Synthesis and biological activity of aminoacyl analogs of ascamycin.
作者:Makoto UBUKATA、Hiroyuki OSADA、Junji MAGAE、Kiyoshi ISONO
DOI:10.1271/bbb1961.52.1117
日期:——
L-Prolyl and other aminoacyl derivatives of ascamycin (1) were synthesized by a condensation reaction of N6-t-butyloxycarbonyl-2-chloro-9-(2', 3'-O-isopropylidene-5'-O-sulfamoyl-β-D-ribofuranosyl)adenine (9) with the corresponding t-butyloxycarbonylaminoacylimidazole in the presence of Cs2CO3 in DMF as the key step. The L-prolyl derivative (2) and L-phenylalanyl derivative (3) as well as 1 showed selective toxicity against Xanthomonas citri. The L-prolyl-L-prolyl derivative (5) as well as dealanylascamycin (6) showed broad toxicity against various Gram-negative and Gram-positive bacteria. The D-alanyl derivative (4) lost its antibacterial activity. 2 was the best substrate (15.3M/min per mg of protein) for an Xc-aminopeptidase (an ascamycin-dealanylating enzyme from X. citri cells) among these analogs. This enzyme scarcely hydrolyzed 4 (0.2 M/min per mg of protein). The substrate specificity of the enzyme accounts for antibacterial activity of the analogs. 2 showed greater selective toxicity against Kirsten sarcoma virus transformed Balb3T3 (KN-3T3) cells than against nontransformed cells (Balb 3T3).
通过N6-叔丁氧基羰基-2-氯-9-(2', 3'-O-异亚丙基-5'-O-氨磺酰基-β)的缩合反应合成了L-Prolyl和其他Ascamycin氨酰基衍生物(1) -D-呋喃核糖基)腺嘌呤 (9) 与相应的叔丁氧基羰基氨基酰基咪唑在 Cs2CO3 存在下在 DMF 中反应作为关键步骤。 L-脯氨酰衍生物(2)和L-苯丙氨酰衍生物(3)以及1对柑橘黄单胞菌表现出选择性毒性。 L-脯氨酰-L-脯氨酰衍生物 (5) 以及 dealanylascamycin (6) 对各种革兰氏阴性和革兰氏阳性细菌表现出广泛的毒性。 D-丙氨酰衍生物(4)失去了抗菌活性。在这些类似物中,2 是 Xc-氨基肽酶(来自柑橘小杆菌细胞的泡霉素脱丙氨酶)的最佳底物(15.3M/分钟/毫克蛋白质)。该酶几乎不水解 4(每毫克蛋白质 0.2 M/分钟)。该酶的底物特异性决定了类似物的抗菌活性。图2显示对克尔斯滕肉瘤病毒转化的Balb3T3(KN-3T3)细胞比对非转化细胞(Balb 3T3)更大的选择性毒性。