The antimicrobial activity and essential oil constituents of the leaves and trunks of Aquilaria banaensis P.H.Hô (Thymelaeceae) from Vietnam.

The aim of the present paper was to report the chemical constituents and antimicrobial activity of essential hydrodistilled from the leaves and trunk of Aquilaria banaensis P.H.Hô (Thymelaeceae) from Vietnam. The essential oils were analysed comprehensively for their constituents by using Gas chromatography coupled with Mass spectrometry (GC/MS). The antimicrobial activity was determined by agar well diffusion and broth microdilution methods. The leaf essential oil comprised mainly of sesquiterpenes while fatty acids constitutes the bulk of the trunk essential oil. The main constituents of the leaf essential oil were ß-caryophyllene (17.11%), α-selinene (10.99%), α-humulene (8.98%), ß-selinene (8.01%), ß-guaiol (6.69%) and ß-elemene (5.65%). However, hexadecanoic acid (48.46%), oleic acid (19.80%) and tetradecanoic acid (5.32%) were the major compounds identified in the trunk essential oil. The trunk essential oil displayed antimicrobial activity against Staphylococcus aureus, with the minimum inhibitory concentration (MIC) value of about 256.0 µg/mL.

Chemical composition and antimicrobial activity of essential oil from Popowia pisocarpa (Bl.) Endl., Walp. Repert. (Annonaceae).

The volatile compositions and antimicrobial activity of aerial parts of Popowia pisocarpa from Vietnam were reported for the first time. From the GC/MS spectral, spathulenol (35.9%), bicyclogermacrene (5.7%) and muurola-4,10(14)-dien-1ß-ol (4.2%) among the sesquiterpenoids, along with 4,4-dimethyl-3-(3-methylbut-3-enylidene)-2-methylenebicyclo[4,1,0]heptane (17.7%), an unsaturated cyclic compound, were the main constituents of the essential oil. Monoterpenoids were not identified in the essential oil. The essential oil displayed antimicrobial activity against the Gram-negative Escherichia coli ATCC 25922 with MIC value of 16.0 µg/mL and IC50 value of 8.52 µg/mL. In addition, the essential oil also exhibited activity towards the Gram-positive bacteria of Staphylococcus aureus ATCC 13709, Bacillus subtilis ATCC 6633, and Lactobacillus fermentum N4 with MIC value of 64.0 µg/mL each and corresponding IC50 values of 11.06 µg/mL, 26.47 µg/mL and 15.68 µg/mL, respectively. The essential oil did not inhibit the growth of Pseudomonas aeruginosa ATCC 15442, Salmonella enterica and the yeast Candida albicans ATCC 10231.

Chemical composition and acetylcholinesterase inhibitory activity of essential oil from the leaves of Mitrephora poilanei Weeras. & R.M.K. Saunders.

The present study provides the first information on the chemical composition and acetylcholinesterase inhibitory activity of the essential oil (EO) from the leaves of Mitrephora poilanei Weeras. & R.M.K.Saunders from Vietnam. Gas chromatography and gas chromatography-mass spectrometry analysis revealed that the main components of the M. poilanei EO were ß-caryophyllene (13.2%), α-humulene (10.5%), germacrene D (8.1%), ß-elemene (5.2%) and bicyclogermacrene (5.1%). The anti-acetylcholinesterase assay showed that the EO displayed moderate activity with IC50 value of 31.16 ± 3.06 µg/mL. These findings proposed that the plant can be exploited for its anti-acetylcholinestrate potential.

Chemical composition and anti-inflammatory activity of the essential oil from the leaves of Limnocitrus littoralis (Miq.) Swingle from Vietnam.

The oil from the leaves of Limnocitrus littoralis (Miq.) Swingle was obtained by hydrodistillation and investigated by gas chromatography combined with mass spectrometry (GC/MS), the anti-inflammatory effect of the oil was examined on a LPS-induced RAW264.7 cells. An aggregate of forty components were identified, representing 93.0% of the oil. This oil was subjugated by monoterpene hydrocarbons (27.7%), sesquiterpene hydrocarbons (32.3%) and oxygenated sesquiterpenes (4.6%). The significant constituents of L. littoralis essential oil were determined as follows; myrcene (24.9%), γ-muurolene (11.0%), and oleic acid (10.3%). The essential oil of L. littoralis showed activity against the nitric oxide (NO) generation with the IC50 value to 12.50 ± 1.19 µg/L. The anti-inflammatory effect of essential oil from the leaves of L. littoralis is reported for the first time.

Biological activities of essential oil extracted from leaves of Atalantia sessiflora Guillauminin Vietnam.

INTRODUCTION: The present study aimed to determine the chemical compositions and bioactivities of the essential oil of Atalantia sessiflora Guillaumin (A. sessiflora), including antibacterial, antimycotic, antitrichomonas, anti-inflammatory and antiviral effects. METHODOLOGY: The essential oil from leaves of A. sessiflora was extracted by hydrodistillation using a Clevenger apparatus. Chemical compositions of oil were identified by GC/MS. Antimicrobial and antitrichomonas activity were determined by the microdilution method; anti-inflammatory and antiviral were determined by the MTT method. RESULTS: The average yield of oil was 0.46 ± 0.01% (v/w, dry leaves). A number of 45 constituents were identified by GC/MS. The essential oil comprised four main components. The oil showed antimicrobial activities against Gram-positive strains as Staphylococcus; Gram-negative bacteria such as Klebsiella pneumoniae and Escherichia coli; and finally four Candida species. Enterococcus faecalis and Pseudomonas aeruginosa were least susceptible to the oil of A. sessiflora, as seen in their MIC and MLC values over 16% (v/v). Activity against Trichomonas vaginalis was also undertaken, showing IC50, IC90 and MLC values of 0.016, 0.03 and 0.06% (v/v) respectively, after 48 hours of incubation. The oil of A. sessiflora displayed activity against the nitric oxide generation with the IC50 of 95.94 ± 6.18 µg/mL. The oil was completely ineffective against tested viruses, ssRNA+, ssRNA-, dsRNA, and dsDNA viruses. CONCLUSIONS: This is the first yet comprehensive scientific report about the chemical compositions and pharmacological properties of the essential oil of A. sessiflora. Further studies should be done to evaluate the safety and toxicity of A. sessiflora oil.