RATE CONSTANTS FOR THE DEHYDRATION OF SINGLE AND DOUBLE HYDRATES OF CYTIDYLYL (3‘‐5’)–CYTIDINE
RATE CONSTANTS FOR THE DEHYDRATION OF SINGLE AND DOUBLE HYDRATES OF CYTIDYLYL (3‘‐5’)–CYTIDINE
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胞苷基 (3‘‐5’)-胞苷单水合物和双水合物脱水的速率常数
DOI：
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发表时间：
1968
影响因子：
3.3
通讯作者：
H. Johns
中科院分区：
文献类型：
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作者：
P. V. Hariharan;H. Johns
摘要-胞苷酰（3′-5′）胞苷（CpC）用紫外光（u. v.）以产生单水合物（C*pC和CpC* 的混合物）和双水合物C*pC*，其通过电泳分离。这些光产物迅速地转化为CpC并脱氨为U*pC和CpU* 的混合物。在0°C下，在3至8的pH值范围内评估水合物脱水和脱氨基的速率常数。据观察，C*pC* 的衰减速率常数位于C*pC和CpC* 之间的所有pH值的研究。单水合物和双水合物均在pH 4·5左右显示最低稳定性，在pH 8左右显示最高稳定性。C*pC*、C*pC和CpC* 脱水的最大速率常数分别为0.26、0.145和0.35 hr-1，最小值分别为0.024、0.011和0.091 hr-1，均在0 ℃下。测量在0°C下在一定pH值范围内C*pC脱氨为U*pC的速率常数。脱氨基产物的量根据pH值的不同从水合物的约2%至10%不等，在pH值8左右产生最大量。
Abstract— Cytidylyl (3′‐5′) cytidine (CpC) was irradiated with ultraviolet light (u.v.) to produce the single hydrate (a mixture of C*pC and CpC*) and the double hydrate C*pC* which were separated by electrophoresis. These photoproducts rapidly dehydrate to CpC and deaminate to a mixture of U*pC and CpU*. The rate constants for dehydration and deamination of the hydrates were evaluated for a range of pH values from 3 to 8 at 0°C. It is observed that the rate constants for decay of C*pC* lie between those for C*pC and CpC* for all pH values studied. Both single and double hydrates show minimum stability around pH 4·5 and maximum stability around pH 8. The maximum rate constants for dehydration of C*pC*, C*pC and CpC* are 0·26, 0·145 and 0.35 hr‐1 respectively and the minimum values are 0.024, 0.011 and 0.091 hr‐1 respectively all at 0°C. The rate constants for deamination of C*pC to U*pC for a range of pH values at 0°C were measured. The amount of deamination product varies from about 2 to 10 per cent of the hydrate depending on pH with the maximum amount being produced around pH 8.