南海红树内生真菌1947号次级代谢产物的研究

红树植物是一类生长于潮间带的乔灌木的通称。近年来,国内外对红树内生真菌代谢产物的研究呈快速发展趋势。本课题组自上世纪90年代以来开始研究南海红树内生真菌代谢产物,迄今已从南海红树内生真菌分离得到许多有意义的代谢产物[1-5]。编号为1947号的内生真菌分离自香港江口红     

南海红树林内生真菌Cephalosporium sp．（2090#）次级代谢产物研究

海洋微生物是寻找海洋药物先导化合物的一个新的源泉,人们已经从海洋微生物的次级代谢产物中分离得到了很多结构新颖或强药理活性的化合物[1]。我们在对中国南海红树林内生真菌的研究中,发现了大量的生物活性化合物,这也揭示了我国南海海洋真菌具有极大的药用开发前景[2-5]。红     

螳螂共生真菌TG-3生物碱的研究

报道了螳螂共生真菌TG-3生物碱的研究,从其液体发酵产物中共分离得到7个生物碱,用波谱学方法鉴定其结构分别为:pseurotin A1(1)、pseurotin A2(2)、pseurotin D(3)、fumitremorgin C(4)、desoxybrevianamide E(5)、6-methoxyspirotryprostatin B(6)、dihydroxy-fumitremorgin C(7)。     

一株红树内生真菌Penicillium sp.(ZZF29#)次级代谢产物分离与鉴定

研究了一株药用红树内生真菌Penicillium sp.(ZZF29#)的次级代谢产物。用硅胶柱层析、制备薄层层析和重结晶等方法,从该菌发酵液的乙酸乙酯相中分离获得8种单体化合物,运用现代波谱技术并与文献数据对照,鉴定其结构分别为:环(苯丙-丙)二肽(1)、环(苯丙-甘)二肽(2)、环(苯丙-苯丙)二肽(3)、环(苯丙-酪)二肽(4)、大黄素(5)、大黄素甲醚(6)、麦角甾醇(7)和过氧化麦角甾醇(8)。     

一株昆虫内生真菌Alternaria sp.次级代谢产物研究

采用硅胶柱色谱,Sephadex LH-20凝胶柱色谱及HPLC等方法从昆虫共生真菌Alternaria sp.(Be-1)的发酵液分离得到7个代谢产物,经NMR,MS及理化性质等确定为4个环肽和3个聚酮类化合物,4-甲氧基格链孢酚(1),5'-methoxy-6-methyl-biphenyl-3,4,3'-triol(2),altenusin(3),二氢腾毒素(4),腾毒素(5),环(4-羟基-脯-亮)二肽(6)和cyclo(L-Phenylalanine-trans-4-hydroxy-L-proline)(7)。测定了化合物1-7对抗肿瘤治疗靶点-受体酪氨酸激酶的抑制活性,药理实验结果表明,化合物1-6对三种酪氨酸激酶(EGFR,VEGFR-1,c-Met)具有不同程度的抑制活性,化合物1,3,6对EGFR,VEGFR-1,c-Met均具有强的抑制作用,而且化合物6还有选择性抑制EGFR和c-Met的活性。     

海洋来源真菌Eutypella sp.F0219次级代谢产物研究（英文）

弯孢聚壳属真菌能产生结构丰富多样的活性化合物.对一株来自海洋沉积物的真菌Eutypellasp.F0219代谢产物研究中,分离得到一个新的异戊烯基取代二氢异香豆素和一个新的色烯酰胺衍生物,分别命名为eutypellarins A和B(1和2),以及两个已知的异戊二烯取代苯甲醛衍生物(3和4).通过高分辨质谱、核磁共振波谱以及量子化学计算对新化合物的结构进行确定.首次从弯孢聚壳属真菌中发现异戊二烯取代二氢异香豆素和色烯酰胺衍生物.采用2,2’-联氮-双-3-乙基苯并噻唑啉-6-磺酸(ABTS)自由基清除法和铁离子还原(FRAP)法对所有化合物进行总抗氧化能力的测定.结果显示化合物1和4具有中等的抗氧化效果,其Trolox等效抗氧化能力分别为(0.51±0.016)和(0.76±0.007).     

南海红树林内生真菌ZSU-H26生物碱类代谢产物的研究

海洋微生物资源由于具有可持续开发性,而且其活性物质不像来源于其它海洋生物(如海绵、海藻、海兔、珊瑚等)产生的生物活性物质,其生产不受天然资源难再生的限制,能通过发酵进行胞外生产,与现代微生物技术相结合,较容易实现工业化生产,特别是其生产不对环境造成危害,符合当今绿色化学发展的方向.     

南海海洋真菌#2526中蒽醌类代谢产物的研究

从分离自香港红树林的南海海洋真菌sterigmatocystin,通过完整的波谱数据分别解析它们为averufin(A),nidurufin(B),versicolorin C(C)和大黄素甲醚(D);初步生理活性试验表明,化合物A不显示有意义的抑菌活性,并且和化合物D一样,不显示有意义的hTOPI酶抑制活性.     

南海红树林内生真菌ZH-111代谢产物研究

本文首次报道对南海红树林内生真菌ZH-111代谢产物的研究工作,从菌体中分离得到6个化合物:4-羟甲基-7-甲氧基-6-甲基-1(3H)-异苯并呋喃酮(1),环缩肽(Exumolide A)(2),双内酯(3),7,8-二甲基苯并[g]蝶啶-2,4(1H,3H)-二酮(4),弯孢霉菌素(5),5,5′-氧-二亚甲基-双...     

南海红树林内生真菌No．ZZF71代谢产物研究

由于海洋环境的特殊性和微生物在生态系统的功能,海洋微生物已经发展出独特的代谢方式,提供了在陆地微生物中未遇到过的代谢产物。研究海洋微生物的活性物质,不但能发现结构新颖的化合物,丰富和发展有机化学理论,而且为寻找新的强效活性药物及其它有用物质提供了一个重要途径[1     

Secondary Metabolites from the Fungus Chaetomium brasiliense

Two new depsidones, mollicellins I and J ( 1 and 2 , resp.), and a new chromone, 2‐(hydroxymethyl)‐6‐methylmethyleugenin ( 3 ), along with six known compounds, 4 – 9 , were isolated from the ethyl acetate extract of a solid‐state fermented culture of Chaetomium brasiliense. Their structures were elucidated based on spectroscopic analysis. Mollicellins I and H ( 5 ) exhibited significant growth inhibitory activity against human breast cancer (Bre04), human lung (Lu04), and human neuroma (N04) cell lines with GI₅₀ values between 2.5–8.6 μg/ml.     

Brasiliensic and isobrasiliensic acids: isolation from Calophyllum brasiliense Cambess. and anti-Helicobacter pylori activity

The occurrence of chromanone derivatives has been noticed as a distinctive feature of the genus Calophyllum (Calophyllaceae). Previous studies have demonstrated that the extract of the stem bark of Calophyllum brasiliense and its chromanone-rich fractions show anti-ulcer activity in murine gastric ulcer models. In this work, brasiliensic and isobrasiliensic acids, the two main compounds of the n-hexane extract of the stem bark extract of C. brasiliense, were isolated by flash chromatography using silica gel impregnated with silver nitrate and their structures were elucidated by NMR techniques and mass spectrometry. ¹³C NMR data is available for the first time for both compounds. Brasiliensic and isobrasiliensic acids showed good in vitro bacteriostatic activity against Helicobacter pylori, and are responsible, at least in part, for the bacteriostatic anti-H. pylori activity of the n-hexane extract of the stem bark of C. brasiliense.     

Biomimetic epoxidation in aqueous media catalyzed by cyclic dipeptides

We have developed a practical epoxidation of electron-deficient enones in aqueous media using cyclic dipeptides as bioinspired green catalyst. Optimizing the reaction conditions in a triphasic system led to efficient conditions providing epoxides with good enantioselectivities. Depending on the catalyst substituent chirality, both enantiomers are obtained. The cyclic rigidity impacts significantly the enantioselectivity.     

Fragmentation of deprotonated cyclic dipeptides by electrospray ionization mass spectrometry

The fragmentation pathways of deprotonated cyclic dipeptides have been studied by electrospray ionization multi‐stage mass spectrometry (ESI‐MSⁿ) in negative mode. The results showed that the fragmentation pathways of deprotonated cyclic dipeptides depended significantly on the different substituents, the side chains of amino acid residues at the diketopiperazine ring. In the spectra of deprotonated cyclic dipeptides, the ion [M? H? substituent radical]^? was firstly observed in the ESI mode. The characteristic fragment ions [M? H? substituent radical]^? and [M? H? (substituent? H)]^? could be used as the symbols of particular cyclic dipeptides. The hydrogen/deuterium (H/D) exchange experiment, the high‐resolution mass spectrometry (Q‐TOF) and theoretical calculations were used to rationalize the proposed fragmentation pathways and to verify the differences between the fragmentation pathways. The relative Gibbs free energies (ΔG) of the product ions and possible fragmentation pathways were estimated using the B3LYP/6–31++G(d, p) model. The results have some potential applications in the structural elucidation and interpretation of the mass spectra of homologous compounds and will enrich the gas‐phase ESI‐MS ion chemistry of cyclic dipeptides. Copyright © 2009 John Wiley & Sons, Ltd.     

Two Cyclic Peptides Produced by the Endophytic Fungus # 2221 from Castaniopsis fissa on the South China Sea Coast

New cyclic peptides 1 and 2 were isolated from the endophytic fungus #2221 from Castaniopsisfissa on the south China sea coast. By 2D NMR methods and chiral HPLC technique, their structures were elucidated as cyclo (L-Val-L-Leu-L-Val-L-Leu) and cyclo(L-Leu-L-Ala-L-Leu-L-Ala), respectively.     

Secondary metabolites from Antarctic marine-derived fungus Penicillium crustosum HDN153086

A new polyene compound (1) and a new diketopiperazine (2), as well as three known compounds (3–5), were isolated from the Antarctic marine-derived fungus Penicillium crustosum HDN153086. The structures of 1–5 were deduced based on MS, NMR and TD-DFT calculations of specific ECD spectra. These compounds were evaluated for their cytotoxic activities against K562 cell line and only compound 2 exhibited cytotoxicity against K562 cell, with IC₅₀ value of 12.7 μM.     

Polyketides and nitrogenous metabolites from the endophytic fungus Phomopsis sp. D15a2a

Three new polyketides, phomopones A−C (1–3), one new cyclic tetrapeptide, 18-hydroxydihydrotentoxin (4), and a new amide, 6-hydroxyenamidin (5) together with a known derivative, enamindin (6) were obtained from the endophytic fungus Phomopsis sp. D15a2a isolated from the plant Alternanthera bettzickiana. The structures of the new compounds were elucidated by 1D, 2D NMR and HRMS data. The absolute configurations of the isolated metabolites were determined either by X-ray crystallography, Marfey’s method or by converting the compounds to Mosher esters.     

Acetylcholinesterase inhibitory active metabolites from the endophytic fungus Colletotrichum sp. YMF432

An endophytic fungus, Chaetomium sp. YMF432, was isolated from Huperzia serrata (Thunb. ex Murray) Trev. and subjected to phytochemical investigation based on its special environment. From the extracts of fermentation solid of strain YMF 432, eight compounds including 1-O-methylemodin (1), 5-methoxy-2-methyl-3-tricosyl-1,4-benzoquinone (2), 4,8-dihydroxy-1-tetralone (3), (3β,5α,6α, 22E)-3-hydroxy-5,6-epoxy-7-one-8(14),22-dien-ergosta (4), ergosta-4,6,8(14),22-tetraen-3-one (5), β-sitostenone (6), β-sitosterol (7) and (22E,24R)-ergosta-5,7,22 -trien-3β-ol (8) were obtained. Their structures were elucidated on the basis of their spectroscopic data. These compounds were evaluated for acetylcholinesterase inhibitory activities in vitro. Compounds 1, 2, and 4 showed moderate acetylcholinesterase inhibitory activities (IC₅₀ from 37.7 ± 1.5 to 370.0 ± 2.9 μM).