tailieunhanh - Báo cáo hóa học: " New potential antitumoral fluorescent tetracyclic thieno[3,2-b]pyridine derivatives: interaction with DNA and nanosized liposomes"

Tuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành hóa học dành cho các bạn yêu hóa học tham khảo đề tài: New potential antitumoral fluorescent tetracyclic thieno[3,2-b]pyridine derivatives: interaction with DNA and nanosized liposomes | Castanheira et al. Nanoscale Research Letters 2011 6 379 http content 6 1 379 o Nanoscale Research Letters a SpringerOpen Journal NANO EXPRESS Open Access New potential antitumoral fluorescent tetracyclic thieno 3 2-b pyridine derivatives interaction with DNA and nanosized liposomes 1 1 2 Elisabete MS Castanheira Maria Solange D Carvalho 1 Ana Rita O Rodrigues Ricardo C Calhelha and Maria-João RP Queiroz2 Abstract Fluorescence properties of two new potential antitumoral tetracyclic thieno 3 2-b pyridine derivatives were studied in solution and in liposomes of DPPC dipalmitoyl phosphatidylcholine egg lecithin phosphatidylcholine from egg yolk Egg-PC and DODAB dioctadecyldimethylammonium bromide . Compound 1 pyrido 2 3 3 2 thieno 4 5-d pyrido 1 2-a pyrimidin-6-one exhibits reasonably high fluorescence quantum yields in all solvents studied OF while for compound 2 3- p-methoxyphenyl ethynyl pyrido 2 3 3 2 thieno 4 5-d pyrido 1 2-a pyrimidin-6-one the values are much lower OF . The interaction of these compounds with salmon sperm DNA was studied using spectroscopic methods allowing the determination of intrinsic binding constants Kị X 103 M-1 for compound 1 and Kị X 103 M-1 for 2 and binding site sizes of n 11 3 and n 7 2 base pairs respectively. Compound 2 is the most intercalative compound in salmon sperm DNA 35 while for compound 1 only 11 of the molecules are intercalated. Studies of incorporation of both compounds in liposomes of DPPC Egg-PC and DODAB revealed that compound 2 is mainly located in the hydrophobic region of the lipid bilayer while compound 1 prefers a hydrated and fluid environment. Introduction Liposomes are among technological delivery developments for chemotherapeutic drugs in the treatment of cancer. This technique can potentially overcome many common pharmacologic problems such as those involving solubility pharmacokinetics in vivo stability and toxicity 1-3 . Liposomes are closed