BETA-GLUCOSYLATION OF PLANT PHENOLICS BY PHENOL BETA-GLUCOSYLTRANSFERASE IN LARVAL TISSUES OF THE TOBACCO HORNWORM, MANDUCA-SEXTA (L)
BETA-GLUCOSYLATION OF PLANT PHENOLICS BY PHENOL BETA-GLUCOSYLTRANSFERASE IN LARVAL TISSUES OF THE TOBACCO HORNWORM, MANDUCA-SEXTA (L)
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DOI：
10.1016/0965-1748(93)90031-m
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发表时间：
1993-07-01
影响因子：
3.8
通讯作者：
HOPKINS, TL
中科院分区：
文献类型：
--
作者：
AHMAD, SA;HOPKINS, TL
通过对形成的 β-葡萄糖苷产物进行 HPLC 分析，测定了喂养第 5 代体育场幼虫烟草天蛾 (Manduca sexta) 的唇腺和脂肪体组织制剂中苯酚 β-葡萄糖基转移酶 (PGT) 对多种植物酚类物质的活性。以尿苷 5'-二磷酸葡萄糖为辅因子的 15,000 g 组织匀浆级分中的酶在结合简单的单酚、二酚和三酚方面表现出广泛的活性；酚酸、醛和醇；以及香豆素和类黄酮。唇腺和脂肪体酶制剂的最高比活性出现在二酚底物如儿茶酚、氢醌和香草醛中，而最低的活性通常出现在类黄酮底物中。唇腺PGT对简单酚类底物比脂肪体酶具有更高的比活性。然而，两种酶制剂对香豆素和类黄酮的糖基化速率几乎相同。尽管 PGT 在唇腺和脂肪体中的功能尚不清楚，但这项研究的证据表明，它们在结合幼虫饮食中存在的许多潜在有毒植物酚方面可能很重要。
Activity of phenol beta-glucosyltransferase (PGT) in labial gland and fat body tissue preparations from feeding 5th stadium larval tobacco hornworms, Manduca sexta, towards a variety of plant phenolics was determined by HPLC analysis of the beta-glucoside products formed. The enzymes in the 15,000 g fractions of tissue homogenates with uridine 5'-diphosphoglucose as a cofactor showed a wide range of activity in conjugating simple mono-, di-, and triphenols; phenolic acids, aldehydes, and alcohols; and coumarins and flavonoids. Highest specific activity of both labial gland and fat body enzyme preparations occurred with diphenol substrates such as catechol, hydroquinone, and vanillin, whereas lowest activities generally were observed with flavonoid substrates. The labial gland PGT had higher specific activity for the simple phenolic substrates than did the fat body enzyme. However, the coumarins and flavonoids were glucosylated at nearly the same rates by both enzyme preparations. Although the functions of PGT in labial glands and fat body are unknown, evidence from this study suggests that they could be important in conjugating a number of potentially toxic plant phenols occurring in the larval diet.