초록
퓨린 港代謝物에는 沆癌活性인 것과 非活性인 것이 있는데, 이들을 EHT 方法으로 계산하여 면밀히 검토해 본 결과, 沆癌活性인 것은 DNA 염기의 당이 결합한 위치에 대응되는 위치인 N(9)에서 electron donating ability를 나타내지만, 非活性인 것은 이와 반대임을 알았고 N(9)와 당에 해당되는 위치 (10)간의 overlap population이 가장 작게 나타났다. 이것은 nuclotide level로 전환되어 沆癌活性을 나타낸다는 실험사실과 일치한다.
EHMO calculations were performed on several antitumor active as well as inactive purine antimetabolites. Results showed that the N atom (position 9) which corresponds to the position of sugar (position 10) linkage in DNA bases has a net negative charge for antitumor active whereas it has a positive charge for inactive purines. It was also found that overlap population was the smallest for bond between atoms 9 and 10, which agrees with the experimental findings that antitumor activity is effected after conversion to nucleotide level.