Objectives This study aimed to investigate the essential oil extracted from the in continuation of an extensive research on the chemical compositions and biological potentials of essential oils from Vietnamese plants as they are made available, we studied the leaves of Canarium subulatum Guillaumin (Burseraceae) and Illicium petelotii A. C. Smith (Schisandraceae). Methods Chemical compounds in essential oils were identified using GC-FID/MS (gas chromatography-flame ionization detection/mass spectrometry) analysis. The broth microdilution method was used for the antimicrobial assay. The larvicidal activity was evaluated against Aedes aegypti and Culex quinquefasciatus larvae, with lethal concentration (LC50 and LC90) values calculated after 24 and 48 h of exposure. Results The leaves were collected from P & ugrave; Hoat Natural Reserve, Vietnam. From the mass spectral analysis, (E)-caryophyllene (17.0%), alpha-pinene (16.9%), limonene (15.1%), and (E)-beta-ocimene (13.8%) were the major compounds in C. subulatum. Caryophyllene oxide (26.8%), and (Z)-beta-elemene (11.3%) are the significant constituents of I. petelotii. The antimicrobial results showed that I. petelotii exhibited minimum inhibitory concentration (MIC) value of 64.0 mu g/mL against three microbes of namely exhibited Enterococcus faecalis ATCC 29212, Staphylococcus aureus ATCC 25923, and Bacillus cereus ATCC 14579. C. subulatum exhibited MIC value of 128.0 mu g/mL to the mentioned microbes. Both C. subulatum and I. petelotii showed anti-candidal activity at MIC of 64.0 mu g/mL against Candida albicans ATCC 10231. The essential oils of C. subulatum and I. petelotii were toxic against Aedes aegypti with median lethal concentrations (LC50) values of 39.33 mu g/mL and 36.88 mu g/mL, respectively at 24 h. Both samples. Both oil samples displayed larvicidal activity towards Culex quinquefasciatus with LC50 values of 32.60 mu g/mL and 48.94 mu g/mL, respectively, at 24 h. This is the first reported data on C. subulatum and I. petelotii volatile contents, antimicrobial and larvicidal activities. Conclusion This study provides a comprehensive analysis of the chemical composition and biological activities of Canarium subulatum and Illicium petelotii essential oil. The findings highlight its potent antimicrobial and mosquito larvicidal properties. Further research is warranted to explore its mechanisms of action and potential applications in pharmaceuticals and pest control.

The chemical constituents and antimicrobial activity of the essential oil isolated from the rhizomes of Alpinia menghaiensis S.Q. Tong & Y.M. Xia in S.Q. Tong from Vietnam was studied and reported. The techniques of gas chromatography (GC) and gas chromatography coupled with mass spectrometry (GC/MS) were used to characterize the chemical constituents of the essential oil while the microdilution assay was used to evaluate the antimicrobial activity. The main compounds identified in the rhizome essential oil consist of β-pinene (46.5%), β-phellandrene (25.7%) and α-pinene (8.5%). The studied essential oil inhibited the growth of Pseudomonas aeruginosa ATCC27853 with minimum inhibitory concentrations (MIC) value of 15.32 μg/mL ±0.01, and median inhibitory concentration (IC50) value of 32.0 ±0.01 μg/mL. The essential oil also displayed activity against Staphylococcus aureus ATCC25923 (MIC 31.57 ±0.01 μg/mL) and Bacillus cereus ATCC14579 (MIC, 34.21 μg/mL ±0.01 μg/mL), and IC50 value of 64.0 ±0.01 μg/mL. This is the first report on the rhizome oil composition, as well as the antimicrobial of essential oils from A. menghaiensis. The paper discusses further the comparative analysis of essential oils from A. menghaiensis.

The chemical constituents and antimicrobial activity of the essential oils isolated from the leaves of Machilus cicatricosa S.K. Lee and Machilus bonii Lecomte from Vietnam were studied and reported. The techniques of gas chromatography (GC) and gas chromatography coupled with mass spectrometry (GC-MS) were used to characterize the chemical constituents of the essential oil while the microdilution assay was used to evaluate the antimicrobial activity. The main constituents of the leaf oil of M. cicatricosa were alpha-pinene (20.6%), bicyclogermacrene (15.2%), linalool (14.9%), and beta-pinene (8.4%). On the other hand (E)-beta-ocimene (26.3%), bicyclogermacrene (23.6%) and (E)-nerolidol (9.1%) were the major constituents of M. bonii leaf essential oil. The studied essential oils displayed antimicrobial activity against Enterococcus faecalis ATCC 29212, and Staphylococcus aureus ATCC 25923, with minimum inhibitory concentration (MIC) value of 64.0 mu g/mL. In addition, essential oil from the leaf of M. bonii was the most active towards Bacillus cereus ATCC14579 with MIC value of 64.0 mu g/mL, while M. cicatricosa showed stronger anti-candidal activity against Candida albicans ATCC 10231 with MIC value of 32.0 mu g/mL. This is the first report on the chemical constituents and antimicrobial activity of the essential oils of M. cicatricosa and M. bonii.

Objectives The objective of this study was to investigate the essential oil (EO) extracted from the leaves of Vernonia volkameriifolia DC., a Vietnamese plant belonging to the Asteraceae family. The focus was on determining the chemical composition of the EO and assessing its antimicrobial and antioxidant activities. Methods The EO obtained from V. volkameriifolia underwent comprehensive analysis using gas chromatography (GC) and gas chromatography–mass spectrometry (GC–MS) to identify its chemical constituents. Antimicrobial activity was determined against eight microorganisms using the broth microdilution susceptibility method, with minimum inhibitory concentration (MIC) values calculated. Additionally, antioxidant activity was assessed through DPPH and ABTS assays, with half maximal inhibitory concentration (IC50) values indicating the potency of the EO. Results The main components of the V. volkameriifolia EO were identified as β-bisabolene (25.2%), β-pinene (19.1%), germacrene D (13.1%), and cis-β-elemene (11.4%). The EO exhibited significant antimicrobial activity, with a MIC value of 200 μg/mL against Bacillus subtilis, Staphylococcus aureus, Escherichia coli, Aspergillus niger, and Saccharomyces cerevisiae. Additionally, it displayed activity against Candida albicans with a MIC value of 100 μg/mL. In antioxidant tests, the EO demonstrated notable potential, with IC50 values of 144.1 μg/mL and 179.8 μg/mL for DPPH and ABTS, respectively. Conclusion This study represents the inaugural investigation into the EO extracted from the leaves of V. volkameriifolia. The identified chemical components, along with the demonstrated antimicrobial and antioxidant activities, contribute valuable insights into the potential applications of V. volkameriifolia EO in pharmaceutical and therapeutic contexts. Further research can build upon these findings to uncover additional properties and applications of this EO.

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 β-caryophyllene (17.11%), α-selinene (10.99%), α-humulene (8.98%), β-selinene (8.01%), β-guaiol (6.69%) and β-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.

The chemical constituents and antimicrobial activity of the essential oil isolated from the rhizomes ofAlpinia menghaiensis S.Q. Tong & Y.M. Xia in S.Q. Tong from Vietnam was studied and reported. The techniques of gas chromatography (GC) and gas chromatography coupled with mass spectrometry (GC/MS) were used to characterize the chemical constituents of the essential oil while the microdilution assay was used to evaluate the antimicrobial activity. The main compounds identified in the rhizome essential oil consist of J3-pinene (46.5%), J3-phellandrene (25.7%) and alpha-pinene (8.5%). The studied essential oil inhibited the growth of Pseudomonas aeruginosa ATCC27853 with minimum inhibitory concentrations (MIC) value of 15.32 mu g/mL +/- 0.01, and median inhibitory concentration (IC50) value of 32.0 +/- 0.01 mu g/mL. The essential oil also displayed activity against Staphylococcus aureus ATCC25923 (MIC 31.57 +/- 0.01 mu g/mL) and Bacillus cereus ATCC14579 (MIC, 34.21 mu g/mL +/- 0.01 mu g/mL), and IC50 value of 64.0 +/- 0.01 mu g/mL. This is the first report on the rhizome oil composition, as well as the antimicrobial of essential oils from A. menghaiensis. The paper discusses further the comparative analysis of essential oils from A. menghaiensis.

Lindera chunii Merr. is an important member of the Lauraceae family of plants which are known for their medicinal values. In this research article, the chemical constituents and antimicrobial activity of essential oils from the leaves of L. chunii grown in Vietnam were reported. The essential oil was obtained by hydrodistillation of the leaves of L. chunii while the constituents were determined by using gas chromatography (GC) and gas chromatography-mass (GC/MS) spectrometry methods. The antimicrobial activity was evaluated using a microdilution broth susceptibility assay. The constituents occurring in higher amounts in the leaf essential oil of L. chunii were mainly the monoterpene hydrocarbons comprising terpinolene (13.0%), alpha-pinene (8.0%), beta-pinene (7.6%), camphene (7.3%), beta-phellandrene (7.1%) and myrcene (5.0%). The leaf essential oil of L. chunii inhibited the growth of Enterococcus faecalis ATCC29212, Staphylococcus aureus ATCC25923 and Salmonella enterica ATCC13076, each with minimum inhibitory concentration (MIC) value of 64.0 mu g/mL. The corresponding median lethal concentration (IC50) values were 19.45 mu g/mL, 20.45 mu g/mL and 18.78 mu g/mL, respectively. The essential oil also displayed anti-candidal activity towards Candida albicans ATCC10231 with MIC value of 64.0 mu g/mL, and IC50 value of 23.12 mu g/mL. The antimicrobial activity of L. chunii essential oil was reported for the first time as a confirmation of the traditional uses of the plant in the treatment of microbial infections. Furthermore, the paper discusses the chemotaxonomy of Lindera oil samples.

In this study, the antimicrobial activity and constituents of essential oils from the leaves of Cinnamomum auricolor Kosterm. and C. petelotii Kosterm collected from PU Ho?t Natural Reserve (H?nh D?ch Commune, Qu? Phong District), Vietnam were reported. The essential oils obtained by separate hydrodistillation were analyzed by means of gas chromatography (GC) and gas chromatography coupled with mass spectrometry (GC-MS). The antimicrobial activities were evaluated by microbroth dilution susceptibility assay. The main constituents of C. auricolor comprised of oxygenated sesquiterpenes mainly caryophyllene oxide (26.0%), spathulenol (11.1%), and (E)-nerolidol (10.7%). However, oxygen-containing monoterpenes were the main compounds identified in S. petelotii and they are linalool (34.3%), 1,8-cineole (20.8%) and terpinene-4-ol (9.9%). The essential oil of C. auricolor displayed prominent antimicrobial activity towards Bacillus cereus ATCC14579 and Staphylococcus aureus ATCC25923 with minimum inhibitory concentration (MIC) value of 16.0 mu g/mL. In addition, the essential oil of C. auricolor also exhibited antimicrobial activity against Enterococcus faecalis ATCC29212, and anti-candidal activity towards Candida albicans ATCC10231 with MIC value of 32.0 mu g/mL. The leaf essential oil of C. petelotii only exhibited activity towards S. aureus and C. albicans with MIC value of 64.0 mu g/mL. The chemical constituents and antimicrobial activity of both essential oils are being reported for the first time.

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 β-caryophyllene (13.2%), α-humulene (10.5%), germacrene D (8.1%), β-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.

Plant essential oils have been used for hundreds of years as natural medicines to combat a multitude of pathogens, including bacteria, fungi, and viruses. The paper reports the chemical compositions of essential oil hydrodistilled from the leaves and rhizomes of Amomum unifolium Gagnep. from Vietnam. The main classes of compounds present in the essential oils were monoterpene hydrocarbons (10.1% and 23.9%, respectively), oxygenated monoterpenes (14.5% and 4.9%, respectively), sesquiterpene hydrocarbons (40.9% and 21.9%, respectively), and oxygenated sesquiterpenes (20.1% and 26.8%, respectively). Diterpenes (16.1%) were identified in sizeable proportion in the rhizome essential oil. The constituents occurring in higher amounts in the leaf essential oil were aromadendrene (6.9%), occidenol (6.8%), beta-phellandrene (6.2%), beta-elemene (5.7%), and delta-elemene (5.0%). However, the main compounds of the rhizome essential oil were beta-phellandrene (18.5%), torulosol (16.1%), germacrene D (5.7%), alpha-cadinol (5.5%) and (6S, 7R)-bisabolene (5.1%). The leaf essential oil of A. unifolium displayed higher antibacterial activity than the rhizome oil. The leaf oil showed activity towards S. aureus ATCC 6538, and B. pumilus ATCC 14884, with MIC values of 75.0 mu g/mL and 37.5 mu g/mL, respectively. On the other hand, the rhizome essential oil displayed activity against the organisms at MIC value of 150.0 mu g/mL. Both essential oils exhibited antibacterial activity to E. coli ATCC 8739, with MIC value of 150.0 mu g/mL. The antimicrobial activity of A. unifolium essential oils are being reported for the first time as a confirmation of the ethnomedical uses of A. unifolium in the treatment of diseases especially antimicrobial infections. Furthermore, the paper discusses the chemotaxonomy of Amomum oil samples.

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-1β-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.

The paper reports that the main constituent of essential oil from the leaves of Macclurodendron oligophlebia (Merr.) Hartl. growing in Vietnam was alpha-pinene (81.7%), while alpha-pinene (67.4%) and limonene (11.2%) were the major compounds in fruit essential oil. The composition of essential oils from the leaves and fruits of Melicope ptelefolia (Champ. ex Benth.) T.G. Hartley was characterized as germacrene D (34.0% and 31.1%, respectively), bicyclogermacrene (5.5% and 7.6%, respectively), d-elemene (9.9% and 9.0%, respectively) and alpha-pinene (6.5% and 9.8%, respectively). The fruit essential oil contains limonene (4.9%) and (E)-beta-ocimene (8.1%). The fruit essential oils of M. oligophlebia and M. ptelefolia exhibited anti-candial activity towards Candida albicans ATCC 10231, with minimum inhibitory concentration (MIC) value of 8.0 mu g/mL and 32.0 mu g/mL, respectively. M. oligophlebia fruit oil also showed action against Enterococcus faecalis ATCC 29212, Staphylococcus aureus ATCC 25923, and Bacillus cereus ATCC 14579, each with MIC value of 32.0 mu g/mL. Also, M. oligophlebia leaf showed higher activity against Pseudomonas aeruginosa ATCC 27853 (MIC, 32.0 mu g/mL). The other oil samples exhibited varying degrees of antimicrobial activity with MIC values of either 64.0 mu g/mL or 128. 0 mu g/mL. The leaf essential oil of M. oligophlebia displayed larvicidal activity against Aedes aegypti larvae with minimum lethal concentration (LC50) values of 16.71 mu g/mL and 11.40 mu g/mL, respectively at 24 h and 48 h. The fruit oil did not exhibit any larvicidal action. However, M. ptelefolia leaf and fruit showed activity at 24 h with LC50 values of 33.18 mu g/mL and 35.06 mu g/mL, respectively.

Syzygium plants are known as sources of biologically active substances. The essential oils constituents and antimicrobial activity of Syzygium petelotii Merr. & Perry and Syzygium syzygioides (Miq.) Merr. & Perry from Vietnam are being reported. Essential oils were obtained by hydrodistillation of the leaves of S. petelotii and S. syzygioides collected from Pu Ho ạt Nature Reserve, Vietnam. The constituents of the essential oils were determined by using gas chromatography (GC) and gas chromatography-mass (GC/MS) spectrometry methods. The antimicrobial activity was evaluated by microdilution broth susceptibility assay. The results indicate that & gamma;-guaiene (24.1%), & beta;-caryphyllene (9.3%), & alpha;-pinene (7.8%), and & beta;-pinene (6.1%) were the major compounds of S. petelotii. The main constituents of S. syzygioides were caryophyllene oxide (14.8%), & alpha;-pinene (10.6%), & beta;-pinene (6.6%) and spathulenol (6.4%). The essential oil of S. petelotii showed pronounced antimicrobial activity against Pseudomonas aeruginosa ATCC27853 and Enterococcus faecalis ATCC299212, with minimum inhibitory concentration (MIC) values of 16.0 & mu;g/mL and 64.0 & mu;g/mL, respectively. The essential oil of S. syzygioides only displayed activity towards Pseudomonas aeruginosa ATCC27853 with MIC value of 32.0 & mu;g/mL. Both essential oils exhibited antimicrobial activity towards Bacillus cereus ATCC14579 (MIC value, 128.0 & mu;g/mL), and anti-candidal action against Candida albicans ATCC10231 with MIC value of 64.0 & mu;g/mL. The chemical compositions and antimicrobial activity of essential oils of S. petelotii and S. syzygioides are being reported for the first time.

The chemical constituents of essential oils from Zingiber plants are known to exhibit chemical variability. The objective of this work was to analyze for the first time the contents and the chemical diversity of the essential oils from the leaves, stems and roots of Zingiber pellitum Gagnep, belonging to Zingiberaceae family collected in Binh Chau-Phuoc Buu Nature Reserve, Ba Ria-Vung Tau, Vietnam. The essential oils were isolated by hydrodistillation and their constituents were investigated by gas chromatography-mass spectrometry (GC/MS-FID). The essential oils from Z. pellitum were obtained in yield of 0.20% (leaves), 0.12% (stems) and 0.27% (roots). The essential oils from the leaves of Z. pellitum consist mainly of beta-caryophyllene (51.7%), beta-pinene (12.0%), alpha-pinene (10.0%), while beta-caryophyllene (24.9%), beta-pinene (19.8%) and alpha-humulene (18.8%) were the main constituents of the stems essential oil. On the other hand, 9-epi(E)-caryophyllene (7.5%), humulene epoxide II (7.4%), alpha-humulene (6.4%), caryophyllene oxide (5.9%), beta-caryophyllene (4.9%), camphene (4.3%), epi-alpha-cadinol (4.0%) and cyperotundone (4.0%) were the significant compounds of essential oil from the roots of Z. pellitum. Since the composition of the studied leaves, stems and roots of Z. pellitum essential oils differed considerably from each other and previous reports on the other parts of the plant, the paper discusses further the chemotaxonomic implications of the obtained data with respect to Zingiber pellitum and other Zingiber essential oils from Vietnam.

This study is the first to investigate the chemical composition of essential oil and antioxidant activity of the essential oil and methanol extracts from the leaves of Knema globularia (Lam.) Warb. from Vietnam. According to gas chromatography and gas chromatography-mass spectrometry analysis, the major constituents of K. globularia essential oil were β-elemene (25.48%), α-copaene (17.05%), β-caryophyllene (9.37%), and α-humulene (8.42%). The antioxidant activity of the samples was determined using DPPH and ABTS methods. In both assays, the polar subfraction of the methanolic extract showed better antioxidative capacity than the nonpolar subfraction and the essential oil. In addition, the amounts of total phenol value in the polar subfraction and the nonpolar subfraction were determined to be 113.84 μg/mg and 47.52 μg/mg, respectively. The findings demonstrate that the essential oil and methanol extracts of K. globularia possess significant antioxidant activities and may be a new potential source of natural antioxidants.