In this study, Magnolia citrata Noot and Chalermglin (Magnoliaceae) essential oil (MCEO) was evaluated for insecticidal activity against the yellow fever mosquito Aedes aegypti and attractant activity for the Mediterranean fruit fly Ceratitis capitata. The leaves of Magnolia citrata (Giổi chanh) were collected from northwestern Vietnam, and the water-distilled MCEO was analyzed by gas-chromatography and mass spectrometry (GC-MS). The major constituents of MCEO were identified as linalool 19%, geranial 16%, citronellal 14%, neral 14%, and sabinene 12%. MCEO showed 100% mortality at 1 μg/μL against 1st instar larvae of Ae. aegypti (Orlando strain, ORL), and the oil exhibited 54% (ORL) and 68% (Puerto Rico strain) mortality at 5 μg/mosquito against Ae. aegypti adult females. Initial screens showed that MCEO had weak insecticidal activity compared to the positive control permethrin. In bioassays with sterile male C. capitata, MCEO exhibited moderately strong attraction, comparable to that observed with a positive control, Tetradenia riparia essential oil (TREO). Herein, the insecticidal and attractant activities of MCEO are reported for the first time.

Using essential oils to control vectors, intermediate hosts, and disease-causing microorganisms is a promising approach. The genus Croton in the family Euphorbiaceae is a large genus, with many species containing large amounts of essential oils, however, essential oil studies are limited in terms of the number of Croton species investigated. In this work, the aerial parts of C. hirtus growing wild in Vietnam were collected and analyzed by gas chromatography/mass spectrometry (GC/MS). A total of 141 compounds were identified in C. hirtus essential oil, in which sesquiterpenoids dominated, comprising 95.4%, including the main components β-caryophyllene (32.8%), germacrene D (11.6%), β-elemene (9.1%), α-humulene (8.5%), and caryophyllene oxide (5.0%). The essential oil of C. hirtus showed very strong biological activities against the larvae of four mosquito species with 24 h LC₅₀ values in the range of 15.38–78.27 μg/mL, against Physella acuta adults with a 48 h LC₅₀ value of 10.09 μg/mL, and against ATCC microorganisms with MIC values in the range of 8–16 μg/mL. In order to provide a comparison with previous works, a literature survey on the chemical composition, mosquito larvicidal, molluscicidal, antiparasitic, and antimicrobial activities of essential oils of Croton species was conducted. Seventy-two references (seventy articles and one book) out of a total of two hundred and forty-four references related to the chemical composition and bioactivity of essential oils of Croton species were used for this paper. The essential oils of some Croton species were characterized by their phenylpropanoid compounds. The experimental results of this research and the survey of the literature showed that Croton essential oils have the potential to be used to control mosquito-borne and mollusk-borne diseases, as well as microbial infections. Research on unstudied Croton species is needed to search for species with high essential oil contents and excellent biological activities.

Sphagneticola trilobata, Vitex rotundifolia, Vitex trifolia, and Annona glabra are medicinal plants found in Xuan Thuy mangrove forest that contain essential oils (EOs) and the potential to treat infections. The obtained yields of hydrodistillation essential oil from aerial parts and leaves ranged from 0.01% to 0.12% (v/w) on a fresh-weight basis. Subsequently, in vitro assessments indicated that the EOs of A. glabra, S. trilobata, and V. trifolia displayed antibacterial effects against methicillin-resistant Staphylococcus aureus (MRSA), with S. trilobata exhibiting bactericidal effects at minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) values of 0.2% EO, and A. glabra exhibiting bacteriostatic effects with both MIC and MBC values of 0.8% EO. However, the EO of V. rotundifolia showed no inhibitory effects against S. aureus, even at concentrations of up to 0.8% EO. Furthermore, docking results showed that six compounds exhibited particularly high binding energies (< -7 kcal/mol): α-phellandrene, β-caryophyllene, β-guaiene, alloaromadendrene, bicyclosesquiphellandrene, and bicyclogermacrene. Among these, α-phellandrene, β-caryophyllene, bicyclosesquiphellandrene, and bicyclogermacrene are the main components in the S. trilobata EO; β-caryophyllene, β-guaiene, and alloaromadendrene are the main components in the A. glabra EO; and β-caryophyllene and alloaromadendrene are the main components in the V. trifolia EO. These findings highlight the antibacterial potential of EOs from mangrove plants; therefore, expanded investigations into EOs and the biological properties of mangrove plants may be a promising strategy for combating antimicrobial resistance.

Vietnam is extremely rich in biodiversity, with a remarkable range of habitats and more than 13,500 species of vascular plants recorded for the flora of Vietnam. This number represents about 3 to 5% of the world’s diversity of vascular plants. Over the past 30 years, there were two important documents on the vascular plants of Vietnam published, An Illustrated Flora of Vietnam (IFV) and Checklist of Plant Species of Vietnam (CPSV). During the past half century, the advent of molecular phylogenetics has witnessed dramatic changes in the classifications of vascular plants, and some modern classification systems of vascular plants have been established, e.g., PPG I, GPG, and APG. However, the vascular plants of Vietnam have not yet been classified according to these modern classification systems. In this paper, we present the history of the classification of vascular plants in Vietnam, compare the circumscription of all families of vascular plants occurring within Vietnam in IFV, CPSV, and the modern classification systems when applicable, and summarize familial assignments of all controversial genera in the different classifications. Furthermore, we also arrange the 37 families of lycophytes and ferns occurring within Vietnam according to the latest classification system (PPG I) and the 8 families of gymnosperms according to the latest Christenhusz’s system (GPG). The 246 families of angiosperms are arranged according to the fourth edition of the latest Angiosperm Phylogeny Group (APG IV). These results are the foundation stones and would be helpful for future research on the flora of Vietnam and the arrangement of plant collections in Vietnamese herbaria based on the updated classifications.

This study aimed to compare the chemical composition and antimicrobial activity of essential oils obtained from the rhizomes and leaves of Conamomum pierreanum (Zingiberaceae), and to evaluate interactions of selected constituents with microbial targets using molecular docking and molecular dynamics simulations. Gas chromatography–mass spectrometry (GC-MS) identified 21 compounds in the rhizome essential oil (EO) and 10 in the leaf EO of C. pierreanum, with 1,8-cineole (54.44% and 75.73%, respectively) as the predominant constituent. Notably, the rhizome EO was uniquely characterized by epi-γ-eudesmol (3.47%) and isobornyl acetate (3.39%), which were absent in the leaf oil. In vitro assays revealed that the rhizome EO possessed stronger antibacterial and antifungal activities (MIC = MBC = MFC = 0.4%) compared to the leaf EO (0.8%) against Staphylococcus aureus and Candida albicans. Molecular docking identified epi-γ-eudesmol as the most potential ligand, exhibiting remarkably high binding affinities for S. aureus DHFR (−8.1 kcal/mol) and C. albicans CYP51 (−8.5 kcal/mol), significantly outperforming the major constituents. A total of 100 ns molecular dynamics simulations and MM-PBSA analysis further confirmed the structural stability and energetically favorable binding of these complexes, with epi-γ-eudesmol maintaining a low average RMSD (<1.2 Å) throughout the simulation. The enhanced efficacy of the rhizome oil is attributed to the synergistic contribution of these high-affinity minor constituents. These findings suggest that C. pierreanum rhizome EO may serve as a potential source of bioactive compounds for antimicrobial applications, warranting further investigation.

Mục tiêu: Đánh giá hiệu suất chiết cao methanol và tác dụng kháng khuẩn của 12 loài cây dược liệu. Đối tượng và phương pháp: Lá của 12 loài dược liệu thu vào tháng 5 và tháng 7 năm 2023 tại Vườn quốc gia Xuân Thủy được chiết bằng methanol dưới sự hỗ trợ của siêu âm. Cao chiết thu được được khảo sát hoạt tính kháng khuẩn với 06 chủng vi sinh vật và 01 chủng nấm men. Kết quả: Cao chiết MeOH toàn phần của 12 loài dược liệu đạt hiệu suất chiết từ 4,5 – 28,4%. Hiệu suất chiết của loài Sú là cao nhất (28,4%), tiếp đến là Đước vòi (28,1%), Trang (27,5%), Bần chua (19,5%). Thấp nhất là Sài đất ba thùy và Cóc hoa trắng với hiệu suất chiết lần lượt là 4,8 % và 4,5%. Kết quả đánh giá hoạt tính kháng khuẩn cho thấy 02 loài thuộc chi Bần gồm Bần không cánh và Bần chua thể hiện hoạt tính ức chế mạnh nhất ở nồng độ 320 mg/mL. Các mẫu dược liệu còn lại có khả năng ức chế các chủng vi khuẩn thử nghiệm ở nồng độ từ 640 – 1280 mg/mL. Kết luận: Hiệu suất chiết cao MeOH toàn phần của 12 loại dược liệu đạt hiệu suất chiết từ 4,5 – 28,4%. Cao chiết từ lá hai loài Bần (Bần không cánh và Bần chua) thể hiện khả năng ức chế mạnh nhất MIC= 320 mg/mL trên vi khuẩn Salmonella enterica.