Fasihuddin bin Ahmad

Antiplatelet Aggregation and Platelet Activating Factor (PAF) Receptor Antagonistic Activities of the Essential Oils of Five Goniothalamus Species

Nine essential oils, hydrodistilled from different parts of five Goniothalamus species (G. velutinus Airy-Shaw, G. woodii Merr., G. clemensii Ban, G. tapis Miq. and G. tapisoides Mat Salleh) were evaluated for their ability to inhibit platelet aggregation in human whole blood using an electrical impedance method and their inhibitory effects on platelet activating factor (PAF) receptor binding with rabbit platelets using 3H-PAF as a ligand. The chemical composition of the oils was analyzed by gas chromatography (GC) and gas chromatography–mass spectrometry (GC–MS). The bark oil of G. velutinus was the most effective sample as it inhibited both arachidonic acid (AA) and ADP-induced platelet aggregation with IC50 values of 93.6 and 87.7 µg/mL, respectively. Among the studied oils, the bark oils of G. clemensii, G. woodii, G. velutinus and the root oil of G. tapis showed significant inhibitory effects on PAF receptor binding, with IC50 values ranging from 3.5 to 10.5 µg/mL. The strong PAF antagonistic activity of the active oils is related to their high contents of sesquiterpenes and sesquiterpenoids, and the individual components in the oils could possibly produce a synergistic effect in the overall antiplatelet activity of the oils.

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%).

Chemical constituents of the bark oil of Goniothalamus macrophyllus Hook. f. from Malaysia

Abstract The bark oils of Goniothalamus macrophyllus Hook. f., obtained from two different sites, were investigated by capillary GC and GC/MS. The oils were found to possess little differences in the chemical composition but considerable variation in the levels of the individual components. The oils were rich in monoterpenoids (91.8–94.0%), with terpinen-4-ol at 38.8% and 42.7%, respectively, as the dominant component. The major differences between the oils were the presence of appreciable amounts of 1,8-cineole (18.1%), geranyl acetate (11.1%) and geraniol (9.7%) in one sample and relatively low amounts of these compounds in the other sample. However, the latter sample contained signifi cantly higher concentrations of (Z)-β-ocimene (25.4%) and α-terpineol (10.0%).

Constituents of the Rhizome Oil of Hedychium cylindricum Ridl.

Abstract The chemical composition of the rhizome oil of Hedychium cylindricum Ridl. was determined by GC retention indices (on two columns of different polarity) and GC/MS. Forty-nine compounds were identified with monoterpernoids accounting for more than 88% of the oil. The major constituents of the oil were terpinen-4-ol (40.5%), sabinene (9.9%), p-cymene (8.5%), limonene (6.0%), (β-pinene (5.6%), γ-terpinene (4.5%), and α-terpineol (2.2%).

Antioxidant and antimicrobial properties of Litsea elliptica Blume and Litsea resinosa Blume (Lauraceae).

OBJECTIVEnTo investigate antioxidant and antimicrobial activities of two plant species, Litsea elliptica (L. elliptica) and Litsea resinosa (L. resinosa).nnnMETHODSnIn vitro method-2,2-diphenyl-1-picrylhydrazyl radical scavenging assay was conducted for antioxidant activity determination while antimicrobial assay consisted of agar well diffusion assay and mycelial radial growth assay.nnnRESULTSnMethanol extracts of root and stem of L. elliptica and L. resinosa exhibited the highest antioxidant activity with EC50 of 23.99, 41.69, 11.22 and 35.48 mg/L respectively. All methanol extracts of L. resinosa as well as root extracts from L. elliptica showed significant scavenging activity. Hexane extract from stem of L. resinosa presented the largest inhibition zone in Gram-negative bacteria Pseudomonas aeruginosa and Escherichia coli while chloroform extract from inner bark of L. resinosa showed major inhibition towards Gram-positive bacteria Bacillus subtilis. Essential oils from the root of both species showed significant antifungal activities which are 80.11% and 66.85% respectively.nnnCONCLUSIONSnOverall, methanol extracts from root and stem of both species showed antioxidant activity comparable to standard butylated hydroxytoluene. Extracts from L. resinosa demonstrated stronger antimicrobial properties compared to that from L. elliptica.

n-Butyl­dichlorido(2-{(1E)-1-[2-(pyridin-2-yl)hydrazin-1-yl­idene]eth­yl}phenolato)tin(IV)

Two independent molecules comprise the asymmetric unit of the title compound, [Sn(C4H9)(C13H12N3O)Cl2]. The Sn atom in each is coordinated by the tridentate ligand via the phenoxide O, hydrazine N and pyridyl N atoms, forming five- and six-membered chelate rings. The approximately octahedral coordination geometry is completed by the α-C atom of the n-butyl group (which is trans to the hydrazine N atom) and two mutually trans Cl atoms. Differences between the molecules are evident in the relative planarity of the chelate rings and in the conformations of the n-butyl groups [C—C—C—C = 177.2u2005(5) and −64.4u2005(11)°]. Significant differences in the Sn—Cl bond lengths are related to the formation of N—H⋯Cl hydrogen bonds, which link the molecules comprising the asymmetric unit into dimeric aggregates. These are consolidated in the crystal packing by C—H⋯Cl contacts. The structure was refined as an inversion twin; the minor twin component is 37u2005(3)%.