1. Chlovalicin B, a Chlorinated Sesquiterpene Isolated from the Marine Mushroom Digitatispora marina
Marte Jenssen, Venke Kristoffersen, Kumar Motiram-Corral, Johan Isaksson, Teppo Rämä, Jeanette H Andersen, Espen H Hansen, Kine Østnes Hansen Molecules. 2021 Dec 13;26(24):7560. doi: 10.3390/molecules26247560.
As part of our search for bioactive metabolites from understudied marine microorganisms, the new chlorinated metabolite chlovalicin B (1) was isolated from liquid cultures of the marine basidiomycete Digitatispora marina, which was collected and isolated from driftwood found at Vannøya, Norway. The structure of the novel compound was elucidated by spectroscopic methods including 1D and 2D NMR and analysis of HRMS data, revealing that 1 shares its molecular scaffold with a previously isolated compound, chlovalicin. This represents the first compound isolated from the Digitatispora genus, and the first reported fumagillin/ovalicin-like compound isolated from Basidiomycota. Compound 1 was evaluated for antibacterial activities against a panel of five bacteria, its ability to inhibit bacterial biofilm formation, for antifungal activity against Candida albicans, and for cytotoxic activities against malignant and non-malignant human cell lines. Compound 1 displayed weak cytotoxic activity against the human melanoma cell line A2058 (~50% survival at 50 µM). No activity was detected against biofilm formation or C. albicans at 50 µM, or against bacterial growth at 100 µM nor against the production of cytokines by the human acute monocytic leukemia cell line THP-1 at 50 µM.
2. New cytotoxic furan from the marine sediment-derived fungi Aspergillus niger
Paula Karina S Uchoa, Antonia T A Pimenta, Raimundo Braz-Filho, Maria da Conceição F de Oliveira, Natália N Saraiva, Barbara S F Rodrigues, Ludwig H Pfenning, Lucas M Abreu, Diego V Wilke, Katharine G D Florêncio, Mary Anne S Lima Nat Prod Res. 2017 Nov;31(22):2599-2603. doi: 10.1080/14786419.2017.1283499. Epub 2017 Jan 30.
A fungal strain of Aspergillus niger was recovered from sediments collected in the Northeast coast of Brazil (Pecém's offshore port terminal). Cultivation in different growth media yielded a new ester furan derivative, 1, along with malformin A1, malformin C, cyclo (trans-4-hydroxy-L-Pro-L-Leu), cyclo (trans-4-hydroxy-L-Pro-L-Phe), cyclo (L-Pro-L-Leu), cyclo (L-Pro-L-Phe), pseurotin D, pseurotin A, chlovalicin, cyclo (L-Pro-L-Tyr) and cyclo (L-Pro-L-Val). Compound 1 was cytotoxic against HCT-116 cell line, showing IC50 = 2.9 μg/mL (CI 95% from 1.8 to 4.7 μg/mL).
3. Chlovalicin, a new cytocidal antibiotic produced by Sporothrix sp. FO-4649. II. Physicochemical properties and structural elucidation
S Takamatsu, Y P Kim, T Komiya, T Sunazuka, M Hayashi, H Tanaka, K Komiyama, S Omura J Antibiot (Tokyo). 1996 Jul;49(7):635-8. doi: 10.7164/antibiotics.49.635.
A new growth inhibitor of IL-6 responsive MH60 cells, chlovalicin (MW; 332, C16H25O5Cl), was found in cultures of Sporothrix sp. FO-4649, together with a known sesquiterpene, ovalicin. The structure of chlovalicin was elucidated by spectroscopic methods. Chlovalicin possesses a chlorinated methylene moiety at the C-1 position, and it corresponds to halogenated products derived from the epoxide ring attached to the C-1 position of ovalicin. The absolute configuration of chlovalicin was clarified as 1S, 2R, 3S, 1'S, 2'R by chemical transformation from ovalicin.