Extinction Risk Assessment and Chemical Composition of Aerial Parts Essential Oils from Two Endangered Endemic Malagasy Salvia Species.

Seven essential oil samples of two endemic species of Malagasy sage, Salvia sessilifolia Baker and Salvia leucodermis Baker, were investigated via GC(RI), GC-MS and 13C NMR spectrometry. In total, 81compounds were identified accounting for 93.5% to 98.7% of the total composition. The main constituents for the both species were (E)-ß-caryophyllene (29.2% to 60.1%), myrcene (1.2% to 21.7%), α-humulene (5.2% to 19.7%), (E)-nerolidol (0.8% to 15.5%) and caryophyllene oxide (1.4% to 10.8%). Ethnobotanical survey of 46 informants revealed that decoctions of leafy twigs and chewed leaves were usually used. Due to the repeated fires, over-harvesting and grazing, the populations of S. sessilifolia and S. leucodermis are drastically fragmented. These risk factors led to threats to the habitats of the target species. Salvia sessilifolia Baker and Salvia leucodermis Baker are proposed to be classified as endangered species.

Chemical composition of the essential oil from Croton kimosorum, an endemic species to Madagascar.

Croton kimosorum Leandri is an endemic species to Madagascar. The chemical composition of aerial parts, leaf and stem oils is reported for the first time. Analysis was carried out by combination of chromatographic (CC, GC), spectroscopic and spectrometric (MS, 13C NMR) techniques. In total, 76 compounds have been identified. Essential oil isolated from aerial parts contained mainly linalool (21.6%), sabinene (10.4%), 1,8-cineole (6.3%), beta-pinene (6.2%), (E)-beta-caryophyllene (5.9%), terpinen-4-ol (4.8%), geraniol (4,5%) and germacrene D (2.3%). In comparison with the first sample, the composition of leaf and stem oils varied slightly, while essential oil isolated by vapor distillation from a semi-industrial still exhibited similar composition.

Leaf oil from Vepris madagascarica (Rutaceae), source of (E)-anethole.

The volatile components isolated from leaves of Vepris madagascarica (Baillon) H. Perier (Rutaceae), an endemic species of north-eastern, sub-humid forests of Madagascar, were investigated by GC (Retention Indices), GC-MS and 13C NMR spectroscopy. Oil samples obtained on laboratory and industrial scales exhibited similar composition, dominated by phenylpropanoids. (E)-anethole (78.2% and 78.6%) was the major component followed by estragole (15.6% and 15.4%). In addition, trunk bark oil also contained (E)-anethole as its major component (84.6%), as well as various sesquiterpenes in low contents.