Identification and quantification of flavonoids in Carica papaya leaf and peroxynitrite-scavenging activity

Objective: To characterize the types, contents, and peroxynitrite-scavenging activities of flavonoids in the leaf of Carica papaya(C. papaya).Methods: Chromatographic and spectroscopic techniques along with high performance liquid chromatography quantitative analysis and peroxynitrite-scavenging assay were performed to isolate and quantify flavonoid compounds in the flavonoid-rich fraction(Bu OH fraction) derived from Me OH extract of C. papaya leaves and evaluate their peroxynitrite-scavenging activities.Results: Seven flavonoids were isolated from the leaves of C. papaya, including quercetin 3-(2~G-rhamnosylrutinoside), kaempferol 3-(2~G-rhamnosylrutinoside), quercetin 3-rutinoside, myricetin 3-rhamnoside, kaempferol 3-rutinoside, quercetin, and kaempferol. All of the substances exhibited potent activities on peroxynitrite scavenging(IC50 4.15 mmol/L), which were stronger than the positive control, L-penicillamine(6.90 mmol/L). The content of kaempferol 3-(2~G-rhamnosylrutinoside) was significantly higher than other identified compounds(123.18 mg/g Bu OH fraction and 7.23 mg/g Me OH extract).Conclusions: The results of the present study demonstrate the potent antioxidant flavonoids of C. papaya leaf, with kaempferol 3-(2~G-rhamnosylrutinoside) as the major one.

Identification and quantitative estimation of Emodin in Rhei Emodi Wall.Rhizome and the relevant polyherbal ayurvedic formulation

The present study explored quality control of plant drug and polyherbal formulation using HPTLC and HPLC fingerprinting.The study combined qualitative analysis of Emodin and Rhein biomarker compound in Rhei Emodi Wall.rhizome extract and polyherbal formulation extract by HPTLC method with quantitative estimation of Emodin by HPLC method,aiming to help in accurate identification of Emodin and Rhein in plant materials,polyherbal formulations.This study also checked adulteration,with the purpose of improving bio-efficacy of ayurvedic formulation.All the samples showed characteristic peaks of Emodin at same retention time as that of standard Emodin.According to the HPTLC fingerprinting results,the Rf values of Rhein reference standard at 0.42 and Emodin at 0.62 were observed in test solution of Rhei emodi Wall.rhizome extract and polyherbal formulation extract and both were found comparable.The quantitative evaluation of Emodin present in the polyherbal formulation and Rhei emodi Wall.rhizome extracts were 0.0177% and 0.3106% respectively.