Cyclooxygenase-2 enzyme inhibitory triterpenoids from Picrorhiza kurroa seeds.
A bioassay guided phytochemical study of the ethyl acetate extract of the seeds of Picrorhiza kurroa afforded a new triterpenoid, 2alpha, 3beta, 19beta, 23-tetrahydroxyolean-12-en-28-O-beta-D-glucoside (1), along with five known triterpenoids, 2alpha, 3beta, 19beta, 23-tetrahydroxyolean-12-en-28-oic acid (2), 2alpha, 3beta, 23-trihydroxyolean-12-en-28-O-beta-d-glucoside (3), 2alpha, 3beta, 23-trihydroxyolean-12-en-28-oic acid (4), 2alpha, 3beta, 19beta, trihydroxyolean-12-en-28-oic acid (5), and 2alpha, 3beta, 6beta, 23-tetrahydroxyolean-12-en-28-oic acid (6). Their structures were established by extensive NMR spectral studies. The acetyl derivatives, compounds 7 and 8, were prepared from compounds 1 and 2, respectively, to aid in their structure elucidation. The inhibition of cyclooxygenase-2 (COX-2) enzyme by compounds 1--6 at 100 microg/mL was 38.3%, 39%, 37%, 49.6%, 25%, and 45.0%, respectively. However, compounds 1--6, at 100 microg/mL, did not inhibit cyclooxygenase-1 (COX-1) enzyme. Compound 1 is a novel triterpenoid and compounds 1--6 are isolated for the first time from the seeds of P. kurroa.
Zhang
Yanjun
Y
Bioactive Natural Products and Phytoceuticals, Department of Horticulture and National Food Safety and Toxicology Center, Michigan State University, East Lansing, Michigan 48824, USA.
Dewitt
David L
DL
Murugesan
Sorimuthu
S
Nair
Muraleedharan G
MG
D051545:Cyclooxygenase 1; D051546:Cyclooxygenase 2; D052246:Cyclooxygenase 2 Inhibitors; D016861:Cyclooxygenase Inhibitors / Q000302:isolation & purification* / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D009682:Magnetic Resonance Spectroscopy; D015394:Molecular Structure; D032261:Picrorhiza / Q000737:chemistry*; D011451:Prostaglandin-Endoperoxide Synthases / Q000737:chemistry; D012639:Seeds / Q000737:chemistry; D013329:Structure-Activity Relationship; D014315:Triterpenes / Q000302:isolation & purification* / Q000494:pharmacology
D052246:Cyclooxygenase 2 Inhibitors; D016861:Cyclooxygenase Inhibitors; D014315:Triterpenes; D051545:Cyclooxygenase 1; D051546:Cyclooxygenase 2; D011451:Prostaglandin-Endoperoxide Synthases