Cost-Effective Simultaneous Separation and Quantification of Phenolics in Green and Processed Tea Using HPLC–UV–ESI Single-Quadrupole MS Detector and Python Script

Phenolic composition of green tea (Camellia sinensis) varies according to manufacturing processes that result in deglycosylation of glycosylated phenolics and condensation, epimerization, and degalloylation of flavan-3-ols (catechins). Ambiguous phenolic assignments based on UV absorbance alone can occur when the chromatographic peaks overlapped slightly. We established an improved method using an HPLC–UV coupled with a single-quadrupole MS detector (MS1) that can reject false UV peaks after checking the preceding MS1 peaks. Adjusted UV data coded by the Python algorithm were deployed to compare tea phenolics. Performance validation of the MS1 and UV analysis methods for 19 phenolics revealed a sensitivity of 0.17 and 0.47 pmol/injection, limit of detection of 15 and 33 μg/L, limit of quantification of 50 and 110 μg/L, intra-day precision of 5% and 1% relative standard deviation, and trueness of 83–135% and 97–100%, respectively. Our results suggest that the HPLC–UV–MS1 method, which is a low operational cost method, potentially provides the precise phenolic composition of teas.

Biological Activities of Stem, Leaves and Essential Oil of Cedrus deodara from District Poonch, Rawalakot Azad Kashmir, Pakistan

Cedrus deodara (Roxb. ex D. Don) Loudon, is a high value medicinal plant found in flora of Poonch part of Himalayan region. The present study was conducted to determine and compare the antioxidant activity, quantification of phenolics and flavonoids, chelating ability, biofilm inhibition, thrombolytic activity and cytotoxicity of the stem, leaves of crudes extracts and essential oil. It can be claimed that that all parts of C. deodara including its essential oil is a rich source of phytochemicals that exhibited high quantity of phenolics ranged from (49.76±0.22 GAE to 60.36±0.44GAE mg/g) and flavonoids ranged from (4.78±0.61mg/g to 6.62±0.45 mg/g)but also exhibited antioxidant, metal chelating agent ability, antibacterial potential ranged from (35.59±0.50 to 61.61±0.61%)and thrombolytic activities ranged from (22.86±0.7 to 32. 64±0.5 %)with minimal toxicity ranged from (0.40±0.35 to 3.73±0.23%). Further studies are required to determine the bioactive compounds and bioactivity of plant extracts and fractions.

Quantification of phenolics, flavonoids and antioxidant activity of Tamarindus indica from selected areas in Tanzania

Mbunde M, Mdegela RH, Laswai HS, Mabiki FP. 2018. Quantification of phenolics, flavonoids and antioxidant activity of Tamarindus indica from selected areas in Tanzania. Biofarmasi J Nat Prod Biochem15: 22-28. The objective of this study was to establish the quantities and antioxidant activity in fruits and leaves of Tamarindus indica L. collected from three agro-ecological zones of Tanzania represented by Morogoro, Tanga and Dodoma regions. Samples were examined for their total phenolic and flavonoid contents as well as their antioxidant activity. The total phenolic content showed significant difference in all extracts of the fruits and leaves and ranged from 1994.4±530.77 to 17874.67±5234 mg GAE/100 g. Similarly, the total flavonoid content in tamarind leaf and fruit extracts ranged from 880±609.45 to 11483.11±2559.67 mg CE /100 g dry weight. There was a significant difference between the antioxidant activity in the leaf (54.39±0.13%) and fruit extracts (40.11±0.03%). Tamarind leaf extracts exhibited significantly higher radical scavenging activity than fruit extracts. The antioxidant activity in fruit extracts expressed in percentage ranged between 29.27±0.06% and 40.11±0.03% while in leaf extracts the activity ranged from 22.33±0.08% to 54.39±0.13%. The radical scavenging activity from Coastal leaf extracts had the highest activity followed by Eastern leaf extracts and lastly Central leaf extracts. In the fruit samples, the highest activity was shown by Coastal fruit extracts followed by Central fruit extracts and Eastern fruit extract being the least active. The values in Ferric reducing power (FRAP) assay ranged between 6968±3655.91 µM Fe (II)/g and 76822.67±23259.9 µM Fe (II)/g for leaves and fruits dry mass respectively. These values correspond to the antioxidant activity which positively correlated with the total phenolic and flavonoid contents. Geographical location and climatic conditions have been reported to have enormous effects on the amount and activity of antioxidants available in both tamarind leaves and fruits. Findings from the study indicated that tamarind can be utilized as a cheap source of antioxidants. However, more agronomic studies should be considered to confirm the effects of agroecological differences on antioxidant activity.