کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
7622927 | 1494540 | 2016 | 13 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
3 or 3â²-Galloyl substitution plays an important role in association of catechins and theaflavins with porcine pancreatic α-amylase: The kinetics of inhibition of α-amylase by tea polyphenols
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کلمات کلیدی
GTEOTETf2KmappKICPPATESepicatechinEGCGepigallocatechinEGCtf1 - TF1α-Amylase - α-آمیلازporcine pancreatic α-amylase - α-آمیلاز پانکراس خوکیTannic acid - اسید تانیکECG - الکتروکاردیوگرام یا نوار قلبepicatechin gallate - اپیکتچین گالاتepigallocatechin gallate - اپی گالوستاچین گالاتInhibition - بازداریTheaflavin - تئوفلاوینKinetics - سینتیک (جنبش شناسی) Tea extracts - عصاره چایGreen tea extracts - عصاره چای سبزBTE - وسایل کمکTea polyphenols - پلی فنل چایKIU - چیCatechin - کاتچین، کتیچینCaffeine - کافئینGallic acid - گالیک اسید
موضوعات مرتبط
مهندسی و علوم پایه
شیمی
شیمی آنالیزی یا شیمی تجزیه
پیش نمایش صفحه اول مقاله
![عکس صفحه اول مقاله: 3 or 3â²-Galloyl substitution plays an important role in association of catechins and theaflavins with porcine pancreatic α-amylase: The kinetics of inhibition of α-amylase by tea polyphenols 3 or 3â²-Galloyl substitution plays an important role in association of catechins and theaflavins with porcine pancreatic α-amylase: The kinetics of inhibition of α-amylase by tea polyphenols](/preview/png/7622927.png)
چکیده انگلیسی
The inhibitory activities of three tea extracts (TEs) and individual phenolic compounds in TEs against porcine pancreatic α-amylase (PPA) were studied by measuring their half inhibitory (IC50) concentrations. The kinetics of inhibition by these extracts and compounds were investigated through Dixon, Cornish-Bowden, and Lineweaver-Burk plots. The results showed that green, oolong and black tea extracts, epigallocatechin gallate, theaflavin-3, 3â²-digallate and tannic acid were competitive inhibitors of PPA, whereas epicatechin gallate, theaflavin-3â²-gallate and theaflavin were mixed-type inhibitors with both competitive and uncompetitive inhibitory characteristics. Only catechins with a galloyl substituent at the 3-position showed measurable inhibition. The competitive inhibition constants (Kic) were lower for theaflavins than catechins, with the lowest value for theaflavin-3, 3â²-digallate. The lower Kic than the uncompetitive inhibition constant for the mixed-type inhibitors suggests that they bind more tightly with free PPA than with the PPA-starch complex. A 3 and/or 3â²-galloyl moiety in catechin and theaflavin structures was consistently found to increase inhibition of PPA through enhanced association with the enzyme active site.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Functional Foods - Volume 26, October 2016, Pages 144-156
Journal: Journal of Functional Foods - Volume 26, October 2016, Pages 144-156
نویسندگان
Lijun Sun, Fredrick J. Warren, Gabriele Netzel, Michael J. Gidley,