Isolation, Characterization, and NO Inhibitory Activities of Sesquiterpenes from Blumea balsamifera

Blumea balsamifera belongs
to the
family Compositae, and its leaves have been used as a flavoring ingredient
and a tea. A phytochemical investigation of the aerial parts of B. balsamifera led to the isolation of 10 new (1–10) and 1 known (11) sesquiterpenes.
Their structures were elucidated on the basis of extensive one- and
two-dimensional nuclear magnetic resonance (heteronuclear multiple-quantum
coherence, heteronuclear multiple-bond correlation, 1H–1H correlation spectroscopy, and nuclear Overhauser effect
spectrometry) spectroscopic data analyses, and the structure of compound 1 was confirmed by X-ray crystallography. The inhibitory activities
on lipopolysaccharide-induced NO production in murine microglial BV-2
cells of these sesquiterpenes were evaluated, and all of the compounds
showed inhibitory effects.