Supplementary Information
Ruthenium(II) polypyridyl complexes as carriers for DNA
delivery
Satish S. Bhat,
a
Avinash S. Kumbhar,*
a
Anupa A. Kumbhar,
a
Ayesha Khan,
b
Peter Lönnecke,
c
and Evamarie Hey-Hawkins
c
Experimental Section
Chemicals. All chemicals and solvents were purchased commercially and were distilled
before use. 2,3-Bis(bromomethyl)quinoxaline was purchased from Sigma Aldrich.
RuCl
3
·3H
2
O was purchased from S. D. Fine chemicals, Mumbai (India) and calf thymus
DNA was purchased from SRL, Kolkata (India) and used as received. pBR322 DNA was
purchased from Chromos Biotech Pvt. Ltd. India.
Syntheses. The ligands 1,10-phenenthroline-5,6-dione (phendione),
1
bpg [4b,5,7,7a–
tetrahydro-4b,7a-epiminomethanoimino-6H-imidazo[4,5-f] [1,10] phenanthroline-6,13-
dione]
2-4
were synthesized according to the literature. The precursor complexes of the type
cis-[Ru(N-N)
2
Cl
2
]
5, 6
are prepared according to the literature method.
Synthesis of bis(2,3- dimethylquinoxaline)bipyridine glycoluril (bqbg) (1). DMSO (8 mL)
was purged with nitrogen for 30 minutes. Powdered KOH (343 mg, 6.1 mmol) is added and
stirred for another 30 minutes then bipyridine glycoluril (300 mg, 1.02 mmol) and 2, 3-
bis(bromomethyl)quinoxaline (645 mg, 2.04 mmol) were added in one portion and the
reaction mixture was cooled in a water bath (15 °C). The reaction mixture was stirred for 8 h.
Then reaction mixture was poured into 300ml of water and product was extracted with
chloroform (3100 mL) and the combined organic layers were washed with water and then
dried (MgSO
4
). After filtration and rotary evaporation, the residue was purified by column
chromatography (SiO
2
, CHCl
3
/MeOH 25:1). Yield: 217 mg (40%).
1
H NMR (DMSO-d
6
, 300
MHz, 25 °C):
1
H NMR (CDCl
3
, 300 MHz, 25 °C):
ppm
= 9.01 (d, 2H), 8.04 (m, 6H ), 7.75
(m, 4H), 7.42 (dd, 2H), 5.45 (4H, NCH
2
Ar), 5.03 (4H, NCH
2
Ar);
13
C{1H) NMR (CDCl
3
,
75.47MHz):
ppm
= 157.57, 152.03, 150.49, 147.53, 140.58, 135.56, 130.69, 128.81, 126.51,
124.04, 76.51, 47.77; IR (KBr pellet, cm
-1
): ν= 3068, (ArH), 2889, 2820 (CH
2
), 1711 (C=O),
1579, 1568, 1446, (C=C, C=N); ESI-MS (m/z, (%) positive mode) : 603.6 (M+H]
+
(100%).
Anal. Calcd for C
34
H
22
N
10
O
2
· CH
3
OH; C, 66.24; H, 4.13; N, 22.07; found: C, 66.01; H, 4.49;
N, 21.89.
[Ru(bpy)
2
(bqbg)]Cl
2
(2). The precursor complex cis-[Ru(bpy)
2
Cl
2
]·2H
2
O (100 mg, 0.0192
mmol) and bqbg (115 mg, 0.0192 mmol) were dissolved in methanol-water (1:1, 50 mL) and
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