New Anti-inflammatory Compounds from the Deep-Sea Fungus Cystobasidium laryngis

Abstract

As demonstrated by Brimble’s review, extremophiles are rich source of novel secondary metabolites. However, when compared to the large number of extremophilic microorganisms which have been reported, very few have been screened for the production of interesting secondary metabolites[1]. In our continuing search for bioactive compounds from extremophiles, we encountered a rare marine-derived yeast-like fungus Cystobasidium laryngis isolated from a deep-sea sediment sample collected from the Indian Ocean Ridge at the depth of 4,317 m in 2017[2]. From this deep-sea derived fungus, we could isolate three new anti-inflammatory metabolites. The structures of the new compounds were determined by analysis of spectroscopic data, semi-synthesis and comparison of optical rotation values. These compounds showed nitric oxide (NO) production inhibitory effect against lipopolysaccharide (LPS)-induced murine macrophage RAW 264.7 cells without cytotoxicity at concentrations up to 30 μg/mL.