Rhodomyrtus tomentosa (Aiton) Hassk, a representative specimen of the genus Rhodomyrtus and commonly known as rose myrtle, is an abundant flowering evergreen shrub growing in southern and southeastern Asia, particularly in southern China. It has been reputed for the medical uses of its leaves and the nutriceutical properties of the edible bell-shaped fruits. In traditional Chinese medicine, R. tomentosa has conventionally been served as a highly active agent to treat colic diarrhoea, dysentery, abscesses, haemorrhage, and gynecopathy.
Dr. Hongxin Liu and Haibo Tan from the Program of Natural Product Chemical Biology, headed by Prof. Shengxiang Qiu of South China Botanical Garden, conducted the systematic investigation on the leaves of R. toemtnosa with an aim to uncover natural products with novel structures and promising anti-MRSA activities, which resulted in the discovery of a series of hetero-dimer composed acylphloroglucinols with monoterpene (pinene-type: tementosenol A) or sesquiterpene (caryophyllene-type: tementodiones A-B and rhodomentones A-B) moieties. Absolute configurations of these novel compounds were determined by 1D and 2D NMR techniques and X-ray crystallographic analysis. It is noteworthy that tementosenol A and tomentosone C were found to exhibit potent antibacterial activity with a MIC value of 4.74 and 5.8 μM, respectively. Furthermore, in order to confirm the structure and obtain sufficient amounts of these new compounds for detailed biological evaluation and mechanic study,, total synthesis of these new compounds were also luanched and complished with success.. These results were published in RSC Advances (2016, 6, 25882-25886; 2016, 6, 48231-48236), Organic & Biomolecular Chemistry (2016, 14, 7354-7360), and Journal of Asian Natural Products Research (2016, 6, 535-541).
This project was funded by the National Science and Technology Major Projects of China (2014ZX10005002-005), National Natural Science Foundation of China (NSFC) (No. 81502949), Guangdong Province Science Natural Science Foundation of Guangdong Province (2015A030310482, 2016A030313149) and Technology Project (2016A010105015) .
