Xanthine Oxidase Inhibition by Monoterpene-Chalcone Conjugates from Kaempferia subglobosaand Molecular Docking Insights.

Kaempferia subglobosa is a perennial medicinal plant in the Zingiberaceae family, identified as a new species in January 2024. To uncover the biological benefits of K. subglobosa and its compounds, investigation of the metabolites of the roots and rhizomes, yielded three new monoterpene-chalcone conjugates, the globosones A-C, representing a rare metabolite group within the Zingiberaceae, along with six known compounds. The biogenetic pathway for the globosones involves an oxidative [3+2] cycloaddition between α-phellandrene and 4'-methoxy-4,2',6'-trihydroxychalcone. Biological testing revealed potent xanthine oxidase (XO) inhibition by globosones A and B, with IC50 values of 7.0 ± 1.0 and 3.0 ± 0.2 µM, respectively, surpassing the positive control drug allopurinol (IC50 7.2 ± 0.1 µM). Globosones A-C also showed good aromatase inhibition (IC50 3.0-3.5 µM). Molecular docking studies indicated that globosones A and B may inhibit xanthine oxidase through binding at the FAD domain site. The physicochemical properties of these isolates suggest that they possess characteristics suitable for additional biological assessment in more advanced test systems. This study enhances an understanding of monoterpene-chalcone conjugate inhibitors of XO, and offers preliminary insights into the metabolites and bioactivities of K. subglobosa, uncovering potent biological activities associated with this newly discovered plant species.

Antifungal activity of 8-methoxynaphthalen-1-ol isolated from the endophytic fungus Diatrype palmicola MFLUCC 17-0313 against the plant pathogenic fungus Athelia rolfsii on tomatoes.

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.

Cytotoxic endophyte from Camellia oleifera Abel - Penicillium chermesinum NR121310.

Ten unknown endophytes were isolated from several parts of Camellia oleifera Abel and their biological activities were studied. One endophyte, Tea2-L1, showed the highest inhibition in various antioxidant capacity assay and cytotoxicity assays. The phylogenetic study suggested that Tea2-L1 endophyte is identified as Penicillium chermesinum NR121310 species. This shows the importance of the Penicillium species as a potential drug source.

Antagonistic Activity against Dirty Panicle Rice Fungal Pathogens and Plant Growth-Promoting Activity of Bacillus amyloliquefaciens BAS23.

Bacterial strain BAS23 was isolated from rice field soil and identified as Bacillus amyloliquefaciens. Based on dual culture method results, the bacterium BAS23 exhibited potent in vitro inhibitory activity on mycelial growth against a broad range of dirty panicle fungal pathogens of rice (Curvularia lunata, Fusarium semitectum and Helminthosporium oryzae). Cell-free culture of BAS23 displayed a significant effect on germ tube elongation and mycelial growth. The highest dry weight reduction (%) values of C. lunata, H. oryzae and F. semitectum were 92.7%, 75.7% and 68.9%, respectively. Analysis of electrospray ionization-mass spectrometry (ESI-MS) and 1H nuclear magnetic resonance (NMR) spectroscopy revealed that the lipopeptides were iturin A with a C14 side chain (C14 iturinic acid) and with a C15 side chain (C15 iturinic acid), which were produced by BAS23 when it was cultured in nutrient broth (NB) for 72 h at 30°C.BAS23, the efficient antagonistic bacterium, also possessed in vitromultipletraits for plant growth promotionand improved rice seedling growth. The results indicated that B.amyloliquefaciens BAS23 represents a useful option either for biocontrol or as a plant growth-promoting agent.

In vitro acanthamoebicidal activity of fusaric acid and dehydrofusaric acid from an endophytic fungus Fusarium sp. Tlau3.

Acanthamoeba is a genus of free-living protozoa that can cause sight- and life-threatening diseases in man. Its control is still problematic due to the lack of effective and nontoxic acanthamoebicidal agents. Herein, we report the first finding of an in vitro killing effect of fusaric acid and dehydrofusaric acid, isolated from metabolites of the Fusarium fujikuroi species complex Tlau3, on Acanthamoeba trophozoites isolated from two clinical (AS, AR) and two soil (S3, S5) samples. AS, AR, and S3 were classified as members of the T4 genotype, whereas S5 belongs to T5. The fungal extract was found to exhibit acanthamoebicidal activity, and activity-guided fractionation led to the isolation and identification of active principles, fusaric acid and dehydrofusaric acid. Their effects were in concentration- and time-dependent manners. Fusaric acid and dehydrofusaric acid showed IC50 values against AS trophozoites of 0.31 and 0.34 µM, respectively. Commercial fusaric acid displayed the same acanthamoebicidal activity as that of the isolated fusaric acid, and therefore, commercial fusaric acid was used throughout this study. IC50 values of commercial fusaric acid against AR, S3, and S5 trophozoites were 0.33, 0.33, and 0.66 µM, respectively. Fusaric acid calcium salt has a history of usage as a hypotensive agent in humans with no observed toxicity. The present study suggests that fusaric acid may serve as a starting point for the development towards therapeutic and environmental acanthamoebicides with low toxicity to humans.

Radical scavenging and antioxidant activities of isocoumarins and a phthalide from the endophytic fungus Colletotrichum sp.

Five known isocoumarins, monocerin (1), derivative 2, and fusarentin derivatives 3-5, and a new phthalide (6) were isolated from the endophytic fungus Colletotrichum sp. 2 selectively exhibited cytotoxic activity toward the HepG2 cell line. Compounds 2 and 4 scavenged 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radicals (IC(50) values of 23.4 and 16.4 µM, respectively) and inhibited superoxide anion radical formation (IC(50) values of 52.6 and 4.3 µM, respectively). The C-7 hydroxyl group in 2 and 4 might be important for radical scavenging activities. Isocoumarins 1-3 and phthalide 6 showed potent antioxidant activity.

Cytotoxic mycoepoxydiene derivatives from an endophytic fungus Phomopsis sp. isolated from Hydnocarpus anthelminthicus.

Mycoepoxydiene ( 1) and derivatives, deacetylmycoepoxydiene ( 2) and 2,3-dihydromycoepoxydiene ( 3), were isolated from a broth extract of the endophytic fungus, phomopsis sp., which was isolated from a Thai medicinal plant, Hydnocarpus anthelminthicus. Compounds 1 and 2 exhibited potent cytotoxic activity, while a dihydro derivative 3 was inactive. The present work suggests that the alpha,beta-unsaturated lactone moiety in mycoepoxydienes might be responsible for the cytotoxicity.