Isolation and Characterization of Batatasin III and 3,4’- Dihydroxy-5-methoxybibenzyl: A Pair of Positional Isomers from &lt;i&gt;Sunipia scariosa&lt;/i&gt;

Jz Yang,Ym Zhang,H Jiang,Yg Chen,Wj Wang,Y Liu

doi:10.4314/tjpr.v13i4.7

Abstract

Purpose : To isolate and characterize chemical compounds of biological importance from the whole plant of Sunipia scariosa. Methods : The whole plant of Sunipia scariosa was extracted with methanol (MeOH) and chromatographed on silica gel and sephadex LH-20 to afford the pure isolates. High perfomance liquild chromatography (HPLC) was used for further purification of the isolated compounds. Characterization of the isolated compounds was achieved by 1H and 13C nuclear magnetic resonance spectroscopy (NMR) and mass spectrometry (MS). Results : Batatasin III (3,3’-dihydroxy-5-methoxybibenzyl) and 3,4’-dihydroxy-5-methoxybibenzyl, a pair of positional isomers, were isolated from the whole plant of Sunipia scariosa. The yields of the two isomers were 60 and 40 %, respectively, from the mixture of two compounds. Conclusion : Batatasin III and 3,4’-dihydroxy-5-methoxybibenzyl, a pair of positional isomers were successfully isolated from the whole plant of Sunipia scariosa for the first time. Keywords : Sunipia scariosa, Batatasin III, 3,4’-Dihydroxy-5-methoxybibenzyl, Isomers

Highlights

Bibenzyls are regarded as important secondary metabolites occurring exclusively in the plants of Orchidaceae, which is distributed in both tropical and subtropical regions of the world, and comprises of about 700 genus and 20000 species [1]
Batatasin III (3,3’-dihydroxy-5-methoxybibenzyl, Fig 1), the most common bibenzyl isolated from many Orchidaceae plants, shows spasmolytic, allelopathic and inhibitory activities on germination and radicle growth [10,11,12,13]. 3,4’dihydroxy-5-methoxybibenzyl, a positional isomer of batatasin III displays phytotoxic activity [11,13] but both are rarely obtained from a plant simultaneously
In the course of our search for new bioactive compounds from the whole plant of S. scariosa, we study the plant and isolated batatasin III and 3,4’-dihydroxy-5-methoxybibenzyl, a pair of positional isomers from the plant

Summary

INTRODUCTION

Bibenzyls are regarded as important secondary metabolites occurring exclusively in the plants of Orchidaceae, which is distributed in both tropical and subtropical regions of the world, and comprises of about 700 genus and 20000 species [1]. Batatasin III (3,3’-dihydroxy-5-methoxybibenzyl, Fig 1), the most common bibenzyl isolated from many Orchidaceae plants, shows spasmolytic, allelopathic and inhibitory activities on germination and radicle growth [10,11,12,13]. In the course of our search for new bioactive compounds from the whole plant of S. scariosa, we study the plant and isolated batatasin III and 3,4’-dihydroxy-5-methoxybibenzyl, a pair of positional isomers from the plant. The fourth fraction (1.84 g, petroleum ether/acetone, 5:1, v/v portion) was purified by column chromatography, first on silica gel (CHCl3/MeOH: 1:0→0:1) to afford 7 fractions, and the third fraction (293 mg, CHCl3/MeOH, 50:1, v/v portion) was purified on Sephadex LH-20 (CHCl3/MeOH: 3:2) to yield a mixture of two isomers (145 mg), which was further purified on semi-preparative HPLC using MeOH–H2O (v/v, 9:11) at 1.0 mL/min to yield 1 (41 mg) and 2 (27 mg). MS were determined on an API Qstar Pulsa LC/TOF mass spectrometer, and NMR spectra were measured on a Bruker DRX-500 spectrometer with CD3OD as solvent

RESULTS

DISCUSSION

CONCLUSION