Paraverrucsins A-F, Antifeedant, and Antiphytopathogenic Polyketides from Rhizospheric Paraphaeosphaeria verruculosa and Induced Bioactivity Enhancement by Coculturing with Host Plant Dendrobium officinale

Ming Hu; Xue-Qiong Yang; Cui-Fang Wang; Tong-De Zhao; Dai-Li Wang; Ya-Bin Yang; Zhong-Tao Ding

doi:10.1021/acsomega.0c04548

Paraverrucsins A-F, Antifeedant, and Antiphytopathogenic Polyketides from Rhizospheric Paraphaeosphaeria verruculosa and Induced Bioactivity Enhancement by Coculturing with Host Plant Dendrobium officinale

ACS Omega. 2020 Nov 17;5(47):30596-30602. doi: 10.1021/acsomega.0c04548. eCollection 2020 Dec 1.

Authors

Ming Hu^{1

2}, Xue-Qiong Yang^{1

2}, Cui-Fang Wang^{1

2}, Tong-De Zhao^{1

2}, Dai-Li Wang^{1

2}, Ya-Bin Yang^{1

2}, Zhong-Tao Ding^{1

2}

Affiliations

¹ Functional Molecules Analysis and Biotransformation Key Laboratory of Universities in Yunnan Province, Yunnan University, 2nd Cuihu North Road, Kunming 650091, China.
² Key Laboratory of Medicinal Chemistry for Natural Resource, Ministry Education and Yunnan Province, School of Chemical Science and Technology, Yunnan University, 2nd Cuihu North Road, Kunming 650091, China.

Abstract

Six new polyketides named paraverrucsins A-F (1-6) with oxabicyclic and dioxatricyclic skeletons, together with eight known metabolites (7-14), were discovered and isolated from the fermentation medium of Paraphaeosphaeria verruculosa. Paraverrucsin A-C possessed a novel decarboxylated skeleton compared with that of trichocladinols. Their structures were elucidated by extensive spectral analysis and DP4+ calculations. Paraverrucsins B/C and D/E were isolated as a mixture for the mutarotation occurred at C-2. Paraverrucsins B/C, D/E, F/trichocladinol B, 8, and 9 displayed antifeedant activities against silkworm larvae, with antifeedant index percentages ranging from 62.5 to 93.0%, at a concentration of 50 μg/cm². Among them, Paraverrucsins B/C and 9 had EC₅₀ values at 13.9 and 18.2 μg/cm². Most compounds showed antifungal activities against phytopathogenic fungi with minimum inhibitory concentration (MIC) values of 16-64 μg/mL. Coculture of P. verruculosa and host plant Dendrobium officinale leads to the enhancement of antifeedant and antiphytopathogenic activities. Compounds 1, 2/3, 4/5, 6/14 were tested for cytotoxicity against five human carcinoma cell lines, HL-60, A549, MCF-7, SW480, and SMMC-7721, while they exhibited selected cytotoxicity against SW480 with inhibition ratios of 32-38% at a concentration of 40 μM.