کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
8891810 | 1628508 | 2018 | 28 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Separation of catechins from green tea (Camellia sinensis L.) by microwave assisted acetylation, evaluation of antioxidant potential of individual components and spectroscopic analysis
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کلمات کلیدی
موضوعات مرتبط
علوم زیستی و بیوفناوری
علوم کشاورزی و بیولوژیک
دانش تغذیه
پیش نمایش صفحه اول مقاله
![عکس صفحه اول مقاله: Separation of catechins from green tea (Camellia sinensis L.) by microwave assisted acetylation, evaluation of antioxidant potential of individual components and spectroscopic analysis Separation of catechins from green tea (Camellia sinensis L.) by microwave assisted acetylation, evaluation of antioxidant potential of individual components and spectroscopic analysis](/preview/png/8891810.png)
چکیده انگلیسی
Separation of individual green tea catechins has the limitation due to their structural resemblance and unequal distribution. Hence, the objective of this study was to develop separation methods based on 1.Preparative Thin Layer Chromatography (TLC) using oxalic acid impregnation and 2. Microwave (MW) mediated acetylation followed by classical silica gel column chromatography separation. The yield of total catechins by different extraction techniques was, conventional (7.3%), liquid-liquid (7.8%), Soxhlet (8.3%) and microwave (8.8%). Acetylation of total catechins under various MW conditions explored with acetic anhydride, triethylamine and standardized at 15â¯minâ¯at 1g scale and subjected to separation. Subsequently, the individual catechin acetates deacetylated under MW conditions and characterized by TLC, High-Resolution Mass Spectrometry (HRMS), Fourier Transform Infrared Spectroscopy (FT-IR), 1H and 13C Nuclear Magnetic Resonance (NMR) spectroscopic studies. The total polyphenol content of the extract was 931.17â¯Â±â¯0.67â¯g GAE kgâ1. The antioxidant activity of deacetylated catechins was evaluated by Ferric-Reducing Antioxidant Potential (FRAP) in terms of Trolox equivalence (TE) and % inhibition of 1, 1-diphenyl-2-picryl-hydrazyl (DPPH). Accordingly, the TE and DPPH % inhibition was epigallocatechingallate (12.3 and 71.9%), epicatechingallate (11.5 and 55.5%), epigallocatechin (9.10 and 46.0%), epicatechin (7.40 and 35.1%) respectively.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: LWT - Volume 91, May 2018, Pages 391-397
Journal: LWT - Volume 91, May 2018, Pages 391-397
نویسندگان
Ignasimuthu Kalai Selvi, Subban Nagarajan,