human breast adenocarcinoma (MCF7), human melanoma (C32), and normal human fetal lung cell line, MRC-5. The acridones tested exhibited weak cytotoxicity but the amides showed moderate nonselective cytotoxic activity.     

New quinone sulfates from the crinoids Tropiometra afra macrodiscus and Oxycomanthus japonicus

Quinone pigments in the crinoids were investigated. New quinone sulfates 1 and 3 were isolated from Tropiometra afra macrodiscus and Oxycomanthus japonicus, respectively. The structures 1 and 3 were determined to be 1,6,8-trihydroxy-3-propylanthraquinone-2-carboxylic acid 6-O-sulfate (ptilometric acid 6-O-sulfate) and 2-butanoyl-3,6,8-trihydroxy-1,4-naphtoquinone 6-O-sulfate, respectively, by chemical and spectroscopic analysis. Ptilometric acid 6-O-sulfate (1) showed an antifeedant activity on fish.     

Polyoxygenated ergostane-type sterols from the liquid culture of Ganoderma applanatum

A new polyoxygenated ergostane-type sterol, 3β,5α,6β,8β,14α-pentahydroxy-(22E,24R)-ergost-22-en-7-one (1), has been isolated from the liquid culture of the basidiomycete Ganoderma applanatum together with four known sterols, 3β,5α,9α-trihydroxy-(22E,24R)-ergosta-7,22-dien-6-one (2), ergosterol peroxide (3), 6-dehydrocerevisterol (4) and cerevisterol (5). Two of these sterols (2, 4) are reported to have been isolated from this species for the first time. The structures of these compounds were determined by chemical and spectroscopic analyses, including 1D- and 2D-NMR, as well as by comparison of their spectroscopic data with those reported in the literature.     

藏药短穗兔耳草化学成分的研究

从短穗兔耳草(Lagotis brachystachya Maxim)的全草中分离出一种新的黄酮甙,经光谱和化学方法确定为[3,5-二羟基-3′,5′-二甲氧基-7-O-葡萄糖甙],定名为兔耳草甙(2)(Lagotiside),还分离鉴定了6种已知化合物。     

Three new megastigmane glucopyranosides from the Cardamine komarovii

Three new megastigmane glucopyranosides, komaroveside A [(3S,4R,5Z,7E)-3,4-dihydroxy-5,7-megastigmadien-9-one-3-O-β-D-glucopyranoside] (1), komaroveside B [(3S,4S,5S,6R,7E)-5,6-epoxy-3,4-dihydroxy-7-megastigmen-9-one-3-O-β-D-glucopyranoside] (2) and komaroveside C [(3S,4S,5S,6R,7E,9S)-5,6-epoxy-3,4,9-trihydroxy-7-megastigmen-3-O-β-D-glucopyranoside] (3) were isolated, together with eight known compounds, from Cardamine komarovii. The identification of these compounds and the elucidation of their structures were based on 1D- and 2D-NMR spectral data analysis. The isolated compounds were tested for their cytotoxicity against four human tumor cell lines (A549, SK-OV-3, SK-MEL-2, HCT15) in vitro using the sulforhodamine B bioassay.     

Preparation, Structure and Electrochemical Property of a Pyrazole-substituted Diiron Dithiolate Complex

A pyrazole-substituted diiron dithiolate complex [Fe2(μ-pdt)(CO)5(3,5-Me2Pz)](1,3,5-Me 2Pz=3,5-dimethylpyrazole) was prepared as a biomimetic model for the active site of [FeFe]-hydrogenase by CO-substitution of all-carbonyl complex [Fe2(μ-pdt)(CO)6] with 3,5-Me2Pz. The molecular structure was confirmed by MS, IR, 1H NMR, elemental analysis and single-crystal X-ray analysis. Complex 1 crystallizes in the triclinic system, space group P1 with a=9.108(7), b=9.743(8), c=11.192(9), α=109.235(5), β=101.914(9), γ=96.605(6)o. In CH3CN solution, reversible transformation between 1 and the acetonitrile-substituted species [Fe2(μ-pdt)-(CO)5(NCCH3)] was detected by both IR and cyclic voltammetry (CV). The electrochemical proton reduction catalyzed by 1 in the presence of acetic acid was also studied in CH2Cl2.     

Synthesis of 3,5-disubstituted 1-amino-1,3,5-triazine-2,4,6-triones (or 1-aminocyanurates) by cyclic transformation of 1,3,4-oxadiazol-2(3H)-one derivatives

The 5-aryl(or methyl)-3-phenylcarbamoyl-1,3,4-oxadiazol-2(3H)-ones 2 , in the presence of sodium hydride in anhydrous dimethylformamide, were transformed into 1-benzamido(or acetamido)-3,5-diphenyl-1,3,5-triazine-2,4,6-trione derivatives 7 in poor yields. However, compounds 7 were obtained in better yields when the sodium salts of 5-aryl(or methyl)-1,3,4-oxadiazol-2(3H)-ones 1 were treated with two equivalents of aryl(or ethyl)isocyanates. Acidic hydrolysis of 1-acetamido-3,5-diphenyl-1,3,5-triazine-2,4,6-trione ( 7i ) provided the corresponding free N-amino derivative 9 . Nitrous deamination of 9 gave the known 3,5-diphenyl-1,3,5-triazine-2,4,6-trione ( 11 ). This cyclic transformation is the first one to be reported providing 1,3,5-triazine-2,4,6-trione derivatives.     

Synthesis of (R)-2-methyl-4-deoxy and (R)-2-methyl-4,5-dideoxy analogues of 6-phosphogluconate as potential inhibitors of 6-phosphogluconate dehydrogenase

The synthesis of (2R)-2-methyl-4,5-dideoxy and (2R)-2-methyl-4-deoxy analogues of 6-phosphogluconate is described. The synthetic strategy relies on the Evans aldol reaction for the installation of the chiral centres in the 2- and 3-positions. The selective phosphorylation at the primary alcohol function of (2R,3S)-3,6-dihydroxy-2-methylhexanoic acid benzyl ester (5) and (2R,3S,5S)-3,5,6-trihydroxy-2-methylhexanoic acid benzyl ester (20) was achieved with dibenzyl phosphochloridate and dibenzyl phosphoiodinate respectively, working at low temperature. (2R,3S)-3-Hydroxy-2-methyl-6-phosphonoxyhexanoic acid (9) was obtained in 25% overall yield from 4-benzyloxybutanol and (2R,3S,5S)-3,5-dihydroxy-2-methyl-6-phosphonoxyhexanoic acid (28) in 10% overall yield from L-malic acid.     

19-nor-11-Oxooleanan-12-ene and 18,19-seco-19-oxours-11,13(18)-diene triterpenes from Diospyros decandra bark

Four new triterpenes, 2α,3β-dihydroxy-19-nor-11-oxo-20-dimethylurs-12-en-24,28-dioic acid (equivalent to 2α,3β-dihydroxy-19-nor-11-oxoolean-12-en-24,28-dioic acid), 2α,3β-dihydroxy-18,19-seco-19-oxours-11,13(18)-dien-24,28-dioic acid, 2α,3β,19α-trihydroxy-11-oxours-12-en-24,28-dioic acid and 2α,3β,19α-trihydroxy-28-1′-β-d-[glucopyranosyl-(1″→6′)-glucopyranosyl]-urs-12-en-24,28-dioic acid were isolated from the methanol extract of the bark of Diospyros decandra as their acetate-methyl ester derivatives. The first two compounds represent the biosynthetic transformation products of 2α,3β,19-trihydroxyurs-24,28-dioic acid via oxidative rearrangement of ring E.     

2'-C-branched ribonucleosides. 2. Synthesis of 2'-C-beta-trifluoromethyl pyrimidine ribonucleosides

[structure: see text]. The first synthesis of 2'-C-beta-trifluoromethyl pyrimidine ribonucleosides is described. 1,2,3,5-Tetra-O-benzoyl-2-C-beta-trifluoromethyl-alpha-D-ribofuranose (3) is prepared from 1,3,5-tri-O-benzoyl-alpha-D-ribofuranose (1) in three steps and converted to 3,5-di-O-benzoyl-2-C-beta-trifluoromethyl-alpha-D-1-ribofuranosyl bromide (5). The 1-bromo derivative (5) is found to be a powerful reaction intermediate for the synthesis of ribonucleosides. The reaction of silylated pyrimidines with (5) in the presence of HgO/HgBr2 affords exclusively the beta-anomers (6-8). Deprotection of (6-8) with ammonia in methanol yields the 2'-C-beta-trifluoromethyl nucleosides (9-11).     

Two New Sesquiterpenes from Eupatorium lindleyanum

Various germacrane sesquiterpenes have been isolated from many species of the Eupatorium.In recent years these compounds have been increasing interest due to their insecticidal,cytotoxic,antitumor-promoting and insect-antifeedant activities1.In our present study,we have investigated the chemical constituents of Eupatorium lindleyanum DC.,which is a geo-authentic medicine of Jiangsu province.It is used as a antipyretic drug.Two novel germacrane sesquiterpenes(Figure1)were found by us from th…     

Synthesis of some symmetrically substituted compounds derived from 1,3‐bis(6‐azauracil‐1‐yl)benzene and 1,3,5‐tris(6‐azauracil‐1‐yl)benzene

The 3,5‐bis(5‐carboxy‐6‐azauracil‐1‐yl)aniline ( 7 ) and 1,3,5‐tris(5‐carboxy‐6‐azauracil‐1‐yl)benzene ( 10 ) were prepared from 3‐amino‐5‐nitroacetanilide ( 1 ) via intermediates 2–6 . A series of other substituted 6‐azauracil derivatives 9, 11‐14 were also prepared.     

Organometallic fragments coordinated to a multiisocyanide ligand and their physical properties

Preparation of a triisocyanide ligand, 1,3,5-tris[(4-isocyano-3,5-diisoproyl-phenyl)ethynyl]benzene (5), is presented. Ligand 5 is obtained in three steps in 76% overall yield. Reaction of 5 with (eta5-Cp*)Rh(Cabs,s')(Cabs,s'= 1,2-S2C2B10H10-S,S') produced the rhodadithiolene adduct [[(eta5-Cp*)Rh(Cabs,s')(CNC6H2iPr2-2,6-CC-3)]3C6H3-1,3,5] (6). Ligand 5 reacts with Cr(CO)5(THF) to give the triisocyanide complex [[Cr(CO)5(CNC6H2iPr2-2,6-CC-3)]3C6H3-1,3,5] (8) and with [AuCl(SMe2)] to give the triisocyanide complex [[AuCl(CNC6H2iPr2-2,6-CC-3)]3C6H3-1,3,5] (9). As revealed by a single-crystal X-ray diffraction study, the C(9)-N(3)-C(61) angle of 5.9 degrees of trichromium complex 8 occurs in the plane of the bridge and the gold center has a slightly bent linear configuration with a Cl(1)-Au(1)-C(21) angle of 175.4(4) degrees . The rhenation and platination of 5 employing [Re(bpy)(CO)3(AN)]PF6 (AN= acetonitrile) and [(CwedgeNwedgeN)PtCl] ((HCwedgeNwedgeN)= 6-phenyl-2,2'-bipyridine) yielded the luminescent Re(I) and Pt(II) complexes. Full characterization includes structural study of complexes 2, 8, and 9.