Nigrosphaerin A a new isochromene derivative from the endophytic fungus Nigrospora sphaerica

Nigrosphaerin A, a new isochromene derivative (1), was isolated from the endophytic fungus Nigrospora sphaerica and chemically identified as 3-(3,4-dihydroxyphenyl)-4,6,8-trihydroxy-1H-isochromen-1-one-6-O-β-d-glucopyranoside. In addition nineteen known compounds (2–20) were isolated from the same fungus and chemically identified. Compounds (1–3, 5, and 7–16) were isolated for the first time from this fungus. In vitro antileukemic, antileishmanial, antifungal, antibacterial and antimalarial activities of (1–20) were examined. Compounds 5, 7, 9 and 10 showed good antileukemic activity against HL60 cells with IC₅₀ values of 0.03, 0.39, 0.2 and 0.4 μg/mL, respectively and against K562 cells with IC₅₀ values of 0.35, 0.35, 0.49 and 0.01 μg/mL, respectively. Compounds 3, 4 and 6 showed moderate antileishmanial activity with IC₅₀ values of 30.2, 26.4 and 36.4 μg/ml, respectively. Compound 7 showed moderate antifungal activity against Cryptococcus neoformans with IC₅₀ value of 14.8 μg/mL.     

Secondary metabolites and cytotoxic activities from the endophytic fungus Annulohypoxylon squamulosum

One new dihydrobenzofuran-2,4-dione derivative, designated as annulosquamulin (1), together with 10 known compounds (2–11), were isolated from the n-BuOH-soluble fraction of the 95% EtOH extract of long-grain rice fermented with the endophytic fungus Annulohypoxylon squamulosum BCRC 34022, derived from the stem bark of medicinal plant Cinnamomum sp. Annulosquamulin (1) comprises one dihydrobenzofuran-2,4-dione skeleton, 1-hydroxydecyl side chain, and one γ-lactone ring. Their structures were elucidated by means of spectroscopic and mass-spectrometric analyses, particularly 1D and 2D NMR spectroscopy as well as HRESIMS. All known isolates except 11, were isolated for the first time from this species. In addition, isolated compounds (1–5) were evaluated for their cytotoxicity against the MCF-7, NCI-H460 and SF-268 cell lines using the MTT assay.     

Antifungal and cytotoxic activities of the secondary metabolites from endophytic fungus Massrison sp.

Three novel compounds with spiro-5, 6-lactone ring skeleton has been isolated from the fermentation broth of Massrison sp. which could be isolated repeatedly from wild Rehmannia glutinosa. Psetariae oryza P-2b was applied to guide fractionation of bioactive compounds produced by Massrison sp. The molecular structures were established by a variety of one- and two-dimensional NMR experiments and the compounds with similar skeleton were reported for the first time from endophytic fungi of terraneous plant. Antifungal and cytotoxic activities of the compounds were tested, compounds 2 and 3 displayed stronger antifungal and cytotoxic activities. The compounds have the potential to be antibiotic against fungal pathogens and tumor cells.     

红豆杉内生真菌次生代谢物的分离鉴定及其抗菌活性 分析

以产紫杉醇类化合物的云南红豆杉内生真菌12.3.2为目标菌株,对其次生代谢物进行分离鉴定和抗菌活性研究。通过硅胶柱层析,共分离得到3个主要成分,红外光谱、质谱、核磁共振氢谱等光谱解析鉴定其分别为松柏烯、邻苯二甲酸二异辛酯、油酸乙酯。生物活性试验表明3种化合物对金黄色葡萄球菌、枯草杆菌、大肠杆菌、绿脓杆菌和白色链球菌这5种致病菌都有一定的抑制作用。其中松柏烯对金黄色葡球菌、枯草杆菌和白色念珠菌有较强的抑制作用。松柏烯是首次报道从植物内生真菌次生代谢物中分离得到,这为松柏烯的来源开辟了一条重要的途径,同时也为松柏烯的进一步开发利用奠定了基础。     

Fusarithioamide B,a new benzamide derivative from the endophytic fungus Fusarium chlamydosporium with potent cytotoxic and antimicrobial activities

Fusarithioamide B (6), a new aminobenzamide derivative with unprecedented carbon skeleton and five known metabolites: stigmast-4-ene-3-one (1), stigmasta-4,6,8(14),22-tetraen-3-one (2), p-hydroxyacetophenone (3), tyrosol (4), and fusarithioamide A (5) were separated from Fusarium chlamydosporium EtOAc extract isolated from Anvillea garcinii (Burm.f.) DC. leaves (Asteraceae). The structure elucidation and complete assignment of the isolated metabolites were performed mainly by the aid of various NMR and MS data. Fusarithioamide B (6) has been assessed for antibacterial and antifungal activities towards various microbial strains by disc diffusion assay. It exhibited selective antifungal activity towards C. albicans (MIC 1.9?µg/ml and IZD 14.5?mm), comparing to clotrimazole (MIC 2.8?µg/ml and IZD 17.9?mm). Also, it possessed high antibacterial potential towards E. coli, B. cereus, and S. aureus compared to ciprofloxacin. Furthermore, 6 was tested for the in vitro cytotoxic effect against KB, HCT-116, BT-549, MCF-7, SKOV-3, and SK-MEL cell lines. It had selective and potent effect towards BT-549, MCF-7, SKOV-3, and HCT-116 cell lines with IC₅₀s 0.09, 0.21, 1.23, and 0.59?μM, respectively compared to doxorubicin (IC₅₀s 0.046, 0.05, 0.321, and 0.24?μM, respectively). Fusarithioamide B may provide a lead molecule for future developing of antitumor and antimicrobial agents.     

一株无花果内生真菌及其次生代谢产物

从无花果Ficus carica 叶中分离获得1株具有抗菌活性的内生真菌ZJWCF255,通过形态学和ITS rDNA序列分析将菌种鉴定为炭角菌属Xylaria sp.,其发酵液经活性跟踪分离,采用硅胶柱层析及HPLC等方法获得4个化合物。根据波谱数据,化合物1–4分别鉴定为cytochalasin C、D、Q、R。Cytochalasin Q（3）对11种植物病原真菌均具有较强的抑制活性,对蔓枯病菌的抑制率最强,EC50值为0.04μg/mL。该化合物对3种肿瘤细胞SMMC-772、MCF-7、MGC80-3具有较强体外抑制活性,其IC50值分别为（17.24±2.55）、（7.75±1.37）、（10.30±1.34）μg/mL。首次报道了cytochalasin Q（3）的抗菌活性及对3种肿瘤细胞的体外抑制活性,植物内生真菌是获得抗菌与抗肿瘤活性先导化合物的重要来源。     

内生条纹拟盘多毛孢发酵液中细胞毒活性成分研究

从条纹拟盘多毛孢Pestalotopsis virgatula发酵液中分离得到8个化合物,其结构分别被鉴定为：2-(1-甲氧基-1-H-吲哚-3-基)乙醇 (1),2-(1-甲氧基-1-H-吲哚-3-基)乙酸 (2),3β-羟基-5α,8α-过氧化麦角甾-6,22-二烯 (3),麦角甾-4,6,8(14),22-四烯-3-酮 (4),对羟基苯乙醇 (5),邻苯二甲酸二异丁酯 (6),(E)-3-(4-羟基-3-甲氧苯基)败脂酸 (7) 和丁二酸 (8),化合物1–8均为首次从该菌种中分离得到。利用MTT法测试了化合物1 和2对5种人体肿瘤细胞的细胞毒活性,结果显示化合物1和2对5株肿瘤细胞株均具有一定选择性抑制活性。     

灯台树内生放线菌多样性及抗菌活性评价

从云南西双版纳采集7份灯台树样品,经过表面消毒,用4种分离培养基分离得到105株内生放线菌。经16S rRNA基因序列分析鉴定,分布于7个科9个属。利用5种植物病原真菌指示菌对所有菌株的发酵液进行抗菌活性检测。结果显示,有12.4%、14.3%、11.4%、12.4%、8.6%的菌株分别对镰刀霉、疫霉、赤星霉、苹果炭疽、白色念珠菌有抗性。对3株具有广谱抗菌活性的菌株进行再次发酵和抗菌活性复筛,结果显示这3株的抗菌活性稳定,并可能含有生物碱类化合物。     

蛇足石杉内生真菌无柄盘菌Pezicula sp. JR14中抑制乙酰胆碱酯酶的次级代谢产物分离

采用形态学及ITS-rDNA序列分析法,对具有抑制乙酰胆碱酯酶活性的蛇足石杉内生菌株JR14进行鉴定,确定为无柄盘菌Pezicula sp.。开展了乙酰胆碱酯酶抑制活性化合物的分离,从Pezicula sp. JR14乙酸乙酯提取物中分离到4个化合物,利用核磁共振及质谱技术将其鉴定为behenic acid (1)、himeic acid B (2)、secalonic acid A (3)和palmitic acid (4)。采用改进的Ellman比色法对分离的化合物进行活性检测,结果表明,himeic acid B (2)具有较强的乙酰胆碱酯酶抑制活性,其IC₅₀为205μg/mL（0.64mmol/L）。     

Bioactive metabolites produced by Chaetomium globosum,an endophytic fungus isolated from Ginkgo biloba

A novel cytotoxic chlorinated azaphilone derivative named chaetomugilin D (1), together with three known metabolites, chaetomugilin A (2), chaetoglobosins A (3) and C (4), has been isolated by a bioassay-guided fractionation from the EtOAc extract of the cultures of Chaetomium globosum, an endophytic fungus found in the leaves of Ginkgo biloba. Structure of 1 was established by analyses of spectroscopic methods, including 2D-NMR experiments (COSY, NOESY, HMQC, and HMBC). Compounds 1–4 displayed significant growth inhibitory activity against the brine shrimp (Artemia salina) and Mucor miehei.     

Myrotheciumones: Bicyclic cytotoxic lactones isolated from an endophytic fungus of Ajuga decumbens

Two new bicyclic lactones, myrotheciumones A (1) and B (2) which possessed a rare ring-fusion system were isolated from Myrothecium roridum (M. roridum), an endophytic fungus of the medicinal herb plant Ajuga decumbens (A. decumbens) via an in vitro cytotoxicity assay. Structures were deduced from 1D and 2D NMR (Nuclear magnetic resonance) data. Myrotheciumone A’s in vitro cytotoxicity and apoptotic activity were evaluated and myrotheciumone A was shown to exert cytotoxicity via inducing apoptosis in cancer cell line.     

First report of secondary metabolites,Violaceol I and Violaceol II produced by endophytic fungus,Trichoderma polyalthiae and their antimicrobial activity

Bioactive compounds of endophytic fungus Trichoderma polyalthiae were extracted from culture broth media. The crude extracts showed strong antimicrobial activity against human pathogens. Biologically active compounds were isolated and purified by chromatographic methods. The structures of the pure compounds were elucidated by spectroscopic methods. They were identified as Violaceol I and Violaceol II. These compounds were detected as secondary metabolites produced by this genus for the first time. Violaceol I and II had a broad spectrum of antimicrobial activity against human pathogens, including Gram-positive bacteria (Staphylococcus saprophyticus, Staphylococcus aureus, Methicillin-Resistant S. aureus, Bacillus subtilis, Bacillus cereus) and Gram-negative bacteria (Salmonella typhimurium, Shigella sonnei) and Candida albicans. Violaceol I exhibited Minimal Inhibitory Concentration (MIC) values (<9.765–156.25 μg/mL) that were higher than Violaceol II (<9.765–312.5 μg/mL). Additionally, the MIC value of the phenol violaceol from this taxon was lower than the previous reports.     

Bioactive metabolites from the endophytic fungus Ampelomyces sp. isolated from the medicinal plant Urospermum picroides

Extracts of cultures grown in liquid or on solid rice media of the fungal endophyte Ampelomyces sp. isolated from the medicinal plant Urospermum picroides exhibited considerable cytotoxic activity when tested in vitro against L5178Y cells. Chromatographic separation yielded 14 natural products that were unequivocally identified based on their ¹H and ¹³C NMR as well as mass spectra and comparison with previously published data. Six compounds (2, 4, 5, 7, 9 and 11) were natural products. Both fungal extracts differed considerably in their secondary metabolites. The extract obtained from liquid cultures afforded a pyrone (2) and sulfated anthraquinones (7 and 9) along with the known compounds 1, 3, 6 and 8. When grown on solid rice medium the fungus yielded three compounds 4, 5 and 11 in addition to several known metabolites including 6, 8, 10, 12, 13 and 14. Compounds 4, 8 and 10 showed the strongest cytotoxic activity against L5178Y cells with EC₅₀ values ranging from 0.2–7.3 μg/ml. Furthermore, 8 and 10 displayed antimicrobial activity against the Gram-positive pathogens, Staphylococcus aureus, S. epidermidis and Enterococcus faecalis at minimal inhibitory concentrations (MIC) of 12.5 μg/ml and 12.5–25 μg/ml, respectively. Interestingly, 6 and 8 were also identified as constituents of an extract derived from a healthy plant sample of the host plant U. picroides thereby indicating that the production of bioactive natural products by the endophyte proceeds also under in situ conditions within the host plant.     

浙贝母内生真菌Nectria sp. JZ6分泌抑菌活性代谢产物的初步研究

Nectria sp.JZ6是从浙贝母新鲜鳞茎中首次分离到的一株内生真菌,其发酵液具有抑菌活性。为建立该真菌稳定分泌抑菌活性成分的发酵体系,本研究利用单因素实验和正交实验确定了发酵培养基的配方并初步优化了发酵条件。结果表明,将活化后的菌种接种于改良查氏培养基(8%葡萄糖,0.5%蛋白胨,0.05%KCl,0.1%K2HPO4,0.15%MgSO4,pH6.5)中,28℃、150r/min振荡培养6d后获得的发酵液抑菌活性比优化前提高了26%。该发酵液经100℃水浴30min不失活,在pH1-5时抑菌活性相对稳定,其后逐渐减弱,并在pH9.0及以上时丧失。Nectriasp.JZ6发酵液的乙酸乙酯浸膏抑菌活性最强,对金黄色葡萄球菌、藤黄八叠球菌、枯草芽孢杆菌、绿脓杆菌和大肠杆菌的最低抑菌浓度(MIC)分别为0.625、0.625、1.25、1.25和1.25mg/mL。     

一株内生真菌Talaromyces sp.次级代谢产物及其活性

为了研究红树杨叶肖槿来源内生真菌Talaromyces sp. YX-001的次级代谢产物及其乙酰胆碱酯酶(acetylcholinesterase, AChE)抑制活性,该文运用硅胶柱层析和HPLC等手段从菌株YX-001的PDB培养基发酵提取物中分离得到单体化合物,而后结合1/2D NMR和MS等现代波谱技术并与文献数据对比鉴定其结构,最后通过比色法测定各单体化合物的AChE抑制活性。结果表明:(1)共分离得到9个单体化合物,分别为asterrelenin(1),aszonalenin(2),cladosporisteroid C(3),sitosterol(4),ergosterol(5),cyclo-Ile-Pro-diketopiperazine(6),cyclo(-Pro-Val)(7),4-methoxy-2-methylisoquinolin-1-one(8)和allantoin(9)。(2)其中化合物1和2显示出一定的AChE抑制活性,IC₅₀值分别为81.5、105.8 μmol·L^-1。该文首次对杨叶肖槿来源内生真菌次级代谢产物及其AChE抑制活性进行了研究,为后续红树植物杨叶肖槿来源内生真菌资源的开发与再利用奠定了基础。     

Metabolite fingerprinting,in vitro antimicrobial and antioxidant activities and in-silico docking in Alloteropsis cimicina and its endophytic fungus Penicillium pinophilum

Molecular Biology Reports - Endophytic fungal interaction with medicinal plant resulting in the production of bioactive compounds influenced the present study. Endophytic fungus Penicillium...     

Pestalachlorides A-C, antifungal metabolites from the plant endophytic fungus Pestalotiopsis adusta

Pestalachlorides A-C (1-3), three new chlorinated benzophenone derivatives, have been isolated from cultures of an isolate of the plant endophytic fungus Pestalotiopsis adusta. The structures of these compounds were determined mainly by NMR spectroscopy, and the structures of 1 and 3 were further confirmed by X-ray crystallography. Pestalachloride A (1) was obtained as a mixture of two inseparable atropisomers (1a and 1b), whereas pestalachloride C (3) was found to be a racemic mixture. Compounds 1 and 2 displayed significant antifungal activities against three plant pathogens.     

来自普哥滨珊瑚的一株Talaromyces sp.真菌的活性次生代谢产物

利用硅胶柱层析、制备型HPLC和重结晶等手段从普哥滨珊瑚分离的一株Talaromyces sp.真菌C21-1中筛选得到2个活性化合物,运用核磁共振、质谱和圆二色谱等技术鉴定这两个化合物分别为(R)-(-)-hydroxysydonic acid（1）和homodimeric WIN 64821（2）,补充完善了化合物2的核磁共振信号归属,并对化合物进行抗菌活性和乙酰胆碱酯酶抑制活性的测定,发现化合物1对白色假丝酵母Canidia albicans和耐甲氧基青霉素的金黄色葡萄球菌Methicillin-resistant Staphylococcus aureus（MRSA）具有一定的抑制作用,其最低抑菌浓度（MIC）分别为0.075mmol/L和0.2mmol/L,对副溶血弧菌Vibrio parahemolyticus的抑制活性较弱,在0.2mmol/L浓度下的抑制率为17%;化合物2最大浓度0.2mmol/L条件下对这3种菌均没有明显的抑制效果。化合物2表现出剂量依赖的乙酰胆碱酯酶抑制活性,0.5mmol/L时抑制率达到35.1%。     

Antiproliferative metabolites from the endophytic fungus Penicillium sp. FJ-1 isolated from a mangrove Avicennia marina

Two new compounds, named as 4-(2′,3′-dihydroxy-3′-methyl-butanoxy)-phenethanol (1), and 15-hydroxy-6α,12-epoxy-7β,10αH,11βH-spiroax-4-ene-12-one (2), were isolated from the endophytic fungus Penicillium sp.FJ-1 of Avicennia marina. Their structures were elucidated on the basis of spectroscopic analysis. Additionally, compounds 1 and 2 exhibited antiproliferative activities, and compound 2 significantly inhibited the tumor growth of human xenograft osteosarcoma in nude mice.