Abstract
A new sterol, stigmast-5-ene-3β,17α-diol (1), together with six known compounds, stigmast-5-ene-3β-yl formate (2), stigmast-5-ene-3β,7α-diol (3), stigmast-5-ene-7α-methoxy-3β-ol (4), stigmast-5-ene-3-one (5), 3β-sitostanol (6), and 3β-sitosterol (7), was isolated from the fruits of Syzygium siamense, of which compound 2 is reported for the first time from a natural source. Their structures were elucidated by spectroscopic methods. The isolated compounds (1–7) were evaluated for their cytotoxic activities against human oral epidermoid carcinoma cancer (KB), human breast cancer (BC), and human small cell lung cancer (NCI-H187) cell lines.
Acknowledgements
We are grateful to the Thailand Research Fund, the Commission on Higher Education (Grant No. MRG5280148), and Prince of Songkla University for the financial support. We would like to extend our appreciation to Assistant Professor Dr Surat Laphookhieo, School of Science, Mae Fah Luang University for giving valuable suggestions and to Dr Sergey Novikov, Faculty of Science and Industrial Technology, Prince of Songkla University for English editing.