ABSTRACT
Two new species of Oreocharis Benth. from Fan Si Pan, the highest mountain in Vietnam (Sa Pa) are described and illustrated. Oreocharis grandiflora W.H.Chen, Q.H.Nguyen & Y.M.Shui, is similar to O. flavida Merr. from Hainan province, China, but differs mainly by its larger and infundibuliform corolla, stamens adnate to the base of the corolla tube and stamens coherent in two pairs. The second, Oreocharis longituba W.H.Chen, Q.H.Nguyen & Y.M.Shui, is similar to O. hirsuta Barnett, endemic to northern Thailand, but mainly differs in its pubescence, coherent stamens and glabrous filaments.
ABSTRACT
The chemical compositions of essential oils obtained by hydrodistillation from leaves and stems of Xyloselinum vietnamense and X. leonidii, two new species belonging to the family Apiaceae, were analyzed by GC-MS. The major components in both species were sabinene, alpha- and beta-pinene, myrcene, beta-phellandrene, (Z)-beta-ocimene, and terpinen-4-ol. The monoterpene sabinene was most abundant in the leaves of X. vietnamense (75.0%). These compounds might be considered as chemotaxonomic markers of Xyloselinum species. In the DPPH radical scavenging assay, all four essential oils showed moderate activity, while the water extracts exhibited stronger effects. The strong DPPH scavenging activity of the water residues of X. vietnamens and X. leonidii might be due to their phenolic components. This paper is the first report on the chemical compositions and antioxidant activity of X. vietnamens and X. leonidii.
