Comparative Study on Quantification of Total Catechins Using UV-Vis Spectrophotometric Method and High Performance Liquid Chromatography Techniques

Bioavailability of catechinsin wider range of plants was established earlier and it’s utility as medicine against cardiovascular disease, cancer, etc. were also demonstrated. Recent techniques in relation to quantitative analysis of total catechins seem to be laborious and time consuming process to handle huge number of samples. Established spectrophotometry and HPLC methods developed earlier for quantitative determination of total catechins in tea extracts were compared in the present study.UV-Vis spectrophotometric method was adopted to monitor the absorbance at 500 nm of the reaction mixture (catechins and vanillin-H2SO4reagents). Hewlett Packard automated HPLC was used and equipped with Phenomenex Luna 5  phenyl-hexyl column fitted with a Phenomenex guard column. Binary elution was carried out using Mobile phase A (acetic acid and acetonitrile) and Mobile phase B (acetonitrile). Method adopted showed a good resolution of catechin fractions and was found to be accurate for the quantification of total catechins (sum of individual catechins). Results of the both the methods are comparable and variation amongst the two methods ranged between -3.59 and 2.79% among the clones and varied with seasons.As expected UPASI released tea clones exhibited variations in their bioavailability. Lean season edge over the cropping period sampling in terms of total catechins. Results obtained from both the methods are comparable. Two methods can be used for the routine quantitative analysis of total catechins; however, spectrophotometric method found to be simple, rapid and cost effective than that of HPLC method unless individual catechins composition is warranted.

[18F]Fluorination Optimisation and the Fully Automated Production of [18F]MEL050 Using a Microfluidic System

The [18F]radiolabelling of the melanin-targeting positron-emission tomography radiotracer [18F]MEL050 was rapidly optimised using a commercial continuous-flow microfluidic system. The optimal [18F]fluorination incorporation conditions were then translated to production-scale experiments (35–150 GBq) suitable for preclinical imaging, complete with automated HPLC–solid phase extraction purification and formulation. [18F]MEL050 was obtained in 43 ± 10 % radiochemical yield in ~50 min.