Novel cyclohexene and benzamide derivatives from marine-associated Streptomyces sp. ZZ502

Abstract

Three new compounds and the known benzamides of 2-acetamido-3-hydroxybenzamide, 2-amino-3-hydroxybenzamide, and 2-aminobenzamide were isolated from the culture of a marine actinomycete Streptomyces sp. ZZ502. Structures of the new compounds were determined as 3-amino-2-carboxamine-6(R)-chloro-4(R),5(S)-dihydroxy-cyclohex-2-en-1-one, 3-amino-2-carboxamine-4(S),6(S)-dihydroxy-cyclohex-2-en-1-one, and 3-hydroxy-2-propionamidobenzamide based on extensive NMR spectroscopical analysis, HRESIMS data, ECD calculation, and X-ray diffraction analysis. None of these isolated compounds showed activity in inhibiting the proliferation of glioma cells nor the growth of methicillin-resistant Staphylococcus aureus, Escherichia coli, and Candida albicans.

Keywords:

• Streptomyces sp. ZZ502
• marine actinomycete
• new compounds
• structure elucidation

Acknowledgements

This study was supported by the National Natural Science Foundation of China (81273428, 81773587, and 81773769). Authors appreciate Dr. Jianyang Pan (Pharmaceutical Informatics Institute of Zhejiang University) for performing NMR spectrometry for structure elucidation and Dr. Jiyong Liu (Department of Chemistry of Zhejiang University) for performing the X-ray diffraction analysis. We also thank Professors Zhongjun Ma, Pinmei Wang, and Bin Wu (Ocean College of Zhejiang University) for the gifts of methicillin-resistant Staphylococcus aureus ATCC 43300, Escherichia coli ATCC 25922, and Candida albicans.

Disclosure statement

No potential conflict of interest was reported by the authors.