Chaetominine, (+)-alantrypinone,questin, isorhodoptilometrin,and 4-hydroxybenzaldehyde produced by the endophytic fungus Aspergillus sp. YL-6 inhibit wheat (Triticum aestivum) and radish (Raphanus sativus) germination

Five phytotoxic substances with allelopathic activity were isolated from endophytic fungi Aspergillus sp. YL-6 habited in Pleioblastus amarus. The chemical structures of these substances were determined as chaetominine (1), (+)-alantrypinone (2), questin (3), isorhodoptilometrin (4), and 4-hydroxybenzaldehyde (5) by nuclear magnetic resonance and mass spectrometry data. The potential allelopathic effects of compounds 1–5 were evaluated on wheat (Triticum aestivum) and radish (Raphanus sativus). Under lab condition, at concentrations of 10 and 20 ppm, compounds 1–5 inhibit the germination and growth of the two tested seeds completely. An idole-3-acetic acid (IAA) derivative, (+)-alantrypinone (2) displayed the best inhibitory effects on radish seeds among these tested compounds with the similar activity as the positive control glyphosate, a broad-spectrum systemic herbicide. In the further evaluation of compounds 1–5, Questin (3), an anthraquinone derivative, can inhibit shoot and root elongation of wheat, the inhibitory effects assessed were similar to the positive control glyphosate.     

Screening of free radical scavengers from Erigeron breviscapus using on-line HPLC-ABTS/DPPH based assay and mass spectrometer detection

Erigeron breviscapus is a well-known traditional Chinese herbal medicine. In this study, on-line HPLC-ABTS/DPPH assay coupled with MS detection were applied to screen and identify the free radical scavengers in 70% methanol extracts of E. breviscapus. Using on-line HPLC-ABTS-MS and HPLC-DPPH-MS assay, 13 radical scavengers (including 4-O-caffeoylquinic acid (4-CQA) (1), 9-caffeoyl-2,7-anhydro-2-octulosonic acid (9-COA) (2), 3-caffeoyl-2,7-anhydro-3-deoxy-2-octulopyranosonic acid (3-CDOA) (3), erigeside I (4), quercetin-3-O-glucuronide (5), eriodictyol-7-O-glucuronide (6), scutellarin (7), 1,4-di-O-caffeoylquinic acid (1,4-di-CQA) (8), 3,5-di-CQA (9), 1-malonyl-3,5-di-CQA (10), erigoster B (11), 4,5-di-CQA (12) and 4,9-di-CDOA (13)) and 9 radical scavengers (including 1, 4, 7, 8, 9, 10, 11, 12 and 13) were discovered, respectively. Furthermore, the anti-oxidative activities of 4 compounds, including 7, 9, 11 and 12 were evaluated. Reverse anti-oxidative activity order of scutellarin and 3,5-di-CQA was observed in on-line HPLC-ABTS assay and on-line HPLC-DPPH assay. To validate their anti-oxidative activities, the off-line ABTS and DPPH assays were performed. Given sufficient reaction time, 3,5-di-CQA showed higher activity than scutellarin, which was consistent with the order obtained in on-line HPLC-ABTS assay. These results revealed that on-line HPLC-ABTS assay is a more sensitive method for screening and determining free radical scavengers, especially more suitable for those compounds with slower reaction kinetics.     

薏苡糠壳的化学成分及其种子萌发活性研究

为了解薏苡(Coix lachryma-jobi)糠壳的化学成分,利用多种柱色谱技术对其乙醇提取物乙酸乙酯萃取部位进行分离,经波谱数据分析鉴定了15个化合物,分别为香豆酸(1)、香豆酸甲酯(2)、2-羟乙基-香豆酸酯(3)、咖啡酸甲酯(4)、阿魏酸甲酯(5)、(E)-3-(4-甲氧基苯基)丙烯酸(6)、2,3-二羟基-...     

Regioselective acylation of several polyhydroxylated natural compounds by Candida antarctica lipase B

Regioselective acylation of four polyhydroxylated natural compounds, deacetyl asperulosidic acid (1), asperulosidic acid (2), puerarin (3) and resveratrol (4) by Candida antarctica Lipase B in the presence of various acyl donors (vinyl acetate, vinyl decanoate or vinyl cinnamoate) was studied. Compounds 1, 2 and 4 were regioselectively acetylated with vinyl acetate to afford products, 3′-O-acetyl-10-O-deacetylasperulosidic acid (1a), 3′,6′-O-diacetyl-10-O-deacetylasperulosidic acid (1b), 3′-O-acetylasperulosidic acid (2a), 3′,6′-O-diacetylasperulosidic acid (2b), 4′-O-acetylresveratrol (4a), respectively, with yields of 22 to 50%, while reactions with vinyl decanoate and vinyl cinnamoate were slow with lower yields. Compound 3 was readily acylated with all three acyl donors and quantitatively converted to products 6″-O-acetylpuerarin (3a), 6″-O-decanoylpuerarin (3b), 6″-O-cinnamoylpuerarin (3c), respectively. The structures of these acylated products were determined by spectroscopic methods (MS and NMR).     

一株海洋真菌Aspergillus jensenii LW128的次级代谢产物及其抗菌活性研究

【目的】研究一株西北太平洋深海沉积物来源真菌Aspergillus jensenii LW128的次级代谢产物及其抗菌活性。【方法】利用硅胶柱色谱(silica gel column chromatography)、凝胶柱色谱(Sephadex LH-20 column chromatography)和反相高效液相色谱(reversed-phase high-performance liquid chromatography, RP-HPLC)等方法对菌株的发酵粗提物进行分离纯化得到单体化合物;将核磁共振波谱(nuclear magnetic resonance, NMR)、质谱(mass spectrometry, MS)数据与相关文献报道数据进行比对后确定化合物结构;采用肉汤微量稀释法测定化合物的抗菌活性。【结果】从海洋真菌Aspergillus jensenii LW128中分离并鉴定了10个已知化合物,分别为diorcinol D(1)、diorcinol K(2)、diorcinol I(3)、(+)-(7S)-7-O-methylsydonic acid (4)、(+)-s...     

稀有放线菌Lechevalieria rhizosphaerae NEAU-A2的次级代谢产物研究及遗传操作系统的建立

【背景】菌株Lechevalieria rhizosphaerae NEAU-A2是一株新的稀有放线菌,其基因组中包含多个与次级代谢产物生物合成相关的基因簇,具有产生丰富代谢产物的潜力。【目的】对稀有放线菌L. rhizosphaerae NEAU-A2的次级代谢产物进行研究,以期发现结构新颖或生物活性独特的化合物,并建立其遗传操作系统。【方法】应用硅胶柱色谱和高效液相色谱等方法对菌株NEAU-A2的次级代谢产物进行分离和纯化,整合质谱分析、核磁共振等方法进行结构解析。在对该菌株全基因组测序的基础上,以基因组序列中编码杂合的聚酮合酶-非核糖体肽合成酶(PolyketideSynthase-Nonribosomal Peptide Synthetase,PKS-NRPSs)基因1609为目标基因,利用PCR-Targeting介导的基因置换技术构建重组质粒,通过接合转移的方式导入野生菌株。【结果】从菌株NEAU-A2中分离鉴定了2个新的吲哚二聚化合物(1,2)和5个已知化合物N-乙酰色胺(3)、4-((2-(1H-Indol-3-Yl)Ethyl)Amino)-4-Oxobutanoic Acid (4)、Brevianamide F (5)、4S,7R-Germacra-1(10)E,5E-Diene-11-Ol (6)、1H-吡咯-2-羧酸(7)。接合子通过培养2代即可获得双交换突变菌株,PCR分析结果显示PKS-NRPS基因被成功中断。【结论】从稀有放线菌L. rhizosphaerae NEAU-A2中分离鉴定出7个化合物,并成功建立了该菌的遗传操作系统。     

New lanostane-type triterpenoids, inonotsutriols D, and E, from Inonotus obliquus

Two new lanostane-type triterpenoids, inonotsutriols D (1) and E (2), were isolated from the sclerotia of Inonotus obliquus (Pers.: Fr.) Pil. (Japanese name: kabanoanatake; Russian name: chaga). Their structures were determined to be lanost-8-ene-3β,22R,24R-triol (1) and lanost-8-ene-3β,22R,24S-triol (2) on the basis of spectral data, including 2D NMR analysis. In addition, major compounds, inotodiol (3), trametenolic acid (4), 3β-hydroxylanosta-8,24-dien-21-al (5), 21-hydroxylanosterol (6), inonotsuoxide A (7) and inonotsuoxide B (8) were identified, and all compounds, except 2, were evaluated for their cancer cell growth inhibitory activity against P388, HL-60, L1210 and KB cell lines.     

Kushenol A and 8-prenylkaempferol,tyrosinase inhibitors,derived from Sophora flavescens

Tyrosinase is known for an enzyme that plays a key role in producing the initial precursor of melanin biosynthesis. Inhibition of the catalytic reaction of this enzyme led to some advantage such as skin-whitening and anti-insect agents. To find a natural compound with inhibitory activity towards tyrosinase, the five flavonoids of kushenol A (1), 8-prenylkaempferol (2), kushenol C (3), formononetin (4) and 8-prenylnaringenin (5) were isolated by column chromatography from a 95% methanol extract of Sophora flavescens. The ability of these flavonoids to block the conversion of L-tyrosine to L-DOPA by tyrosinase was tested in vitro. Compounds 1 and 2 exhibited potent inhibitory activity, with IC50 values less than 10?µM. Furthermore, enzyme kinetics and molecular docking analysis revealed the formation of a binary encounter complex between compounds 1–4 and the enzyme. Also, all of the isolated compounds (1–5) were confirmed to possess antioxidant activity.     

Purification and Properties of β-Galactosidases from Bacillus circulans

Six compounds, Z- and E-fadyenolide (3, 4), 1-ally1-2,3-(methylenedioxy)-4,5-dimethoxy-benzene (5), 4-methoxy-3,5-bis (3′-methyl-2′-butenyl)-benzoic acid (6), 2,6-dihydroxy-4-methoxy-dihydrochalcone (7), and 5-hydroxy-7-methoxyflavanone (8) were isolated from three species of Jamaican Piper, Piper fadyenii, C.D.C., Piper aduncum L. and Piper hispidum Sw. Three amides (9 ~ 11) of 3,5-dimethoxy-4-oxo-5-phenylpent-2-enoic acid using piperidine, pyrrolidine and morpholine, respectively, were synthesized from compounds 3 and 4, and tested for insecticidal activity against the tick Boophilus microplus (Canestrini) and the flour feetle, Tribolium confusum Duval. In our experiment, compounds 9 ~ 11 inhibited ovogenesis of B. microplus and were toxic to T. confusum. Compounds 3 ~ 8 were found to have no activity.     

领春木枝叶化学成分的研究

为了研究领春木(Euptelea pleiospermum Hook.f.et Thoms)的化学成分,利用各种柱色谱及高压液相色谱等方法进行分离和纯化,根据理化性质和光谱数据分析鉴定了9个化合物。他们分别为:白桦脂酸(1);齐墩果酸(2);N-反式对羟基肉桂酰基-对羟基苯乙胺(3);N-反式阿魏酰酪胺(4);N-顺式阿魏酰酪胺(5);丁香脂素(6);N-顺式阿魏酰-3-甲氧基酪胺(7);N-反式阿魏酰-3-甲氧基酪胺(8);3-羟基-30-去甲基-20-酮基-28-羽扇豆酸(9)。所有化合物均为首次从领春木中分离得到。     

Conferin,potent antioxidant and anti-inflammatory isoflavone from Caragana conferta Benth

Conferin (1), a new isoflavone, has been isolated from the ethyl acetate soluble fraction of Caragana conferta Benth. along with seven known compounds, namely biochanin A (2), p-hydroxybenzoic acid (3), 3,5- dimethoxybenzoic acid (4), ursolic acid (5), erythrodiol (6), pinoresinol (7), and syringresinol (8), reported for the first time from this species. The structure of the new isoflavone was deduced on the basis of spectroscopic studies. Compounds 1 and 2 were investigated for biological activities and showed significant anti-inflammatory activity in carrageenan induced paw edema of rats. Evaluation of antioxidant activity by the radical scavenging method indicated that compound 1 is a potent antioxidant while 2 is moderately active. It was also shown that the reducing capability of compound 2 was remarkably increased in a concentration dependent manner as compared to 1. Compound 1 showed moderate inhibitory activity against the enzyme lipoxygenase, while 2 showed weak activity.     

Study of the antioxidant activity of Thymus sibthorpii Bentham (Lamiaceae)

Abstract

From the aerial parts of Thymus sibthorpii Bentham (Lamiaceae), five flavonoids apigenin (1), 7-methoxy-apigenin (2), naringenin (3), eriodictyol (4) and eriodictyol-7-glucoside (5), have been isolated together with caffeic acid methyl ester (6), rosmarinic acid (7) and rosmarinic acid methyl ester (8). The structures of the isolated compounds were established by spectroscopic methods. The extracts and the isolated compounds were tested for their free radical scavenging activity using the following in vitro assays: (i) interaction with the free stable radical of DPPH (1,1-diphenyl-2-picrylhydrazyl), (ii) inhibition of linoleic acid lipid peroxidation induced by the dihydrochloric acid of 2,2-azobis-2-amidinepropane (AAPH) and (iii) the scavenging activity of enzymatically produced superoxide anion. Their inhibitory activity toward soybean lipoxygenase was evaluated in vitro, using linoleic acid as a substrate. The antioxidant results of the extracts are discussed in terms of their constitution in phenolic compounds, which were determined following the Folin–Ciocalteu method.     

A new epoxidic ganoderic acid and other phytoconstituents from Ganoderma lucidum

A new epoxidic ganoderic acid, 8α,9α-epoxy-3,7,11,15,23-pentaoxo-5α-lanosta-26-oic acid (1), together with the known compounds 3β-hydroxy-7,11,15,23-tetraoxo-5α-lanosta-8-en-26-oic acid (2), ergosta-7,22-diene-3β-yl pentadecanoate (3), ergosta-7,22-diene-3β-ol (4), β-sitosterol (5), fatty acids (6–10), fatty acid ester (11) and octadecane (12) were isolated from the fruiting bodies of Ganoderma lucidum from south India. Their structures were determined by ¹H, ¹³C, ¹³C DEPT, ¹H–¹H COSY, HMBC, HSQC, NOESY NMR, FT-IR, UV–vis and FABMS spectral analysis. Compounds (1–3) exhibited good antifungal activity against Candida albicans in disc diffusion assay (100 μg/disc). Steroid ester (3) showed moderate anti-inflammatory activity (59.7% inhibition, 100 mg/kg body weight) in carrageenan-induced paw edema.     

白花鬼针草中多烯炔类成分的分离及其生物活性研究

为了解白花鬼针草(Bidens pilosa var.radiata)的化学成分,采用多种色谱技术从其提取物中分离多烯炔类成分,并对其生物活性进行研究.结果表明,从白花鬼针草乙酸乙酯提取部位中分离鉴定出4个多烯炔类化合物,分别为5-acetoxy-2-phenyl-ethinyl-thiophene(1)、1-phen...     

Constituents with tyrosinase inhibitory activities from branches of Ficus erecta var. sieboldii King

Phytochemical investigation of the branches of Ficus erecta var. sieboldii King resulted in the isolation of eight constituents: p-hydroxybenzoic acid (1), methyl p-hydroxybenzoate (2), vanillic acid (3), methyl vanillate (4), syringic acid (5), β-sitosterol (6), α-amyrin acetate (7), and ethyl linoleate (8). Their chemical structures were identified via spectroscopic means as well as by comparing their data with literature values. Studies on tyrosinase inhibition activities were conducted for the isolated compounds. Among them, p-hydroxybenzoic acid (1) and methyl p-hydroxybenzoate (2) were identified as active tyrosinase inhibitors with IC₅₀ values of 0.98?±?0.042 and 0.66?±?0.025?mM, respectively, showing comparable activities to that of arbutin (IC₅₀?=?0.32?±?0.015?mM), a standard control. Inhibition kinetics, as analyzed by Lineweaver-Burk plots, indicated that compounds 1 and 2 were competitive inhibitors of diphenolase of mushroom tyrosinase. Notably, isolated compounds 1–8 were reported for the first time as constituents of F. erecta.     

Cholinesterase inhibitory triterpenoids from the bark of Garcinia hombroniana

Abstract

Context: Garcinia hombroniana Pierre, known as manggis hutan in Malaysia is a rich source of xanthones and benzophenones.

Objectives: This study was aimed to isolate and characterize potential cholinesterase inhibitors from the extracts of G. hombroniana bark and investigate their interactions with the enzymes.

Materials and methods: The dichloromethane extract afforded five triterpenoids which were characterized by NMR and mass spectral techniques. Cholinesterase inhibitory assay and molecular docking were performed to get insight of the inhibitory activity and molecular interactions of the compounds. The compounds were also tested for their antioxidant capacity.

Results: The isolated triterpenoids were identified as: 2β-hydroxy-3α-O-caffeoyltaraxar-14-en-28-oic acid (1), taraxerol (2), taraxerone (3), betulin (4) and betulinic acid (5). Compound 1 was the most active dual inhibitor of both AChE and BChE. Compound 1 also showed good antioxidant activities.

Conclusion: Compound 1 had dual and moderate inhibitory activity on AChE and BChE worthy for further investigations.     

Biotransformation of gallic acid by <Emphasis Type="Italic">Beauveria sulfurescens</Emphasis> ATCC 7159

Preparative-scale fermentation of gallic acid (3,4,5-trihydroxybenzoic acid) (1) with Beauveria sulfurescens ATCC 7159 gave two new glucosidated compounds, 4-(3,4-dihydroxy-6-hydroxymethyl-5-methoxy-tetrahydro-pyran-2-yloxy)-3-hydroxy-5-methoxy-benzoic acid (4), 3-hydroxy-4,5-dimethoxy-benzoic acid 3,4-dihydroxy-6-hydroxymethyl-5-methoxy-tetrahydro-pyran-2-yl ester (7), along with four known compounds, 3-O-methylgallic acid (2), 4-O-methylgallic acid (3), 3,4-O-dimethylgallic acid (5), and 3,5-O-dimethylgallic acid (6). The new metabolite genistein 7-O-β-D-4″-O-methyl-glucopyranoside (8) was also obtained as a byproduct due to the use of soybean meal in the fermentation medium. The structural elucidation of the metabolites was based primarily on 1D-, 2D-NMR, and HRFABMS analyses. Among these compounds, 2, 3, and 5 are metabolites of gallic acid in mammals. This result demonstrated that microbial culture parallels mammalian metabolism; therefore, B. sulfurescens might be a useful tool for generating mammalian metabolites of related analogs of gallic acid (1) for complete structural identification and for further use in investigating pharmacological and toxicological properties in this series of compounds. In addition, a GRE (glucocorticoid response element)-mediated luciferase reporter gene assay was used to initially screen for the biological activity of the 6 compounds, 2–6 and 8, along with 1 and its chemical O-methylated derivatives 9–13. Among the 12 compounds tested, 11–13 were found to be significant, but less active than the reference compounds of methylprednisolone and dexamethasone.     

树豆内酯A粗品皂化产物的化学结构鉴定

对天然产物树豆内酯A进行皂化反应以期获得具有降血糖、降血脂活性的天然药物先导物树豆酮酸A。利用含有树豆内酯A和球松素各约50%的粗品,经0.65%KOH含水乙醇回流3.5 h皂化,产物经柱层析分离纯化获得皂化产物;通过理化和波谱学分析鉴定产物的化学结构。分离并鉴定了全部5个皂化产物,除了预期产物树豆酮酸A以外,其余4个低得率的副产物结构分别为1-(2,6-二羟基-4-甲氧基苯基)乙酮(2)、球松素查尔酮(3)、cajanotone(4)和1个新化合物(1),化合物1鉴定为CAA的异构体,命名为树豆酮酸B(Cajanonic acid B)。这为进一步研究开发树豆(Cajanus cajan)叶生物活性成分提供了新的实验依据。     

Antioxidant and α-Amylase Inhibitory Compounds from Aerial Parts of Varthemia iphionoides Boiss

Various extracts of aerial parts of Varthemia (Varthemia iphionoides Boiss) were investigated for radical-scavenging activity, antioxidative activity, and porcine pancreas α-amylase inhibitory activity. The ethanol and water extracts showed a pronounced 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical-scavenging activity, with inhibition of about 90% at a concentration of 100 μg/ml, and α-amylase inhibitory activity of about 70% at a concentration of 200 μg/ml by the 2-chloro-4-nitrophenyl α-maltotrioside (CNP-G₃) degradation method. The ethanol extract was purified by column chromatography to give seven 3-methoxyflavones (1–7) and eudesmane sesquiterpene, selina-4,11(13)-dien-3-on-12-oic acid (8). The structures of these compounds were established by NMR, MS, and UV spectroscopy. Of 3-methoxyflavones, 5,7,4′-trihydroxy-3,6-dimethoxyflavone (1), 5,7,4′-trihydroxy-3,3′-dimethoxyflavone (2), and 5,4′-dihydroxy-3,7,3′-trimethoxyflavone (3,7,3′-tri-O-methyl-quercetin) (7) exhibited pronounced radical-scavenging activity. The antioxidative activity in the linoleic acid system was considerable in compounds 1, 2, and 5,4′-dihydroxy-3,6,7-trimethoxyflavone (4). Compounds 1, 2, 4, 5 (5,7,4′-trihydroxy-3-methoxyflavone), and 6 (5,4′-dihydroxy-3,7-dimethoxyflavone) showed markedly high inhibitory activity against porcine pancreas α-amylase. Eudesmane sesquiterpene did not show any activity.     

New antibacterial pentacyclic triterpenes from Myricaria elegans Royle. (tamariscineae)

Two new pentacyclic triterpenes eleganene-A (1) and eleganene-B (2), along with four known pentacyclic triterpenes betulin (3), ursolic acid (4), erythrodiol (5) and corosolic acid (6) were isolated from the aerial parts of Myricaria elegans. These compounds exhibited significant antibacterial activity. The structure of compounds 1 and 2 were deduced on the basis of their spectral analysis.