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A new hTopo I isomerase inhibitor, (+)-3,3',7,7',8,8'-hexahydroxy-5,5'-dimethylbianthraquinone (2240A), was isolated from the mangrove endophytic fungus no. 2240 collected from an estuarine mangrove at the South China Sea coast. Its structure was elucidated by spectral analyses including two-dimensional NMR, HR-EI-MS, IR, and UV. The hTopo I isomerase inhibition experiment showed that 2240A (1) possessed strong inhibiting activity. When its inhibition concentration was 4.65 μmol/l, its percent inhibition rate was 59.1%, while the lowest inhibition concentration of the positive control camptothecin was 1.00 × 103 μmol/l. [ABSTRACT FROM AUTHOR]

Two new metabolites, named no. 2106 A (1) and cyclo-(N-MeVal-N-MeAla) (2), have been produced by the endophytic fungus no. 2106 isolated from the seeds of the mangrove Avicennia marina in Hong Kong. The structures were elucidated by 2D NMR, HR-MS, and X-ray diffraction analyses. [ABSTRACT FROM AUTHOR]

The novel natural product xyloallenoide A, isolated from the marine mangrove endophytic fungus from the South China Sea, and its diastereoisomer xyloallenoide A1, which contain N-methyl-substituted amino acids, were synthesized. The absolute configurations of the amino acid units of xyloallenoide A were finally confirmed to be L-Lys, Me- D-Val, and Me- L-Ala. This report represents a practical and attractive alternative for the synthesis of N-methyl-substituted cyclotripeptides. In the preliminary bioassay, synthetic xyloallenoide A showed marginal activities against KB ( IC50=9.6 μ M) and KBv200 cells ( IC50=10.3 μ M), and xyloallenoide A1 was inactive against KB and KBv200 cells. [ABSTRACT FROM AUTHOR]

Two new meroterpenes, 'acetoxydehydroaustin B' ( 1) and '1,2-dihydro-acetoxydehydroaustin B' ( 2) were isolated in the form of a mixed crystal from the mangrove endophytic fungus Aspergillus sp. 085241B. Their structures and absolute configurations were determined by extensive analysis of their spectra and X-ray diffraction data. In a preliminary bioassay, the mixed crystal did not exhibit activities against cancer cell lines of MDA-MB-435, SKBR3, HepG2, HEP3B, PC-3, and A549, as well as against α-glucosidase and tyrosinase. [ABSTRACT FROM AUTHOR]

Four new dimeric naphtho- γ-pyrones, named rubasperone D ( 1), rubasperone E ( 2), rubasperone F ( 3), and its atropisomer rubasperone G ( 4), together with four known monomeric naphtho- γ-pyrones, TMC 256 A1 ( 5), rubrofusarin B ( 6), fonsecin ( 7), and flavasperone ( 8), were isolated from the mangrove endophytic fungus Aspergillus tubingensis (GX1-5E) cultivated in solid rice medium. Their structures were elucidated by spectroscopic methods, including IR, 1D- and 2D-NMR, and MS. In the in vitro cytotoxicity assays, 5 displayed inhibitory activities against tumor cell lines of MCF-7, MDA-MB-435, Hep3B, Huh7, SNB19, and U87 MG with IC50 values between 19.92 and 47.98 μ M. Compounds 1, 6, and 8 also showed mild cytotoxic activity. [ABSTRACT FROM AUTHOR]

Abstract: Two new metabolites named 6-oxo-de-O-methyllasiodiplodin (1) and (E)-9-etheno-lasiodiplodin (2), with three known compounds lasiodiplodin (3), de-O-methyllasiodiplodin (4), and 5-hydroxy-de-O-methyllasiodiplodin (5), were isolated from the mycelium extracts of a brown alga endophytic fungus (No. ZZF36) obtained from the South China Sea. Their structures were elucidated using spectroscopic methods, mainly 1D and 2D NMR. Additionally, the structure of compound 1 was confirmed by single crystal X-ray diffraction analysis. The antimicrobial activities of lasiodiplodins, and the 13-acetyl and 12,14-dibromo derivatives of lasiodiplodin were tested for the first time and the results were compared to each other. [Copyright &y& Elsevier]

Abstract: Two new metabolites, 3R,5R-Sonnerlactone (1) and 3R,5S-Sonnerlactone (2), were isolated from the mangrove endophytic fungus Zh6-B1 obtained from the South China Sea. Their structures were elucidated by MS and NMR. The absolute configuration of compound 1 was determined by single-crystal X-ray analysis using Cu Kα radiation. The absolute configuration of compound 2 was determined by NOESY analysis and comparing circular dichroism spectroscopy with compound 1. The antiproliferative activity of compound 1 and 2 against the multi-drug resistant human oral floor carcinoma cells (KV) was evaluated. [Copyright &y& Elsevier]

Abstract: 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 IC50 values of 0.57 and 6.5μg/mL, respectively. [Copyright &y& Elsevier]

Palitantin (II) and the new analogue, 13-hydroxypalitantin (I), exhibit acetylcholinesterase (AchE) inhibitory activities. [ABSTRACT FROM AUTHOR]