کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
10545083 | 963618 | 2005 | 7 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
The effects of different extraction solvents of varying polarities on polyphenols of Orthosiphon stamineus and evaluation of the free radical-scavenging activity
دانلود مقاله + سفارش ترجمه
دانلود مقاله ISI انگلیسی
رایگان برای ایرانیان
موضوعات مرتبط
مهندسی و علوم پایه
شیمی
شیمی آنالیزی یا شیمی تجزیه
پیش نمایش صفحه اول مقاله
چکیده انگلیسی
Leaf powder of Orthosiphon stamineus was extracted with the following solvents; distilled water, 50% aqueous methanol, methanol, 70% aqueous acetone and chloroform, at 2, 4 and 8 h, respectively, on a water bath at 40 °C. The extracts were subjected to qualitative and quantitative HPLC analyses of the polyphenols, the most dominant chemical constituents in the leaf. Chloroform extraction from 4 to 8 h at 40 °C gave the highest amount of sinensetin and eupatorin. The extraction with 70% aqueous acetone extracts at 4 and 8 h gave a high yield of 3â²-hydroxy-5,6,7,4â²-tetramethoxyflavone. The yield of rosmarinic acid was high in 50% methanol extracts at 2, 4 and 8 h of extraction. The extracts were screened for free radical-scavenging potential, using a 1,1-diphenyl-2-picrylhydrazyl in vitro model system. The extracts exhibited significant radical-scavenging activity and the acetone extracts showed the highest activity.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Food Chemistry - Volume 93, Issue 2, November 2005, Pages 311-317
Journal: Food Chemistry - Volume 93, Issue 2, November 2005, Pages 311-317
نویسندگان
G.A. Akowuah, Z. Ismail, I. Norhayati, A. Sadikun,