Comparative study of volatile oil compositions of twoPlectranthusspecies from northern India

Abstract

The leaf and inflorescence essential oils of Plectranthus rugosus Wall. (syn. Rabdosia rugosa Wall.) and Plectranthus incanus L. (syn. Plectranthus mollis L.), which grow wild in Uttarakhand, India, were analysed and compared by capillary gas chromatography and gas chromatography-mass spectrometry. The analysis led to the identification of 43 constituents, forming 89.5-93.6% of the total oil compositions. Both leaf and inflorescence oil of P. rugosus were dominated by sesquiterpene hydrocarbons (71.8%, 71.7%) represented by β-caryophyllene (36.2%, 29.8%), germacrene D (25.2%, 28.2%) and α-humulene (6.6%, 8.6%) as the major constituents. Conversely, the leaf and inflorescence oil of P. incanus were dominated by monoterpenoids (74.4%, 65.8%) with piperitenone oxide (44.2%, 38.5%), piperitone (8.6%, 12.2%) and terpinolene (14.5%, 10.2%) as major constituents. Piperitenone oxide, piperitone, cis- and trans-piperitols and trans-piperitol acetate were the marker constituents in P. incanus, which were not noted in the essential oil of P. rugosus.

In-vitro and in-vivo validation of ethnopharmacological uses of methanol extract of Isodon rugosus Wall. ex Benth. (Lamiaceae)

“…The compounds exhibited DNA protective activity in yeast strains [8,9]. Moreover, the analysis of volatile oil fractions from leaves and inflorescence indicated presence of sesquiterpene hydrocarbons, including β-caryophyllene, germacrene-D and α-humulene as the major constituents [10]. Furthermore, plant extracts and fractions by different solvents exhibited antifungal [5], antibacterial, phytotoxic [11] and antioxidant activities [12].…”

Characterization of the Essential Oil Composition of Isodon rugosus (Wall. ex Benth.) Codd. from Garhwal region of Western Himalaya

“…It is used as an important substance in the manufacture of a variety of synthetic aroma chemicals and its epoxide is isomerised to produce campholenic aldehyde, which is an intermediate for the sandalwood fragrance, santalol [26]. [18,19,21,22]. However, this study identified a total of 92 constituents, which included 40 previously reported constituents.…”

“…Tiwari et al reported β-caryophyllene (38.4%), germacrene D (23.8%), spathulenol (3.2%), α-cadinol (2.2%), p-cymene (3.6%), γ-terpinene (2.8%) and limonene (2.7%) as major constituents of the oil [18]. Similarly, the essential oil of the population collected from Nainital (Kumaon region, western Himalaya) was dominated by sesquiterpene hydrocarbons, represented by β-caryophyllene (29.8-36.2%), germacrene D (25.2-28.2%), α-humulene (6.6-8.6%) and (E)-β-farnesene (2.3-3.8%) as the major constituents [19]. However, recently Irshad et al reported spathulenol (21.0%), β-caryophyllene (10.6%), germacrene D (20.0%), 3-carene (4.8%), myrcene (4.0%), α-myrecene (4.0%) and limonene (2.7%) as major constituents of I. rugosus essential oil [22].…”

“…In addition to these, triterpenoids, namely, plectranthoic acid A and B, acetyl plectranthoic acid and plectranthadiol have also been isolated from the plant [16,17]. Moreover, studies on the essential oil composition indicate the presence of sesquiterpene hydrocarbons, including β-caryophyllene, germacrene-D and α-humulene as the major constituents [18,19]. Despite the multipurpose usage, there exists merger data on the chemical composition of I. rugosus populations growing in temperate Himalayan region.…”

Chemical Composition, Antioxidant and Anti-bacterial Potential of Essential Oil of Medicinal plantIsodon rugosus

“…Thus it is clear that the essential oil of I. rugosus possess excellent antioxidant I % = (A 0 -A)/A 0 x 100 33 . Similarly the same plant collected from different locality from Nainital (Kumaon region, western Himalaya) was showing high amount of sesquiterpene hydrocarbons, β-caryophyllene (29.8-36.2 %), along with α-farnesene (2.3-3.8 %), humulene (6.6-8.6 %) and (E)-β germacrene D (25.2-28.2 %), as the major constituents 34 . Some researchers showed that limonene (2.7 %), α-myrecene (4.0 %), myrcene (4.0 %), 3-carene (4.8 %), germacrene D (20.0 %), spathulenol (21.0 %) and β-caryophyllene (10.6 %), as major component ofessential oil of I. rugosus 35 .…”