title: Design and synthesis of nitrate esters of aromatic heterocyclic compounds as pharmacological preconditioning agents.
abstract: Ischemic preconditioning (IPC) constitutes an endogenous protective mechanism in which one or more brief periods of myocardial ischemia and reperfusion render the myocardium resistant to a subsequent more-sustained ischemic insult. Pharmacological preconditioning represents an ideal alternative of IPC. We now describe the design and synthesis of indole, quinoline, and purine systems with an attached pharmacophoric nitrate ester group. The indole and quinoline derivatives 4 and 5 possess structural features of the nitrate containing K(ATP) channel openers. Purine analogues 11 and 12, substituted at the position 6 by a piperidine moiety and at position 9 by an alkyl nitrate, could combine the effects of the nitrate containing K(ATP) channel openers and those of adenosine. Compound 13 bears the nicotinamide moiety of nicorandil instead of nitrate ester. Compounds 4, 5, and 11 reduced infarction and the levels of malondialdehyde (MDA) at reperfusion in anesthetized rabbits. Compounds 12 and 13 did not significantly reduce the infarct size. Analogues 4 and 5 increased cGMP and MDA during ischemia, while combined analogue 4 and mitoK(ATP) blocker 5-hydroxydecanoic acid (5-HD) abrogated this benefit suggesting an action through mitoK(ATP) channel opening. Treatment with derivative 11 combined with 5-HD as well as treatment with 11 and adenosine receptor blocker 8-(p-sulfophenyl)theophylline (SPT) did not abrogate cardioprotection. Compound 11 is a lead molecule for the synthesis of novel analogues possessing a dual mode of action through cGMP-mitoK(ATP) channel opening-free radicals and through adenosine receptors.
authors.affiliation: National Hellenic Research Foundation, Institute of Organic and Pharmaceutical Chemistry, 48, Vas. Constantinou Avenue, 11635 Athens, Greece.
authors.forename: Theano
authors.initials: T
authors.lastname: Fotopoulou
authors.forename: Efstathios K
authors.initials: EK
authors.lastname: Iliodromitis
authors.forename: Maria
authors.initials: M
authors.lastname: Koufaki
authors.forename: Andrew
authors.initials: A
authors.lastname: Tsotinis
authors.forename: Anastasia
authors.initials: A
authors.lastname: Zoga
authors.forename: Vassilis
authors.initials: V
authors.lastname: Gizas
authors.forename: Anastasia
authors.initials: A
authors.lastname: Pyriochou
authors.forename: Andreas
authors.initials: A
authors.lastname: Papapetropoulos
authors.forename: Ioanna
authors.initials: I
authors.lastname: Andreadou
authors.forename: Dimitrios Th
authors.initials: DT
authors.lastname: Kremastinos
mesh_terms: D000818:Animals; D006152:Cyclic GMP / Q000378:metabolism; D015195:Drug Design; D004952:Esters / Q000737:chemistry*; D006571:Heterocyclic Compounds / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology*; D019194:Ischemic Preconditioning; D008297:Male; D008315:Malondialdehyde / Q000378:metabolism; D015394:Molecular Structure; D009566:Nitrates / Q000737:chemistry*; D011817:Rabbits; D015427:Reperfusion Injury / Q000378:metabolism / Q000473:pathology; D013329:Structure-Activity Relationship
chemical_list: D004952:Esters; D006571:Heterocyclic Compounds; D009566:Nitrates; D008315:Malondialdehyde; D006152:Cyclic GMP