Elucidation of Potential Anticancer, Antioxidant and Antimicrobial Properties of Some New Triazole Compounds Bearing Pyridine-4-yl Moiety and Cyclobutane Ring

Structure Elucidation of a Novel Polysaccharide Isolated from Euonymus fortunei and Establishing Its Antioxidant and Anticancer Properties

Euonymusfortunei polysaccharides (EFPs) have not been extensively investigated yet in terms of their extraction and biological activity. The orthogonal experimental design was employed in this study to evaluate the optimum yield of EFPs. A maximum yield of 2.63 ± 0.23% was attained using material-liquid ratios of 60 mL/g, extraction temperature of 80°C, ultrasonic power of 144 W, and extraction time of 75 mins. The polysaccharide content reached 53.47 ± 0.31% when deproteinized thrice. An analysis of monosaccharide composition revealed that these polysaccharides consist of Gal, Glc, Man, Fuc, and Rha with a molar ratio of 7.14 ∶ 23.99 ∶ 6.29 ∶ 6.55 ∶ 1.00, respectively, in EFPs. Subsequently, the in vitro scavenging capacities of 2,2-diphenylpicrylhydrazyl (DPPH) and ·OH and superoxide anion radicals, along with the reducing power of EFPs, were studied. Results revealed that EFPs have higher antioxidant activity, particularly ·OH scavenging, as well as reducing power, as compared to Astragalus polysaccharides (ASPs) and Lycium barbarum polysaccharides (LBPs). The Cell Counting Kit-8 (CCK-8) method was used to evaluate the effects of different concentrations of polysaccharides on SKOV3 cell proliferation, and the results revealed their inhibition at concentrations in the range of 200-800 μg/mL. In addition, findings from flow cytometry further confirmed that EFPs blocked the cell cycle at G0/G1 and S phases and induced SKOV3 cell apoptosis. In a word, EFPs could be exploited and used further based on the experimental results from this study.

Secondary metabolites produced by endophytic fungi, Alternaria alternata, as potential inhibitors of the human immunodeficiency virus

Antiretroviral treatment has significantly reduced human immunodeficiency virus infection and mortality. However, the current treatment regimen is limited by adverse side effects, the emergence of drug resistance, and the inability to eliminate viral reservoirs. Here, fifteen endophytic fungi were isolated from Sclerocarya birrea and Hypoxis plants. Crude extracts of Alternaria alternata (strain ID PO4PR1, PO4PR2, and PO2PL1) of the fifteen isolate's crude extracts showed anti-HIV-1 activity in TZM-bl cell line at inhibitory concentration (IC₅₀) values ranging from 0.017 to 1.170 μg/ml. The three crude extracts also maintained the virus replication inhibition profile on PBMCs and CD4⁺ T cells at concentrations ranging from 0.3 to 50.2 ng/ml. Partial purification using the solid phase extraction and analysis with Gas Chromatography-Mass spectrophotometry showed a diverse profile. The bioactive compounds were identified based on peak area, retention time, similarity index. The major compounds from GC-MS analysis of A. Alternata revealed the existence of cyclotrisiloxane octamethyl (22.92%); Propaninitrile (16,67%); Pyrrolol[1,2-a]pyrazine-1,4-dione, hexahydro-3-(2-methyl propyl) (10.42%); Silane, diethylethoxy(2-ethoxyethyloxy) (4.17%); Coumarin, 3,4-dihydro-4,5,7-trimethyl- 4,5,7-Trimethyl-2-chromanone (13.7%) and 1,2-Cyclobutanedicarbonitrile (2.08%) with previously reported biological activities such as antimicrobial, anti-inflammatory and antioxidant properties. Therefore, these bioactive compounds from A. alternata fungal endophytes could be repurposed as potential anti-HIV agents. This study showed the potential of endophytic fungi, Alternaria alternata from S. birrea, and Hypoxis species as producers of anti-HIV compounds.