Anand B. Melkani

Composition of the Essential Oil of Tanacetum nubigenum Wallich ex DC.

Abstract The oil of Tanacetum nubigenum Wallich ex DC. was analyzed by GC and GC/MS. In addition to 10.7% of sabinene, nearly 44% of the oil of T. nubigenum collected above 3600 m in the Kumaun region of the Indian Himalaya consisted of (-)-cis-chrysanthenol and its esters. The oil also contained ∼3% of esters of exo-6-hydroxycamphor, ∼1.6% 3,6;6,9-bisepoxyfarnesa-l,7(14),10-trienes as well as ∼3.5% of 6,9-epoxyfarnesa-l,7(14),10-trien-3-ols.

Chemical variations in Cymbopogon distans and their chemosystematic implications

Abstract Cymbopogon distans collections from different parts of N. W. Himalayan region of India show four distinct chemotypes. The terpenoid composition, morphological data and chemosystematic significance are discussed.

Steam Volatile Terpenoids from Salvia leucantha

Abstract The essential oil from the aerial parts of Salvia leucantha Cav. (Lamiaceae) was analyzed by GC, GC/MS and NMR spectroscopy. The oil was found rich in sesquiterpene hydrocarbons; β-caryophyllene (13.9%), α-guaiene (12.6%), cis-muurola-3,5-diene (10.8%), germacrene D (13.8%) and bicyclogermacrene (8.7%). Bornyl acetate constituted 23.9% of the oil. This is the first detailed report on the essential oil composition based on capillary GC and GC/MS analyses.

Comparative investigation of the sesquiterpenoids present in the leaf oil of Cymbopogon distans (Steud.) Wats. var. Loharhket and the root oil of Cymbopogon jwarancusa (Jones) Schult

ABSTRACT The leaf oil of Cymbopogon distans (Steud.) Wats, chemotype Loharhket and the root oil of Cymbopogon jwarancusa (Jones) Schult. were examined by GC and GC/MS and found to qualitatively exhibit a very similar sesquiterpenoid composition. The sesquiterpenoid content of the C. Distans and C. Jwarancusa oils was 79.6% and 38.0%, respectively. Most of the sesquiterpenoids were isolated by liquid chromatography and their structures assigned on the basis of their IR, MS, 1H- and 13C-NMR spectra. The main components in C. distans leaf oil were eudesmanediol (34.4%) and 5-epi-7-epi-α-eudesmol (11.2%), while the largest sequiterpenoid component in the root oil of C. jwarancusa was agarospirol (9.5%).

Composition and antibacterial activity of essential oil from Scutellaria grossa Wall ex Benth.

The chemical composition of the steam volatile oil of the whole aerial part of Scutellaria grossa Wall ex Benth. (Lamiaceae), obtained by steam distillation, has been analysed by capillary GC and GC-MS. The oil was found to be rich in oxygenated monoterpenes (88.6%). A total of 50 constituents were identified, representing 94.4% of the total oil composition. Linalool (37.0%) and 1-octen-3-ol (32.0%) were found to be the principal constituents. The antibacterial activity of the oil was determined against 10 bacterial strains by measuring the growth inhibitory zones. The oil showed significant antibacterial activity against Gram-positive bacteria, Bacillus subtilis and Enterococcus faecalis, and the Gram-negative, Klebsiella pneumoniae and Salmonella enterica enterica. A minimum inhibitory concentration of 31.25 µL mL–1 was observed against E. faecalis.

Essential Oil from Nepeta govaniana Benth. Study of its Major Terpenes

Abstract Essential oil from steam distilled whole plants of Nepeta govaniana Benth. gathered in the flowering stage from the Garhwal region of India was examined. The three main components were isolated and identified as pregeijerene (38.4%), (+)-isoiridomyrmecin (16.5%) and 4aα,7α,7aα-nepetalacetone (13.9%). The structure of (+)-isoiridomyrmecin was established by X-ray crystallography. Another 13 compounds (24.5%) were identified by GC/MS.

A eudesmanediol from Cymbopogon distans

Abstract -[2R-(2α,4aβ,8α,8aα)]-Decahydro-8a-hydroxy-α,α4a,8-tetramethyl-2-naphthalenemethanol, isolated from the essential oil of Cymbopogon distans, was studied spectroscopically and identified by means of X-ray diffraction. The absolute configuration was determined based on anomalous scattering from oxygen.

1,10β-Epoxy-6-oxofuranoeremophilane and Other Terpenoids from the Essential Oil of Senecio royleanus DC.

Abstract The composition of the essential oil from whole aerial parts, flowers, leaves and stems of Senecio royleanus collected from sub-alpine region of central Himalaya, India, has been analyzed by GC, GC/MS, NMR spectroscopy and X-Ray diffraction. A total of fifty components were identified representing 95.0–97.3% of the oil. 1,10 b-Epoxy-6-oxofuranoeremophelane constituted the major component (39.4–69.2%) of the oil.

Terpenoid composition of the essential oil from Pimpinella acuminata (Edgew.) CB Clarke

Abstract The essential oils from the roots and aerial parts of Pimpinella acuminata (Edgew.) CB Clarke were analyzed by GC, GC/MS and NMR spectroscopy. The oil from the aerial parts contained β-caryophyllene (12.5%), dill apiole (20.4%) and parsley apiole (39.9%), while the root oil contained myristicin (16.2%), dill apiole (11.3%) and parsley apiole (61.8%) as the major components. This is the frst report of the composition of the oils from the aerial parts and roots of P. acuminata.

Terpenoid Composition and Antimicrobial Activity of the Essential Oil from Salvia nubicola Wall ex Sweet.

Abstract The essential oil of Salvia nubicola Wall ex Sweet. (Lamiaceae) was analyzed by GC and GC/MS. Sixty-four compounds were identified, constituting 94.0% of the oil. The oil was found rich in sesquiterpene hydrocarbons (73.3%). Germacrene D (46.2%) was the principal constituent. Oxygenated sesquiterpenes constituted 12.3% of the oil. The oil showed activity against tested bacterial and fungal strains used, and which was found comparable with the standard antibiotics (Ampicillin, Erythromycin and Clotrimazole) used for comparison.