Sakagami H, Yamamura T S, Takahashi H, Shibuya I, Takeda M
First Department of Biochemistry, School of Medicine, Showa University, Tokyo, Japan.
Anticancer Res. 1995 Jul-Aug;15(4):1269-74.
The stability of sodium 5,6-benzylidene-L-ascorbate (SBA), consisting of two diastereomers, was investigated by high-performance liquid chromatography. In extensively acidic buffer, the acetal in SBA was immediately cleaved to liberate ascorbic acid and benzaldehyde. At higher pH, the cleavage of SBA was significantly reduced, but the degradation (due to possible opening of the lactone ring) of SBA was stimulated. The degradation rate of SBA was significantly increased with increasing temperature, and was higher than that of ascorbic acid or benzaldehyde. SBA was degraded with incubation time in culture medium, with accompanying loss of its biological activity, but only a marginal concentration of benzaldehyde, but not of ascorbic acid, was produced from SBA. The amount of SBA extracted from the apoptosing leukemic cells by 70% acetonitrile amounted to about 0.04% of that present in the medium fraction. These data suggest that SBA itself, but not contaminating ascorbic acid nor benzaldehyde, is responsible for the antitumor activity of SBA.
由两种非对映异构体组成的5,6-亚苄基-L-抗坏血酸钠（SBA）的稳定性通过高效液相色谱法进行了研究。在广泛的酸性缓冲液中，SBA中的缩醛会立即裂解，释放出抗坏血酸和苯甲醛。在较高pH值下，SBA的裂解显著减少，但SBA的降解（由于内酯环可能打开）受到刺激。SBA的降解速率随温度升高而显著增加，且高于抗坏血酸或苯甲醛的降解速率。SBA在培养基中随孵育时间而降解，同时其生物活性丧失，但SBA仅产生少量的苯甲醛，而不产生抗坏血酸。用70%乙腈从凋亡白血病细胞中提取的SBA量约占培养基部分中SBA含量的0.04%。这些数据表明，是SBA本身而非污染的抗坏血酸或苯甲醛负责SBA的抗肿瘤活性。
