Search

AbstractThis work aimed to determine the chemical composition and antioxidant activity of rhizome essential oil (EO) of Meistera verrucosagrowing wild in Ha Giang Province, Vietnam. The EO was isolated using hydrodistillation, then the chemical composition was analyzed by Gas chromatography-mass spectroscopy (GC-MS). In addition, the antioxidant activities were determined by the DPPH scavenging method and ferric reducing antioxidant power (FRAP) assay. The results showed that α-pinene, β-pinene, and (E)-β-ocimene were major components in the EO, accounting for 39.6%, 20.7%, and 12.2%, respectively. The EO showed antioxidant activity, the IC50value of DPPH scavenging activity, and the EC50value of FRAP assay were 91.01 mg/mL and 17.50 mg/mL, respectively. Furthermore, to evaluate the inhibitory interaction potential of Keap1, docking analysis indicated that α-pinene has the strongest affinity among the major compounds surveyed. The key interactions observed in the complexes of the major compounds with Keap1 are predominantly hydrophobic interactions (pi-sigma and pi-alkyl), which significantly contribute to their binding affinities. These results provide more information on the volatile compounds of the EO from the rhizomes of M. verrucosaand first reveal its antioxidant power.

AbstractThe present study aims to describe the chemical composition of essential oils from three Vietnamese Annonaceae species, Meiogyne virgata, M. vietnamica, and Orophea polycarpa, and their antimicrobial activity. Essential oils were extracted by hydro-distillation. From the GC-FID/MS (gas chromatography-flame ionization detection and mass spectrometry) analysis, the leaf essential oil of M. virgatawas reported to contain the major compound germacrene D (42.48%). Spathulenol (24.51%), bicyclogermacrene (18.58%), β-selinene (11.14%), and germacrene D (8.20%) can be seen as the main compound in M. vietnamicaleaf essential oil. α-Phellandrene (39.35%), bicyclogermacrene (13.07%), β-phellandrene (10.87%), and limonene (8.27%) represented O. polycarpaleaf essential oil. Essential oil of M. virgataleaves exhibited strong antimicrobial activity against the Gram (+) bacterium Bacillus subtilisATCC 5230, the Gram (-) bacterium Escherichia coliATCC 8739, and the fungus Aspergillus nigerATCC 9587 with the same MIC value of 16 μg/mL. The docking method showed that germacrene D has the ΔGbinding(binding affinity) values of –6.68, –5.265, and –5.602 kcal/mol with the proteins E. coliDNA gyrase, B. subtilisTasA, and A. nigerPhyA, respectively. Alkyl and pi-alkyl interactions are the main contributors to the binding affinity between the studied proteins and ligands. Furthermore, germacrene D is predicted to have low toxicity and is not active against any of the considered organ targets.

AbstractThe Zingibergenus has been widely applied in food and pharmaceuticals due to its varied chemical composition and significant benefits. Zingiber plicatumŠkorničk. & Q.B. Nguyễn was described in Vietnam in 2015, yet there has been no report on its phytochemicals and bioactivity. In this study, we first analyzed the chemical composition of essential oil and its antioxidant activities. Isolation of the rhizome essential oil was performed through hydrodistillation using a Clevenger apparatus for 3.5 h, then volatile compositions were determined using gas chromatography-mass spectroscopy (GC-MS). Additionally, the antioxidant activities were assessed using 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging and ferric reducing power assays. The GC-MS analysis showed a total of 54 volatile components, mainly belonging to monoterpene hydrocarbons (57.69%) and sesquiterpene hydrocarbons (28.98%). The main compounds were β-pinene (26.85%), α-pinene (11.73%), limonene (10.03%), and germacrene D (5.26%). The essential oil also showed antioxidant activities, with an IC50of 84.53 mg/mL for DPPH scavenging activity and an EC50of 17.3 mg/mL for ferric reducing power. These findings first provided data on the chemical components and antioxidant properties of Z. plicatumessential oil.

AbstractIn the present work, chemical composition, enzyme inhibitory activities, and molecular docking studies of essential oil (EO) of Knema globularialeaves collected from Vinh Phuc Province, Vietnam, were investigated. The EO from the leaves of K. globulariawas obtained by hydrodistillation and analyzed by gas chromatography-mass spectrometry (GC-MS) analysis. The leaf EO yield was 0.14 ± 0.01% (w/w), comprising 39 identified components, constituting 96.77% of the EO content. Notable constituents included β-caryophyllene (54.11%), α-humulene (12.67%), and (E)-β-ocimene (8.82%). Enzyme inhibitions were assessed via the α-amylase inhibitory assay (IC50= 282.71 ± 10.06 μg/mL) and tyrosinase inhibitory assay (IC50= 993.92 ± 37.40 μg/mL). The molecular docking method has been employed to observe valuable binding interactions and binding energy with the main compounds on the target enzymes α-amylase and tyrosinase. Caryophyllene oxide exhibits the strongest affinity with α-amylase among the other major compounds. Meanwhile, viridiflorene shows the best binding energy with the tyrosinase enzyme. This is the first study providing valuable scientific data on the in vitroinhibitory activities of α-amylase and tyrosinase enzymes of the leaf EO of K. globulariaand evaluating its main compounds through a molecular docking approach on these enzyme targets.

AbstractCurcuma zedoaroidesChaveer. & Tanee (Vietnamese name: Nghệ đắng) belongs to the Zingiberaceae family which is the new Curcumaspecies discovered in Thailand and Vietnam in recent years. This study aimed to determine the chemical compositions and the cytotoxic activities of C. zedoaroidesrhizome essential oil for the first time. The essential oil was obtained from the rhizomes through hydro-distillation and analyzed by gas chromatography-mass spectrometry (GC-MS) technique. Results showed that the majority of the rhizome essential oil of C. zedoaroideswas dominated by oxygenated sesquiterpenes (61.54%) mainly curdione (27.45%), followed by widdrol (8.03%) and trans-β-elemenone (5.47%). Notably, the essential oil of C. zedoaroidesrhizomes exhibited cytotoxic activities using the MTT assay with the IC50(half-maximal effective concentration) values of 75.16 ± 2.79, 77.08 ± 1.98, 81.35 ± 1.55, 83.67 ± 2.26, 32.74 ± 1.95, 23.14 ± 1.43, 73.35 ± 2.20 μg/mL against A549, MCF-7, HepG2, HT29, HL-60, K562 and MDA-MB-231 cells, respectively. In addition, three major compounds targeting specific proteins related to essential oil’s anti-cancer activity were assessed using molecular docking simulation. From the results observed, widdrol was suggested to have the highest binding affinity for both EGFR and HER2, with ΔG values of -6.246 kcal/mol and -6.916 kcal/ mol, respectively. These results suggest the potential of the rhizome essential oil of C. zedoaroidesto provide leads for the development of anti-cancer agents as well as considered a valuable source of bioactive components.

AbstractKaempferia champasakensisPicheans. & Koonterm (Zingiberaceae) is locally known as “Dia Lien hoa trang” in Vietnam. Despite a previous study on the essential oils (EO) of K. champasakensisleaves, no other studies have reported the chemical components and biological activities of K. champasakensis. Therefore, this study aims to identify the chemical constituents of the EO from the rhizomes of K. champasakensisand evaluate their antimicrobial activity, which has been re-confirmed through molecular docking studies. The gas chromatography-mass spectrometry (GC/MS) analysis revealed sixty-one constituents (95.4%) present in the EO of K. champasakensisrhizomes. Among them, camphene (40.7%), α-pinene (10.2%), and β-pinene (7.6%) were identified as the main compounds in the EO. Bioassays indicated its antimicrobial activity in the order of inhibitory effectiveness: Staphylococcus aureus> Enterococcus faecalis≈ Candida albicans> Bacillus cereus≈ Escherichia coli> Salmonella enterica> Pseudomonas aeruginosa. The molecular docking study of ligand-protein interactions involving the major constituents of EO was conducted against target proteins related to Staphylococcus aureus, Enterococcus faecalis, Candida albicans, Bacillus cereus, and Escherichia colimain activities. The results revealed that α-pinene exhibited strong binding affinity against E. coli, β-pinene demonstrated more effective inhibition against E. faecalisand B. cereus, and camphene primarily exhibited activity against C. albicansand S. aureus. Furthermore, the analysis of interactions between the main compounds and the selected proteins was elucidated in the current study. This is the first time that chemical components of the EO of K. champasakensisrhizomes and their antimicrobial activity have been reported. These findings contributed to the basis for further studies on the chemical compositions and biological effects of K. champasakensis.