title: A gradient based facile HPLC method for simultaneous estimation of antioxidants extracted from tea powder.
abstract: A new simple, rapid and precise RP-HPLC method was developed for the extraction and quantitative estimation of caffeine (C), (-)-epigallocatechin gallate (EGCG), (+)-catechin(Ct), (-)-epicatechin(EC), and (-)-epicatechin gallate (ECG) (collectively named as Tea Powder Bioactives TPBAs) extracted from tea powder using different ratios of ethanol: water. The simultaneous determination of TPBAs was performed using the UV spectrophotometric method which employs the absorbance at 205 nm (λmax of caffeine and polyphenols). This method is a gradient based HPLC method with a flow rate of 0.8 mL/min using Inertsil ODS 100 × 4.6 mm, 3 μm column with methanol and ammonium dihydrogen phosphate (pH-2.8) as mobile phase. The method was validated in terms of specificity, precision, linearity, accuracy, limit of quantification (LOQ), and limit of detection (LOD). The linearity of the proposed method was investigated for concentration ranging between 0.5-60 μg/mL with regression co-efficient, R(2) = 0.999-1.0. This method estimates all the TPBAs simultaneously with enhanced precision and linearity as per the ICH guidelines. Also, to confirm the individual TPBA, the antioxidant property of the each TPBA was analyzed which was commensurate with that of the previous reports.
authors.affiliation: Department of Chemistry, Sri Jayachamarajendra College of Engineering, JSS Technical Institutions Campus, Mysore, 570 006 India ; Institute of Excellence, Vijnana Bhavana, Manasagangotri, Mysore, 570 006 India.
authors.forename: Shankara H
authors.initials: SH
authors.lastname: Nanjegowda
authors.affiliation: Department of Studies in Chemistry, University of Mysore, Mysore, 570 006 India.
authors.forename: Manasa G
authors.initials: MG
authors.lastname: Papanna
authors.affiliation: Faculty of Life Sciences, JSS University, Mysore, 570 015 India.
authors.forename: Raghu Ram
authors.initials: RR
authors.lastname: Achar
authors.affiliation: Department of Studies in Chemistry, University of Mysore, Mysore, 570 006 India.
authors.forename: Kanchugarakoppal S
authors.initials: KS
authors.lastname: Rangappa
authors.affiliation: Department of Chemistry, Sri Jayachamarajendra College of Engineering, JSS Technical Institutions Campus, Mysore, 570 006 India.
authors.forename: Puttaswamappa
authors.initials: P
authors.lastname: Mallu
authors.affiliation: Department of Biotechnology, Sri Jayachamarajendra College of Engineering, JSS Technical Institutions Campus, Mysore, 570 006 India.
authors.forename: Shivananju Nanjunda
authors.initials: SN
authors.lastname: Swamy
keywords: (+)-Catechin; (−)-Epicatechin; (−)-Epicatechin gallate; (−)-Epigallocatechin gallate; Assam tea; Caffeine; ICH guidelines; RP-HPLC; Tea powder bioactives (TPBAs)