• Archives of Pharmacal Research
• /
• v.21 no.4
• /
• pp.385-390
• /
• 1998

Adozelesin and carzelesin are synthetic analogues of the extremely potent antitumor antibiotic CC-1065, which alkylates N3 of adenine in a consensus sequence $5^1$-(A/T)(A/T)$A^*$ ($A^*$ is the site of alkylation). We have investigated the DNA sequence selectivity of adozelesin and carzelesin by thermally ind ced DNA strand cleavage assay using radiolabeled restriction DNA fragments. An analysis of alkylation patterns shows that the consensus sequences for carzelesin and adozelesin have been found to be $5^1$-(A/T)(A/T)$A^*$ and $5^1$-(A/F)(G/C)(A/T)$A^*$. A new consensus sequence, $5^1$-(A/T)(A/T)$CA^*$, has been observed to display an additional alkylation site for adozelesin but not for carzelesin. These results indicate that the pattern of sequence selectivity induced by carzelesin is similar but not identical to those induced by adozelosin.

• Proceedings of the Korean Society of Applied Pharmacology
• /
• 1992.05a
• /
• pp.53-53
• /
• 1992

galangin은 1차 발암물질인 MNNG, EMS, 2차 발암물질인 B(a)P 및 DMBA에 의해 유도된 소핵생성에 대하여 억제효과를 나타내었으나 ADM에 대해서는 억제효과를 나타내지 않았다. 한편, S-9 mixture 존재하 benzo(a)pyrene에 의한 자매염색분체교환 빈도에 대해서도 억제효과를 나타내었다. 또한, radiomimetic agent인 BLM 유도 염색체 이상에 대해서도 억제효과를 나타내었다. 이같은 결과를 종합하면 galangin은 DNA alkylation이나 adduct를 형성하는 발암물질에 대하여 억제효과가 큰 것으로 보아 DNA alkylation 및 DNA adduct를 형성을 차단하거나 방향족 탄화수소의 대사 활성화를 방해하여 특정 발암물질들의 염색체 손상작용을 억제해주는 Anticlastogen으로서의 가능성을 보여주었다.

• Bulletin of the Korean Chemical Society
• /
• v.25 no.1
• /
• pp.69-72
• /
• 2004

The N-alkylation of 4-aminopyrimidine with a tetrahydro-3-aza-cyclopropa[c]inden-5-one, which is a model reaction of the pharmacophore of duocarmycins, was studied with a quantum chemical method. We consider two factors for the acceleration of the N-alkylation; distortion and protonation of the model pharmacophores. The distortion of the spirocyclopropyl moiety in the model spirocyclopropylcyclohexadienone could induce an intrinsic energy of 3-4 kcal/mol, but the protonation on the carbonyl oxygen of the model cyclohexadienone lowers the transition energy of the N-alkylation of 4-aminopyrimidine dramatically (~46 kcal/mol) and is considered to play a major role in the enzyme reaction. The distorted and protonated spirocyclohexadienone is exothermally relieved to a phenol with the heat of reaction of -37 kcal/mol. The protonation process is proposed to be the mode of action of duocarmycins in the DNA alkylation.

• Archives of Pharmacal Research
• /
• v.24 no.5
• /
• pp.455-465
• /
• 2001

The highly potent cytotoxic DNA-DNA cross-linker consists of two cyclopropa[c]pyrrolo[3,4-3]indol-4(5H)-ones insoles [(+)-CPI-I] joined by a bisamido pyrrole (abbreviated to "Pyrrole"). The Pyrrole is a synthetic analog of Bizelesin, which is currently in phase II clinical trials due to its excellent in vivo antitumor activity. The Pyrrole has 10 times more potent cytotoxicity than Bizelesin and mostly form DNA-DNA interstrand cross-links through the N3 of adenines spaced 7 bp apart. The Pyrrole requires a centrally positioned GC base pair for high cross-linking reactivity (i.e., $5^1$-T$AT_2$A*-$3^1$), while Bizelesin prefers purely AT-rich sequences (i.e., $5^1$-T$AT_4$A*-$3^1$, where /(equation omitted) represents the cross-strand adenine alkylation and A* represents an adenine alkylation) (Park et al., 1996). In this study, the high-field $^1$H-NMR and rMD studies are conducted on the 1 1-mer DNA duplex adduct of the Pyrrole where the 5′(equation omitted)TAGTTA*-3′sequence is cross-linked by the drug. A severe structural perturbation is observed in the intervening sequences of cross-linking site, while a normal B-DNA structure is maintained in the region next to the drug-modified adenines. Based upon these observations, we propose that the interplay between the bisamido pyrrole unit of the drug and central C/C base pair (hydrogen-bonding interactions) is involved in the process of cross-linking reaction, and sequence specificity is the outcome of those interactions. This study suggests a mechanism for the sequence specific cross-linking reaction of the Pyrrole, and provides a further insight to develop new DNA sequence selective and distortive cross-linking agents.

• Archives of Pharmacal Research
• /
• v.25 no.1
• /
• pp.11-24
• /
• 2002

The antitumor antibiotic (+)-CC-1065 can alkylate N3 of guanine in certain sequences. A previous high-field $^1H$ NMR study on the$(+)-CC-1065d[GCGCAATTG*CGC]_2$ adduct ($^*$ indicates the drug alkylation site) showed that drag modification on N3 of guanine results in protonation of the cross-strand cytosine [Park, H-J.; Hurley, L. H. J. Am. Chem. Soc.1997, 119,629]. In this contribution we describe a further analysis of the NMR data sets together with restrained molecular dynamics. This study provides not only a solution structure of the (+)-CC-1065(N3- guanine) DNA duplex adduct but also new insight into the molecular basis for the sequence- specific interaction between (+)-CC-1065 and N3-guanine in the DNA duplex. On the basis of NOESY data, we propose that the narrow minor groove at the 7T8T step and conformational kinks at the junctions of 16C17A and 18A19T are both related to DNA bending in the drugDNA adduct. Analysis of the one-dimensional $^1H$ NMR (in $H_2O$) data and rMD trajectories strongly suggests that hydrogen bonding linkages between the 8-OH group of the (+)-CC-1065 A-sub-unit and the 9G10C phosphate via a water molecule are present. All the phenomena observed here in the (+)-CC-1065(N3-guanine) adduct at 5'$-AATTG^*$are reminiscent of those obtained from the studies on the (+)-CC-1065(N3-adenine) adduct at $5'-AGTTA^*$, suggesting that (+)-CC-1065 takes advantage of the conformational flexibility of the 5'-TPu step to entrap the bent structure required for the covalent bonding reaction. This study reveals a common molecular basis for (+)-CC-1065 alkylation at both $5'-TTG^*$ and $5'-TTA^*$, which involves a trapping out of sequence-dependent DNA conformational flexibility as well as sequence-dependent general acid and general base catalysis by duplex DNA.

• Proceedings of the Korean Society of Applied Pharmacology
• /
• 1994.11a
• /
• pp.147-172
• /
• 1994

Aziridinylbenzoquinones such as 3, 6-diaziridinyl-1, 4-benzoquinone (DZQ) and its 2, 5-methyl analog (MeDZQ) require bioreductive activation in order to elicit their anticancer activities. To determine the involvement of DTD in the activation of these drugs, we have used a ligation-mediated polymerase chain reaction to map the intracellular alkylation sites in a sing1e copy gene at the nucleotide level. We have performed this analysis in two human colon carcinoma cells, one proficient (HT-29) and one deficient (BE) in DT-diaphorase (DTD) activity. In the DTD proficient HT-29 cell line, DZQ and MeDZQ were found to alkylate both 5'-(A/T)G(C)-3' and 5'-(A/T)A-3' sequences. This is consistent with the nucleotide preferences observed when DZQ and MeDZQ are activated by purified DTD to reactive metabolites capable of alkylating DNA in vitro [Lee, C. -S., Hartley, J. A., Berardini, M. D., Butler, J., Siegel., D., Ross, D., & Gibson, N. W. (1992) Biochemistry, 31: 3019-3025]. Surprisingly in the DTD-deficient BE cell line a pattern of alkylation induced by DZQ and MeDZQ similar to that observed in the DTD-proficient HT-29 cells was observed. This suggests that reductive enzymes other than DTD can be involved in activating DZQ and MeDZQ to DNA reactive species in vivo.

• YAKHAK HOEJI
• /
• v.30 no.5
• /
• pp.238-244
• /
• 1986

As one of the starting materials, methylthioacetyl chloride(7) was synthesized in fair yield from mercaptoacetic acid via methyl methylthioacetate(5) prepared by alkylation employing N, N'-dicyclohexyl-O-methylisourea(4). Then 1-$\beta$-D-arabinofuranosylcytosine-5'-methylthioacetate (3) was prepared by esterification of ara-C with obtained methylthioacetyl chloride and tested for inhibitory activity on DNA synthesis in the growing primary hepatocytes and hepatoma strains($H_4$-II-E and HTC cells). In these in vitro cell lines, the inhibitory effect of ara-C-MTA(3) on DNA synthesis was similar to that of its parent ara-C but slightly lower.

• Archives of Pharmacal Research
• /
• v.21 no.5
• /
• pp.595-598
• /
• 1998

The rate of the GSH conjugate formation, the inhibition of DNA topoisomerase-I and the cytotoxic activity against L1210 cells of the naphthoquinones showed the same order; 5,8-dimethoxy-1,4-naphthoquinone (DMNQ)>6-(1-hydroxyethyl)-DMNQ>2-(1-hydroxyethyl)-DMNQ; the steric hindrance of the substituents, particularly 2-substutuent, in reacting with cellular nucleophiles must be the main cause for lowering the bioactivities. Acetylation of 2-(1-hydroxyethyl)-DMNQ producing 2-(acetyloxyethyl)-DMNQ potentiated the bioactivities; 2-(-hydroxyethyl)-DMNQ did not react with GSH and the enzyme, and showed $ED_{50}$ of 0.146 mg/ml for the cytotoxcity. Furthermore, the acetylation 2-(1-hydroxyethyl)-DMNQ(T/C, 119%) enhanced the T/C values for the mice bearing S-180 tumor {T/C of 2-(1-acetyloxyethyl)-DMNQ, 276%]. It was assumed that the difference in bioactivities ensued by acetylation was based on the mechanism of the so-called bioreductive alkylation.

• Proceedings of the Korean Society of Applied Pharmacology
• /
• 1992.05a
• /
• pp.16-16
• /
• 1992

1940년대에 처음으로 암의 화학요법이 시도된 이래 많은 항암제들이 도입되어 사용되고 있다. 현재 항암제를 사용하여 비교적 치료율이 높은 암은 leukemia나 lymphoma와 같은 혈액암에 국한되어 있다. 고형암에 대하여는 고환암과 같은 극히 일부가 항암제에 의해 비교적 잘 치료되나 대부분은 여전히 치료가 되지 않고 있는 상태에 있다. 고형암의 발생빈도는 전체 암의 90％를 차지하고 있는 상태로 사망율이 매우 높아, 현대의 40대 이상 사망원인의 1위를 나타내고 있어 그 치료제의 개발이 매우 시급히 요구되고 있다. 이에 따라 고형암의 치료를 목적으로 많은 화합물들이 검토되어 왔다. 이중 최근 매우 큰 가능성을 보여주고 있는 diarysulfonylurea 유도체가 발견되어 임상시험에 도입됨으로서 이 화합물들에 대한 관심이 고조되고 있다. 이와 관련하여 고형암의 치료제를 개발할 목적으로 diarysulfonylurea의 특성과 강력한 항암효과를 발현하는 alkylating agent의 특성을 갖을 것으로 예상되는 새로운 2-alkoxy-1-arylsufonylimidazoline 유도체를 설계하고, 이들 유도체의 합성법을 개발하였다. 이들 유도체들은 일차적으로 생체내에서 DNA 또는 효소등에 alkylation을 일으킨후 diarysulfonylurea로 변하여 작용함으로서 보다 큰 항암효과를 발현할 것으로 기대된다.