Huoshanmycins A‒C, New Polyketide Dimers Produced by Endophytic Streptomyces sp. HS-3-L-1 From Dendrobium huoshanense

Youjuan Zhu; Yichao Kong; Yu Hong; Ling Zhang; Simin Li; Shurong Hou; Xiabin Chen; Tian Xie; Yang Hu; Xiachang Wang

doi:10.3389/fchem.2021.807508

Huoshanmycins A‒C, New Polyketide Dimers Produced by Endophytic Streptomyces sp. HS-3-L-1 From Dendrobium huoshanense

Front Chem. 2022 Feb 14:9:807508. doi: 10.3389/fchem.2021.807508. eCollection 2021.

Authors

Youjuan Zhu¹, Yichao Kong², Yu Hong¹, Ling Zhang¹, Simin Li¹, Shurong Hou², Xiabin Chen², Tian Xie², Yang Hu¹, Xiachang Wang¹

Affiliations

¹ Jiangsu Key Laboratory for Functional Substances of Chinese Medicine, Nanjing University of Chinese Medicine, Nanjing, China.
² Key Laboratory of Element Class Anti-Cancer Chinese Medicines, Engineering Laboratory of Development and Application of Traditional Chinese Medicines, Collaborative Innovation Center of Traditional Chinese Medicines of Zhejiang Province, School of Pharmacy, Hangzhou Normal University, Hangzhou, China.

Abstract

Three new polyketide dimers named huoshanmycins A‒C (1-3) were isolated from a plant endophytic Streptomyces sp. HS-3-L-1 in the leaf of Dendrobium huoshanense, which was collected from the Cultivation base in Jiuxianzun Huoshanshihu Co., Ltd. The dimeric structures of huoshanmycins were composed of unusual polyketides SEK43, SEK15, or UWM4, with a unique methylene linkage. Their structures were elucidated through comprehensive 1D-/2D-NMR and HRESIMS spectroscopic data analysis. The cytotoxicity against MV4-11 human leukemia cell by the Cell Counting Kit-8 (CCK8) method was evaluated using isolated compounds with triptolide as positive control (IC₅₀: 1.1 ± 0.4 μM). Huoshanmycins A and B (1, 2) displayed moderate cytotoxicity with IC₅₀ values of 32.9 ± 7.2 and 33.2 ± 6.1 μM, respectively.

Keywords: Dendrobium huoshanense; Streptomyces; endophyte; huoshanmycin; polyketide.