Analysis of essential oil constituents of three Dasymaschalon species (Annonaceae) from Vietnam

Biologically Active Constituents from Plants of the Genus Desmos

The combination of traditional knowledge of medicinal plants with scientific rationale has yielded positive results in recent years. Bioactive compounds isolated from herbaceous plants have long been used as drugs that benefit human health, as well as providing useful compounds for drug development lead compound optimization. This chapter aims to provide a systematic overview of the structural types of Desmos secondary metabolites, along with their biological potential. Various chromatographic and spectroscopic methods have been utilized for isolating, purifying, and elucidating the structures of compounds from Desmos species. From 1982 to the present time, more than 200 metabolites have been isolated from members of this genus. Desmos spp. constituents include terpenoids, phytosterols, polyoxygenated cyclohexanes and cyclohexenes, oxepinones, fatty acids, with flavonoids, alkaloids, and miscellaneous phenols being the predominant compounds. The essential oils of Desmos species have also been investigated. Both crude plant extracts and isolated compounds from this genus have been evaluated for their biological activities. Desmos constituents have been found to exhibit cytotoxic, antimicrobial, antioxidative, anti-inflammatory, and aromatase and NFAT transcriptive inhibition effects.

In vitro Antimicrobial Activity of Essential Oil Extracted from Leaves of Leoheo domatiophorus Chaowasku, D.T. Ngo and H.T. Le in Vietnam

:The present study aimed to determine the antimicrobial activity and chemical composition of leaves-extracted essential oil of Leoheo domatiophorus Chaowasku, D.T. Ngo and H.T. Le (L. domatiophorus), including antibacterial, antimycotic, antitrichomonas and antiviral effects. The essential oil was obtained using hydrodistillation, with an average yield of 0.34 ± 0.01% (v/w, dry leaves). There were 52 constituents as identified by GC/MS with available authentic standards, representing 96.74% of the entire leaves oil. The essential oil was comprised of three main components, namely viridiflorene (16.47%), (-)-δ-cadinene(15.58%) and γ-muurolene (8.00%). The oil showed good antimicrobial activities against several species: Gram-positive strains: Staphylococcus aureus (two strains) and Enterococcus faecalis, with Minimum Inhibitory Concentration (MIC) and Minimum Lethal Concentration (MLC) values from 0.25 to 1% (v/v); Gram-negative strains such as Escherichia coli (two strains), Pseudomonas aeruginosa (two strains) and Klebsiella pneumoniae, with MIC and MLC values between 2% and 8% (v/v); and finally Candida species, having MIC and MLC between 0.12 and 4% (v/v).Antitrichomonas activity of the oil was also undertaken, showing IC₅₀, IC₉₀ and MLC values of 0.008%, 0.016% and 0.03% (v/v), respectively, after 48h of incubation. The essential oil resultedin being completely ineffective against tested viruses, ssRNA+ (HIV-1, YFV, BVDV, Sb-1, CV-B4), ssRNA- (hRSVA2, VSV), dsRNA (Reo-1), and dsDNA (HSV-1, VV) viruses with EC₅₀ values over 100 µg/mL. This is the first, yet comprehensive, scientific report about the chemical composition and pharmacological properties of the essential oil in L. domatiophorus.

Constituents of Essential Oils from Dasymaschalon bachmaensis and Phaeanthus vietnamensis

The present paper reports the volatile compounds identified in the essential oils of Dasymaschalon bachmaensis N.S. Lý, T.H. Lê, T.B. Vương & N.Đ.Đỗ and Phaeanthus vietnamensis Bân (Annonanceae) grown in Vietnam. The essential oils were obtained by hydrodistillation from the leaf, stem and bark of the plants. The combined techniques of gas chromatography (GC) and gas chromatography coupled to mass spectrometry (GC-MS) were used for the analysis of the chemical constituents of the oil samples. The major constituents of the leaf oil of D. bachmaensis were limonene (25.7%), eugenol (11.5%), α-phellandrene (11.3%) and benzyl benzoate (9.0%) while the stem contained benzyl benzoate (35.3%), ( Z)-13-docosenamide (12.4%) and limonene (9.4%) In addition, ( Z)-13-docosenamide (23.2%), limonene (25.3%) and α-phellandrene (11.5%) were present in the bark. However, limonene (31.8%), ( Z)-9-octadecamide (20.2%) and α-phellandrene (13.8%) were the compounds occurring in higher amount in the leaf oil of P. vietnamensis while the bark was dominated by ( Z)-9-octadecamide (57.4%) and benzyl benzoate (15.0%). The volatile constituents of both D. bachmaensis and P. vietnamensis are reported for the first time

Chemical Composition of Vietnamese Essential Oils of Cinnamomum rigidifolium, Dasymaschalon longiusculum, Fissistigma maclurei and Goniothalamus albiflorus

Cinnamomum rigidifolium, Dasymaschalon longiusculum, Fissistigma maclurei and Goniothalamus albiflorus were collected from different landscapes in Vietnam and hydro distilled to produce essential oils with yields from 0.15 – 0.35%. The oils were analyzed by GC-MS-FID and rechecked by measurements on two different instrumentation configurations. The main components of the studied essential oils were for Cinnamomum rigidifolium linalool (19.4%), α-pinene (13.8%), verbenone (9.9%) and cis-verbenol (8.9%), total identified 90.5%; for Dasymaschalon longiusculum spathulenol (21.4%), caryophyllene oxide (17.6%), α-pinene (5.5%) and β-pinene (5.2%), total identified 70.1%; for Fissistigma maclurei spathulenol (17.8%), guaia-6,10(14)-diene-4β-ol (10.3%), (E)-β-caryophyllene (7.3%) and caryophyllene oxide (7.0%), total identified 75.3% and for Goniothalamus albiflorus 1,8-cineole (13.2%), α-pinene (10.6%), ledol (7.5%) and caryophyllene oxide (7.3%), total identified 78.0%.