apigenin and flavanone

As part of an ongoing search for new natural products from medicinal plants to treat respiratory disease, six new compounds, a dihydroflavonol (1) and five C-geranylated flavanones (3, 6, 8, 13, and 14), and 13 known compounds were isolated from mature fruits of Paulownia tomentosa. The structures of the new compounds were determined via interpretation of their spectroscopic data (1D and 2D NMR, UV, IR, ECD, and MS). In biological activity assays with human alveolar basal epithelial cells, the expression of TNF-α-induced proinflammatory cytokines (IL-8 and IL-6) was reduced significantly by the EtOAc fraction of a P. tomentosa extract as well as by the new compounds isolated from this fraction. Furthermore, the majority of the isolates (1-19 except 5-7) were found to inhibit human neutrophil elastase (HNE) activity, with IC

Topics: Anti-Inflammatory Agents, Non-Steroidal; Flavanones; Fruit; Humans; Interleukin-6; Interleukin-8; Magnoliopsida; Molecular Structure; Nuclear Magnetic Resonance, Biomolecular; Proteinase Inhibitory Proteins, Secretory; Republic of Korea; Tumor Necrosis Factor-alpha

Random Forest screening of the phytochemical constituents of 240 herbs used in traditional Chinese medicine identified a number of compounds as potential inhibitors of the human aromatase enzyme (CYP19). Molecular modelling/docking studies indicated that three of these compounds (myricetin, liquiritigenin and gossypetin) would be likely to form stable complexes with the enzyme. The results of the virtual screening studies were subsequently confirmed experimentally, by in vitro (fluorimetric) assay of the compounds' inhibitory activity. The IC-50s for the flavones, myricetin and gossypetin were determined as 10 and 11 microM, respectively, whilst the flavanone, liquiritigenin, gave an IC-50 of 0.34 microM--showing about a 10-fold increase in potency, therefore, over the first generation aromatase inhibitor, aminoglutethimide.

Topics: Algorithms; Aminoglutethimide; Aromatase Inhibitors; Drug Evaluation, Preclinical; Drugs, Chinese Herbal; Flavanones; Flavonoids; Fluorometry; Humans; Inhibitory Concentration 50; Models, Molecular; Structure-Activity Relationship