A New Cyclic Peptide and a New Steroid from the Fungus Penicillium sp. GD6 Isolated from the Mangrove Bruguiera gymnorrhiza

A rare new cyclic tetrapeptide, 5,5′‐epoxy‐MKN‐349A ( 1 ), featured by a MKN‐349A ( 5 ) skeleton and containing an uncommon ether bridge between C(5) and C(5′), and a new steroid, named 11‐O‐acetyl‐NGA0187 ( 2 ), together with two known steroids, 3 and 4 , were isolated from an endophytic fungus Penicillium sp. GD6 associated with the Chinese mangrove Bruguiera gymnorrhiza. The structures of the new compounds were elucidated on the basis of extensive spectroscopic analyses and by comparison with the data of related compounds reported in literature. Neither of the compounds 3 and 4 , isolated in this study, showed obvious bioactivities in the antibacterial bioassay experiments.     

Protein tyrosine phosphatase 1B inhibitors from a marine-derived fungal strain aspergillus sp. SF-5929

Abstract

In the course of our continuing investigation of bioactive secondary metabolites from marine-derived fungal strains, a racemate of a novel diphenolic derivative named (±)-tylopilusin D (1) along with ten previously known secondary metabolites (2–11) were isolated from a marine-derived fungal strain Aspergillus sp. SF-5929. Their structures were elucidated mainly by analysis of NMR and MS data. In addition, the inhibitory effects of the isolated compounds against protein tyrosine phosphatase 1B (PTP1B) activity were evaluated, and compounds 1, 2, and 5–7 inhibited PTP1B activity with IC₅₀ values ranging from 3.3 to 8.1?µM. Kinetics studies suggested that compounds 1, 2, and 5 had noncompetitive inhibitory effects against PTP1B.     

食用菌类中矿物质元素的研究

用火焰原子吸收分光光度法对广东清远笔架山的 1 7种食用菌、 2种木耳及灵芝中赤芝的 8种矿物质元素进行了测定。结果表明 ,食用菌类是优质食品 ,富含对人体有益的微量元素 ,有较高营养价值     

He-Ne激光选育高木质素降解率的白腐真菌Lx

用He-Ne激光对一株木质素降解活性较高的白腐真菌L₁进行选育.将该菌的菌丝体和原生质体多次照射诱变,结果得出:在波长632.5nm,用功率为6mW和7mW照射该菌的菌丝体,选育出的菌株L₆和L₇木质素降解率可达38.1%和39.88%,比出发菌株L₁提高了33%和39%.用功率9mW的He-Ne激光辐照原生质体,照射20min时,原生质体致死率已达100%.在照射时间为10min时,选育出一株木质素降解率达43.03%的菌株L_x,比出发菌株L₁提高了50%.同工酶分析显示该菌株发生了稳定的遗传突变.     

Aromatic compounds produced by endophytic fungi isolated from red alga Asparagopsis taxiformis - Falkenbergia stage

Endophytic fungi were isolated from red alga Asparagopsis taxiformis - Falkenbergia stage, collected from the Brazilian coast, and were identified as Annulohypoxylon stygium (AT-03) and A. yungensis (AT-06) based on their macro/micromorphological and molecular features. Bioassay-guided fractionation of the EtOAc extract from laboratory cultures of both strains yielded known compounds pyrogallol from A. stygium, (3R)-scytalone and (3R,4R)-4-hydroxy-scytalone from A. yungensis. Pyrogallol was active against methicillin-resistant Staphylococcus aureus (MRSA) and Escherichia coli strains. An inactive fraction from A. stygium afforded two additional compounds, (3R,4R)-3,4,5-trihydroxy-1-tetralone and tyrosol. Optically active compounds had their stereochemistry determined by circular dichroism (CD) spectroscopy.     

Remisporine B, a novel dimeric chromenone derived from spontaneous Diels-Alder reaction of remisporine A

A novel cyclopentachromenone, remisporine A, has been isolated from liquid culture of the marine fungus Remispora maritima. Remisporine A is not stable under normal conditions and autocatalytically dimerizes to give rise to a stereospecific product remisporine B via Diels-Alder reaction. The structure of remisporine B was elucidated by spectroscopic analyses including 2D-NMR and HRMS data.     

A new phthalide from the endophytic fungus Xylaria sp. GDG-102

A new phthalide derivative, xylarphthalide A (1), along with two known compounds (-)-5-carboxylmellein (2) and (-)-5-methylmellein (3), were isolated from the endophytic fungus Xylaria sp. GDG-102 cultured from the Chinese medicinal plant Sophora tonkinensis. Their structures were identified by MS and NMR experiments, and the absolute configuration of 1 was further confirmed by single-crystal X-ray diffraction analysis. Compound 1–3 showed antibacterial activities against Bacillus megaterium, Bacillus subtilis, Staphylococcus aureus, Escherichia coli and Shigella dysenteriae with MIC values of 12.5–25 μg/mL.     

Three New Polyketide Metabolites from the Endophytic Fungal Strain Cladosporium tenuissimum LR463 of Maytenus hookeri

Three new polyketide metabolites, the twelve‐membered macrolides (6R,12S)‐6‐hydroxy‐12‐methyloxacyclodoecane‐2,5‐dione ( 1 ), (10S,12S)‐10‐hydroxy‐12‐methyloxacyclododecane‐2,5‐dione ( 2 ), and 4,5‐dihydroxy‐12‐methyloxacyclododecan‐2‐one ( 3 ), were isolated from the endophytic fungal strain Cladosporium tenuissimum LR463 of Maytenus hookeri, together with three known compounds, cladospolide A, cladospolide B, and isocladospolide B. Their structures were elucidated by spectroscopic analysis including 1D‐ and 2D‐NMR experiments, and the absolute configurations of 1 and 2 were determined by the Mosher ester method.     

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.     

珊瑚姜精油的超临界萃取及其抗真菌和细菌活性

珊瑚姜(ZingibercorallinumHance)为姜科姜属植物,产于贵州、广西、广东,贵州主要分布在南、北盘江下游河谷地带,为贵州苗族习用药材,称Jabbangxhnaibdiel(加榜海丢)或阴姜,少数民族常以珊瑚姜块茎入药,具有消肿、解毒、抗菌的功能,用于治疗感冒、咳嗽、腰痛、腹泻[1]。其挥发油的药理研究表明,有抑制离体肠肌引起的痉挛性收缩的自发运动、拮抗组织胺引起的胃肠收缩反应和解除毛果芸香碱、乙酰胆碱、氯化钠等引起的肠痉挛性收缩[2]。挥发油还具有显著的抗真菌作用[3],用于治疗皮癣[4]。超临界CO2萃取是一项新兴的提取分离技术,在中药…