Didymellanosine, a new decahydrofluorene analogue, and ascolactone C from Didymella sp. IEA-3B.1, an endophyte of Terminalia catappa. Issue 12 (18th February 2020)

• Record Type: Journal Article
• Authors: Ariantari, Ni P.; Ancheeva, Elena; Frank, Marian; Stuhldreier, Fabian; Meier, Dieter; Gröner, Yvonne; Reimche, Irene; Teusch, Nicole; Wesselborg, Sebastian; Müller, Werner E. G.; Kalscheuer, Rainer; Liu, Zhen; Proksch, Peter
• Is Part Of: RSC advances. Volume 10:Issue 12(2020)
• Page Start: 7232
• Page End: 7240
• Publication Date: 2020-02-18
• Subjects: Chemistry -- Periodicals; 540.5
• DOI: 10.1039/c9ra10685e
• Languages: English
• ISSNs: 2046-2069

Abstract

Abstract : An unusual decahydrofluorene-class alkaloid from Didymella sp. exhibited NFκB inhibitory and antimicrobial activities. Abstract : Didymellanosine (1 ), the first analogue of the decahydrofluorene-class of natural products bearing a 13-membered macrocyclic alkaloid conjugated with adenosine, and a new benzolactone derivative, ascolactone C (4 ) along with eight known compounds (2, 3, 5–10 ), were isolated from a solid rice fermentation of the endophytic fungus Didymella sp. IEA-3B.1 derived from the host plant Terminalia catappa . In addition, ascochitamine (11 ) was obtained when (NH4 )2 SO4 was added to rice medium and is reported here for the first time as a natural product. Didymellanosine (1 ) displayed strong activity against the murine lymphoma cell line L5178Y, Burkitt's lymphoma B cells (Ramos) and adult lymphoblastic leukemia T cells (Jurkat J16), with IC50 values of 2.0, 3.3 and 4.4 µM, respectively. When subjected to a NFκB inhibition assay, didymellanosine (1 ) moderately blocked NFκB activation in the triple-negative breast cancer cell line MDA-MB 231. In an antimicrobial assay, ascomylactam C (3 ) was the most active compound when tested against a panel of Gram-positive bacteria including drug-resistant strains with MICs of 3.1–6.3 µM, while 1 revealed weaker activity. Interestingly, both compounds were also found active against Gram-negative Acinetobacter baumannii with MICs of 3.1 µM, in the presence of a sublethal concentration (0.1 µM) of colistin.