Xyloketal H from the mangrove endophytic fungus Xylaria sp. 2508

(3R*,3aR*,9aR*)-3,9a-Dimethyl-2,3,3a,9a-tetrahydro-4H-furo[2,3-b]chromene-5,7-diol (xyloketal H), a representative of a new family of xyloketals, was isolated from the marine-derived mangrove fungus Xylaria sp. 2508. Its structure was elucidated by spectroscopic data and single-crystal X-ray diffraction analysis. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 6, pp. 1051–1052, June, 2006.     

Xyloketal G,a Novel Metabolite from the Mangrove Fungus <Emphasis Type="Italic">Xylaria sp.</Emphasis> 2508

A novel metabolite 1, named xyloketal G, was isolated from cultures of marine derived mangrove fungus Xylaria sp. 2508. Its structure was elucidated by analysis of spectroscopic data.__________Published in Khimiya Prirodnykh Soedinenii, No. 1, pp. 22–23, January–February, 2005.     

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)。     

红树林湿地土壤矿物的分析

以湛江湾南海堤典型红树林湿地土壤为研究对象,采用X射线衍射(XRD)和傅立叶变换红外光谱(FTIR)快速批量鉴定土壤中矿物成分,利用扫描电子显微镜(SEM)观察土壤颗粒形貌特征并获得化学成分组成信息;同时采集附近光滩土壤样品进行对比研究,以揭示红树林湿地土壤特殊的生态环境特征。结果表明,红树林湿地土壤矿物主要由高岭石、石英、白云母、埃洛石、地开石和蛇纹石等组成;与光滩土壤相比,红树林湿地土壤矿物类型多样,而光滩土壤矿物相对单一,主要为石英和高岭石;红树林湿地土壤颗粒以片状聚合体为主,主要元素组成为C、O、S、Al、Si、Mg、Fe等,常见含有Cu、Zn、Mo等重金属元素。同时发现红树林湿地土壤颗粒含有较丰富的硫化物;而光滩土壤未发现上述特征,表明红树林湿地处于一个特殊的生态环境,土壤沉积物中富含有机质、Fe、S等,比一般潮滩更易于富集硫化物或重金属。     

A new compound: Xyloketal H from mangrove fungus <Emphasis Type="Italic">Xylaria</Emphasis> sp. from the South China Sea coast

A new metabolite xyloketal H (1), was isolated from mangrove fungus Xylaria sp. (No.2508) obtained from the South China Sea. By spectroscopic analyses, primarily 2D NMR methods and X-ray diffraction experiments, its structure was elucidated. Published in Khimiya Prirodnykh Soedinenii, No. 1, pp. 5–6, January–February, 2008.     

A new biphenyl derivative from an unidentified marine fungus E33

A new biphenyl derivative 3,5′-dihydroxy-4′,5-dimethoxy-2′-methyl-[1,1′-biphenyl]-2-carboxylic acid methyl ester (1), was isolated from the culture broth of a fungus isolated from the rhizosphere soil of mangrove root on the South China Sea. The structure of 1 was determined by comprehensive spectroscopic methods, primarily 2D NMR techniques. Published in Khimiya Prirodnykh Soedinenii, No. 2, pp. 128–129, March–April, 2008.     

Degradation of medium-chain-length polyhydroxyalkanoates in tropical forest and mangrove soils

Bacterial polyhydroxyalkanoates (PHAs) are perceived to be a suitable alternative to petrochemical plastics because they have similar material properties, are environmentally degradable, and are produced from renewable resources. In this study, the in situ degradation of medium-chain-length PHA (PHA_MCL) films in tropical forest and mangrove soils was assessed. The PHA_MCL was produced by Pseudomonas putida PGA1 using saponified palm kernel oil (SPKO) as the carbon source. After 112 d of burial, there was 16.7% reduction in gross weight of the films buried in acidic forest soil (FS), 3.0% in the ones buried in alkaline forest soil by the side of a stream (FSst) and 4.5% in those buried in mangrove soil (MS). There was a slight decrease in molecular weight for the films buried in FS but not for the films buried in FSst and in MS. However, no changes were observed for the melting temperature, glass transition temperature, monomer compositions, structure, and functional group analyses of the films from any of the burial sites during the test period. This means that the integral properties of the films were maintained during that period and degradation was by surface erosion. Scanning electron microscopy of the films from the three sites revealed holes on the film surfaces which could be attributed to attack by microorganisms and bigger organisms such as detritivores. For comparison purposes, films of polyhydroxybutyrate (PHB), a short-chain-length PHA, and polyethylene (PE) were buried together with the PHA_MCL films in all three sites. The PHB films disintegrated completely in MS and lost 73.5% of their initial weight in FSst, but only 4.6% in FS suggesting that water movement played a major role in breaking up the brittle PHB films. The PE films did not register any weight loss in any of the test sites.     

Brugnanin,a new syn-2,3-dihydrobenzofuran neolignan dioate from the mangrove <Emphasis Type="Italic">Bruguiera gymnorrhiza</Emphasis>

Brugnanin (1), a neolignan dioate, was isolated from a mangrove plant Bruguiera gymnorrhiza. Based on spectroscopic interpretation of MS, IR, and NMR data, 1 was elucidated as (7R*,8S*,E)-3-hydroxy-5,5′-dimethoxy-7-O-4′,8-3′-neolignan-7′-ene-9,9′-dioic acid dioctadecyl ester. MTT assay showed that 1 had weak inhibitory activity against growth of CNE-1 nasopharyngeal carcinoma cell line. Published in Khimiya Prirodnykh Soedinenii, No. 2, pp. 147–149, March–April, 2008.     

New oxidized sterols from Aspergillus awamori and the endo‐boat conformation adopted by the cyclohexene oxide system

Two new oxidized sterols 1 and 2 were obtained from the active fraction of a mangrove fungus Aspergillus awamori isolated from the soils around the mangrove plant Acrostichum speciosum. Their structures were elucidated using spectroscopic methods as 22E‐7α‐methoxy‐5α,6α‐epoxyergosta‐8(14),22‐dien‐3β‐ol (1) and 22E‐3β‐hydroxy‐5α,6α,8α,14α‐diepoxyergosta‐22‐en‐7‐one (2). The NMR data and complete assignments for both DMSO‐d₆ and CDCl₃ were given. Their cytotoxic activity against A549 cell line was evaluated. Furthermore, the detailed conformation analysis for ring B (cyclohexene oxide system) of sterol 1 was given on the basis of NOEs. The endo‐boat conformation was considered as the preferred conformation for ring B rather than half‐chair conformation. Copyright © 2009 John Wiley & Sons, Ltd.     

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