Azide and Solvent Trapping of Electrophilic Intermediates Generated during the Hydrolysis of N-(Sulfonatooxy)-N-acetyl-4-aminostilbene
摘要:
Hydrolysis of the carcinogenic title compound 1a in 5 vol % CH3CN-H2O, mu = 0.5, 20 degrees C at pH 7.2 in 0.02 M phosphate buffer, yields the rearranged material 3-(sulfonatooxy)-N-acetyl-4-aminostilbene (4) (23 +/- 1%), threo-1,2-dihydroxy-1-phenyl-2-(4-acetamidophenyl)ethane (5) (57 +/- 2%), and erythro-1,2-dihydroxy-1-phenyl-2-(4-acetamidophenyl)ethane (6) (20 +/- 2%) in the absence of added nucleophiles. Addition of N-3(-) has no effect on the rate constant for decomposition of 1a (ca. 1.9 x 10(-2) s(-1)), but generates a number of adducts that result from trapping of three different electrophilic intermediates. The ortho-N-3 adduct 3-azido-N-acetyl-4-aminostilbene (7) is produced from trapping of the nitrenium ion 2. A fit of the product yield data as a function of [N-3(-)] provides the ratio k(az)/k(s) of 280 +/- 10 M-1 for competitive trapping of 2 by N-3(-) and H2O. The nucleophilic aromatic substitution product 7 is a minor reaction product. The predominant site of attack by N-3(-) On 2 (ca. 85%) is at the beta-vinyl carbon to produce the quinone imide methide 3b. Attack of H2O at the same site produces the analogous intermediate 3a. Both of these electrophilic species are competitively trapped by N-3(-) and H2O with trapping ratios k(az)'/k(s)' for 3b of 107 +/- 8 M-1 and k(az)"/ k(s)" for 3a of 39 +/- 2 M-1. The reactivity patterns of 2 are unlike those of other N-arylnitrenium ions that undergo predominant nucleophilic aromatic substitution with nucleophiles such as N-3(-). The quinone imide methides that are produced by nucleophilic attack on the beta-carbon of 2 react selectively enough with nonsolvent nucleophiles that they may be physiologically relevant.
The present invention relates to a system of multi-stage stem cell carcinogenesis and a method of generating such multi-stage stem cell carcinogenesis system. Various stages of cancer stem cells can be generated from normal stem cells via mutagenesis. The system of the present invention enables monitoring changes in the ability of cells to transition from one stage of carcinogenesis to another and to identify genetic pathways and molecules that influence carcinogenesis. The present invention also enables a high-throughput and nonbiased screening for targets that preferentially affect cancer stem cells relative to non-cancer stem cells or their derivatives during stem cell carcinogenesis, thus is useful in developing anti-cancer therapeutics.
[EN] MULTI-STAGE STEM CELL CARCINOGENESIS<br/>[FR] CARCINOGENESE DE CELLULES SOUCHES MULTIETAPES
申请人:STEMLIFELINE INC
公开号:WO2010037134A2
公开(公告)日:2010-04-01
The present invention relates to a system of multi-stage stem cell carcinogenesis and a method of generating such multi-stage stem cell carcinogenesis system. Various stages of cancer stem cells can be generated from normal stem cells via mutagenesis. The system of the present invention enables monitoring changes in the ability of cells to transition from one stage of carcinogenesis to another and to identify genetic pathways and molecules that influence carcinogenesis. The present invention also enables a high-throughput and nonbiased screening for targets that preferentially affect cancer stem cells relative to non-cancer stem cells or their derivatives during stem cell carcinogenesis, thus is useful in developing anti-cancer therapeutics.