Actinofuranones D-I from a Lichen-Associated Actinomycetes, Streptomyces gramineus, and Their Anti-Inflammatory Effects.

Jian Ma,Yu Mu,Chengbin Liu,Yi Jiang,Peipei Guan,Bixuan Cao,Li Han,Xueshi Huang

doi:10.3390/molecules23092393

Jian Ma, Yu Mu + Show 6 more

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https://doi.org/10.3390/molecules23092393

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Abstract

Six new metabolites, actinofuranones D-I (compounds 1–6), were isolated together with three known compounds—JBIR-108 (7), E-975 (8), and E-492 (9)—from a fermentation broth of Streptomyces gramineus derived from the lichen Leptogium trichophorum. The structures of the new compounds 1–6 were established using comprehensive NMR spectroscopic data analysis, as well as UV, IR, and MS data. The anti-inflammatory activity of these isolated compounds were evaluated by examining their ability to inhibit nitric oxide (NO) production in LPS-stimulated RAW 264.7 macrophage cells. Compounds 4, 5, 8, and 9 attenuated the production of NO due to the suppression of the expression of nitric oxide synthase (iNOS) in LPS-induced RAW 264.7 cells. Moreover, 4, 5, 8, and 9 also inhibited LPS-induced release of proinflammatory cytokines interleukin-6 (IL-6) and tumor necrosis factor α (TNF-α).

Highlights

Lichens are symbiotic organisms, composed of fungi and algae or cyanobacteria
As part of our continuous search for the new anti-inflammatory compounds compounds from lichen-associated actinomycetes, we investigated the anti-inflammatory activity of from lichen-associated actinomycetes, we investigated the anti-inflammatory activity of the isolates the isolates by examining their ability to inhibit production of nitric oxide (NO), interleukin-6 (IL-6)
S. gramineus was centrifuged centrifuged and and the the supernatant was fermentation broth gramineus was supernatant was extracted with ethyl acetate

Summary

Introduction

Lichens are symbiotic organisms, composed of fungi (mycobiont) and algae or cyanobacteria (photobiont or phycobiont). With discovery of some new secondary metabolites from them, lichen-associated actinomycetes have attracted extensive attention [4,5,6,7,8]. The diversity of cultivable actinomycetes associated with lichen symbiosis in samples collected from Yunnan Province, P. Antimicrobical activities and biosynthetic potential studies of the isolated actinomycetes were conducted in the research and the results showed the actinomycetes associated with lichen could be considered as a potential microbial resource for discovering novel bioactive natural products [9]. Streptomyces gramineus (YIM 130461), occurring in the lichen Leptogium trichophorum, collected from an evergreen broad-leaf forest in Benzilan, Diqing (Yunnan Province, China) was chosen to investigated its secondary metabolites. A small scale (100 mL) fermentation broth of S. gramineus showed diverse

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