Development and validation of RP-HPLC method for estimation of quercetin present in hydro alcoholic extract of Erigeron bonariensis Linn

Erigeron bonariensis Linn (EB) is a species of Erigeron, belonging to Asteraceae. It found throughout the tropics and subtropics as a pioneer plant; its precise origin is unknown, but most likely it stems from Cen tral America or South America. It has become naturalized in many other regions, including North America, Europe and Australia. In South Africa, this plant is well known as Conyza bonariensis and listed under "Red List of South African Plants" . Its extract contains many bioactives such as quercetin, naringenin, stigmasterol, apigenin, baicalein, rutin, luteolin and caffeic acid. These have good therapeutic potential. Among them, quercetin (QUE) is widely found in EB's extract. In this current research, QUE was successfully detected in EB extract utilising a gradient reverse phase high performance liquid chromatography (RPHPLC) method. The method was developed and validated using a C18 column (250 mm length x 4.5 mm internal diameter). The mobile phase used was methanol and water. A flow rate of 1 mL/min was used during the elution. Initially the water -to -methanol ratio at 75:25 v/v (water: methanol) for 3 min, then at 50:50 v/v (water: methanol) for 3-7 min, then at 50:50 v/v (water: methanol) for 10-15 min, and lastly at 10:90 v/v (water: methanol) for 20 min, to achieve the best elution. The developed analytical technique was validated in terms of linearity, LOD, LOQ, recovery, precision, and specificity using ICH Q2 R1 guidelines. The amount of QUE in EB was determined and reported by us for the first time. The extraction was carried out using 970 g of whole plant powder, was macerated in 4 L of hydroethanol (50: 50 v/v) and was concentrated under vacuum. The percentage yield was found to be 5.5% w/w (2.75 g/55 g of EB extract) and HPLC method was developed using sample concentration of 60 mg/100 mL (600 mu g/mL) in methanol and retention time (RT) of the standard and QUE in extract was found to be 15.3 and 15.7 min, respectively. The linearity, correlation coefficient, limit of detection (LOD), limit of quantification (LOQ), and RSD were found to be 200-1000 mu g/mL, 0.9991, 35.66 mu g/mL, 108.18 mu g/mL, and smaller than 1 % respectively indicating the developed method was precise. Hence the current research laid a platform to identify the important drug leads like QUE (1% w/w) and further research targeting the phytochemical and biological exploration is in progress. The current analytical investigation was successful in phytochemical fingerprint and quantification of QUE in EB. (c) 2024 SAAB. Published by Elsevier B.V. All rights reserved.