Forty-four endophytes were isolated from Zingiber cassumunar and identified morphologically. The ethyl acetate extracts of all endophytes were obtained. The ethyl acetate extracts were subjected to study antibacterial and antioxidant activities. The ethyl acetate extract of the Arthrinium sp. MFLUCC16-1053 showed activity against both gram-positive and gram-negative bacteria. Specifically, the minimum inhibition concentration against Staphylococcus aureus and Escherichia coli was 31.25 and 7.81 µg/mL, respectively. In addition, the crude extract showed highest antioxidant activity in 2,2-diphenyl-1-picrylhydrazyl scavenging at IC50 value of 28.47 µg/mL. Gas chromatography-mass spectrometry analysis revealed that the extract of the Arthrinium sp. MFLUCC16-1053 contains various antibacterial and antioxidant compounds which are β-cyclocitral, 3E-cembrene A, laurenan-2-one, sclareol, 2Z,6E-farnesol, cembrene, β-isocomene and γ-curcumene. The fungus Arthrinium sp. MFLUCC16-1053 was also identified by molecular and phylogenetic methods.

Five new xanthones, garciniacowones A-E (1-5), together with 14 known xanthones, 6-19, were isolated from the young fruits and fresh flowers of Garcinia cowa. The structures of 1-5 were elucidated by analysis of their 1D and 2D NMR spectra and mass spectrometric data. The compounds 1-19 were tested in vitro for their antimicrobial activity and for their ability to inhibit α-glucosidase. Compounds 16 and 17 showed the most potent α-glucosidase inhibitory activity, with IC50 values of 7.8 ± 0.5 and 8.7 ± 0.3 μM, respectively. Compounds 8, 9, and 19 showed antibacterial activity against Bacillus subtilis TISTR 088 with identical MIC values of 2 μg/mL, while 8, 10, and 19 exhibited antibacterial activity against Bacillus cereus TISTR 688 with identical MIC values of 4 μg/mL.

Vermelhotin exhibited potential anti-inflammatory activity through inhibition of nitric oxide production (IC₅₀ = 5.35 ± 0.59 μM) in LPS-stimulated RAW 264.7 macrophage cells. Vermelhotin suppressed expression of inducible nitric oxide synthase (iNOS) at mRNA and protein levels, in a dose-dependent manner. Mechanistic studies revealed that vermelhotin abrogated upstream signaling of iNOS expression by selectively inhibiting p38 phosphorylation, while ERK and JNK activations were not affected.

The biflavonoid, 3'',4',4''',5,5'',7,7''-heptahydroxy-3,8-biflavanone, known as GB1 (1), was isolated as a major constituent from Garcinia kola stem bark. GB1 (1) exhibited alpha-glucosidase and aromatase inhibitory activities, as well as antiplasmodial activity, but was not toxic against cell lines tested. GB1 (1) may be a potential dietary supplement or phytomedicine for the prevention of breast cancer and type 2 diabetes mellitus.

Three new isoflavanones (1-3) and thirteen known compounds (4-16) were isolated from the roots of Mucuna pruriens. The absolute configurations of isoflavanones 1-3 and parvisoflavanone (4), lespedeol C (5), and uncinanone C (6) were addressed by a circular dichroism technique. Isoflavanones, isoflavones, and pterocarpans of M. pruriens were found to be α-glucosidase inhibitors. Medicarpin (7) and parvisoflavone B (9) were potent α-glucosidase inhibitors (twofold less active than the standard drug acarbose). The production of bioactive metabolites in M. pruriens seems to be season-dependent.

Thirty-four endophytic fungal isolates were obtained from the leaves of the medicinal plant Polyscias fruticosa, and their antagonistic activities against the growth of the common tomatoes plant pathogenic fungus Athelia rolfsii were initially screened using a dual culture assay. The endophytic fungus MFLUCC 17-0313, which was later molecularly identified as Diatrype palmicola, displayed the highest inhibition percentage (49.98%) in comparison to the others. This fungus was then chosen for further evaluation. Its culture broth and mycelia from a 10 L scale were separated and extracted using ethyl acetate, methanol, and hexane. Each extract was tested for antifungal activity against the same pathogen using a disc diffusion assay. Only the crude hexane extract of fungal mycelium showed antifungal activity. The hexane extract was fractioned using sephadex gel filtration chromatography and each fraction was tested for antifungal activity until the one with the highest inhibition percentage was obtained. The bioactive compound was identified as 8-methoxynaphthalen-1-ol using nuclear magnetic resonance spectroscopy and mass spectrometry. The minimum inhibition concentration of 8-methoxynaphthalen-1-ol was demonstrated at 250 µg/mL against the selected pathogen. Using the leaf assay, the solution of 8-methoxynapthalen-1-ol was tested for phytotoxic activity against A. rolfsii and was found to have no phytotoxic effects. These results showed that 8-methoxynaphthalen-1-ol has the potential for controlling the growth of A. rolfsii, the cause of Southern blight disease on tomatoes. This study may provide the foundation for future use of this compound as a biofungicide.

Phytochemical investigation of Garcinia propinqua roots led to the isolation and identification of a new xanthone, doitunggarcinone D (1), together with 15 known compounds (2–16). Their structures were elucidated by intensive analysis of spectroscopic data. Compounds 3, 6, 7, 14, 15 and 16 exhibited strong antibacterial activity against Bacillus subtilis TISTR 088 with MIC values in the range of 1–4 μg/mL. Compounds 3, 7, 10 and 14 also showed good antibacterial activity against B. cereus TISTR 688 with MIC values ranging from 4–8 μg/mL.

The present work reports the chemical compositions, antibacterial and antioxidant activities of essential oils from T. jasminoides flowers collected from two different geographical areas, Chiang Rai and Chiang Mai, Thailand. The essential oil of T. jasminoides from the Chiang Rai area had 99 compounds representing 97.9% of the total oil composition, with E-nerolidol and -phellandrene as the major constituents. In contrast, the essential oil of T. jasminoides collected from the Chiang Mai area contained 93 components representing 94.8% of the total oil, with trans-linalool oxide and citronellol as the major compounds. Flower oils of T. jasminoides exhibited greater antibacterial activities against Gram-negative bacteria than Gram-positive bacteria. Both oils displayed antioxidant activities.