High-performance thin-layer chromatography method development and validation for quantification of rutin in different parts of Capparis zeylanica Linn. plant

Medicinal plant extracts include a multitude of chemical compounds. Therefore, there is a need for suitable analytical methods for their identification and standardization. The aim of the present study was to extract, isolate, and identify rutin from Capparis zeylanica (CZ) leaves and determine its content in the stems, leaves, roots, and flowers of CZ plant by a simple, sensitive, precise, accurate, and specific high-performance thin-layer chromatography (HPTLC) method for the first time. The HPTLC method used silica gel 60 F₂₅₄ for the stationary phase, ethyl acetate‒glacial acetic acid‒formic acid–water (10:1.1:1.1:2.6, V/V) as the mobile phase, and scanning under ultraviolet (UV) 264 nm light, by using deuterium lamp, without chemical reagents. The calibration curves for rutin were found to be linear in the range between 400 and 1400 ng per spot with R² = 0.9953 ± 0.0004. This method showed good peak symmetry for rutin (R_F: 0.418 ± 0.004) with limit of detection and limit of quantification of 14.10 and 42.73 ng/spot, respectively. The precision, accuracy, robustness, and specificity studies for CZ extracts and rutin are within the limits as per the International Council for Harmonisation guidelines. This study confirms the presence of rutin with content (% w/w) of 3.16 ± 0.01 in leaves, 5.92 ± 0.04 in stems, and 2.23 ± 0.02 in flowers, on dry weight basis of CZ extracts. However, it is not found at detectable levels in the roots of CZ plant. In conclusion, the proposed method is simple, reliable, and specific for the quantification of rutin. The results also show that CZ could be an important nutritional source of rutin.