Isoterchebulin and 4,6-O-isoterchebuloyl-D-glucose, novel hydrolyzable tannins from Terminalia macroptera

Two new hydrolyzable tannins, isoterchebulin (1) and 4,6-O-isoterchebuloyl-D-glucose (2), together with six known tannins, 3-8, were isolated from the bark of Terminalia macroptera. Their structures were elucidated by extensive 1D and 2D NMR studies, MS, and chemical transformations. Biological activities of all compounds were evaluated against the snail Biomphalaria glabrata, the bacteria Bacillus subtilis and Pseudomonas fluorescens, the nematode Caenorhabditis elegans, and four cancer cell lines (Hep G2, MCF-7/S, MDA-MB-231, and 5637 cells). All compounds except 3 showed antimicrobial activities against B. subtilis (MIC 8-64 microg/mL), whereas only 1 was active against C. elegans (100 microg/mL) and B. glabrata(LC(100) = 60 microg/mL). 3 and 8 were toxic against 5637 cells with LC(50) = 84.66 and 41.40 microM, respectively.     

Two auronols from Pseudolarix amabilis.

Two new auronols, amaronols A (1) and B (2), were isolated from the bark of Pseudolarix amabilis, along with pseudolaric acid B (3), pseudolaric acid C (4), demethoxydeacetoxy-pseudolaric acid B (5), pseudolaric acid B-beta-D-glucoside (6), pseudolaric acid A-beta-D-glucoside (7), and myricetin (8). The structures of amaronols A and B were established by spectral data interpretation as 2,4,6-trihydroxy-2-[(3',4',5'-trihydroxyphenyl) methyl]-3(2H)-benzofuranone and 2,4,6-trihydroxy-2-[(3', 5'-dihydroxy-4'-methoxyphenyl) methyl]-3(2H)-benzofuranone, respectively. Antimicrobial testing results of the eight compounds indicated that only pseudolaric acid B was active against Candida albicans (MIC, 3.125 microg/mL; MFC, 6.25 microg/mL), while myricetin was marginally active against Trichophyton mentagrophytes (MIC, 50 microg/mL).     

New bioactive coumarins from Kielmeyera albopunctata

The CH(2)Cl(2) extract of the stem bark of Kielmeyera albopunctata was subjected to a bioassay-linked LC-MS dereplication procedure using the KB cell line to afford the new coumarins 4-(1-methylpropyl)-5,7-dihydroxy-8-(4-hydroxy-3-methylbutyryl)-6-(3-methylbut-2-enyl)chromen-2-one (1), 9-(1-methylpropyl)-4-hydroxy-5-(4-hydroxy-3-methylbutyryl)-2-(1-hydroxy-1-methylethyl)-2,3-dihydrofuro[2,3-f]chromen-7-one (2), and 5,7-dihydroxy-8-(4-hydroxy-3-methylbutyryl)-6-(3-methylbut-2-enyl)-4-phenylchromen-2-one (3). Coumarins 1 and 3 showed moderate cytotoxicity, while 2 was inactive at 20 microg/mL. Compound 1was active in vitro against the trypomastigote form of the parasite Trypanosoma cruzi, killing 80% of the parasites after 24 h contact at 4 degrees C when added at 125 microg/mL to infected murine blood.     

Antibacterial activity of Tabebuia impetiginosa Martius ex DC (Taheebo) against Helicobacter pylori

The growth-inhibiting activity of Tabebuia impetiginosa Martius ex DC dried inner bark-derived constituents against Helicobacter pylori ATCC 43504 was examined using paper disc diffusion and minimum inhibitory concentration (MIC) bioassays. The activity of the isolated compounds was compared to that of the commercially available anti-Helicobacter pylori agents, amoxicillin, metronidazole, and tetracycline. The biologically active components of Tabebuia impetiginosa dried inner bark (taheebo) were characterized by spectroscopic analysis as 2-(hydroxymethyl)anthraquinone, anthraquinone-2-carboxylic acid, and 2-hydroxy-3-(3-methyl-2-butenyl)-1,4-naphthoquinone (lapachol). With the paper disc diffusion assay 2-(hydroxymethyl)anthraquinone exhibited strong activity against Helicobacter pylori ATCC 43504 at 0.01 mg/disc. Anthraquinone-2-carboxylic acid, lapachol and metronidazole were less effective, exhibiting moderate anti-Helicobacter pylori activity at 0.1 mg/disc. Amoxicillin and tetracycline were the most potent compounds tested, displaying very strong activity at 0.005 mg/disc. 2-(Hydroxymethyl)anthraquinone exhibited moderate activity at this dose. Tetracycline still had strong activity at 0.001 mg/disc while amoxicillin had little activity at this dose. In the MIC bioassay, 2-(hydroxymethyl)anthraquinone (2 microg/mL), anthraquinone-2-carboxylic acid (8 microg/mL), and lapachol (4 microg/mL) were more active than metronidazole (32 microg/mL) but less effective than amoxicillin (0.063 microg/mL) and tetracycline (0.5 microg/mL). The anti-Helicobacter pylori activity of seven 1,4-naphthoquinone derivatives (structurally related to lapachol), 1,4-naphthoquinone, 5,8-dihydroxy-1,4-naphthoquinone (naphthazarin), 2-methyl-1,4-naphthoquinone (menadione), 2-hydroxy-1,4-naphthoquinone (lawsone), 5-hydroxy-2-methyl-1,4-naphthoquinone (plumbagin), 5-hydroxy-1,4-naphthoquinone (juglone), and 2,3-dichloro-1,4-naphthoquinone (dichlone) was also evaluated using the paper disc assay. Menadione and plumbagin were the most potent compounds tested with the later still exhibiting very strong activity at 0.001 mg/disc. Menadione, juglone and tetracycline had strong activity at this low dose while the latter two compounds and amoxicillin had very strong activity at 0.005 mg/disc. Lawsone was unusual in that it had very strong activity at 0.1 and 0.05 mg/disc but weak activity at doses of 0.01 mg/disc and lower. Naphthazalin, lapachol and dichlone had similar activities while metronidazole had the lowest activity of all compounds tested. These results may be an indication of at least one of the pharmacological actions of taheebo. The Tabebuia impetiginosa dried inner bark-derived materials, particularly 2-(hydroxymethyl)anthraquinone, merit further study as potential Helicobacter pylori eradicating agents or lead compounds.     

红藻扇形叉枝藻中的降碳倍半萜及其衍生物

目的：对红藻扇形叉枝藻Gymnogongrus flabelliformis进行化学成分研究。方法：利用正相和反相硅胶柱色谱、Sephadex LH-20凝胶柱色谱和反相HPLC等手段进行分离纯化,借助MS,1D和2D NMR等波谱方法鉴定化合物结构；通过MTT法对分离鉴定的单体化合物在人肺癌细胞株(A549)、人肝癌细胞株(Bel 7402)、人胃癌细胞株(BGC 823)、人结肠癌细胞株(HCT-8)和人卵巢癌细胞株(A2780)上进行肿瘤细胞毒活性筛选。结果：从红藻扇形叉枝藻中分离得到5个降碳倍半萜类化合物,分别鉴定为(3S,6R,7E)-(+)-3-hydroxyl-4,7-megastigmadien-9-one(1),(3S,5R,6S,7E)-(-)-3-hydroxy-5,6-epoxy-7-megastig-mene-9-one(2),(3S,5S,6R,7E)-(+)3-hydroxy-5,6-epoxy-7-megastigmene-9-one(3),dehydrovomifoliol(4)和(3R)-(-)-4-［(2R,4S)-4-acetoxy-2-hydroxy-2,6,6-trimethylcyclohexylidene］-3-buten-2-one(5)。结论：以上化合物均为首次从该属海藻中分离得到,其中化合物1为新天然产物。细胞毒活性试验结果显示所有化合物在10 μg·mL^-1均无明显细胞毒活性。     

Bioactive polyketides from Peperomia duclouxii

Four new compounds (1-4) were isolated along with 16 known compounds from whole plants of Peperomia duclouxii. The new structures were elucidated as 4-hydroxy-2-[(3,4-methylenedioxyphenyl)nonanoyl]cyclohexane-1,3-dione (1), 4-hydroxy-2-[(3,4-methylenedioxyphenyl)undecanoyl]cyclohexane-1,3-dione (2), 4-hydroxy-2-[(3,4-methylenedioxyphenyl)tridecanoyl]cyclohexane-1,3-dione (3), and 2-[(3,4-methylenedioxyphenyl)dodecyl]-4-hydroxy-2,3,4,6,7,8-hexahydro-2H-1-benzopyran-5-one (4), by analysis of their spectroscopic data. The known polyketides, surinone A and oleiferinone, showed cell growth inhibitory activity against the WI-38, VA-13, and HepG2 cell lines with IC50 values that ranged from 4.4 to 9.6 microg/mL. The known sesquiterpenoid, sinugibberodiol, showed a more potent effect on calcein accumulation than verapamil at 2.5 and 25 microg/mL. Compounds 3 and 4, surinone A, and oleiferinone showed moderate to weak inhibitory activity on the induction of the intercellular adhesion molecule-1 (ICAM-1) in the presence of IL-1alpha or TNF-alpha.     

Trypanocidal diarylheptanoids from Aframomum letestuianum

Three new diarylheptanoids, (4Z,6E)-5-hydroxy-1-(4-hydroxy-3-methoxyphenyl)-7-(4-hydroxyphenyl)hepta-4,6-dien-3-one, letestuianin A (1), (4Z,6E)-5-hydroxy-1,7-bis(4-hydroxy-3-methoxyphenyl)hepta-4,6-dien-3-one, letestuianin B (2), and 1,7-bis(4-hydroxyphenyl)heptan-3,5-dione, letestuianin C (3), as well as the known (4Z,6E)-5-hydroxy-1,7-bis(4-hydroxyphenyl)hepta-4,6-dien-3-one (5) were isolated from Aframomum letestuianum. The known flavonoids 3-acetoxy-5,7,4'-trihydroxyflavanone, 3-acetoxy-7-methoxy-5,4'-dihydroxyflavanone, 7-methoxy-3,5,4'-trihydroxyflavone, and 3,3',4',5,7-pentahydroxyflavan were also obtained from this plant. Their structures were determined using a combination of 1D and 2D NMR techniques. The four diarylheptanoids were tested for growth inhibitory activity in vitro versus bloodstream forms of African trypanosomes. IC(50) values in the range of 1-3 microg/mL were found for compounds 3 and 5.     

Microbial and chemical transformation studies of the bioactive marine sesquiterpenes (S)-(+)-curcuphenol and -curcudiol isolated from a deep reef collection of the Jamaican sponge Didiscus oxeata

Microbial and chemical transformation studies of the marine sesquiterpene phenols (S)-(+)-curcuphenol (1) and (S)-(+)-curcudiol (2), isolated from the Jamaican sponge Didiscus oxeata, were accomplished. Preparative-scale fermentation of 1 with Kluyveromyces marxianus var. lactis (ATCC 2628) has resulted in the isolation of six new metabolites: (S)-(+)-15-hydroxycurcuphenol (3), (S)-(+)-12-hydroxycurcuphenol (4), (S)-(+)-12,15-dihydroxycurcuphenol (5), (S)-(+)-15-hydroxycurcuphenol-12-al (6), (S)-(+)-12-carboxy-10,11-dihydrocurcuphenol (7), and (S)-(+)-12-hydroxy-10,11-dihydrocurcuphenol (8). Fourteen-days incubation of 1 with Aspergillus alliaceus (NRRL 315) afforded the new compounds (S)-(+)-10beta-hydroxycurcudiol (9), (S)-(+)-curcudiol-10-one (10), and (S)-(+)-4-[1-(2-hydroxy-4-methyl)phenyl)]pentanoic acid (11). Rhizopus arrhizus (ATCC 11145) and Rhodotorula glutinus (ATCC 15125) afforded (S)-curcuphenol-1alpha-D-glucopyranoside (12) and (S)-curcudiol-1alpha-D-glucopyranoside (13) when incubated for 6 and 8 days with 1 and 2, respectively. The absolute configuration of C(10) and C(11) of metabolites 7-9 was established by optical rotation computations. Reaction of 1 with NaNO(2) and HCl afforded (S)-(+)-4-nitrocurcuphenol (14) and (S)-(+)-2-nitrocurcuphenol (15) in a 2:1 ratio. Acylation of 1 and 2 with isonicotinoyl chloride afforded the expected esters (S)-(+)-curcuphenol-1-O-isonicotinate (16) and (S)-(+)-curcudiol-1-O-isonicotinate (17), respectively. Curcuphenol (1) shows potent antimicrobial activity against Candida albicans, Cryptococcus neoformans, methicillin-resistant Staphylococcus aureus, and S. aureus with MIC and MFC/MBC ranges of 7.5-25 and 12.5-50 microg/mL, respectively. Compounds 1 and 3 also display in vitro antimalarial activity against Palsmodium falciparium (D6 clone) with MIC values of 3600 and 3800 ng/mL, respectively (selectivity index >1.3). Both compounds were also active against P. falciparium (W2 clone) with MIC values of 1800 (S.I. >2.6) and 2900 (S.I. >1.6) ng/mL, respectively. Compound 14 shows anti-hepatitis B virus activity with an EC(50) of 61 microg/mL.     

A new naphthopyrone derivative from Cassia quinquangulata and structural revision of quinquangulin and its glycosides

A novel naphthopyrone derivative, named quinquangulone (1), has been isolated from Cassia quinquangulata, along with the known compounds quinquangulin (2) and its two glycosides (3 and 4), rubrofusarin (5) and its two glycosides (6 and 7), nor-rubrofusarin (8) and its 6-O-glucoside (9), and three stilbenes (10-12). The structure of quinquangulone was established by spectral interpretation as 5,9-dihydroxy-8-methoxy-2,9-dimethyl-6-oxo-4H,6H,9H-naphtho-[2,3-b]pyran-4-one. Reinvestigation of the NMR spectra of quinquangulin led to revision of its structure as 5,6-dihydroxy-8-methoxy-2,9-dimethyl-4H-naphtho[2,3-b]pyran-4-one (2a). The structures of two quinguangulin glycosides, 3 and 4, were also revised accordingly. Compound 2a exhibited activity against Staphylococcus aureus and methicillin-resistant S. aureus (MIC, 3.125 and 6.25 microg/mL, respectively).     

刺五加的化学成分研究

目的研究五加科五加属植物刺五加Acanthopanax senticosus的化学成分。方法利用各种色谱技术进行分离,根据光谱数据鉴定结构。结果从刺五加中分离得到12个已知成分,分别鉴定为刺五加酮(1)、刺五加苷B1(2)、4-羟基-2-甲氧基苯基-1-O-β-D-葡萄糖苷(3)、alimoxide(4)、赤式-1-(4-羟基-3-甲氧基苯基)-2-{4-[(E)-3-羟基-1-丙烯基]-2-甲氧基苯氧基}-1,3-丙二醇(5)、erythro-1,2-bis(4-hydroxy-3-methoxyphenyl)-1,3-propanediol(6)、tortoside A(7)、表丁香脂素4′-O-β-D-葡萄糖苷(8)、(+)-lyoniresinol(9)、苯甲基-O-α-L-鼠李吡喃糖基(1→6)-β-D-葡萄吡喃糖苷(10)、2,6-二甲氧基-4-(3-羟基丙烯基)苯基-1-O-α-L-鼠李吡喃糖基-(1→6)-β-D-葡萄吡喃糖苷(11)、β-氨甲酰基吡啶(12)。结论化合物3～5、10～12为首次从该植物中分离得到。     

Antimicrobial activities of naphthazarins from Arnebia euchroma

Bioassay-directed fractionation of extract of Arnebia euchroma led to the isolation of alkannin (1), shikonin (2), and their derivatives (3-8) as the active principles against methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant enterococci (VRE). The stereochemistry of alpha-methylbutyryl alkannin (8) is revealed for the first time, and the antimicrobial activity of 8 was compared with its corresponding diastereomer (9). The derivatives 3-9 showed stronger anti-MRSA activity [minimum inhibitory concentrations (MICs) ranged from 1.56 to 3.13 microg/mL] than alkannin or shikonin (MIC = 6.25 microg/mL). Anti-MRSA activity of derivatives was bactericidal with minimum bactericidal concentration (MBC)/MIC < or = 2. In a time-kill assay, the bactericidal activity against MRSA was achieved as rapidly as 2 h. The derivatives 3-9 were also active against vancomycin-resistant Enterococcus faecium (F935) and vancomycin-resistant Enterococcus faecalis (CKU-17) with MICs similar to those with MRSA. Aromatic ester derivatives were also synthesized for antimicrobial activity comparison. None of these compounds were active against Gram-negative bacteria tested. Their cytotoxicity was also evaluated on selected cancer cell lines, and they expressed their activity in the range 0.6-5.4 microg/mL (CD(50)). Our results indicate that the ester derivatives of alkannin are potential candidates of anti-MRSA and anti-VRE agents with antitumor activity.     

Benzoic acid derivatives, acetophenones, and anti-inflammatory constituents from Melicope semecarpifolia

Two new benzoic acid derivatives, (E)-3-acetyl-6-(3,7-dimethylocta-2,6-dienyloxy)-2,4-dihydroxybenzoic acid (1) and (E)-3-acetyl-4-(3,7-dimethylocta-2,6-dienyloxy)-2,6-dihydroxybenzoic acid (2), and three new acetophenones, (E)-1-(5-(3,7-dimethylocta-2,6-dienyloxy)-7-hydroxy-2,2-dimethyl-2 H-chromen-8-yl)ethanone (3), (E)-1-(5-(3,7-dimethylocta-2,6-dienyloxy)-7-hydroxy-2-methyl-2-(4-methylpent-3-enyl)-2 H-chromen-8-yl)ethanone (4), and (R,E)-1-(5-(3,7-dimethylocta-2,6-dienyloxy)-3,7-dihydroxy-2,2-dimethylchroman-8-yl)ethanone (5), have been isolated from the fruits of Melicope semecarpifolia, together with eight known compounds. The structures were determined through in-depth NMR and mass spectrometric analyses. Among the isolated compounds, 2-(1'-geranyloxy)-4,6,beta-trihydroxyacetophenone (8), 4-(1'-geranyloxy)-2,6,beta-trihydroxyacetophenone (9), 5-hydroxy-3,7,3',4'-tetramethoxyflavone (10), 5,4'-dihydroxy-3,7,3'-trimethoxyflavone (11), and 5,4'-dihydroxy-3,7-dimethoxyflavone (12) exhibited potent inhibition (IC50<4 microg/mL) on superoxide anion generation and elastase release by human neutrophils in response to fMet-Leu-Phe/cytochalasin B.     

Antimicrobial dialkylresorcinols from Pseudomonas sp. Ki19

Four dialkylresorcinols (1-4) were isolated from a liquid culture of Pseudomonas sp. Ki19. Compounds 1 and 2, 2-butyl-5-propylresorcinol and 2-hexyl-5-methylresorcinol, respectively, have not previously been isolated from biological sources, whereas 3 and 4, 2-hexyl-5-propylresorcinol (DB-2073) and 2-hexyl-5-pentylresorcinol (resorstatin), both have been found in biological systems. The compounds inhibited Staphyllococcus aureus at concentrations < or = 10 microg/mL as well as the fungi Aspergillus fumigatus and Fusarium culmorum at 50 microg/mL. The formation of possible antimicrobial quinone oxidation products was investigated under bioassay conditions, and they were not found to be responsible for the main antimicrobial activity.     

New sesquiterpenoids from the root of Guatteria multivenia

A phytochemical investigation of the CHCl(3) fraction of an ethanol extract of the root of Guatteria multivenia furnished nine compounds, of which four are sesquiterpenes (1-4) and five are alkaloids (5-9). Of the four sesquiterpenes, two are new (1, 3), named guatterin A (1) and dihydromadolin-K (3), and two are known (2, 4), identified as madolin-K (2) and madolin-W (4). The five known alkaloids were identified as liriodenine (5), lysicamine (6), lanuginosine (7), guadiscine (8), and O-methylpallidine (9). All the known compounds were isolated from this species for the first time. Structures of the new compounds were determined by extensive NMR studies, including DEPT, COSY, HMQC, HMBC, and NOESY. Compound 7 showed weak inhibitory effect against Candida albicans secreted aspartic proteases (SAP) with IC(50) of 45 microg/mL. Compound 5 was found to have antimicrobial activity against C. albicans, Cryptococcusneoformans, Staphylococcus aureus, and methicillin-resistant S. aureus (MRS) with IC(50)/MIC values of 3.5/6.25, 2.0/12.5, 2.0/3.13, and 2.0/3.13 microg/mL, respectively.     

Cytotoxic and antimicrobial benzophenones from the leaves of Tovomita longifolia

Bioassay-guided fractionation of the chloroform and ethanol extracts of Tovomita longifolia leaves using cytotoxic and antimicrobial assays resulted in the isolation of four new benzophenones, (E)-3-(2-hydroxy-7-methyl-3-methyleneoct-6-enyl)-2,4,6-trihydroxybenzophenone (1), (E)-3-(6-hydroxy-3,7-dimethylocta-2,7-dienyl)-2,4,6-trihydroxybenzophenone (2), 8-benzoyl-2-(4-methylpenten-3-yl)chromane-3,5,7-triol (3), and 5-benzoyl-1,1,4a-trimethyl-2,3,4,4a,9,9a-hexahydro-1H-xanthene-6,8-diol (4), and two known benzophenones, 4-geranyloxy-2,6-dihydroxybenzophenone (5) and 3-geranyl-2,4,6-trihydroxybenzophenone (6). The structures of 1-4 were established by spectroscopic means and by molecular modeling calculations. Compounds 1 and 3-5 demonstrated cytotoxic activities against breast (MCF-7), central nervous system (SF-268), and lung (H-460) human cancer cell lines, while compounds 3-6 showed antimicrobial activity against Klebsiella pneumoniae, Mycobacterium smegmatis, Pseudomonas aeruginosa, Salmonella gallinarum, and Staphylococcus aureus.     

Antibacterial compounds from Planchonia careya leaf extracts

AIM OF THE STUDY: The leaves of Planchonia careya (F. Muell.) R. Knuth (Lecythidaceae) have been traditionally implemented in the treatment of wounds by the indigenous people of northern Australia, although the compounds responsible for the medicinal properties have not been identified. In this study, antibacterial compounds from the leaf extracts were isolated and characterized, and the biological activity of each compound was assessed. MATERIALS AND METHODS: Compounds were isolated from the leaf extracts using HPLC-piloted activity-guided fractionation. The minimum inhibitory concentrations (MICs) were assessed with plate-hole diffusion assays, and the cytotoxicity was determined with MTT assays using monkey kidney epithelial (MA104) cells. RESULTS: Six known compounds were isolated from the leaf extracts and were identified as 1, (+)-gallocatechin; 2, gallocatechin-(4alpha-->8)-gallocatechin; 3, 9(S)-hydroxy-10E,12Z-octadecadienoic acid (alpha-dimorphecolic acid); 4, 2alpha,3beta,24-trihydroxyolean-12-en-28-oic acid (hyptatic acid-A); 5, 3beta-O-cis-p-coumaroyltormentic acid; and 6, 3beta-O-trans-p-coumaroyltormentic acid. Compounds 5 and 6 were weakly selective for vancomycin-resistant Enterococcus (VRE) compared with eukaryotic cells, with an MIC of 59.4microg/mL and a 50% inhibitory concentration (IC(50)) of 72.0microg/mL for MA104 cells. CONCLUSIONS: The isolation of six antibacterial compounds from the leaves of Planchonia careya validates the use of this species as a topical wound-healing remedy.     

Antibacterial compounds from the mushroom Ganoderma colossum from Nigeria

Three colossolactones (colossolactone E, colossolactone B and 23-hydroxycolossolactone E) were isolated and characterized from an n-hexane:dichloromethane (2:7) extract of Ganoderma colossum using chromatographic techniques. The antimicrobial activity of the three compounds was then tested against Gram-positive and Gram-negative bacteria. The activity was evaluated by the thin-layer chromatography agar overlay method. The results showed that colossolactone E and 23-hydroxycolossolactone E were active against Bacillus subtilis and Pseudomonas syringae. Colossolactone B was not active against the bacteria. Their structures were elucidated by spectroscopic methods. Potency of the compounds against bacteria tested supports the use of this mushroom in therapeutic medicine.     

Anti-TB polyynes from the roots of Angelica sinensis

Following chemotaxonomic evidence, the PE and CHCl(3) extracts of the roots of the botanical Angelica sinensis (Oliv.) Diels (Dang Gui) were investigated for in vitro anti-TB activity, in parallel to studying their serotonergic and GABAergic potential. The activities were confirmed to overlap chemically with the neurotropic active principles present in medium lipophilic fractions. Phytochemical investigations led to the isolation of five polyynes: falcarindiol (1), 9Z,17-octadecadiene-12,14-diyne-1,11,16-triol,1-acetate (2), oplopandiol (3), heptadeca-1-ene-9,10-epoxy-4,6-diyne-3,8-diol (4) and the new polyyne 8-hydroxy-1-methoxy-(Z)-9-heptadecene-4,6-diyn-3-one (5), as characterized by spectroscopic techniques including 1D, 2D NMR and HR-MS. All compounds were tested against two pathogenic strains of Mycobacterium tuberculosis (H37Rv and Erdman) in vitro in a microplate Alamar Blue assay (MABA). The most potent anti-TB constituents were 1 and 2, exhibiting MIC values of 1.4-26.7 microg/mL; 3 showed moderate MICs (49.5 and 50.2 microg/mL, respectively) while 4 and 5 were weakly active (MIC > 60 microg/mL). Notably, none of the five compounds exhibited significant cytotoxicity against Vero cells. These findings not only reveal a new potential area of therapeutic value for A. sinensis, but also underline the role of polyynes as anti-TB active principles in ethnobotanical preparations, and as lead compounds.     

Chemical constituents from Amentotaxus yunnanensis and Torreyayunnanensis

In a chemical study of taxonomically related Taxaceae plants of Yunnan Province, China, seven compounds, including a new amentoflavone biflavonoid, 2,3-dihydro-7,7' '-dimethoxyamentoflavone (1), were isolated from Amentotaxus yunnanensis, and 12 isolates were obtained from Torreya yunnanensis. From the latter plant, a new abietane diterpene, torreyayunnin (7), is reported for the first time. The known isolates from A. yunnanensis have been identified as sequoiaflavone (3), sotetsuflavone (4), 7,7' '-dimethoxyamentoflavone (5), lutein, beta-sitosterol, and sequoyitol. Amentoflavone (2), sotetsuflavone (4), sciadopitysin (6), 12-hydroxydehydroabietinol, meridinol, balanophonin, (+)-pinoresinol monomethyl ether, (+)-pinoresinol monomethyl ether glucoside, erythro-1-(4-hydroxy-3-methoxyphenyl)-2-[4-[2-formyl-(E)-vinyl]-2- methoxyphenoxy]propane-1,3-diol, threo-1-(4-hydroxy-3-methoxyphenyl)-2- [4-[2-formyl-(E)-vinyl]-2-methoxyphenoxy] propane-1,3-diol, and (E)-2-butenedioic acid were identified as known isolates from T. yunnanensis. The presence of the amentoflavone biflavonoids (1, 3-5) in A. yunnanensis supports its placement in the Taxaceae. The occurrence of the biflavonoid sotetsuflavone (4) in both A. yunnanensis and T. yunnanensis suggests that these two genera are closely related. The identification and structural elucidation of these isolates were based on spectral data analysis including 1D and 2D NMR.     

Antimycobacterial activity of phorbol esters from the fruits of Sapium indicum

Three new phorbol esters, 12-(2-N-methylaminobenzoyl)-4beta,5,20-trideoxyphorbol-13-acetate (1), 12-(2-N-methylaminobenzoyl)-4alpha,5,20-trideoxyphorbol-13-acetate (2), and 12-(2-N-methylaminobenzoyl)-4alpha, 20-dideoxy-5-hydroxyphorbol-13-acetate (6), together with six known compounds (3-5 and 7-9), were isolated from the fruits of Sapium indicum. The chemical structures of 1, 2, and 6 were elucidated by analysis of their spectroscopic data. Compounds 1-3, 5, and 7-9 exhibited antimycobacterial activity with minimum inhibitory concentrations (MIC) between 3.12 and 200 microg/mL, but compounds 4 and 6 were inactive (MIC >200 microg/mL).