title: New 5-deoxyflavonoids and their inhibitory effects on protein tyrosine phosphatase 1B (PTP1B) activity.
abstract: In the course of our program to search for protein tyrosine phosphatase 1B (PTPB) inhibitors, five new 5-deoxyflavonoids along with eight known derivatives were isolated from EtOAc layer of the root bark of Erythrina abyssinica. Their structures were elucidated on the basis of spectroscopic (IR, UV, MS, CD, 1D- and 2D-NMR) and physicochemical analyses. All isolates exhibited moderate inhibitory effects on the enzyme assay with IC₅₀ values ranging from 14.9 ± 1.6 to 98.1 ± 11.3 μM. Compounds with prenyl and methoxy groups in the B ring (1, 2, 4, 8, and 13) possessed strong activity (IC(50) 14.9 ± 1.6 to 19.2 ± 1.1 μM), while compounds (3, 5, and 9) with 2,2-dimethylpyrano ring showed less inhibitory effect (IC₅₀ 22.6 ± 2.3 to 72.9 ± 9.7 μM). These results suggest that prenyl and methoxy groups may be responsible for the increase on the activity of 5-deoxyflavonoids against PTP1B, but the presence of 2,2-dimethylpyrano ring on the B ring may be induced the decrease of PTP1B inhibitory activity.
authors.affiliation: BK21 Project Team, College of Pharmacy, Chosun University, Dong-gu, Gwangju 501-759, Republic of Korea.
authors.forename: Phi Hung
authors.initials: PH
authors.lastname: Nguyen
authors.forename: Trong Tuan
authors.initials: TT
authors.lastname: Dao
authors.forename: Jayeon
authors.initials: J
authors.lastname: Kim
authors.forename: Do Tuan
authors.initials: do T
authors.lastname: Phong
authors.forename: Derek Tantoh
authors.initials: DT
authors.lastname: Ndinteh
authors.forename: Joseph Tanyi
authors.initials: JT
authors.lastname: Mbafor
authors.forename: Won Keun
authors.initials: WK
authors.lastname: Oh
mesh_terms: D002942:Circular Dichroism; D004791:Enzyme Inhibitors / Q000737:chemistry* / Q000302:isolation & purification / Q000494:pharmacology; D004895:Erythrina / Q000737:chemistry; D005419:Flavonoids / Q000737:chemistry* / Q000302:isolation & purification / Q000494:pharmacology; D006801:Humans; D009682:Magnetic Resonance Spectroscopy; D008968:Molecular Conformation; D024301:Plant Bark / Q000737:chemistry; D018517:Plant Roots / Q000737:chemistry; D054562:Protein Tyrosine Phosphatase, Non-Receptor Type 1 / Q000037:antagonists & inhibitors* / Q000378:metabolism
chemical_list: D004791:Enzyme Inhibitors; D005419:Flavonoids; D054562:Protein Tyrosine Phosphatase, Non-Receptor Type 1