ABSTRACT
This paper introduces a unique and novel method for synthesizing thienyl chalcones using iron oxide nanoparticles (FeONPs) as a heterogeneous catalyst. It stands out as a rare example in the literature for the synthesis of these chalcones from 1,3-diketones and various aromatic aldehydes. The magnetic FeONPs employed as the catalyst bring several advantages, including their efficiency, affordability, and ecofriendly nature, making them an attractive choice for producing thiophene chalcones. One noteworthy aspect of this methodology is the utilization of mild reaction conditions, which greatly simplify the operational aspects of the reaction. Synthesized chalcones were confirmed through the application of various techniques, proton-NMR, 13C NMR, mass spectrometry, and single-crystal X-ray diffraction analysis. These analyses provide valuable insights into the chemical compositions and structural characteristics of the synthesized compounds. Significantly, this methodology is reported for the first time in the literature, indicating its novelty and contribution to the field of chalcone synthesis.
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.
