Zhi-Yong Guo

Antibacterial Anthraquinone Derivatives from a Sea Anemone-Derived Fungus Nigrospora sp.

Chemical investigation of a marine-derived fungus Nigrospora sp., isolated from an unidentified sea anemone, yielded two new hydroanthraquinone analogues, 4a-epi-9α-methoxydihydrodeoxybostrycin (1) and 10-deoxybostrycin (2), together with seven known anthraquinone derivatives (3-9). The structures of the two new compounds were established through extensive NMR spectroscopy as well as a single-crystal X-ray diffraction analysis using Cu Kα radiation. The antibacterial activities of compounds 1-9 and 10 acetyl derivatives (6a, 7a, 8a-8g, 9a) were evaluated in vitro. Compound 6a, the acetylated derivative of 6, exhibited promising activity against Bacillus cereus with an MIC value of 48.8 nM, which was stronger than that of the positive control ciprofloxacin (MIC = 1250 nM). Analysis of the antibacterial screening data for the metabolites and their acetyl derivatives revealed the key structural features required for this activity.

New bisabolane sesquiterpenoids from a marine-derived fungus Aspergillus sp. isolated from the sponge Xestospongia testudinaria.

Three new phenolic bisabolane sesquiterpenoid dimers, disydonols A-C (1-3), and one known compound (S)-(+)-sydonol (4) were isolated from the fermentation broth of a marine-derived fungus Aspergillus sp., which was isolated from the sponge Xestospongia testudinaria collected from the South China Sea. Their structures were elucidated on the basis of comprehensive spectral analysis including 1D and 2D NMR spectra and HR-ESI-MS. These compounds were evaluated for cytotoxic activity against HepG-2 and Caski human tumour cell lines. Among them, compounds 1 and 3 exhibited cytotoxicity against the two cell lines.

A new naphtho-γ-pyrone from mangrove endophytic fungus ZSU-H26

A new naphtho-γ-pyrone, 5-hydroxy-6,8-dimethoxy-2-benzyl-4H-naphtho[2,3-b]-pyran-4-one (1), together with three known compounds 5,7-dihydroxy-2-methylbenzopyran-4-one (2), 3,5-dihydroxy-2,7dimethylbenzopyran-4-one (3) and cyclo(Tyr-Tyr) (4) were isolated from the mangrove endophytic fungus Phomopsis sp. ZSU-H26 obtained from the South China Sea. Their structures were elucidated by spectroscopic methods, mainly 1D and 2D NMR spectroscopic techniques. Primary bioassays showed that 1 exhibited cytotoxicity against HEp-2 and HepG2 cells with IC50 values of 10 and 8 μg/mL, respectively.

Chemistry and cytotoxic activities of polyketides produced by the mangrove endophytic fungus Phomopsis SP. ZSU-H76

A new polyketide, 2-(7′-hydroxyoxooctyl)-3-hydroxy-5-methoxybenzeneacetic acid ethyl ester (1), together with three known compounds dothiorelone A (2), B (3), and C (4) were isolated from the mangrove endophytic fungus Phomopsis sp. ZSU-H76 obtained from the South China Sea. Their structures were elucidated by spectroscopic methods, mainly 1D and 2D NMR spectroscopic techniques. Primary bioassays showed that 1 exhibited cytotoxicity against HEp-2 and HepG2 cells with IC50 values of 25 and 30 μg/mL, respectively.

A new xanthone derivative from mangrove endophytic fungus No. ZSU-H16

A new xanthone derivative, 3,5,8-trihydroxy-2,2-dimethyl-3,4,4-trihydro-2H,6H-pyrano[3,2-b]-xanthen-6one (1), together with three known compounds, 5,8-dihydroxy-2,2-dimethyl-2H,6H-pyrano[3,2-b]xanthen6-one (2), cyclo-(N-O-methyl-L-Trp-L-Ile-D-Pip-L-2-amino-8-oxo-decanoyl) (3), and cyclo-(Phe-Tyr) (4), was isolated from the mangrove endophytic fungus No. ZSU-H16 obtained from the South China Sea coast. Their structures were elucidated by spectroscopic methods, mainly 1D and 2D NMR spectroscopic techniques. Compound 1 exhibited cytotoxicity against KB and KBV 200 cells with IC50 values greater than 50 μg/mL, respectively.

Three new steroidal glycosides from roots of Reineckia carnea.

Two new spirostanols and a new furostanol, reinocarnoside A (1), B (2) and C (3), were isolated from the roots of Reineckia carnea, together with two known compounds, (25S)-1β,3β,4β-trihydroxyspirostan-5β-yl-O-β-D-glucopyranoside (4), kitigenin-5β-O-β-D-glucopyranoside (5). The structures of three new compounds were elucidated by spectroscopic methods including 1-D NMR, 2-D NMR and MS spectrums, and their anticancer activities were evaluated by MTT method.

Xanthones from the roots of Calophyllum membranaceum

0009-3130/11/4606-0976 2011 Springer Science+Business Media, Inc. 1) Key Laboratory of Tropical Medicinal Plant Chemistry of Hainan Province, College of Chemistry and Chemical Engineering, Hainan Normal University, Haikou 571158, P. R. China, fax: 0086 898 65889422, e-mail:hchr116@hainnu.edu.cn; 2) Institute of Chemistry and Chemical Engineering, China West Normal University, Nanchong 637002, P. R. China; 3) College of Chemistry and Life Science, China Three Gorges University, Yichang 443002, P. R. China. Published in Khimiya Prirodnykh Soedinenii, No. 6, pp. 830–831, November–December, 2010. Original article submitted July 7, 2009. Chemistry of Natural Compounds, Vol. 46, No. 6, 2011

Paraconfuranones A-H, eight new furanone analogs from the insect-associated fungus Paraconiothyrium brasiliense MZ-1.

Insects that constituted the largest number of organisms on earth possess the richest and most unexplored domains of natural products.Microorganisms livingwithin the insect inner gut system without causing diseases have proven to be potential sources of diverse chemical structures, for example, unprecedented immunosuppressive polyketides from a mantis-associated fungus Daldinia eschscholzii, antifungal naphthalenones from Perenniporia sp. inhabiting the larva of Euops chinesis, cytotoxic angucyclines from Amycolatopsis sp.HCa1, anda rare actinobacteriumderived fromthe gutofOxyachinensis. Asapartofourongoingpiecesof researchon the utilization of fungal sources in Shennongjia Forest District, a National Natural Protection Region of China, a rare fungus Paraconiothyrium brasiliense (strain no. MZ-1) was isolated from the gut of healthy Acrida cinerea collected from the Shennongjia Forest District. To our best knowledge, the strain can produce some novel terpenoid derivatives. When this fungus was cultured under the rice medium in our preliminary experiments, a few terpenoids could be detected. When the culture medium was guided by the one strain–many compounds approach, the secondary metabolites thereby changed. Further investigation led to the isolation of eight new furanone derivatives, named paraconfuranones A–H (Fig. 1). In thispaper,we reported the isolationandstructural elucidation of paraconfuranones A–H and their cytotoxity activity.

Pestalafuranones F–J, Five New Furanone Analogues from the Endophytic Fungus Nigrospora sp. BM-2

Five new 2(5H)-furanone-type derivatives, pestalafuranones F–J (compounds 3–7), together with two known compounds, pestalafuranones A (1) and B (2), were isolated from the ethyl acetate extract from the fermentation broth of the endophytic fungus Nigrospora sp. BM-2 in a hypersaline medium. The structures of these metabolites were elucidated by EIMS, HREIMS and NMR spectroscopic data. Compounds 1–7 exhibited no cytotoxic activities against the MDA-MB-231 and Caski cancer cell lines.

New polyhydroxylated steroid from the South China Sea gorgonian Anthogorgia caerulea

One new polyhydroxylated steroid, caerulsteroid A (1), along with nine known analogues (2–10), was isolated from the gorgonian coral Anthogorgia caerulea collected from the South China Sea. The structure of the new compound was elucidated by 1-D and 2-D NMR, and mass spectrometry. The absolute configuration of 1 was assigned on the basis of the absolute configurations of the related congeners 2 and 3, which were determined by application of the modified Moshers method. The isolated compounds were assayed for their cytotoxicity, antimicrobial activity and lethality towards brine shrimp Artemia salina.