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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.

AbstractFrom the root bark of Pinus krempfiiLecomte, four flavonoids were isolated and evaluated for their inhibitory activities against AChE and BChE enzymes in vitroand in silico. Tectochrysin (1) was found to inhibit AChE with an IC50value of 33.69 ± 2.80 μM. The docking study results also showed agreement with the in vitrotest results. All four compounds also showed the best binding affinity for the AChE enzyme, characterised by binding energy (ΔG) values as low as −8.1 to −9.3 kcal/mol, in which, the compound tectochrysin had the best binding affinity for the AChE protein with a ΔG value of −9.329 kcal/mol. Tectochrysin (1) was also bound to the amino acid Phe295 of AChE with a bond length of 2.8 Å, similar to the control dihydrotanshinone-I. Galangin (2) also showed its in vitroinhibitory activity against BChE with an IC50value of 82.21 ± 2.70 μM. In silico, it also had the best binding energy value of −9.072 kcal/mol with BChE and formed hydrogen bonds with the His438 (2.85 Å) residues of BChE like the positive control (tacrine). The steered molecular dynamics (SMD) simulation results of these two complexes revealed a mechanistic insight that the protein-ligand complexes showed stable trajectories throughout the 20 and 150 ns simulations. Moreover, the drug likeliness suggested that both flavonoids (1and 2) were expected to be drug-like and have an LD50toxicity level of 5. This study has contributed new results for drug discovery and the development of substances with neuroprotective effects, especially for the treatment of Alzheimer’s disease.Communicated by Ramaswamy H. Sarma

In inflammatory diseases, the expression of the target protein tumor necrosis factor‐alpha (TNF‐α) plays a crucial role in the pathogenesis and development of certain conditions, such as autoimmune diseases, rheumatoid arthritis, inflammatory bowel disease, and psoriatic arthritis. TNF‐α inhibitors have several limitations. Screening studies of plant‐derived compounds have shown promising results due to their lower incidence of side effects and reasonable cost. Therefore, this research focuses on identifying compounds isolated from Isodon coetsa, collected from previous studies, that exhibit inhibitory effects on TNF‐α through computational methods such as molecular docking and ADMET prediction. Among the compounds binding to the active site of TNF‐α, five diterpenoids, namely 2α,3α,24‐trihydroxy‐11α,12α‐epoxy‐urs‐20(30)‐en‐28,13β‐olide,2α,3α,24‐trihydroxy‐12,20(30)‐ursadien‐28‐oic acid, xerophilusin B, oridonin, and 15α‐hydroxy‐6,7‐seco‐1α,7:11α,6‐diolide‐ent‐kaur‐16‐en, exhibited higher binding affinity than the reference inhibitor SPD‐304. All the potential compounds predicted by ADME demonstrated favorable pharmacokinetic properties. Moreover, regarding the toxicity of the I. coetsaderived compounds, namely 2α,3α,24‐trihydroxy‐11α,12α‐epoxy‐urs‐20(30)‐en‐28,13β‐olide, xerophilusin B, and 15α‐hydroxy‐6,7‐seco‐1α,7:11α,6‐diolide‐ent‐kaur‐16‐en, they exhibited low toxicity and safety for oral administration. Hence, these compounds may serve as potential candidates to replace the inhibitor SPD‐304 as important therapeutic agents against TNF‐α in the future. The results obtained need to be further investigated through in‐depth in vitroand in vivoexperiment studies.

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.

AbstractKaempferiais a genus of the Zingiberaceae family containing a rich resource of essential oils (EOs) with various important biological activities. In the present study, the chemical compositions and in vitroantimicrobial activity of the EO of Kaempferia attapeuensisPicheans. & Koonterm were reported for the first time. By the Gas Chromatography-Mass Spectrometry (GC/MS) analysis, a number of 46 compounds were identified in K. attapeuensisrhizomes EO (accounted for 90.61 % of the total content), among which germacrone (25.80%), camphene (18.63%) and α-pinene (10.57%) were the major components. In the in vitroantimicrobial assay, K. attapeuensisrhizomes EO exhibited promising activity against the growth of three Gram-positive bacteria strains (Enterococcus faecalis, Staphylococcus aureus, and Bacillus cereus), three Gram-negative bacteria strains (Escherichia coli, Pseudomonas aeruginosa, and Salmonella enterica) and the yeast strain (Candida albicans) with their MIC values all of 32 µg/mL. In general, the present investigation has provided the foundation for additional research on the chemical compositions and biological effects of K. attapeuensis.

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.

Morinda longissimaY. Z. Ruan (“Nhó đông") belongs to the Rubiaceae family. In Vietnam, the stems and roots of this plant are commonly used to treat liver diseases, such as viral hepatitis and acute and chronic cirrhosis. A phytochemical study of this hepatoprotective plant revealed the presence of 21 natural compounds of different classes, including iridoids, naphthalene glycosides, and especially anthraquinones and anthraquinone glycosides. The primary goal of this study was to investigate the anti‐inflammatory potential of bioactive molecules from M. longissimatargeted against TNF‐αusing a molecular docking approach. The results revealed that two anthraquinone glycosides, morindone‐6‐O‐β‐gentiobioside (1) and lucidin‐3‐O‐β‐primeveroside (2), had good binding affinities (∆G values of ‐9.21 and ‐8.75 kcal/mol, respectively), better than that of the TNF‐αinhibitor, SPD‐304 (‐8.71 kcal/mol). The in silicoADME parameters of (1) and (2) and other compounds showed good bioavailability based on their absorption, distribution, metabolism, and excretion parameters. In addition, the oral toxicity of these compounds was determined to be low and safe. All this evidence showed it is worth further study and the development of potential anthraquinone glycosides from M. longissimaroots as TNF‐αnatural inhibitors for the treatment of inflammatory diseases such as rheumatoid arthritis, sclerosis, and hepatitis.