28 research outputs found
Quan sát sự tự sắp xếp thành chuỗi của các hạt tinh thể Nano In2O3 bằng kính hiển vi điện tử quét
Nghiên cứu định lượng một số ginsenosid chính trong sinh khối sâm ngọc linh bằng phương pháp HPLC
Ptp1b Inhibitory Constituents in Vietnam Medicinal Plant Orthosiphon Stamineus Benth..
The methanolic extract of the aerial part of a Vietnam medicinal plant Orthosiphon stamineus Benth in Vietnam shows an inhibitory effect of over 65% inhibition on Protein Tyrosine Phosphatase 1B (PTP1B) enzyme at a concentration of 30 µg/mL. By using assay-guided isolation, four compounds including protocatechuic acid (1), p-hydroxybenzoic acid (2), caffeic acid (3) và methyl 3,4-dihydroxycinnamate (4) have been isolated and structurally identified through spectroscopic (NMR, IR, and MS) data analysis. All of the isolated compounds (1‒4) are tested for their inhibitory effects on PTP1B enzyme activity. As a result, all of these isolated exhibited inhibitory effects on PTP1B with IC50 have values of 29,59 ± 3,99, 24,75 ± 1,12, 27,05 ± 2,94, and 36,12 ± 0,89 µM, respectively. In this essay, ursolic acid shows an IC50 value of 4,12 ± 0,09 µM