Antibacterial phenolic compounds from the spines of Gleditsia sinensis Lam

This study was to isolate antibacterial compounds from Gleditsia sinensis Lam. spines through bioassay-guided fractionation (against a Gram-positive bacterium Xanthomonas vesicatoria and a Gram-negative bacterium Bacillus subtilis). The crude ethanol extract of G. sinensis spines was partitioned sequentially with solvents of increasing polarity. The ethyl acetate fraction, which exhibited the most significant antibacterial activities among all the solvent fractions, was further separated by column chromatograph, yielding seven phenolic compounds including ethyl gallate (1) and caffeic acid (7), and five flavonoids, dihydrokaempferol (2), eriodictyol (3), quercetin (4), 3,3',5',5,7-pentahydroflavanone (5) and (-)-epicatechin (6). Compounds 4, 5 and 7 showed moderate inhibitory activities against both bacterial species, with compound 7 having the lowest minimal inhibitory concentration (MIC) of 0.125 mg mL(-1), while compounds 1 and 2 showed a weak inhibitory activity only against B. subtilis (MIC 1.00 mg mL(-1)), and compounds 3 and 6 showed insignificant activity against the two bacteria.     

Antimicrobial screening and quantitative determination of benzoic acid derivative of Gomphrena celosioides by TLC-densitometry

The antimicrobial activity of ethanolic extract and pure compounds of Gomphrena celosioides have been screened by Kirby-Bauer method. Quantitative determination of 4-hydroxy-3-methoxy-benzoic acid in stems, leaves, flowers and roots was established by TLC-densitometry. Results showed significant activity against Staphylococcus aureus and Salmonella typhi. There were no significant differences in the determined benzoic acid derivative.     

The Allelopathic Activity of Extracts and Isolated from Spirulina platensis

We determined the allelopathic effects of crude organic (hexane, ethyl acetate, and methanol) extracts of the cyanobacterial Spirulina platensis on barnyardgrass (Echinochloa crus-galli (L.) Beauv.) and Chinese amaranth (Amaranthus tricolor L.). The crude ethyl acetate extract showed the highest inhibitory activity and was subsequently fractionated by column chromatography into 23 fractions based on thin-layer chromatography band pattern similarities. Four concentrations (2000, 1000, 500, and 250 ppm) of each fraction were tested for their allelopathic activity. Fractions E6 and E13 exhibited the most significant inhibitory effects against Chinese amaranth. The constituents of the highly active E6F3-E6F5 fractions determined by GC-MS, chromatography, and spectroscopy included the fatty acids, γ-linolenic acid 15, oleic acid 12, and predominantly palmitic acid 7; minor constituents included 2-ethyl-3-methylmaleimide 9 and C₁₁ norisoprenoids (dihydroactinidiolide 10 and 4-oxo-β-ionone 13). Isolation of E13 fraction by column chromatography revealed four C₁₃ norisoprenoids: 3-hydroxy-β-ionone 17, 3-hydroxy-5α,6α-epoxy-β-ionone 18, 3-hydroxy-5β,6β-epoxy-β-ionone 19, and loliolide 20. Their structures were elucidated by NMR spectroscopy. All six isolated norisoprenoids inhibited seed germination and seedling growth of Chinese amaranth at concentrations of 250–1000 ppm. Allelochemicals from S. platensis could be utilized in the development of novel bioactive herbicides.     

培养南海红树林内源真菌Fusarium sp. ZZF60产新型蒽醌衍生物

通过人工发酵培养,从南海红树林内源真菌Fusarium sp.ZZF60的培养液中分离得到:1种新蒽醌衍生物,6,8-二甲氧基-1-甲基-2-(3-氧丁基)蒽醌(1),以及5种已知化合物:7-羟基-3-(4-甲氧基苯基)苯并-γ-吡喃酮(2),2,4-二羟基-6-[(1′E,3′E)-1′,3′-戊二烯基]苯甲醛(3),(E)-4-羟基肉桂酸甲酯(4),4-(4-羟基苯基)-2-丁醇(5),4-羟基苯甲酸(6)。它们的结构通过MS、NMR等波谱分析推导确定。初步药理活性显示,化合物1抑制体外培养人喉癌细胞Hep2和人肝癌细胞HepG2的IC50分别为16和23μmol/L。     

The enantioselective metabolism of p-cymene in rabbits.

p-Cymene (1) was metabolized in rabbits and the following four optically active metabolites, 2-(p-tolyl)-1-propanol (3': R/S = 65:35), 2-(p-tolyl)propanoic acid (5': R/S = 0:100), p-(2-hydroxy-1-methylethyl)benzoic acid (6': R/S = 91:9) and p-(1-carboxyethyl)benzoic acid (8': R/S = 30:70), were isolated in addition to three optically inactive metabolites, 2-(p-tolyl)-2-propanol (2), p-isopropylbenzoic acid (4'), and p-(1-hydroxy-1-methylethyl)benzoic acid (7'). The presumed metabolic pathways of p-cymene in rabbits were confirmed by the administration of the intermediate metabolites (2, 3', 4', and 5'). The enantiomeric ratios of the metabolites, 3' and 6', suggested that omega-hydroxylations of the isopropyl group in 1 and 4' occurred preferentially at the pro-S methyl group. In the metabolism of 1, the S-isomers are predominant in the propanoic acid derivatives, but the R-isomers are rich in the propanol derivatives. It is of interest that the metabolism of 4', however, produced predominantly the corresponding propanol derivative (6'; R/S = 91:9) and propanoic acid derivative (8'; R/S = 80:20) possessing the same R-configuration. Some optically active p-cymene derivatives were also synthesized as standard compounds.     

稠杂环化合物研究 i: 3-(4'-吡啶基)-6-芳基-均-三唑并[3,4-b]-1,3,4-噻二唑的合成及其抗菌性能

本文研究3-(4'-吡啶基)-4-氨基-5-巯基-1,2,4-三唑(1)与取代苯甲酸(2s-s)在氯化氧磷催化下的反应, 制得19种新的3-(4'-吡啶基)-6-芳基-均-三唑并[3,4-b]-1,3,4-噻二唑(3a-s), 确证了结构。初步观察了它们在约0.01%的浓度时, 对枯草杆菌, 大肠杆菌, 变形杆菌和金黄色葡萄球菌繁殖的抑制作用。     

Cytotoxic and antimicrobial aporphine alkaloids from Fissistigma poilanei (Annonaceae) collected in Vietnam

Two new aporphine alkaloids: 8-hydroxy-9-methoxy-1,2-methylenedioxyaporphine (1) and 8-hydroxy-3,9-dimethoxy-1,2-methylenedioxyaporphine (2) were isolated from the ethyl acetate extract of Fissistigma poilanei along with five known compounds: oxocrebanine (3), kuafumine (4), (2R,3R)-3',4',5,7-tetrahydroxydihydroflavonol-3-O-α-L-rhamnopyranoside (5), (+)-catechin 3-O-α-L-rhamnopyranoside (6) and quercetine 3,7-dimethoxy-3'-O-α-L-rhamnopyranosyl-(1?→?2)-β-D-glucopyranoside (7). These two new aporphine alkaloids exhibited a moderate cytotoxic activity against four human cancer cell lines (KB, Hep-G2, MCF-7, LU) as well as antimicrobial activity against Lactobacillus fermentum, Enterococcus faecium, Staphylococcus aureus and Bacillus subtillis.     

5′位羟基异戊烯基查尔酮类天然产物的合成及其抗菌活性研究

首次合成了Bartericin A (1), 2’,6’-二羟基-5’-(2’’-羟基-3’’-甲基-3’’-丁烯基)-4’-甲氧基查尔酮(2), Xanthohumol D (3)和Angusticornin B (4) 4个羟基异戊烯基查尔酮类天然产物.为了探讨天然产物中不同官能团对其核心骨架结构抗菌活性的影响,设计合成了衍生物6.所合成的目标产物和未知中间体化合物经过1H NMR、13C NMR、IR、HRMS进行了确证.选取大肠杆菌[CMCC(B)44102]、绿脓杆菌[CMCC(B)10104]、金黄色葡萄球菌[CMCC(B)260003]和枯草芽孢杆菌[CMCC(B)63 501],采用稀释点样法对所合成的4个天然产物及1个新型衍生物进行了抗菌活性评估.结果显示,天然产物1、4和衍生物6对革兰氏阳性菌金黄色葡萄球菌和枯草芽孢杆菌表现出了一定的抑制活性.天然产物3对枯草芽孢杆菌表现出了较为明显的抑制活性,但对其他3种菌株无抑制活性(最小抑菌浓度>200μg/mL).     

Two new xanthones from the pericarp of Garcinia mangostana

Two new xanthones, 3-hydroxy-6-methoxy-5'-isopropyl-4',5'-dihydrofuro[2',3'?:?7, 8]-6″,6″-dimethyl-4″,5″-dihydropyrano[2″,3″?:?1,2]xanthone (1) and 1,6-dihydroxy-7-methoxy-8-(3-methylbut-3-enyl)-6',6'-dimethyl-4',5'-dihydropyrano[2'3'?:?3,2]xanthone (2), were isolated from the pericarp of Garcinia mangostana. Their structures were elucidated by spectral means (1-D and 2-D NMR, MS).     

Chemical composition of Argentinean propolis collected in extreme regions and its relation with antimicrobial and antioxidant activities

This paper reveals, for the first time, the functional properties of propolis from an extreme region of Argentine (El Rincón, Province of Catamarca, Argentina), as well as the isolation and identification of bioactive compounds. The antioxidant activity was determined by the ABTS method and beta-carotene bleaching. The antibacterial activity was determined on methicillin resistant Staphylococcus aureus (MRSA) by the microdilution method and bioautographic assays. Twelve compounds were isolated and identified by NMR spectroscopy. The main bioactive compounds were 2',4'-dihydroxy-3'-methoxychalcone (3), 2',4'-dihydroxychalcone (9), 2',4',4-trihydroxy-6'- methoxychalcone (8), 5-hydroxy-4',7-dimethoxyflavone (4), 4',5-dihydroxy-3,7,8-trimethoxyflavone (10) and 7-hydroxy- 5,8-dimethoxyflavone (11). All compounds were active against clinical isolates (MIC50 10 microg/mL) and displayed antioxidant activity (SC50 values of 20 microg/mL). The MIC and SC50 values of the isolated compounds were lower than those obtained with crude propolis extracts, chloroform sub-extracts and isolated fractions.     

见血封喉根中类黄酮的结构鉴定

从海南产见血封喉[Antiaris toxicaria (Pers.) Lesch.]根的乙醇提取物中分离得到8个黄酮类化合物, 分别鉴定为antiarones K, B, F～I (1～6), (±)-sigmoidin A (7)和2-[2,3-二氢-4-羟基-2-(2-羟基-2-丙基)-5-甲氧基-1H-茚基]-1-(2,4,6-三羟基苯基)乙酮(8). 其中antiarone K (1)为新的异戊烯基二氢黄酮. 运用现代波谱技术, 包括二维核磁共振谱和高分辨质谱, 对上述化合物的结构进行了确证. 以上化合物经滤纸片法进行抗菌活性测试, 结果表明化合物1和3均具有抗金黄色葡萄球菌活性, 化合物3还具有抗耐甲氧西林金黄色葡萄球菌(MRSA)活性; 经MTT法进行细胞毒活性测试, 结果表明化合物1和6～8对慢性髓原白血病细胞(K562)、人胃癌细胞(SGC-7901)和人肝癌细胞(SMMC-7721)的增殖显示了生长抑制活性.     

Chemical composition, anti-inflammatory, molluscicidal and free-radical scavenging activities of the leaves of Ficus radicans 'Variegata' (Moraceae)

The methanol crude extract of the leaves of Ficus radicans Roxb. 'Variegata' (Moraceae) and the n-hexane, ethyl acetate and aqueous methanol fractions resulting from its fractionation were evaluated for their anti-inflammatory, molluscicidal and free-radical scavenging activities. The crude extract and fractions exhibited significant inhibition of inflammation in both croton oil (CO)-induced ear oedema in mice (p<0.001) and carrageenan-induced rat paw oedema models (p<0.01). The molluscicidal assay against Biomphalaria glabrata showed a weak activity for the n-hexane fraction (DL(50)=?400 μg mL(-1)). A moderated 1,1-diphenyl-1-picrylhydrazyl (DPPH) free-radical scavenging activity was observed for the ethyl acetate fraction (IC(50)=?66.2 μg mL(-1)). Fractionation of the extracts through chromatographic methods afforded the coumarins 7-methoxycoumarin, 7-hydroxy-6-methoxycoumarin and methoxy-3,4-dihydrocoumarin, the steroids β-sitosterol and β-sitosterol 3-O-β-glucopyranoside, as well as a cinnamic acid derivative and a flavonoid identified as trans-4-methoxy-2-β-D-glucopyranosyloxy cinnamic acid and quercetin 3-O-β-D-xylopyranosyl-(1?→?2)-α-L-rhamnopyranoside, respectively. The compounds were identified on the basis of their NMR spectral data and comparison with those previously reported in the literature.     

2,6-二甲基-3,5-二氯-4-吡啶酚糖苷的合成

在相转移催化条件下, 使 a-D-乙酰基化溴代的葡萄糖、半乳糖、葡萄糖醛酸甲酯1a, 1b, 1c分别与2,6-二甲基-3,5-二氯-4-吡啶酚(俗称氯吡醇, 氯羟吡啶)作用, 合成了氯吡醇的糖苷: 1-O-(2',6'-二甲基-3',5'-二氯-4'-吡啶基)-2,3,4,6-四-O-乙酰基-β-D-葡萄吡喃糖苷(2a), 1-O-(2',6'-二甲基-3',5'-二氯-4'-吡啶基)-2,3,4,6-四-O-乙酰基β-D-半乳吡喃糖苷(2b), 1-O-(2'6'-二甲基-3',5'-二氯-4'-吡啶基)-2,3,4-三-O-乙酰基-β-D-葡萄吡喃糖醛酸甲酯(2c)。2a, 2b, 2c分别在甲醇中氨解, 相应得到: 1-O-(2', 6'-二甲基-3',5'-二氯-4'-吡啶基)-β-D-葡萄吡喃糖苷(3a), 1-O(2',6'-二甲基-3',5'-二氯-4'-吡啶基)-β-D-半乳吡喃糖苷(3b),1-O-(2', 6'-二甲基-3',5'-二氯-(4'-吡啶基)-β-D-葡萄吡喃糖醛酸酰胺(3c)。2c用CH~3ONa/CH~3OH处理, 得到1-O-(2',6'-二甲基-3',5'-二氯-4'-吡啶基)-β-D-葡萄吡喃糖醛酸甲酯(3d)。     

Chemical constituents of the methanolic extract of leaves of Leiothrix spiralis Ruhland and their antimicrobial activity

Chemical fractionation of the methanolic extract of leaves of Leiothrix spiralis Ruhland afforded the flavonoids luteolin-6-C-β-D-glucopyranoside (1), 7-methoxyluteolin-6-C-β-D-glucopyranoside (2), 7-methoxyluteolin-8-C-β-D-glucopyranoside (3), 4'-methoxyluteolin-6-C-β-D-glucopyranoside (4), and 6-hydroxy-7-methoxyluteolin (5), and the xanthones 8-carboxymethyl-1,5,6-trihydroxy-3-methoxyxanthone (6), 8-carboxy-methyl-1,3,5,6-tetrahydroxyxanthone (7). Methanolic extract, fractions, and isolated compounds of the leaves of L. spiralis were assayed against Gram-positive (Staphylococcus aureus, Bacillus subtilis and Enterococcus faecalis) and Gram-negative bacteria (Escherichia coli, Pseudomonas aeruginosa, Salmonella setubal and Helicobacter pylori) and fungi (the yeasts Candida albicans, C. tropicalis, C. krusei and C. parapsilosis). We observed the best minimum inhibitory concentration values for the methanolic extract against Candida parapsilosis, for the fraction 5 + 6 against Gram-negative bacteria E. coli and P. aeruginosa, and compound 7 against all tested Candida strains. The methanolic extract contents suggest that this species may be a promising source of compounds to produce natural phytomedicines.     

Two new xanthones isolated from the stem bark of Garcinia lancilimba

Two new xanthones, 1,5,6-trihydroxy-6',6'-dimethyl-2H-pyrano(2',3':3,4)-2-(3-methylbut-2-enyl)xanthone (1) and 1,6,7-trihydroxy-6',6'-dimethyl-2H-pyrano(2',3':3,2)-4-(3-methylbut-2-enyl)xanthone (2), have been isolated from the stem bark of Garcinia lancilimba (Guttiferae), together with six known xanthones. Their structures were identified on the basis of extensive spectral evidence including detailed 2D NMR and HR-MS data. Two new compounds showed moderate inhibitory effect on human breast cancer MDA-MB-435S cell line.     

Four new ginkgolic acids from Ginkgo biloba

Four new compounds, 2-hydroxy-6-(12′-hydroxyheptadec-13′(E)-en-1-yl)benzoic acid (1), 2-hydroxy-6-(13′-hydroxyheptadec-11′(E)-en-1-yl)benzoic acid (2), 2-hydroxy-6-(10′-hydroxypentadec-11′(E)-en-1-yl)benzoic acid (3), and 2-hydroxy-6-(11′-hydroxypentadec-9′(E)-en-1-yl)benzoic acid (4) were isolated from the leaves of Ginkgo biloba and the structures of new ginkgolic acids were deduced on the basis of spectroscopic methods and chemical means. Compounds 1 and 2, and 3 and 4 examined as an inseparable mixture of hydroxyl and double bond positional isomers, were ultimately defined by total synthesis. Compounds 1–4 showed moderate lipid droplets accumulation inhibitory activity on mouse pre-adipocyte cell line, MC3T3-G2/PA6.     

Phenolics of Moringa oleifera leaves

Five flavonol glycosides characterised as kaempferide 3-O-(2',3'-diacetylglucoside), kaempferide 3-O-(2'-O-galloylrhamnoside), kaempferide 3-O-(2'-O-galloylrutinoside)-7-O-alpha-rhamnoside, kaempferol 3-O-[beta-glucosyl-(1 --> 2)]-[alpha-rhamnosyl-(1 --> 6)]-beta-glucoside-7-O-alpha-rhamnoside and kaempferol 3-O-[alpha-rhamnosyl-(1 --> 2)]-[alpha-rhamnosyl-(1 --> 4)]-beta-glucoside-7-O-alpha-rhamnoside together with benzoic acid 4-O-beta-glucoside, benzoic acid 4-O-alpha-rhamnosyl-(1 --> 2)-beta-glucoside and benzaldehyde 4-O-beta-glucoside have been isolated from methanolic extract of Moringa oleifera leaves. Also obtained from the same extract were known compounds, kaempferol 3-O-alpha-rhamnoside, kaempferol, syringic acid, gallic acid, rutin and quercetin 3-O-beta-glucoside. Their structures were determined using spectroscopic methods as well as comparison with data from known compounds.     

Prenylated isoflavones from Flemingia philippinensis

Two new prenylated isoflavones, named flemiphilippinins E and F, were isolated from the roots of Flemingia philippinensis, together with six known ones. The structures of the above compounds were established by spectroscopic methods. Flemiphilippinins E and F were identified as 5,4'-dihydroxy-8-(3,3-dimethylallyl)-6',6'-dimethyl-5'-(1,1-dimethylallyl) pyrano(2',3':7,6)isoflavone and 5,4'-dihydroxy-4',4',5'-trimethyl-4',5'-dihydrofurano(2',3':7,8) isoflavone, respectively, by a combination of HR-EI-MS, (1)H NMR, (13)C NMR, HMQC, HMBC, and NOESY spectra.     

Isolation of three new naturally occurring compounds from the culture of Micromonospora sp. P1068

Bioassay guided isolation of an antibacterial extract prepared from the fermentation broth of a Micromonospora sp. P1068 led to the isolation of eight compounds identified as (3R) 3,4',7-trihydroxy-isoflavanone (1), 3-hydroxydehydrodaidzein, daidzein (2), 3-methyl-1H-indole-2-carboxylic acid (3), 1H-indole-3-carboxaldehyde (4), 3-(p-hydroxyphenyl)-N-methylpropionamide, N-methylphloretamide (5), phenyl acetic acid (6), 2-hydroxy phenyl acetic acid (7) and 4-hydroxy-5-methoxy-benzoic acid (8). Compounds 1 and 5 were found to be novel chemical entities while 3 was isolated from a natural source for the first time. All compounds were evaluated for their antimicrobial activities against a panel of clinically significant microorganisms. Compound 4 was active against Staphylococcus aureus (MIC, 32 microg/ml), Enterococcus faecium (MIC, 32 microg/ml) and Escherichia coli (MIC, 64 microg/ml).     

Cytotoxic pyranonaphthoquinones from Melloa quadrival vis (Bignoniaceae)

Three new pyranonaphthoquinones: 5-hydroxy-6-methoxy-alpha-lapachone, 5,6-dihydroxy-a-lapachone and 4',5-dihydroxy-6-methoxy-alpha-lapachone, and two known compounds: lapachol and 5,5'-dihydroxy-3',4',7-trimethoxyflavanone, were isolated from the stem bark of Melloa quadrivalvis. Their structures were established by spectrometric data, mainly 1D- and 2D-NMR and mass spectra. The methylazoetetrazolium (MTT) method using viable cells of the strain Hep2 and the strain NCIH-292 demonstrated cytotoxic activity. The CI50 was also calculated. The chloroform extract and 5-hydroxy-6-methoxy-alpha-lapachone inhibited cell growth.