Inhibitory Effect of .BETA.-Glucosyl-phenolic Hydroxamic Acids against Urease in the Presence of Microfloral .BETA.-Glucosidase.
作者:JongBeak PARK、Lisa IMAMURA、Kyoichi KOBASHI、Hisatomi ITOH、Toshitsugu MIYAZAKI、Toshio HORISAKI
DOI:10.1248/bpb.18.208
日期:——
Three glucosyl-phenolic hydroxamates, 4-O-(β-D-glucopyranosyl) benzohydroxamic acid, 4-O-(β-D-glucopyranosyl) hippuric hydroxamic acid, and 3-[4-O-(β-D-glucopyranosyl) phenyl] propionohydroxamic acid (Glc-PPHA), were hydrolyzed to their corresponding aglycones by β-glucosidase of intestinal flora of rat without any major adverse hydrolysis in vitro. Inhibitory potency of these glucosyl-hydroxamates on urease was recovered to the same extent as that of the corresponding aglycone hydroxamates by preincubation for 2h with rat intestinal flora. p-Hydroxyphenylpropionohydroxamic acid inhibited noncompetitively jack-bean urease activity and its glucose-ligated form, Glc-PPHA inhibited it competitively. A single oral dose of Glc-PPHA tended to inhibit urease activity in proximal colon contents of rat at 6h after administration (p=0.06). After14C-urea was orally administered to rat, 14CO2 was collected for to measure the ureolysis in vivo. Expired 14CO2 was limited to 40% by a single oral dose of Glc-PPHA during 6h, and 75% of intestinal ureolysis was repressed during the first 1h in the breath test.
4-O-(β-D-吡喃葡萄糖基)苯甲酰羟肟酸、4-O-(β-D-吡喃葡萄糖基)马尿酰羟肟酸和3-[4-O-(β-D-吡喃葡萄糖基)苯基]丙酰羟肟酸(Glc-PPHA)这三种葡萄糖基酚类羟肟酸酯在体外被大鼠肠道菌群中的β-葡萄糖苷酶水解为相应的苷元,而没有出现任何不良水解反应、被大鼠肠道菌群中的β-葡萄糖苷酶水解为相应的苷元,体外水解过程中未出现任何不良反应。通过与大鼠肠道菌群预育 2 小时,这些葡萄糖基羟肟酸对脲酶的抑制效力可恢复到与相应苷元羟肟酸相同的程度。对羟苯基丙酰羟肟酸可非竞争性地抑制大豆脲酶活性,而其葡萄糖连接形式 Glc-PPHA 则可竞争性地抑制脲酶活性。单次口服 Glc-PPHA 有抑制给药后 6 小时大鼠近端结肠内容物中脲酶活性的趋势(p=0.06)。给大鼠口服 14C-脲后,收集 14CO2 以测量体内的尿素分解。在 6 小时内单次口服 Glc-PPHA 可将已排出的 14CO2 限制在 40%,在呼气试验中,75% 的肠道尿解作用在最初的 1 小时内被抑制。