Efficient Preparation of Bafilomycin A1 from Marine Streptomyces lohii Fermentation Using Three-Phase Extraction and High-Speed Counter-Current Chromatography.

Ye Yuan,Xingwang Zhang,Weiyan Zhang,Shan He,Xiaoping He,Xiaoqing Xu,Xiaojun Yan,Zhong Li,Shengying Li,Tingting Wang

doi:10.3390/md18060332

Abstract

An efficient strategy was developed for the rapid separation and enrichment of bafilomycin A1 (baf A1) from a crude extract of the marine microorganism Streptomyces lohii fermentation. This strategy comprises liquid−liquid extraction (LLE) with a three-phase solvent system (n-hexane–ethyl acetate–acetonitrile–water = 7:3:5:5, v/v/v/v) followed by separation using high-speed counter-current chromatography (HSCCC). The results showed that a 480.2-mg fraction of baf A1-enriched extract in the middle phase of the three-phase solvent system was prepared from 4.9 g of crude extract after two consecutive one-step operations. Over 99% of soybean oil, the main hydrophobic waste in the crude extract, and the majority of hydrophilic impurities were distributed in the upper and lower phase, respectively. HSCCC was used with a two-phase solvent system composed of n-hexane–acetonitrile–water (15:8:12, v/v/v) to isolate and purify baf A1 from the middle phase fraction, which yielded 77.4 mg of baf A1 with > 95% purity within 90 min. The overall recovery of baf A1 in the process was determined to be 95.7%. The use of a three-phase solvent system represents a novel strategy for the simultaneous removal of hydrophobic oil and hydrophilic impurities from a microbial fermentation extract.

Highlights

Bafilomycin A1 is a 16-membered ring macrolide antibiotic that was first isolated from Streptomyces griseus in 1983 [1,2]
This study describes a novel and efficient method for the rapid enrichment and separation of bafilomycin A1 (baf A1) from oils and crude extract of marine S. lohii fermentation broth
Compared with classical liquid two-phase extractions and column chromatography, this method is based on a three-phase solvent system capable of very efficiently removing residual soybean oil and most other impurities in the crude extract

Summary

Introduction

Bafilomycin A1 (baf A1) is a 16-membered ring macrolide antibiotic that was first isolated from Streptomyces griseus in 1983 [1,2]. Baf A1 is potential agent for the treatment of osteoporosis and tumors, because it is an effective inhibitor of both vacuolar H+ -ATPase (V-ATPase) [3]. Baf A1 was restricted from becoming a clinical drug due to its marked toxicity to mammalian cells [4]. To lower the toxicity and optimize the pharmacological properties through medicinal chemistry approaches for further drug development, the cost-effective generation of the structurally complex baf A1 supply is important, even though continued efforts on the total synthesis and semi-synthesis of bafilomycin derivatives were made [7,8,9]

Methods

Results

Conclusion