Chemical constituents and nitric oxide inhibitory activity from the leaves of Osmanthus fragrans lour.

Osmanthus fragrans Lour. is a medicinal plant widely used in several Asian countries, including Vietnam, China, Japan, and Korea.Traditionally, it has been utilized for treating weakened vision, halitosis, panting, asthma, cough, toothache, stomachache, diarrhea, rheumatism, body pain, and hepatitis, as well as being commonly used in tea.However, no studies have been reported on the chemical constituents or pharmacological effects of O. fragrans in Vietnam.A phytochemical study of O. fragrans leaves led to the isolation of six compounds (1-6).Their structures were unambiguously elucidated using a combination of NMR spectroscopic data and high-resolution electrospray ionization mass spectrometry (HR-ESI-MS).Moreover, the NO inhibitory activity was also examined.This is the first study to investigate the chemical constituents and pharmacological effects of O. fragrans collected in Vietnam.