ORIGINAL ARTICLE Pestalols A–E, new alkenyl phenol Q1 and benzaldehyde derivatives from endophytic fungus Pestalotiopsis sp. AcBC2 isolated from the Chinese mangrove plant Aegiceras corniculatum Jian-Fan Sun 1,2,4 , Xiuping Lin 1,4 , Xue-Feng Zhou 1 , Junting Wan 3 , Tianyu Zhang 3 , Bin Yang 1 , Xian-Wen Yang 1 , Zhengchao Tu 3 and Yonghong Liu 1 Five alkenyl phenol and benzaldehyde derivatives, pestalols A-E (1–5), as well as seven known compounds (6–12), were isolated from endophytic fungus Pestalotiopsis sp. AcBC2 derived from the Chinese mangrove plant Aegiceras corniculatum. Their structures were determined by spectroscopic analyses. Compounds 2 and 3 showed cytotoxicity against a panel of 10 tumor cell lines. Compounds 1–5, 8, 9, 11, and 12 showed inhibitory activities against Influenza A virus subtype (H 3 N 2 ) and Swine Flu (H 1 N 1 ) viruses. Compound 2 also showed inhibitory activity against tuberculosis. The Journal of Antibiotics (2014) 0, 000–000. doi:10.1038/ja.2014.24 Keywords: Aegiceras corniculatum; anti-tuberculosis; antiviral; benzaldehyde; cytotoxicity; endophytic fungi; Pestalotiopsis sp. AcBC2 INTRODUCTION Endophytes are microorganisms that spend the whole or part of their life cycle colonizing tissues of their host plants without causing apparent symptoms of disease. There is supposed to be an equili- brium between microorganism virulence and plant defense. In this balanced system, the host plant provides nutrients to the entophytes, and in return, the endophytes produce bioactive substances to enhance the growth and competitiveness of the host in its natural habitat. Thus entophytes have been identified as a prolific source of biologically active small molecules. For example, numerous secondary metabolites with novel structures and biological activities have been characterized from mangrove-derived endophytic fungi. 1 Investigation of the secondary metabolites of microorganisms isolated from mangrove plants residing in niche environments may lead to novel biologically active compounds. 2 Aegiceras corniculatum is a shrub or small tree mangrove of the Myrsinaceae family, with a wide distribution in coastal and estuarine areas of southern China. 3 As part of our ongoing efforts toward the discovery of novel and biologically active natural products from endophytic fungi isolated from the marine mangrove of the Chinese sea coasts, we have investigated the chemical constituents of an endophytic fungal strain Pestalotiopsis sp. AcBC2 that was isolated from the inner tissue of stems of the mangrove plant A. corniculatum collected from Nansha mangrove wetland, Guangdong province, China. This paper describes the isolation, structure elucidation and bioactivities of the isolated compounds. RESULTS AND DISCUSSION Fermentation of Pestalotiopsis sp. AcBC2 was performed in flask liquid culture, was grown in potato-dextrose broth (PDB) media. The EtOAc extracts from the culture broth and the mycelium were fractionated by repeated column chromatography on silica gel, reversed-phase silica gel C 18 and Sephadex LH-20, as well as by preparative TLC, to afford 12 metabolites (1–12) (Figure 1). The gross structures of the compounds were elucidated with the aid of COSY, HMQC and HMBC experiments. Pestalol A (1) was isolated as a yellowish oil. The ESIMS spectrum of 1 displayed a pseudomolecular ion peak at m/z 311 [M þ Na] þ for 1 CAS Key Laboratory of Tropical Marine Bio-resources and Ecology/Guangdong Key Laboratory of Marine Materia Medica/RNAM Center for Marine Microbiology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, People’s Republic of China; 2 School of Environment, Jiangsu University, Zhenjiang, People’s Republic of China and 3 State Key Laboratory of Respiratory Diseases, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou, People’s Republic of China Correspondence: Dr Z Tu, State Key Laboratory of Respiratory Diseases, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou 510530, People’s Republic of China. E-mail: tu_zhengchao@gibh.ac.cn. or Professor Y Liu, CAS Key Laboratory of Tropical Marine Bio-resources and Ecology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, People’s Republic of China. E-mail: yonghongliu@scsio.ac.cn 4 These authors contributed equally to this work. Received 4 December 2013; revised 20 January 2014; accepted 2 February 2014 The Journal of Antibiotics (2014), 1–7 & 2014 Japan Antibiotics Research Association All rights reserved 0021-8820/14 www.nature.com/ja