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Kaempferia champasakensis Picheans. & Koonterm (Zingiberaceae) is locally known as "Dia Lien hoa trang" in Vietnam. Despite a previous study on the essential oils (EO) of K. champasakensis leaves, 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. champasakensis and 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. champasakensis rhizomes. 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 coli main activities. The results revealed that α-pinene exhibited strong binding affinity against E. coli, β-pinene demonstrated more effective inhibition against E. faecalis and B. cereus, and camphene primarily exhibited activity against C. albicans and 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. champasakensis rhizomes 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. [ABSTRACT FROM AUTHOR]

Kaempferia is 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 vitro antimicrobial activity of the EO of Kaempferia attapeuensis Picheans. & 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. attapeuensis rhizomes 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 vitro antimicrobial assay, K. attapeuensis rhizomes 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. [ABSTRACT FROM AUTHOR]

Objective/Background: The essential oils (EOs) of Curcuma species contain various volatile compounds with bioactivity. However, the phytochemical profile of Curcuma thorelii and the antimicrobial activities of Curcuma rhabdota, and Curcuma petiolata have received limited attention. This study aims to characterize and compare the major compounds and the antimicrobial activities of EOs extracted from the rhizomes of C. rhabdota, C. thorelii, and C. petiolata collected in Vietnam. Methods: EOs were obtained by hydrodistillation of the rhizomes of three Curcuma species. The chemical profiles were determined using gas chromatography-mass spectrometry (GC-MS). The antimicrobial activities against bacteria and a pathogenic fungus were determined through the broth dilution method. Results: The volatile profiles of C. rhabdota, C. thorelii, and C. petiolata EOs included 63 (97.1%), 47 (98.0%), and 50 (95.6%) compounds, respectively. The major compound in the EO of C. rhabdota rhizomes was 3-carene (16.6%), followed by camphene (9.8%), α-copaene (7.4%), γ-terpinene (7.3%), camphor (5.9%), and β-curcumene (5.7%). The predominant compounds of the EO extracted from C. thorelii rhizome were xanthorrhizol (40.7%), β-curcumene (20.7%), and α-curcumene (8.9%), while camphene (17.0%), (E)-β-elemenone (16.8%), (E)-β-farnesene (13.6%), germacrone (8.9%), 1,8-cineole (7.2%), and camphor (6.0%) were the most abundant components in C. petiolata rhizomes. Except for Pseudomonas aeruginosa, which was less susceptible to the EOs with a minimum inhibitory concentration (MIC) value of 128 μg/mL, the three oil samples exhibited potent antimicrobial activities against all investigated strains with MIC values in the range of 2-32 μg/mL. Especially, the EO of C. thorelii rhizomes showed intense activity against Enterococcus faecalis, Staphylococcus aureus, Bacillus cereus, Escherichia coli, and Candida albicans with a MIC value of 2 µg/mL. Conclusion: The results showed the chemical variability of EOs from three Curcuma species and the prepared EO samples showed potent antimicrobial activities against several microbial strains, indicating a high potential application as a food preservative and in the pharmaceutical industry. [ABSTRACT FROM AUTHOR]