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The spread of tuberculosis (TB), especially multidrug-resistant TB and extensively drug-resistant TB, has strongly motivated the research and development of new anti-TB drugs. New strategies to facilitate drug combinations, including pharmacokinetics-guided dose optimization and toxicology studies of first- and second-line anti-TB drugs have also been introduced and recommended. Liquid chromatography-mass spectrometry (LC-MS) has arguably become the gold standard in the analysis of both endo- and exo-genous compounds. This technique has been applied successfully not only for therapeutic drug monitoring (TDM) but also for pharmacometabolomics analysis. TDM improves the effectiveness of treatment, reduces adverse drug reactions, and the likelihood of drug resistance development in TB patients by determining dosage regimens that produce concentrations within the therapeutic target window. Based on TDM, the dose would be optimized individually to achieve favorable outcomes. Pharmacometabolomics is essential in generating and validating hypotheses regarding the metabolism of anti-TB drugs, aiding in the discovery of potential biomarkers for TB diagnostics, treatment monitoring, and outcome evaluation. This article highlighted the current progresses in TDM of anti-TB drugs based on LC-MS bioassay in the last two decades. Besides, we discussed the advantages and disadvantages of this technique in practical use. The pressing need for non-invasive sampling approaches and stability studies of anti-TB drugs was highlighted. Lastly, we provided perspectives on the prospects of combining LC-MS-based TDM and pharmacometabolomics with other advanced strategies (pharmacometrics, drug and vaccine developments, machine learning/artificial intelligence, among others) to encapsulate in an all-inclusive approach to improve treatment outcomes of TB patients.

Purpose: Cultured lichen mycobionts are valuable sources of new natural compounds. Mycobiont of Graphis handelii growing in Vietnam was isolated, cultivated and chemically investigated. The crude extract of this cultured mycobiont showed potent alpha-glucosidase inhibition with an IC50 value of 50 μg/mL. Methods: Multiple chromatographic methods were applied to the extract to isolate compounds. The combination of Nuclear Magnetic Resonance analysis and high-resolution mass spectroscopy determined their chemical structures. Electrophilic bromination/chlorination was applied to obtain new derivatives using NaBr/H2O2 and NaCl/H2O2 reagents. Compounds were evaluated for enzyme inhibitory activities, including alpha-glucosidase inhibition, HIV-1 reverse transcriptase inhibition, SARS-CoV-2 main protease (Mpro) inhibition, anti-inflammatory activity, and cytotoxicity against several cancer cell lines. A molecular docking study for anti-SARS-CoV-2 was conducted to understand the inhibitory mechanism. Results: A new diphenyl ether, handelone (1) and a known compound xylarinic acid A (2) were isolated and elucidated. Four synthetic products 6′-bromohandelone (1a), 2′-bromohandelone (1b), 2′,6′-dibromohandelone (1c), and 2′,6′-dichlorohandelone (1d) were prepared. Compound 1 showed good activity against Mpro with an IC50 value of 5.2 μM but it showed weak or inactive activity in other tests. Other compounds were inactive in all assays. Conclusion: A new compound, handelone (1) was isolated from the cultured mycobiont of Graphis handelii. From these compounds, four new derivatives were prepared. Compound 1 showed good activity against Mpro with an IC50 value of 5.2 μM but it showed weak or inactive activity in other tests. Other compounds were inactive in all assays.

Little is known about the chemical and biological profiles of Dicranopteris linearis and Psychotria adenophylla. No previous studies have investigated alpha-glucosidase inhibition using extracts from D. linearis and P. adenophylla. In this paper, bioactive-guided isolation procedures were applied to the plants D. linearis and P. adenophylla based on alpha-glucosidase inhibition. From the most active fractions, 20 compounds (DL1–DL13 and PA1–PA7) were isolated. The chemical structures were elucidated using spectroscopic data and compared with those available in the literature. These compounds were evaluated for alpha-glucosidase inhibition, while a molecular docking study was performed to elucidate the mechanisms involved. Consequently, D. linearis and P. adenophylla might serve as a good potential for developing new antidiabetic preparations.

Twenty-two compounds (1-22) were isolated from the stems and twigs of Garcinia schomburgkiana. NMR, IR, UV, and MS were used for structural elucidation, and comparisons were made with previous reports. Compound 1 exhibited the most potent α-glucosidase inhibition (IC50 0.31 ± 0.7 μM), outperforming the positive control (acarbose). Molecular docking results showed that the phenolic hydroxyl groups on the phenyl rings linked with active receptor sites on the protein in 1. By preventing the duplication of DNA sequences, Compound 1 is an excellent inhibitor of the α-glucosidase enzyme, and represents a potential novel class of α-glucosidase inhibitor.

Panax vietnamensis var. vietnamensis (PVV) and Panax vietnamensis var. fuscidiscus (PVF) both belong to Panax vietnamensis species and are chemically and morphologically similar, making it hard to distinguish for the consumer. Herein, 42 PVF and 12 PVV samples were collected in Quang Nam and Lai Chau Province, respectively, and subsequently characterized by ITSr-DNA sequence data to verify their origins. Next, untargeted metabolomics combined with multivariate statistical analysis was developed to differentiate PVV and PVF. The metabolic profiles of PVV and PVF were found to be distinct and classified well using Partial Least-Squares Discriminant Analysis (PLS-DA) in the training set. Among them, seven ginsenosides were of high abundance in PVV, while six were of high abundance in PVF. Next, the test set was used to validate 13 putative differential markers found in the training set, illustrating a complete match with the expression patterns of these ginsenosides in the training set. Finally, PLS-DA and linear Support Vector Machine models both indicated distinct ginsenoside profiles of PVV and PVF without misclassification in the test set. Conclusively, the developed untargeted metabolomics approach might serve as a powerful tool for the authentication of PVV and PVF at the metabolome level.

Boerhavia erecta is a tropical plant that is widely used in folk medicine. Roots of this plant are applied as a diuretic, stomachic, anthelminthic, febrifuge, and expectorant. The whole plant has been used for treating gastrointestinal, liver, and infertility problems. More than 40 metabolites have been identified in its leaves, roots, and the aerial parts. Among them, isoflavonoids such as rotenoids and coumaronochromonoids are major components. Some of these compounds exhibited potent cytotoxicity, COX inhibition and opioid and cannabinoid receptor. However, little is known about the inhibition of α-glucosidase enzyme of these compounds. As part of our ongoing search for α-glucosidase inhibitors from Vietnamese medicinal plants, we conducted bioactive-guided isolation of the aerial part of Boerhavia erecta. Twelve known compounds were isolated and elucidated, including boeravinone M (1), boeravinone G (2), boeravinone P (3), boeravinone B (4), boeravinone E (5), boeravinone A (6), boeravinone H (7), 9-O-methyl-4-hydroxyboeravinone B (8), boeravinone T (9), boeravinone J (10), boeravinone C (11), and 10-demethylboeravinone C (12). Isolates 2–5, 7, and 12 showed potent α-glucosidase inhibition, which is stronger than acarbose, a positive control. Among them, compound 5 showed strongest inhibition with IC50 value of 85.1 µM. A kinetic study indicated that 5 was a mixed-type inhibitor. Compound 5 was determined to be a potential inhibitor of the α-glucosidase enzyme based on in silico molecular docking mode. Compounds were tested for cytotoxicity against K562 and antimicrobial activity against antibiotic-resistant, pathogenic bacteria Enterococcus faecium, Staphylococcus aureus, and Acinetobacter baumannii. Only compounds 4 and 12 showed moderate activity against K562 cell line. As regards antimicrobial activity, compounds 6 and 10 showed strong inhibition toward Enterococcus faecium. In silico studies of cytotoxicity and antimicrobial activity were also performed, indicating that in vitro and in silico data were consistent.

Data on synthesized derivatives of salazinic acid are scarce, with existing reports addressing only derivative hexaacetyl salazinic acid. This study investigated a set of novel potential antidiabetic agents. Analogs of salazinic acid were designed and synthesized using bromination, nucleophilic addition, Friedel-Crafts alkylation, and esterification. Ten synthetic compounds were prepared and structurally elucidated, including eight new compounds (1a-1c, 2a, 3a, 3b, 4a, 4b) and two known analogs. Under bromination, salazinic acid (1) enabled the following reaction chain: oxidation, decarboxylation, and substitution. This yielded products 1a-1c, which were found to have unprecedented scaffolds. Parmosidone F (5) was prepared from 1 with orsellinic acid via Friedel-Crafts alkylation, confirming a previously reported biosynthesis route. These analogs were evaluated for enzyme inhibition of α-glucosidase, and all showed more potent activity than that of acarbose, a positive control (IC50 332 μM), with IC50 values in the range 9.32–39.96 μM. An in silico molecular docking model confirmed that, in terms of enzyme inhibition, the compounds ranked as follows: 3b > 4b > 4a > 1c > 2a > 1b > 1a > 3a. The kinetics of enzyme inhibition showed 4a and 5 to be a non-competitive-type and mixed-type inhibitors, respectively.

The natural product lupeol (1) was isolated from Bombax ceiba leaves, which were used as starting material in the semisynthetic approach. Three new derivatives (2a, 2b, and 3) were synthesized using oxidation and aldolization. Their chemical structures were elucidated by spectroscopic analyses (HRESIMS and NMR). Compounds 3 showed significant α-glucosidase inhibition with an IC50 value of 202 µM, whereas 2a and 2b were inactive.

A new labdane-type diterpenoid, 9-epi-vitexnegundin (1), was isolated from the leaves of Vitex negundo L. together with seven known compounds: 8,13-diepi-manoyl oxide (2), 8-epi-sclareol (3), sclareol (4), 9,13-epoxy-labd-14-ene (5), vitedoin B (6), argyol (7), and predicularis-lactone (8). The chemical structures were elucidated by analysis of spectroscopic data and comparison with published NMR data. The DP4+ probability method was used to determine the relative stereochemistry of 9-epi-vitexnegundin. Complete NMR assignments of compound 2 were determined, revising the previously-reported NMR data for this compound. The stereochemistry of 9,13-epoxy-labd-14-ene (5) was elucidated for the first time, based on NOESY correlations. All isolated compounds 1–8 were evaluated for cytotoxicity against the K562 cell line, as were vitexnegundin (9), vitexilactone (10), vitetrifolin D (11), 13-hydroxy-5(10), 14-halimadien-6-one (12), artemetin (13), vitexicarpin (14), penduletin (15). Compounds 10–15 exhibited moderate cytotoxicity, with IC50 values in the range 15.7–79.8 µM.

Two new cycloartanes, combretanones G and H (1 and 2), were isolated from the leaves of Combretum quadrangulare. Their structures were elucidated by applying a set of spectroscopic methods, while their relative configurations were determined using DFT-NMR chemical shift calculations and subsequent assignment of DP4 probabilities. Compounds 1 and 2 are C-23/C-24 stereoisomers of the previously-reported euphonerin E. Both exhibited moderate cytotoxicity against three human cancer cell lines. Compound 2 was shown to be a potent antiparasitic. Our results confirm the traditional medicinal uses of Combretum quadrangulare in Vietnam.

α-Glucosidase plays a role in hydrolyzing complex carbohydrates into glucose, which is easily absorbed, causing postprandial hyperglycemia. Inhibition of α-glucosidase is therefore an ideal approach to preventing this condition. A novel polyprenylated benzoylphloroglucinol, which we named schomburgkianone I (1), was isolated from the fruit of Garcinia schomburgkiana, along with an already-reported compound, guttiferone K (2). The structures of the two compounds were determined using NMR and HRESIMS analysis, and comparisons were made with previous studies. Compounds 1 and 2 exhibited potent α-glucosidase inhibition (IC50s of 21.2 and 34.8 µM, respectively), outperforming the acarbose positive control. Compound 1 produced wide zones of inhibition against Staphylococcus aureus and Enterococcus faecium (of 21 and 20 mm, respectively), compared with the 19 and 20 mm zones of compound 2, at a concentration of 50 µg/mL. The MIC value of compound 1 against S. aureus was 13.32 µM. An in silico molecular docking model suggested that both compounds are potent inhibitors of enzyme α-glucosidase and are therefore leading candidates as therapies for diabetes mellitus.

Lichen-derived monoaromatic compounds are bioactive compounds, associated with various pharmacological properties: antioxidant, antifungal, antiviral, cytotoxicity, and enzyme inhibition. However, little is known about data regarding alpha-glucosidase inhibition and antimicrobial activity. Very few compounds were reported to have these activities. In this paper, a series of monoaromatic compounds from a lichen source were isolated and structurally elucidated. They are 3,5-dihydroxybenzoic acid (1), 3,5-dihydroxybenzoate methyl (2), 3,5-dihydroxy-4-methylbenzoic acid (3), 3,5-dihydroxy-4-methoxylbenzoic acid (4), 3-hydroxyorcinol (5), atranol (6), and methyl hematommate (7). To obtain more derivatives, available compounds from the previous reports such as methyl β-orsellinate (8), methyl orsellinate (9), and D-montagnetol (10) were selected for bromination. Electrophilic bromination was applied to 8–10 using NaBr/H2O2 reagents to yield products methyl 5-bromo-β-orsellinate (8a), methyl 3,5-dibromo-orsellinate (9a), 3-bromo-D-montagnetol (10a), and 3,5-dibromo-D-montagnetol (10b). Compounds were evaluated for alpha-glucosidase inhibition and antimicrobial activity against antibiotic-resistant, pathogenic bacteria Enterococcus faecium, Staphylococcus aureus, and Acinetobacter baumannii. Compound 4 showed stronger alpha-glucosidase inhibition than others with an IC50 value of 24.0 µg/mL. Synthetic compound 9a exhibited remarkable activity against Staphylococcus aureus with a MIC value of 4 µg/mL. Molecular docking studies were performed to confirm the consistency between in vitro and in silico studies.

Bioactive-guided phytochemical investigation of Euphorbia antiquorum L. growing in Vietnam led to the isolation of five ent-atisanes, one seco-ent-atisane, and one lathyrane (ingol-type). The structures were elucidated as ent-1α,3α,16β,17-tetrahydroxyatisane (1), ethyl ent-3,4-seco-4,16β,17-trihydroxyatisane-3-carboxylate (2), ent-atisane-3-oxo-16β,17-acetonide (3), ent-3α-acetoxy-16β,17-dihydroxyatisane (4), ent-16β,17-dihydroxyatisane-3-one (5), calliterpenone (6), and ingol 12-acetate (7). Their chemical structures were unambiguously determined by analysis of one-dimensional (1D) and two-dimensional (2D) nuclear magnetic resonance (NMR) and high resolution mass spectrometry, as well as by comparison with literature data. Among them, 1 is a new compound while 2 is an ethylated artifact of ent-3,4-seco-4,16β,17-trihydroxyatisane-3-carboxylic acid, a new compound. Isolates were evaluated for alpha-glucosidase inhibition. Compound 3 showed the most significant inhibitory activity against alpha-glucosidase with an IC50 value of 69.62 µM. Further study on mechanism underlying yeast alpha-glucosidase inhibition indicated that 3 could retard the enzyme function by noncompetitive.

Combretum quadrangulare Kurz is widely used in folk medicine in Eastern Asia and is associated with various ethnopharmacological properties including hepatoprotective, antipyretic, analgesic, antidysenteric, and anthelmintic activities. Previous phytochemical investigations reported the presence of numerous triterpenes (mostly cycloartanes, ursanes, lupanes, and oleananes) along with dozens of flavonoids. However, the extracts of C. quadrangulare and isolated flavonoids have not been evaluated for their alpha-glucosidase inhibition. In the frame of our efforts dedicated to the chemical investigation of Vietnamese medicinal plants and their biological activities, a phytochemical study of the MeOH extract of the leaves of C. quadrangulare using bioactive guided isolation was undertaken. In this paper, the isolation and structure elucidation of twelve known compounds, 5-hydroxy-3,7,4′-trimethoxyflavone (1), ayanin (2), kumatakenin (3), rhamnocitrin (4), ombuin (5), myricetin-3,7,3′,5′-tetramethyl ether (6), gardenin D (7), luteolin (12), apigenin (13), mearnsetin (14), isoorientin (15), and vitexin (16) were reported. Bromination was applied to compounds 2 and 3 to provide four new synthetic analogues 8–11. All isolated and synthesized compounds were evaluated for alpha-glucosidase inhibition and antibacterial activity. Compounds 4 and 5 showed moderate antibacterial activity against methicillin-resistant Staphylococcus aureus while others were inactive. All compounds failed to reveal any activity toward extended spectrum beta-lactamase-producing Escherichia coli. Compounds 2, 4, 6–9, and 11–14 showed good alpha-glucosidase inhibition with IC50 values in the range of 30.5–282.0 µM. The kinetic of enzyme inhibition showed that 8 and 11 were noncompetitive type inhibition against alpha-glucosidase. In silico molecular docking model indicated that compounds 8 and 11 were potential inhibitors against enzyme α-glucosidase.

Euphorbia tirucalli is a medicine plant possessing many bioactive properties. This paper focused on phytochemical screening (alkaloid, flavonoid, saponin, tannin, and anthraquinone), quantification of polyphenol and flavonoids, and activating evaluation of antioxidants and antimicrobial properties against Xanthomonas axonopodis of different extracts from Euphorbia tirucalli grown in Binh Thuan, Vietnam. The best activity fraction was used for purification and determining bioactive ingredients. The results showed that the phytochemical study revealed the presence of alkaloids, flavonoids, tannins, and terpenoids in the ethyl acetate fraction. Saponin and anthraquinone did not present in all extracts. The content of polyphenol and flavonoid of Euphorbia tirucalli stem was in the range of 16.65–106.32 mg EqAG/g and 97.97–450.83 μg QE/g. The ethyl acetate fraction showed higher amounts of polyphenol and flavonoids and antimicrobial activity against X. axonopodis than other fractions. The antioxidant (SC50) activity of Euphorbia tirucalli stem was in the range of 12.91 ± 0.70 and 528.33 ± 25.15 μg/mL. At concentrations of 5.0 and 7.5 mg/mL, the diameter of inhibition of the ethyl acetate fraction was 14.33 ± 0.76 mm and 17.87 ± 0.57 mm, respectively. The MIC (minimum inhibitory concentration) was 0.156 mg/mL. Scopoletin, gallic acid, and piperic acid got MICs corresponding to 78, 312, and 312 μg/mL, respectively. Scopoletin, gallic acid, and piperic acid were found in the ethyl acetate fraction of Euphorbia tirucalli and exhibited the treatment of citrus bacteria canker and plant diseases.

Cancer is the second leading cause of death globally, and despite the advances in drug development, it is still necessary to develop new plant-derived medicines. Compared with using conventional chemical drugs to decrease the side effects induced by chemotherapy, natural herbal medicines have many advantages. The present study aimed to discover the potential cytotoxicity of ethanol extract and its derived fractions (chloroform, ethyl acetate, butanol, and aqueous) of Adenosma bracteosum Bonati. (A. bracteosum) on human large cell lung carcinoma (NCI-H460) and hepatocellular carcinoma (HepG2). Among these fractions, the chloroform showed significant activity in the inhibition of proliferation of both cancerous cells because of the presence of bioactive compounds including xanthomicrol, 5,4’-dihydroxy-6,7,8,3’-tetramethoxyflavone, and ursolic acid which were clearly revealed by nuclear magnetic resonance spectroscopy (1H-NMR, 13C-NMR, Heteronuclear Multiple Bond Coherence, and Heteronuclear Single Quantum Coherence Spectroscopy) analyses. According to the radical scavenging capacity, the 5,4’-dihydroxy-6,7,8,3’-tetramethoxyflavone compound (AB2) exhibited the highest anticancer activity on both NCI-H460 and HepG2 with IC50 values of 4.57 ± 0.32 and 5.67 ± 0.09 µg/mL respectively, followed by the ursolic acid with the lower percent inhibition at 13.05 ± 0.55 and 10.00 ± 0.16 µg/mL, respectively (p < 0.05). Remarkably, the AB2 compound induced to significant increase in the production of reactive oxygen species accompanied by attenuation of mitochondrial membrane potential, thus inducing the activation of caspase-3 activity in both human lung and liver cancer cells. These results suggest that A. bracteosum is a promising source of useful natural products and AB2 offers opportunities to develop the novel anticancer drugs.

Two new lindenane sesquiterpenes were obtained from the roots of Lindera myrrha. These compounds were structurally elucidated by HRMS data, extensive NMR analyses, and comparison between experimental and theoretical 13C-NMR data. Myrrhalindenane A is the first monomeric seco-d lindenane displaying a non-rearranged, cyclohexanic C-ring. Myrrhalindenane B is the second occurrence of an angular lindenane-sesquiterpene related to a C6-C7 lactonization.

Bouea macrophylla is a tree widely grown throughout South East Asia. It is used in folk medicine for the treatment of various illnesses. The present study aimed to identify the chemical constituents and to test the antimicrobial and anticancer activities of an ethanol extract from B. macrophylla leaves. The extract exhibited excellent antibacterial properties against 9 out of 10 target microorganisms. including four Gram-negative bacteria (Escherichia coli, Shigella flexneri, Vibrio cholera, and Pseudomonas aeruginosa) and four Gram-positive bacteria (Staphylococcus aureus, Listeria monocytogenes, Enterococcus faecalis, and Bacillus cereus), as well as a fungus (Candida albicans). In addition, the extract was also tested on HeLa and human colorectal carcinoma (HCT116) cells to evaluate its cytostatic effects. The ethanol extract was able to inhibit the proliferation of HeLa and HCT116 cells, showing IC50 = 24 ± 0.8 and 28 ± 0.9 µg/mL, respectively, whereas the IC50 values of doxorubicin (standard) were 13.6 ± 1.3 and 15.8 ± 1.1 µg/mL respectively. Also, we identified various bioactive compounds in the extract such as polyphenols, flavonoids, caryophyllene, phytol, and trans-geranylgeraniol by GC-MS, which could contribute to the extract’s biological activities. Therefore, our findings strongly indicate that the constituents of the B. macrophylla ethanol extract could be active against the tested bacteria and fungi as well as cancer cells. Further investigation is needed to understand the mechanisms mediating the antimicrobial and anticancer effects and identify signaling pathways that could be targeted for therapeutic application.

Two new cycloartane glycosides, nervisides I−J, were isolated from Nervilia concolor whole plants. Their structures were unambiguously established by interpretation of their HRESIMS and 1D and 2D NMR data. These cycloartanes comprised a stereogenic center at C-24, the R configuration of which was assigned based on DFT-NMR calculations and the subsequent DP4 probability score. These compounds were tested for cytotoxicity against K562 and MCF-7 tumor cell lines, revealing mild cytotoxic activity.

A phytochemical investigation of the foliose lichen Parmotrema tsavoense (Krog and Swinscow) Krog and Swinscow (Parmeliaceae) resulted in the isolation of a new trichlorinated xanthone, isodemethylchodatin. The structure elucidation of this new norlichexanthone derivative proved tricky owing to proton deficiency, and to the lack of NMR data of closely related analogues. The structure of this compound was determined based on an integrated interpretation of 13C-NMR chemical shifts, MS spectra, and DP4-based computational chemistry was also performed to provide an independent and unambiguous validation of the determined structure. Isodemethylchodatin represents the first chlorinated lichexanthone/norlichexanthone derivative bearing a methoxy group at C-5.