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.
Bioactive Natural Products and Phytoceuticals, Department of Horticulture and National Food Safety and Toxicology Center, Michigan State University, East Lansing, Michigan 48824, USA.
Yanjun
Y
Zhang
David L
DL
Dewitt
Sorimuthu
S
Murugesan
Muraleedharan G
MG
Nair
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