Heterocyclic compounds from the fruits of Morus alba L. and their anti-angiogenesis activities

 

The mulberry tree (Morus alba L.) is mostly found in semitropical region and has been harvested in East-Asia, especially in Korea. The fruits of M. alba (Moraceae) have been used for a variety of illnesses, especially to treat arthritis, rheumatism and diabetes in Korean traditional medicines [1]. Previous phytochemical investigations on the fruits of M. alba reported the present of a number of lignans, flavonoids, benzofuran derivatives, and phenolic constituents [2 – 5]. Some of the compounds showed a variety of biological activities including antioxidant, cytotoxicity, anti-inflammatory, and antibiotic effects[2,3]. However, there has been rarely reported on bioactive heterocyclic compounds from the fruits of M. alba. In an effort to search for the bioactive compounds from Korean indigenous plants, we investigated a MeOH extract of the fruits of M. alba, which led to the isolation of one new oxolane derivative (1) together with five known compounds (2 – 6). The structures of isolated compounds were identified by spectroscopic methods including ¹H NMR, ¹³C NMR, 2D NMR, and MS analysis. To the best our knowledge, compound 6 is reported for the first time as a natural product in this study, though it has been reported as a synthetic product. In addition, all isolated compounds were examined for their inhibitory effects on angiogenesis in HUVECs. The action mechanism of compound 3 was identified on the basis of western blot results.

Acknowledgements: This research was supported by Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Science, ICT & Future Planning (2015R1C1A1A02037383).

Keywords: Morus alba, Moraceae, heterocyclic compounds, anti-angiogenesis effect.

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