Zhigang She

Statistical Research on Marine Natural Products Based on Data Obtained between 1985 and 2008

Since the 1960s, more than 20,000 compounds were discovered from marine organisms. In this paper we performed a quantitative analysis for the novel marine natural products reported between 1985 and 2008. The data was extracted mainly from the reviews of Faulkner and Blunt [1–26]. The organisms producing these marine natural products are divided into three major biological classes: marine microorganisms (including phytoplankton), marine algae and marine invertebrate. The marine natural products are divided into seven classes based on their chemical structure: terpenoids, steroids (including steroidal saponins), alkaloids, ethers (including ketals), phenols (including quinones), strigolactones, and peptides. The distribution and the temporal trend of these classes (biological classes and chemical structure classes) were investigated. We hope this article provides a comprehensive perspective on the research of marine natural products.

Chemistry and weak antimicrobial activities of phomopsins produced by mangrove endophytic fungus Phomopsis sp. ZSU-H76

Three metabolites named phomopsin A (1), B (2) and C (3), together with two known compounds cytosporone B (4) and C (5), 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 by 1D and 2D NMR spectroscopic techniques. The medium-sized cyclic phenol ether based on 1 or 2 is rare in natural products. In bioassays, compounds 1, 2, and 3 had no significant antibiotic activities, but compounds 4 and 5 inhibited two fungi Candida albicans and Fusarium oxysporum with an MIC ranging from 32 to 64 microg/ml.

Cytotoxic norsesquiterpene peroxides from the endophytic fungus Talaromyces flavus isolated from the mangrove plant Sonneratia apetala.

Four new norsesquiterpene peroxides, named talaperoxides A-D (1-4), as well as one known analogue, steperoxide B (5, or merulin A), have been isolated from a mangrove endophytic fungus, Talaromyces flavus. Their structures were elucidated mainly by 1D and 2D NMR. Structures of 1, 2, and 5 were further confirmed by single-crystal X-ray diffraction, and their absolute configurations were also determined using copper radiation. Cytotoxic activities of compounds 1-5 were evaluated in vitro against human cancer cell lines MCF-7, MDA-MB-435, HepG2, HeLa, and PC-3. Compounds 2 and 4 showed cytotoxicity against the five human cancer cell lines with IC50 values between 0.70 and 2.78 μg/mL.

Three Metabolites from the Mangrove Endophytic Fungus Sporothrix sp. (#4335) from the South China Sea

Three metabolites, sporothrins A, B, and C (1-3), were isolated from the mangrove endophytic fungus Sporothrix sp. (#4335). Their structures were identified by the spectral data and X-ray diffractive techniques, with compound 1 showing strong inhibition of acetylcholine esterase. 1,3,6,8-Tetrahydroxynaphthalene (T4HN) was deduced as one of the precursors in the biosynthesis of 1 and 2. In a primary biosynthesis gene study, the partial gene fragment obtained with the LC1-Im/2c-Im primer pair was shown to be closely related to genes encoding T4HN synthase. The deduced protein sequences were highly homologous to the ketosynthase domains of other fungal PKS genes involved in T4HN biosynthesis.

Bioactive Indole Alkaloids and Phenyl Ether Derivatives from a Marine-Derived Aspergillus sp. Fungus

Two new prenylated indole alkaloids, 17-epi-notoamides Q and M (1 and 2), and two new phenyl ether derivatives, cordyols D and E (9 and 13), together with 10 known compounds (3-8, 10-12, 14) were isolated from a marine-derived Aspergillus sp. fungus. Among them, 1/5 and 2/4 were pairs of epimers. The planar structures and absolute configurations of the new compounds were determined by extensive NMR spectroscopic data as well as CD spectra. The absolute configuration of 3 was confirmed by single-crystal X-ray diffraction analysis for the first time. All isolated metabolites (1-14) and eight synthetic phenyl ether derivatives (12a, 14a-14g) were evaluated for their antibacterial activities in vitro. The polybromide phenyl ether 14g showed pronounced antibacterial activity against Staphylococcus epidermidis with an MIC value of 0.556 μM, stronger than that of the positive control ciprofloxacin (MIC = 3.13 μM).

SZ-685C, a marine anthraquinone, is a potent inducer of apoptosis with anticancer activity by suppression of the Akt/FOXO pathway

Background and purpose:  The aims of this study were to investigate the anti‐cancer activity of SZ‐685C, an anthracycline analogue isolated from marine‐derived mangrove endophytic fungi, and to explore the molecular mechanisms underlying such activity.

Asperterpenoid A, a New Sesterterpenoid as an Inhibitor of Mycobacterium tuberculosis Protein Tyrosine Phosphatase B from the Culture of Aspergillus sp. 16-5c

Asperterpenoid A (1), a novel sesterterpenoid with a new carbon skeleton, has been isolated from a mangrove endophytic fungus Aspergillus sp. 16-5c. Its structure was characterized by extensive spectroscopic methods, and the absolute configuration was determined by single crystal X-ray diffraction analysis. Asperterpenoid A (1) exhibited strong inhibitory activity against Mycobacterium tuberculosis protein tyrosine phosphatase B (mPTPB) with an IC(50) value of 2.2 μM.

Antibacterial Bisabolane-Type Sesquiterpenoids from the Sponge-Derived Fungus Aspergillus sp.

Four new bisabolane-type sesquiterpenoids, aspergiterpenoid A (1), (−)-sydonol (2), (−)-sydonic acid (3), and (−)-5-(hydroxymethyl)-2-(2′,6′,6′-trimethyltetrahydro-2H- pyran-2-yl)phenol (4) together with one known fungal metabolite (5) 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. Four of them (1–4) are optically active compounds. Their structures and absolute configurations were elucidated by using NMR spectroscopic techniques and mass spectrometric analysis, and by comparing their optical rotations with those related known analogues. Compounds 1–5 showed selective antibacterial activity against eight bacterial strains with the MIC (minimum inhibiting concentrations) values between 1.25 and 20.0 µM. The cytotoxic, antifouling, and acetylcholinesterase inhibitory activities of these compounds were also examined.

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.