Σύνθεση συμπλόκων στοιχείων μετάπτωσης με υποκαταστάτες ολιγοπυριδίνες με συζευγμένα αμινοξέα και πεπτίδια: δέσμευσή τους σε νουκλεϊκά οξέα και νουκλεολυτική τους δραστικότητα

Abstract

The ability of the diastereomeric compounds of the general formula Λ- and Δ-[Ru(bpy)2(4-COY-4’-Mebpy)]Cl2 (bpy =2,2’-bipyridine and Y = Gly-Lys1-Lys2CONH2, Lys1-Gly-Lys2CONH2, Lys1-Lys2-GlyCONH2) to bind to the oligonucleotide duplex d(5’-CGCGAATTCGCG-3’) was studied with NMR techniques. Complex Λ-2, Λ-[Ru(bpy)2(4-COLys1-Gly-Lys2CONH2),4’-Mebpy)]Cl2 (Mebpy = methyl-2,2’-bipyridine), interacts non-specifically causing changes for both complex and oligonucleotide 1H NMR signals. Both Λ-1, Λ-[Ru(bpy)2(4-COGly-Lys1-Lys2CONH2),4’-Mebpy)]Cl2 and Λ-3, Λ-[Ru(bpy)2(4-COLys1-Lys2-GlyCONH2),4’-Mebpy)]Cl2, were bound to the oligonucleotide through both lysine aliphatic chains, indicating that the side chains of the sequential lysines create a kind of “clamp” to connect the complex with the oligonucleotide. Complex Δ-1, Δ-[Ru(bpy)2(4-COGly-Lys1-Lys2CONH2),4’-Mebpy)]Cl2, interacts with the oligonucleotide duplex with both lysine side chains in a manner similar to Λ-1. Δ-2, Δ-[Ru(bpy)2(4-COLys1-Gly-Lys2CONH2),4’-Mebpy)]Cl2, interacts with the oligonucleotide with the bipyridine ligands. In addition, the formation of a hydrogen bond between the Gly-NH and the carbonyl groups of the oligonucleotide bases was detected. A completely different binding mode was observed for Δ-3 Δ-[Ru(bpy)2(4-COLys1-Lys2-GlyCONH2),4’-Mebpy)]Cl2, which at a ratio of 1:1 ([Ru]/[nucleotide]) opens the oligonucleotide strands. In addition, participation of all three peptidic NH of Δ-3 in hydrogen bonds was observed.Non-diastereomeric homoleptic [Ru(trpyCO-TrpCONH2)2]Cl2 (1), [Ru(trpyCO-Gly-TrpCONH2)2]Cl2 (2) and the heteroleptic complexes [Ru(trpy)(trpyCO-TrpCONH2)]Cl2 (3), [Ru(trpy)(trpyCO-Gly-TrpCONH2)]Cl2 (4), where trpyCO-TrpCONH2 and trpyCO-Gly-TrpCONH2 are 2,2’:6’,2’’-terpyridine-4-carboxylic acid tryptophanamide and 2,2’:6’,2’’-terpyridine-4-carboxylic acid-glycyl-tryptophanamide respectively, were synthesized and characterized by various spectroscopic and analytical techniques. The interactions of complexes (1) and (4) with the oligonucleotide d(5’-CGCGAATTCGCG-3’)2 were studied by means of NMR spectroscopy. Both complexes bound very weakly to the oligonucleotide, perturbing slightly the helix from B-form, probably through electrostatic interactions between the positive charge of the complexes and the DNA phosphates. In the case of complex (1), the conjugated tryptophane did not approach the oligonucleotide helix, as in the case of complex (4), the ligand trpy of which was clearly orientated towards the oligonucleotide helix. These observations indicate that the bulky substitute on the ligand trpy reduces the binding affinity of the complexes to DNA, allowing only electrostatic interactions. However, complex (4) shows high cytotoxicity against LMS, MCF-7, U2OS and K562 cancer cell lines, with IC50 values ranging 0.464–0.925 nM, which can be attributed to a non classical mechanism for metal based anticancer agents.Binuclear Ru(II)/Ru(II) complexes of the general formula [(ptrpy)Ru(tppz)Ru(trpy-COY)](PF6)4 και [(trpy)Ru(tppz)Ru(trpy-COY)](PF6)4 where trpy-COY = 2,2’:6’,2’’-terpyridine-4-carboxylic, trpy = 2,2’:6’,2’’-terpyridine tppz = 2,3,5,6-tetrakis(2-pyridyl)pyrazine, ptrpy = 4-phenyl-2,2’:6’,2’’-terpyridine and Y = Gly1-Gly2-Lys1-Lys2CONH2, Gly1-Gly2-Gly3-Lys1CONH2, -Ahx-Lys1-Lys2CONH2 , were synthesized and characterized. The complexes [(ptrpy)Ru(tppz)Ru(trpy-CONH-Gly1-Gly2-Gly3-Lys1CONH2)](PF6)5 and [(trpy)Ru(tppz)Ru(trpy-CONH-Gly1-Gly2-Gly3-Lys1CONH2)](PF6)5 were studied for their nuclelytic activity. Both complexes showed necleolytic activity against the dinucleotide guanylyl-cytidine (3’→5’), upon UVA irradiation. Some activity was also observed in the dark.

Στην παρούσα διατριβή συντέθηκαν και χαρακτηρίστηκαν τα μη-εναντιομερή σύμπλοκα του Ru(II), [Ru(trpyCO-TrpCONH2)2]Cl2 (1), [Ru(trpyCO-Gly-TrpCONH2)2]Cl2 (2) [Ru(trpy)(trpyCO-TrpCONH2)]Cl2 (3), [Ru(trpy)(trpyCO-Gly-TrpCONH2)]Cl2 (4). Τα μη-εναντιομερή σύμπλοκα που μελετήθηκαν αλληλεπιδρούν ασθενώς με το ολιγινουκλεοτίδιο d(5’-CGCGAATTCGCG-3’) χωρίς να προκαλούν σημαντικές αλλαγές στη δομή του. Εν τούτοις, το σύμπλοκο [Ru(trpy)(trpyCO-Gly-TrpCONH2)2]Cl2 βρέθηκε να είναι ιδιαίτερα κυτταροτοξικό υποδεικνύοντας ένα διαφορετικό μηχανισμό δράσης από εκείνον του cis-platin και των αναλόγων του.Επίσης μελετήθηκαν τα εναντιομερή σύμπλοκα Λ- και Δ- [Ru(bpy)2(4-COY-4’-Mebpy)]Cl2 όπου Y = Gly-Lys1-Lys2CONH2, Lys1-Gly-Lys2CONH2, Lys1-Lys2-GlyCONH2,. ως προς τις αλληλεπιδράσεις που έχουν με το ολιγινουκλεοτίδιο d(5’-CGCGAATTCGCG-3’) με τεχνικές πυρηνικού μαγνητικού συντονισμού. Τα εναντιομερή σύμπλοκα δεσμεύονται στο DNA με διαφορετικό τρόπο : τα Λ- περισσότερο μη-ειδικά με ηλεκτροστατική δέσμευση, ενώ τα Δ- δεσμεύονται ισχυρότερα. Το σύμπλοκο [Ru(bpy)2(4-CONH-Lys-Lys-Gly-CONH2-H-4'-Mebpy)](PF6) (Δ-3) κατά την δέσμευση του, μέσω δεσμών υδρογόνου από τον πεπτιδικό σκελετό, προκαλεί τοπικό ξετύλιγμα στη διπλή έλικα, λειτουργώντας ως τεχνητή ελικάση Ακόμα συντέθηκαν και χαρακτηρίστηκαν τα διπυρηνικά-ολιγοπυριδινικά, μη-εναντιομερή σύμπλοκα του Ru(II)/Ru(II), [(ptrpy)Ru(tppz)Ru(trpy-COY)](PF6)4 και [(trpy)Ru(tppz)Ru(trpy-COY)](PF6)4 όπου Y = Gly1-Gly2-Lys1-Lys2CONH2, Gly1-Gly2-Gly3-Lys1CONH2,-Ahx-Lys1-Lys2CONH2. Τα διπυρηνικά σύμπλοκα, [(ptrpy)Ru (tppz)Ru(trpy-COΝΗGly1-Gly2-Gly3-Lys1CONH2)](PF6)5 και [(trpy)Ru(tppz)Ru(trpy-COΝΗGly1-Gly2-Gly3-Lys1CONH2)](PF6)5 μελετήθηκαν για την νουκλεολυτική δραστικότητα ως προς το δινουκλεοτίδιο (GC). Τα σύμπλοκα έδειξαν ότι έχουν νουκλεολυτική δραστικότητα απουσία φωτός αλλά και κατόπιν ακτινοβόλησης με UV (254 nm) η οποία εξαρτάται από τη φύση των υποκαταστατών.