Mei-Yan Wei

Five Sesquiterpenoids from a Marine-Derived Fungus Aspergillus sp. Isolated from a Gorgonian Dichotella gemmacea

Three new phenolic bisabolane-type sesquiterpenoids: (+)-methyl sydowate (1), 7-deoxy-7,14-didehydrosydonic acid (2), and 7-deoxy-7,8-didehydrosydonic acid (3), together with two known fungal metabolites were isolated from the fermentation broth of a marine-derived fungus Aspergillus sp., which was isolated in turn from a gorgonian Dichotella gemmacea collected from the South China Sea. Their structures were elucidated by combined spectroscopic methods, and the structure of 1 was further confirmed by single-crystal X-ray data.

Penicinoline, a new pyrrolyl 4-quinolinone alkaloid with an unprecedented ring system from an endophytic fungus Penicillium sp.

A new pyrrolyl 4-quinolinone alkaloid with an unprecedented ring system, named penicinoline (1) was isolated from a mangrove endophytic fungus. The structure of 1 was elucidated by spectroscopic methods and comparison with its derivative, penicinotam (1a), an unexpected lactam that was obtained from 1 by intramolecular dehydration. The structure of 1a was unambiguously confirmed by single-crystal X-ray analysis. Penicinoline (1) showed potent in vitro cytotoxicity toward 95-D and HepG2 cell lines with IC(50) values of 0.57 and 6.5 microg/mL, respectively.

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.

Aspergilones A and B, two benzylazaphilones with an unprecedented carbon skeleton from the gorgonian-derived fungus Aspergillus sp.

Two novel benzylazaphilone derivatives with an unprecedented carbon skeleton, aspergilone A (1), and its symmetrical dimer with a unique methylene bridge, aspergilone B (2), have been isolated from the culture broth of a marine-derived fungus Aspergillus sp. from a gorgonian Dichotella gemmacea. Their structures and relative stereochemistries of 1 and 2 were elucidated using a combination of NMR spectroscopy and X-ray crystallography. Compound 1 not only exhibited in vitro selective cytotoxicity but also showed potent antifouling activity.

Structure elucidation of two new xanthone derivatives from the marine fungus Penicillium sp. (ZZF 32#) from the South China Sea

Two new xanthones, 8‐(methoxycarbonyl)‐1‐hydroxy‐9‐oxo‐9H‐xanthene‐3‐carboxylic acid (1) and dimethyl 8‐methoxy‐9‐oxo‐9H‐xanthene‐1, 6‐dicarboxylate (2) and one known xanthone methyl 8‐hydroxy‐6‐methyl‐9‐oxo‐9H‐xanthene‐1‐carboxylate (3) were isolated from the culture broth of the mangrove fungus Penicillium sp. (ZZF 32#) collected from the South China Sea. Their structures were established by comprehensive analysis of one‐dimensional (1D) and two‐dimensional (2D) NMR data. The structure of compound 3 was confirmed by X‐ray crystallography, which led to the suggestion that janthinone (4) might have the same structure as 3. Compounds 1–3 were inactive against KB or KBv200 cells during cytotoxicity evaluations. Copyright

Structure and Absolute Configuration of Fumiquinazoline L, an Alkaloid from a Gorgonian-Derived Scopulariopsis sp Fungus

Fumiquinazoline L (1), an alkaloid with a heptacyclic skeleton formed via a bridging hemiaminal linkage, was isolated from a gorgonian-derived Scopulariopsis sp. fungus. The structure and absolute configuration of the new compound were identified by comprehensive spectroscopic data and X-ray diffraction analysis. During acid hydrolysis of 1, the isomerization of the valine residue was observed and also studied in different conditions. Fumiquinazoline L (1) showed no cytotoxic or antibacterial activities.

(+)- and (−)-Pestaloxazine A, a Pair of Antiviral Enantiomeric Alkaloid Dimers with a Symmetric Spiro[oxazinane-piperazinedione] Skeleton from Pestalotiopsis sp.

A pair of new enantiomeric alkaloid dimers, (+)- and (-)-pestaloxazine A (1), with an unprecedented symmetric spiro[oxazinane-piperazinedione] skeleton, consisting of 22 carbons and 12 heteroatoms, were isolated from a Pestalotiopsis sp. fungus derived from a soft coral. Separation of the enantiomeric alkaloid dimers was achieved by chiral HPLC. Their structures including absolute configurations were elucidated on the basis of a comprehensive analysis of their spectroscopic and X-ray diffraction data and CD calculations. (+)-Pestaloxazine A exhibited potent antiviral activity against EV71 with an IC50 value of 14.2 ± 1.3 μM, which was stronger than that of the positive control ribavirin (IC50 = 256.1 ± 15.1 μM).

(±)-Pestalachloride D, an Antibacterial Racemate of Chlorinated Benzophenone Derivative from a Soft Coral-Derived Fungus Pestalotiopsis sp.

A new antibacterial chlorinated benzophenone derivative, (±)-pestalachloride D (1), along with a related analog, (±)-pestalachloride C (2), was recently isolated from the marine-derived fungus Pestalotiopsis sp. isolated from a soft coral Sarcophyton sp. collected from Yongxing Island in the South China Sea. Both chiral HPLC analysis and single-crystal X-ray data indicated that 1 is a racemic mixture. Interestingly, 1 did not exhibit any effect in the zebrafish embryo teratogenicity assay, while 2 led to abnormal growth. The potential impact on zebrafish embryo growth is discussed based on their crystal structures. The main difference of crystal structures between 1 and 2 is that the six-member non-aromatic ring (O4, C10, C9, C8, C2′, and C3′) in 1 exhibits a distorted chair conformation, while 2 shows a distorted boat conformation. Moreover, compounds 1 and 2 both exhibited moderate antibacterial activity.

Isolation, structure elucidation, crystal structure, and biological activity of a marine natural alkaloid, viridicatol

0009-3130/11/4702-0322 2011 Springer Science+Business Media, Inc. 1) School of Pharmacy, Guangdong Medical College, Dongguan, 523808, P. R. China; 2) Key Laboratory for the Chemistry and Molecular Engineering of Medicinal Resources, Ministry of Education, School of Chemistry & Chemical Engineering, Guangxi Normal University, Guilin, 541004, P. R. China; 3) Key Laboratory of Marine Drugs, Ministry of Education, School of Medicine and Pharmacy, Ocean University of China, Qingdao, 266003, P. R. China, e-mail: shaochanglun@ouc.edu.cn; changyun@ouc.edu.cn; 4) College of Chemistry and Chemical Engineering, Luoyang Normal University, Luoyang, 471022, P. R. China; 5) School of Chemistry and Chemical Engineering, Sun Yat-sen University, Guangzhou, 510275, P. R. China. Published in Khimiya Prirodnykh Soedinenii, No. 2, pp. 288–290, March–April, 2011. Original article submitted December 20, 2009. Chemistry of Natural Compounds, Vol. 47, No. 2, May, 2011 [Russian original No. 2, March–April, 2011]

Isolation, 1H, 13C NMR Assignments, and crystal structure of chrodrimanin B from A marine fungus Aspergillus sp.

A terrestrial fungal metabolite, chrodrimanin B (1), has been isolated for the first time from the fermentation broth of a marine-derived fungus Aspergillus sp. collected from the South China Sea. Detailed assignments for the proton and carbon of 1 have been unambiguously elucidated by combined spectroscopic methods including 1D and 2D NMR spectral data, and the relative configurations were also confirmed by single- crystal X-ray data.