Abu Said Ahmad

Chemical Composition of the Rhizome Oils of Four Curcuma Species from Malaysia

Abstract The chemical composition of the rhizome oils of four Malaysian Curcuma species (Curcuma mangga, C. xanthorrhiza, C. aeruginosa and C. domestica) was determined by co-chromatography with authentic samples on two columns of different polarity, GC/MS and linear retention indices. Myrcene (81.4%) was the most abundant component in the oil of C. mangga. The oil of C. xanthorrhiza was made up mainly of sesquiterpenoids of which xanthorrhizol (44.5%) was the major constituent. 1,8-Cineole (23.2%) and curzerenone (28.4%) were the predominant constituents of the oil of C. aeruginosa. The oil of C. domestica contained significant amounts of α-tumerone (45.3%), linalool (14.9%) and β-tumerone (13.5%).

Chemical composition of some citrus oils from Malaysia

ABSTRACT The chemical composition of the peel and leaf oils of four Malaysian Citrus species (C. hystrix D.C., C. aurantifolia Swingle, C. maxima Merr. and C. microcarpa Bunge) was examined by co-chromatography, two columns of different polarity, GC/MS and linear retention indices. β-Pinene and limonene were the major constituents of the peel oils of C. hystrix (39.3% and 14.2%) and C. aurantifolia (28.4% and 39.3%). The peel oils of C. maxima and C. microcarpa were found to be rich in limonene (>94%). Citronellal at 72.4% was the most abundant compound in the leaf oil of C. hystrix. The major components of the leaf oil of C. aurantifolia were geranial (19.4%), limonene (16.4%) and neral (11.4%). Sesquiterpenes were present at 70.8% in the leaf oil of C. microcarpa where hedycaryol (19.0%), β-sesquiphellandrene (18.3%) and α-eudesmol (14.4%) were the major constituents. The leaf oil of C. maxima contained significant amounts of phytol (23.1%) and β-caryophyllene (15.4%).

A Comparative Study of the Constituents of the Essential Oils of Three Cinnamomum Species from Malaysia

Abstract The chemical composition of the leaf and bark oils of three Cinnamomum species (C. altissimum Kosterm., C. scortechinii Gamb. and C. microphyllum Ridl.) was examined by co-chromatography with authentic samples on two columns of different polarity, GC/MS and linear retention indices. The leaf and bark oils of C. altissimum were made up mainly of sesquiterpenoids (65.6% and 74.5%). Spathulenol (16.1%) was the major component of C. altissimum leaf oil, while linalool (25.3%) was the most abundant component in the bark oil. Many sesquiterpenoids were also found in the leaf and bark oils of C. scortechinii. However, linalool was the most abundant component, constituting 25.4% and 10.6% of the leaf and the bark oils, respectively. The leaf and bark oils of C. microphyllum are potential natural sources of benzyl benzoate since it constituted up to 90.0% and 92.7% of the leaf and bark oils, respectively.

Constituents of the Rhizome and Seed Oils of Greater Galangal Alpinia galangal (L.) Willd. from Malaysia

Abstract The galangal oils distilled from the rhizomes and seeds of Alpinia galanga (L.) Willd. from Malaysia were examined by capillary GC and GC/MS. The rhizome oil was rich in 1,8-cineole (40.5%). Other compounds that were found in appreciable amounts in the oil were the sesquiterpenoids, β-bisabolene (8.4%), (Z,E)-farnesol (3.8%), β-caryophyllene (3.6%) and (E)- β-farnesene (3.2%). The seed oil was characterized by its richness in sesquiterpenoids with the major ones being β-bisabolene (37.6%), (E)- β-farnesene (22.7%), (E,E)-farnesyl acetate (7.9%), (Z,E)-farnesol (3.9%) and β-caryophyllene (3.0%).

A Comparative Study of the Composition of the Leaf Oils of Three Litsea species from Borneo

Abstract The chemical components of the leaf oils of Litsea resinosa Bl., L. gracilipes Hook. f. and L. paludosa Koesterm. were identified by co-chromatography with authentic samples on two capillary columns of different polarity, GC/MS and linear retention indices. The leaf oils were made up mainly of sesquiterpenoids. The oil of L. resinosa could be differentiated from the other samples due to its high contents of bulnesol (14.9%), β-caryophyllene (10.2%), β-elemene (10.2%) and other sesquiterpenoids. Ledene (9.0%) and aromadendrene (8.3%) were the major constituents in the leaf oil of L. gracilipes. Of the Litsea oils studied, this oil contained the highest concentrations of monoterpenoids with p-menth-1-en-9-ol (1.4%) as the major representative. The leaf oil of L. paludosa was found to possess some compositional similarities to the leaf oil of L. gracilipes but it could be distinguished from the latter by the significant presence of elemol (7.7%), γ-cadinene (2.9%), γ-eudesmol (2.8%), selin-11-en-4α-ol (2.3%), α-cadinene (2.1%), palustrol (1.7%) and selina-3,7(11)-diene (1.1%).

Constituents of the essential oil of Baeckea frutescens L. from Malaysia

The leaf oils of Baeckea frutescens L., water-distilled from samples obtained from four different sites, were analysed by capillary GC and GC–MS. The oils were found to possess some compositional differences and considerable variation in the levels of each component, suggesting the existence of chemical varieties. The oils were rich in pinenes (39.9–55.5%), with the exception of one sample which contained γ-terpinene at 34.1% as the dominant component. 1,8-Cineole, which was present in appreciable amounts in three samples, was conspicuously absent in one sample. Other compounds that were found as the main components of most of the samples were p-cymene, limonene, linalol, α-terpineol, β-caryophyllene and α-humulene.

Constituents of the leaf and bark oils of Cinnamomum subavenium Miq.

Abstract The leaf and bark oils of Cinnamomum subavenium Miq. were analyzed by capillary GC and GC/MS. The oils were found to possess some compositional similarities but considerable variation in the levels of each component. The major components of the leaf oil were patchouli alcohol (27.7%) and benzyl benzoate (19.6%). Other compounds that were present in appreciable amounts in the oil were β-selinene (7.2%), geraniol (3.6%) and linalool (2.9%). The bark oil was characterized by the presence of higher concentrations of α-terpineol (9.7%) and linalool (7.5%) and relatively lower amounts of patchouli alcohol (10.5%) and benzyl benzoate (0.5%).

A Comparative Study of the Oleoresins of Three Pinus Species from Malaysian Pine Plantations

Abstract Distillation of the oleoresins tapped from three Pinus species (P. caribaea Morelet var. hondurensis Barrett et Golfari, P. merkusii Jungh and P. insularis Endl.) at several plantations in peninsular Malaysia yielded turpentine in the range of 25.0–38.8% (v/w). The chemical composition of the turpentine and rosin were examined by co-chromatography with authentic samples on two columns of different polarity, by capillary GC/MS and retention indices. Turpentine derived from the same species at different sites showed little tree-to-tree variation in the chemical composition but with marked variation in the quantity of some components. All oils contained typical turpentine constituents, with α-pinene as the major component in the range of 65–94%. The resin acid composition of the rosin of similar species from different sites was very similar. The major components of the rosin were levopimaric/palustric acid, which were in the range of 36.0–43.9% in P. var. hondurensis, 30.6–35.7 % in P. merkusii and 35.2–45.1% in P. insularis.

Constituents of the leaf oil of Cinnamomum pubescens Kochummen

Abstract The chemical composition of the leaf oil of Cinnamomum pubescens Kochummen was examined by GC with authentic samples on two columns of different polarity, GC/MS and retention indices. Oils hydrodistilled from samples collected from two different sites at different periods were found to possess minor compositional differences but considerable variation in the levels of some components. The oils were rich in benzyl benzoate (46.1–47.1%) and β-phellandrene (14.9–16.4%). The samples could be differentiated from each other in which one sample contained a signifcantly higher concentration of benzyl salicylate and relatively lower concentrations of pinenes and (E)-methyl cinnamate.

Chemical Constituents of the Rhizome Oils of Three Varieties of Scaphochlamys kunstleri (Bak.) Holtt.

Abstract The rhizome oils of three varieties of Scaphochlamys kunstleri (Bak.) Holtt. viz. S. kunstleri (Bak.) Holtt. var. kunstleri, S. kunstleri (Bak.) Holtt. var. rubra Ridl. and S. kunstleri (Bak.) Holtt. var. speciosa C. K. Lim var. nov. were investigated by capillary GC and GC/MS. The oils of S. kunstleri var. kunstleri and S. kunstleri rubra were rich in monoterpenoids and found to possess some compositional similarities but quantitative differences in the concentration of each component. However, the oils could be distinguished from each other by the levels of terpinolene, p-cymen-8-ol, δ-3-carene and p-cymene. In addition, the oil of S. kunstleri var. rubra contained significantly higher concentrations of terpinolene (67.1%) and δ-3-carene and relatively lower concentrations of p-cymen-8-ol and p-cymene than the other two oils. The oil of S. kunstleri var. speciosa comprised mainly of sesquiterpenoids, with (Z)-β-farnesene (7.5%) and γ-cadinene (7.4%) as the major representatives. Geraniol (9.1%) was the most dominant monoterpenoid present in the oil.