Melaleuca quinquenervia is widely grown in tropical areas worldwide. Studies have demonstrated that extracts of its buds, leaves, and branches obtained through hydrodistillation, steam distillation, or solvent extraction exhibit physiological activities, including anti-melanogenic, antibacterial, and antioxidant properties; nevertheless, such extracts are mostly not effectively collected or adequately utilized. Accordingly, this study applied a rapid, effective, and easy-to-operate microwave-assisted water extraction (MAWE) technique for the first time to prepare M. quinquenervia leaf extract (MLE) with improved physiological activities. The results indicated that the optimal irradiation time and liquid/solid ratio for the production of the MLE were 180 s and 20 mL/g, respectively. Under optimal conditions, the freeze-dried MLE achieved a high yield (6.28% ± 0.08%) and highly effective broad-spectrum physiological activities. The MLE exhibited strong antioxidant, antiaging, and anti-inflammatory activities and excellent antityrosinase and antimicrobial activities. Additionally, the MLE was noncytotoxic at concentrations of ≤300 mg/L, at which it exhibited pharmacological activity. The results also indicated that the MLE comprised a total of 24 chemical compounds and 17 phenolic compounds. Among these compounds, luteolin contributed to antityrosinase activity. The extract’s antiaging activity was attributed to ellagic acid and quercetin, its anti-inflammatory activity resulted from ellagic acid and kaempferol, and its antimicrobial activity resulted from quercetin and 3-O-methylellagic acid. In conclusion, the MAWE-derived MLE may be useful as a functional ingredient in cosmetic products, health foods, and botanical drugs.

In this study, a marine brown alga Sargassum cristaefolium-derived fungal strain, Penicillium sumatraense SC29, was isolated and identified. Column chromatography of the extracts from liquid fermented products of the fungal strain was carried out and led to the isolation of six compounds. Their structures were elucidated by spectroscopic analysis and supported by single-crystal X-ray diffraction as four previously undescribed (R)-3-hydroxybutyric acid and glycolic acid derivatives, namely penisterines A (1) and C–E (3–5) and penisterine A methyl ether (2), isolated for the first time from natural resources, along with (R)-3-hydroxybutyric acid (6). Of these compounds identified, penisterine E (5) was a unique 6/6/6-tricyclic ether with an acetal and two hemiketal functionalities. All the isolates were subjected to in vitro anti-angiogenic assays using a human endothelial progenitor cell (EPCs) platform. Among these, penisterine D (4) inhibited EPC growth, migration, and tube formation without any cytotoxic effect. Further, in in vivo bioassays, the percentages of angiogenesis of compound 3 on Tg (fli1:EGFP) transgenic zebrafish were 54% and 37% as the treated concentration increased from 10.2 to 20.4 µg/mL, respectively, and the percentages of angiogenesis of compound 4 were 52% and 41% as the treated concentration increased from 8.6 to 17.2 µg/mL, respectively. The anti-angiogenic activity of penisterine D (4) makes it an attractive candidate for further preclinical investigation.

Introduction: Streptomyces species are prolific producers of bioactive compounds, and they play a role in biological control in agricultural systems. Materials and methods: In the current study, we employed an integrated approach that involved physiological and biochemical characterization, genome mining, comparative genomics, and evolutionary analysis to elucidate the specific genomic determinants underlying the antifungal activity exhibited by STM-2, a novel Streptomyces melanosporofaciens strain, isolated from Chiayi County, Taiwan. Results and discussion: Initial physiological and biochemical characterization, complemented by enzymatic screening, revealed the secretion of antifungal hydrolytic enzymes, including protease, CMCase, pectinase and xylanase, which actively play a role in fungal growth inhibition and fungal cell wall degradation. To elucidate the molecular basis of this activity, a wholegenome sequence was obtained and annotated, revealing a typical high-GC (71%) linear chromosome. Genome mining using antiSMASH predicted an extensive repertoire of 52 biosynthetic gene clusters (BGCs), encompassing type I and II PKS, NRPS, and hybrid PKS–NRPS systems, RiPPs, siderophores, terpenes, and diverse tailoring enzymes (P450s, glycosyltransferases, halogenase candidates). Again, we identified genes tentatively responsible for antifungal activity, including chitinases, β-1,3-glucanases, xylanses, pectinases, and proteases. Comparative pangenomic analysis, supported by high-resolution Average Nucleotide Identity (ANI) and digital DNA–DNA hybridization (dDDH) scores, revealed the evolutionary uniqueness of the strain, identifying an accessory genome containing unique genes specifically associated with specialized antifungal activity. Further in silico structural analysis of these unique gene products using AlphaFold2 yielded threedimensional protein models with very high pLDDT scores, providing high-confidence structural evidence for their specialized functional roles. Collectively, these results provide a comprehensive understanding of the genomic determinants required for potent biocontrol activity, positioning STM-2 as a promising candidate for biocontrol and further research in biotechnological applications.

Au and Ag nanoparticles (NPs) exhibit distinct pharmacological activities, cytotoxicity profiles, and catalytic properties. This study sought to maximize the advantages of both metals while reducing the production of toxic byproducts and promoting the rapid synthesis of Au-Ag alloy NPs. For this, we used Melaleuca quinquenervia leaf extract (MQLE) as a reducing and capping agent alongside microwave-assisted green synthesis techniques. The physicochemical properties and biological activities of the synthesized Au-Ag alloy NPs were systematically evaluated. Our findings confirmed successful synthesis of nearly spherical Au-Ag alloy NPs with an average diameter of 37 nm, achieved within a 60 s irradiation period. Energy-dispersive spectroscopy (EDS) revealed a nearly uniform elemental composition, with Au and Ag constituting 43.56% and 40.21%, respectively, of the alloy. Thermogravimetric (TG) analysis confirmed the complete coating of the NPs with MQLE. Owing to these characteristics, the Au-Ag alloy NPs exhibited low cytotoxicity (half-maximal inhibitory concentration [IC₅₀] > 110 mg/L), strong antioxidant activity (IC₅₀ < 15 mg/L), reasonable antimicrobial efficacy (minimum inhibitory concentration: 2.5–10 mg/L), considerable anti-inflammatory potential (IC₅₀: 9.45–35.41 mg/L), promising wound healing capacity (72.5% in 24 h), and excellent catalytic performance (apparent rate constant: 0.254–0.654 min⁻¹). In conclusion, the rapid, efficient, and environmentally friendly synthesis of Au-Ag alloy NPs demonstrated in this study holds promise for various industrial applications, particularly in pharmaceutical and therapeutic development.