Novel ent-Beyeran-19-oic Acids from Biotransformations of Isosteviol Metabolites by Mortierella isabellina

Che-Ling Lin; Shwu-Jiuan Lin; Wei-Jan Huang; Yuan-Ling Ku; Tung-Hu Tsai; Feng-Lin Hsu

doi:10.1055/s-2007-993756

Planta Medica, Table of Contents

Planta Med 2007; 73(15): 1581-1587
DOI: 10.1055/s-2007-993756

Natural Product Chemistry

Original Paper
© Georg Thieme Verlag KG Stuttgart · New York

Novel ent-Beyeran-19-oic Acids from Biotransformations of Isosteviol Metabolites by Mortierella isabellina

Che-Ling Lin¹ ^, ² , Shwu-Jiuan Lin² , Wei-Jan Huang³ ^, ⁵ , Yuan-Ling Ku⁴ , Tung-Hu Tsai¹ , Feng-Lin Hsu² ^, ⁵

¹Institute of Traditional Medicine, National Yang-Ming University, Taipei, Taiwan
²School and Graduate Institute of Pharmacy, College of Pharmacy, Taipei Medical University, Taipei, Taiwan
³Chia-Yi School, Chang Gung Institute of Technology, Chiayi, Taiwan
⁴Medical and Pharmaceutical Industry Technology and Development Center, Taipei, Taiwan
⁵Graduate Institute of Pharmacognosy, College of Pharmacy, Taipei Medical University, Taipei, Taiwan

Abstract

Biotransformations of ent-16β-hydroxybeyeran-19-oic acid (1) by Mortierella isabellina produced hydroxylated metabolites. The isolated metabolites included three new compounds, ent-14β,16β-dihydroxybeyeran-19-oic acid (3), ent-12β-hydroxy-16-oxobeyeran-19-oic acid (4), and ent-7α,12β-dihydroxy-16-oxobeyeran-19-oic acid (5), and one known compound, ent-7α,16β-dihydroxybeyeran-19-oic acid (2). The structural elucidation was achieved by detailed analysis of LC-MS chromatograms, and MS and NMR spectroscopic data. In this study, M. isabellina hydroxylated the basic skeleton beyeran-19-oic acid at the 7β-, 12α-, and 14α-positions, and oxidized the skeleton at the 16-position. All compounds were evaluated with the cell viability assay. The results of the bioassay indicated that MTT formazan exocytosis occurs upon treatment of the cells with 1.

Key words

ent-16β-Hydroxybeyeran-19-oic acid - Mortierella isabellina - microbial biotransformations - hydroxylation - stevioside - isoteviol - MTT formazan exocytosis

Full Text

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Prof. Dr. Feng-Lin Hsu

Graduate Institute of Pharmacognosy

College of Pharmacy

Taipei Medical University

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