6-substituted purines as inhibitors of 15-lipoxygenase; a structure-activity study.
15-lipoxygenase (15-LO) has been implicated in oxidation of low-density lipoproteins (LDL), a process believed to be important for the development of atherosclerosis, as well as other pathogenic conditions. Potent and selective inhibitors of 15-LO may have a drug potential. In this study, purines with a variety of substituents have been examined as inhibitors of 15-lipoxygenase (15-LO) from soybeans. Several 6-substitued purines where the purine ring and a phenyl ring in the substituent were separated by a "spacer" were synthesized and their ability to inhibit the enzyme was explored. Sepa ration of the purine and the phenyl rings with none, one or two sp3-carbons resulted in essentially inactive compounds, trans-styrylpurines and phenylethynylpurines, on the other hand, they exhibited activity close to the well-known 15-LO inhibitor quercetin. High activity was also found when the "spacer" was a trans-cyclopropyl ring. The shape of the spacer was important; a corresponding cis-cyclopropylpurine exhibited much less affinity for the enzyme. Only minor differences in inhibitory activity against 15-LO were found regardless of whether an N-substituent was situated on N-9 or N-7, even when the N-substituent was relatively large. Also, a variety of substituents in the purine 2- and 8-position were well tolerated.
Bråthe
Anders
A
Department of Chemistry, University of Oslo, Oslo, Norway.
Gundersen
Lise-Lotte
LL
Malterud
Karl E
KE
Rise
Frode
F
D001093:Arachidonate 15-Lipoxygenase / Q000378:metabolism*; D016859:Lipoxygenase Inhibitors / Q000138:chemical synthesis* / Q000494:pharmacology*; D011687:Purines / Q000138:chemical synthesis* / Q000494:pharmacology*; D013329:Structure-Activity Relationship
D016859:Lipoxygenase Inhibitors; D011687:Purines; D001093:Arachidonate 15-Lipoxygenase