2-Alkyl-4-hydroxyquinolines from a Marine-Derived Streptomyces sp. Inhibit Hyphal Growth Induction in Candida albicans.

ABSTRACT: Four 2-alkyl-4-hydroxyquinoline derivatives (1?4) were isolated from a semisolid rice culture of the marine-derived actinomycete Streptomyces sp. MBTG13. The structures of these compounds were elucidated by a combination of spectroscopic methods, and their data were in good agreement with previous reports. Compounds 1 and 2 exhibited weak to moderate antibacterial activity against pathogenic bacteria. Unexpectedly, we found that compound 1 acted as a potent inhibitor of hyphal growth induction in the dimorphic fungus Candida albicans, with an IC50 value of 11.4 ?g/mL. Growth experiments showed that this compound did not inhibit yeast cell growth, but inhibited hyphal growth induction. Semi-quantitative reverse transcription (RT)-PCR analysis of hyphal-inducing signaling pathway components indicated that compound 1 inhibited the expression of mRNAs related to the cAMP-Efg1 pathway. The expression of HWP1 and ALS3 mRNAs (hypha-specific genes positively regulated by Efg1, an important regulator of cell wall dynamics) was significantly inhibited by the addition of compound 1. These results indicate that compound 1 acts on the Efg1-mediated cAMP pathway and regulates hyphal growth in Candida albicans.

SUBMITTER: Kim H 

PROVIDER: S-EPMC6410270 | biostudies-literature | 2019 Feb

REPOSITORIES: biostudies-literature