Bioactive naphthoquinone and anthrone derivatives from endophytic Micromonospora sp. NEAU-gq13

Abstract

Two new naphthalenone derivatives, 5-hydroxy-4-oxo-2-(2-oxopropyl)-1,2,3,4-tetrahydronaphthalen-1-yl acetate (1) and 5-hydroxy-2-(2-hydroxypropyl)naphthalene-1,4-dione (2), together with two new anthrone derivatives, (S)-2,5-dihydroxy-2-methyl-1,2,3,4-tetrahydroanthracene-9,10-dione (3) and 4,5-dihydroxy-2-methyl-9H-xanthen-9-one (4), were isolated from the fermentation broth of endophytic Micromonospora sp. NEAU-gq13. Their structures were determined by 1D-NMR, 2D-NMR, and HR-ESI-MS analysis. Compounds 2 and 3 exhibited strong cytotoxic activity against human central nervous system cancer (SF-268) with the IC₅₀ values of 3.04 and 5.66 μg/ml, respectively. Moreover, compound 2 also displayed potent activity against human liver cancer (HepG2) with an IC₅₀ value of 1.01 μg/ml.

Graphical Abstract

Keywords:

• Endophytic micro-organisms
• Micromonospora sp. NEAU-gq13
• naphthoquinone and anthrone derivatives
• cytotoxic activities

Disclosure statement

No potential conflict of interest was reported by the authors.

Funding

This research was financially supported by grants from the National Outstanding Youth Foundation (No. 31225024) and Chang Jiang Scholar Candidates Program for Provincial Universities in Heilongjiang (CSCP).