Three Bianthraquinone Derivatives from the Mangrove Endophytic Fungus Alternaria sp. ZJ9-6B from the South China Sea

Cai-Huan Huang,Bin Chen,Xun Zhu,Yong-Jun Lu,Zhi-Gang She,Hong-Bo Huang,Yong-Cheng Lin,Jia-Hui Pan,Miao Yu

doi:10.3390/md9050832

Abstract

Three new bianthraquinone derivatives, alterporriol K (1), L (2) and M (3), along with six known compounds were obtained from extracts of the endophytic fungus Alternaria sp. ZJ9-6B, isolated from the mangrove Aegiceras corniculatum collected in the South China Sea. Their structures were elucidated by one- and two-dimensional NMR spectroscopy, MS data analysis and circular dichroism measurements. Compounds 1, 2 and 3 were first isolated alterporriols with a C-2–C-2′ linkage. The crystallographic data of tetrahydroaltersolanol B (7) was reported for the first time. In the primary bioassays, alterporriol K and L exhibited moderate cytotoxic activity towards MDA-MB-435 and MCF-7 cells with IC50 values ranging from 13.1 to 29.1 μM.

Highlights

A wide variety of anthraquinone derivatives isolated from plants, animals and marine fungi have served as candidates for various therapeutic uses [1,2,3]
The alterporriol family of bianthraquinone derivatives were first reported from Alternaria porri by Suemitsu et al in 1984 [10]
All the alterporriols except alterporriols G-J were described from Alternaria sp. [5,11,12,13]

Summary

Introduction

A wide variety of anthraquinone derivatives isolated from plants, animals and marine fungi have served as candidates for various therapeutic uses [1,2,3]. Anthraquinones inhibit the proliferation of human breast, colon and lung cancer cells [4]. They displayed inhibitory ability towards protein kinase, NADH oxidase, quinone reductase and calmodulin [5,6,7,8]. The alterporriol family of bianthraquinone derivatives were first reported from Alternaria porri by Suemitsu et al in 1984 [10]. ZJ9-6B has been isolated from the fruit of the marine mangrove Aegiceras corniculatum in Zhanjiang, Guangdong, China. Chemical investigation of this fungus led to the isolation of nine metabolites, including three new anthraquinone derivatives 1–3 and six known compounds 4–9 (Figure 1). We describe the isolation, structural elucidation and biological activity of these new metabolites

Results and Discussion

General

Extraction and Separation of Metabolites

Cytotoxic Assays

Conclusions