Sử dụng trong sự ức chế in vitro của cyclooxygenase-hướng dẫn phân đoạn, họ đã phân lập một loạt các flavonoid prenylated mà ức chế hoạt động enzyme cyclooxygenase Macaranga triloba và Macaranga conifera (hình 26,7). Flavonoid này bao gồm | PHAN TẤT HOÀ --- NHỮNG CÂY TI H OC CHÂU Á THÁI BÌNH DƯƠNG 158 Lupinifolinol Figure Prenylated flavonoids which inhibit the enzymatic activity of cyclooxygenase from the Macaranga species. the exploration of the pharmacological potential of the Macaranga species has been provided by the work of Jang et 15 Using in vitro inhibition of cyclooxygenase-guided fractionation they isolated a series of prenylated flavonoids which inhibit the enzymatic activity of cyclooxygenase from Macaranga triloba and Macaranga conifera Figure . Such flavonoids include 4 5dihydroxy-40 a-methoxy-6 and a12a-dehydro-a-toxicarol which is possibly involved in the antiinflammatory property of Macaranga tanarius . but it remains to be confirmed by experimentation. Lonchocarpol A sophoraflavanone B lupinifolinol and isolicoflavonol inhibited the enzymatic activity of cyclooxygenase I with IC50 values of and respectively. REFERENCES 1. El-Mekkawy S. Meselhy R. Nakamura N. Hattori M. Kawahata T. and Otake T. 2000. AntiHIV-1 phorbol esters from the seeds of Croton tiglium. Phytochemistry 53 457. 2. Arbain D. and Taylor W. C. 1993. Cyclopeptide alkaloids from Antidesma montana. Phytochemistry 3 1263. 3. Buske A. Schmidt J. and Hoffmann P. 2002. Chemotaxonomy of the tribe Antidesmeae Euphorbiaceae antidesmone and related compounds. Phytochemistry 60 5 489. 4. Buske A. Busemann S. Muhlbacher J. Schmidt J. Porzel A. Bringmann G. and Adam G. 1999. Antidesmone a novel isoquinoline alkaloid from Antidesma membranaceum Euphorbiaceae . Tetrahedron 55 1079. 5. Bringmann G. Schlauer J. Rischer H. Wohlfarth M. Muhlbacher J. Buske A. Porzel A. Schmidt J. and Adam G. 2000. Revised structure of antidesmone an unusual alkaloid from tropical Antidesma plants Euphorbiaceae . Tetrahedron 56 3691. 6. Garain A. K. Chakravarti N. N. and Chakrabartty T. 1973. Chemical investigation of Antidesma ghaesembilla Gaertn. Bull. Calcutta Sch. Trop. Med. 21 26. 7. Lee S. H. .
