Phytochemical investigations of ethyl acetate-soluble part of the aerial part of Hypericum scabrum L. delivered eight pure phenolic compounds 1–8. The pure compounds were identified through physico-chemical, NMR (1D, 2D) and mass spectrometric studies as: 3-8′′-bisapigenin (1), quercetin (2), quercetin-3-O-α-l-arabinofuranoside (3), quercetin-3-O-α-l-rhamnoside (4), quercetin-3-O-β-d-glucopyranoside (5), quercetin-3-O-β-d-galactopyranoside (6), (−)-epicatechin (7), (+)-catechin (8). Total polyphenolic compounds and total flavonoids contents were determined in the extract as 0.107 mg∙mg⁻¹ and 0.023 mg∙mg⁻¹ of the dried extract, respectively. Antioxidant activity using DPPH free radical scavenging assay delivered very strong activity for compounds 2 and 5, 6 and crude extract 10. Protein tyrosine phosphatase 1B (PTP-1B) inhibition experiment of isolated compounds and crude extracts resulted in significant inhibition activity for samples 2, 7a, 8a, 11 and 12 with IC₅₀ values ranging from 1.57 to 2.91 µM. Antimicrobial activity of the pure compounds and extracts produced average results against Staphylococcus aureus, Escherichia coli and Candida albicans strains. From our literature survey, it appears that all pure compounds except 2 were isolated and reported for the first time in H. scabrum.

The root of Geranium collinum Steph is known in Tajik traditional medicine for its hepatoprotective, antioxidant, and anti-inflammatory therapeutic effects. The present study was conducted to evaluate of potential antidiabetic, antioxidant activities, total polyphenolic and flavonoid content from the different extracts (aqueous, aqueous-ethanolic) and individual compounds isolated of the root parts of G. collinum. The 50% aqueous-ethanolic extract possesses potent antidiabetic activity, with IC₅₀ values of 0.10 μg/mL and 0.09 μg/mL for the enzymes protein-tyrosine phosphatase (1B PTP-1B) and α-glucosidase, respectively. Phytochemical investigations of the 50% aqueous-ethanolic extract of G. collinum, led to the isolation of ten pure compounds identified as 3,3′,4,4′-tetra-O-methylellagic acid (1), 3,3′-di-O-methylellagic acid (2), quercetin (3), caffeic acid (4), (+)-catechin (5), (–)-epicatechin (6), (–)-epigallocatechin (7), gallic acid (8), β-sitosterol-3-O-β-d-glucopyranoside (9), and corilagin (10). Their structures were determined based on 1D and 2D NMR and mass spectrometric analyses. Three isolated compounds exhibited strong inhibitory activity against PTP-1B, with IC₅₀ values below 0.9 μg/mL, more effective than the positive control (1.46 μg/mL). Molecular docking analysis suggests polyphenolic compounds such as corilagin, catechin and caffeic acid inhibit PTP-1B and β-sitosterol-3-O-β-d-gluco-pyranoside inhibits α-glucosidase. The experimental results suggest that the biological activity of G. collinum is related to its polyphenol contents. The results are also in agreement with computational investigations. Furthermore, the potent antidiabetic activity of the 50% aqueous-ethanolic extract from G. collinum shows promise for its future application in medicine. To the best of our knowledge, we hereby report, for the first time, the antidiabetic activity of G. collinum.

Seventeen compounds were isolated from the capitula of Coreopsis tinctoria Nutt. with various column chromatographic methods and semi-preparative HPLC. Their structures were identified by the spectroscopic data and comparison with literatures as 2′-hydroxy-4,4′-dimethoxy-chalcone; (1), isoliquiritigenin (2), eriodictyol (3), naringenin (4), maritimetin (5), butin (6), taxifolin (7), luteolin (8), 7,3′,4′-trihydroxyflavone (9), 8,3′,4′-trihydroxyflavone-7-O-β-d-glucoside (10), quercetin (11), quercetagitin-7-O-β-d-glucoside (12), quercetin-7-O-β-d-glucoside (13), 3,4-dihydroxybenzoic acid (14), caffeic acid (15), coreoside B (16), and myo-inositol (17). Compounds 1, 4, 9, 10 and 17 were isolated from C. tinctoria Nutt. for the first time. Compounds 7 and 12 possessed the highest antioxidant activity (IC₅₀ = 64.37 and 32.86 µg/ml, respectively) among the tested compounds (IC₅₀ value of positive control was 5.34 µg/ml). Compound 7 exhibited potent PTP1B enzymatic inhibition with an IC₅₀ value of 7.73 μg/ml (IC₅₀ value of positive control is 1.46 µg/ml). Furthermore, compound 5 showed strong antibacterial activity against the Gram-positive bacterium, S. aureus.

Herein, we report the synthesis and biological evaluation of a novel series of diethyl 2,5-diaminothiophene-3,4-dicarboxylate (DDTD) derivatives as antitumor and anti-influenza virus agents.