engleski

Synthesis and biological activity of quercetin derivatives of endogenous opiod peptides Leu- and Met-enkephalin

Quercetin, 3, 3', 4', 5, 7-pentahydroxyflavon is well-known flavonoid distributed ubiquitously as a glycoside in fruits, vegetables and herbs (apples, onions, Ginkgo biloba) and related products, specially in red wine [1]. In plants, flavonoids are involved in energy production and exhibit strong anti-oxidant properties, possibly protecting plants against harmful ultraviolet rays. Quercetin has become a subject of many investigations because of strong anti-cancer, anti-inflammatory, anti-oxidative and other therapeutic activities of significant potency such as cardioprotective, bacteriostatic and nevertheless its systemic toxicity is quite low. In this paper quercetin derivatives of endogenous opioid peptides Leu- and Met-enkephalin (H-Tyr-Gly-Gly-Phe-Leu/Met-OH) were prepared starting from differently protected N-terminal amino group (Boc- or Z- protection). Different protecting groups were used to exchange the position and number of bounded peptide. Modifications were performed in intention to increase biological activity of quercetine as well as enkephalins which also examine antitumor activity. Antitumor evaluation and interactions with ct-DNA of prepared compounds were investigated.

quercetin, enkephalin

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