Chemometric-assisted fingerprinting profiling of the Pagoda (Clerodendrum paniculatum L.) extract variation using proton nuclear magnetic resonance (1H NMR) method, compound isolation, and cytotoxic activity

One of the best solutions to understanding the chemical data of complex natural substances is to use chemometric techniques. This research aims to apply chemometric techniques, specifically principal component analysis (PCA) and cluster analysis (CA), to determine the fingerprint profiles of nine pagoda extracts (PCP) and their isolated compounds using 1H NMR data and to conduct initial cytotoxicity tests on the extracts. PCP flowers were extracted using various solvents and extraction methods, resulting in 9 types of extracts. The methanol-extracted flower portion was subjected to maceration and the compounds were then isolated using various techniques, including silica gel, column chromatography, and preparative thin layer chromatography (PTLC), which yielded 3 types of compounds. The structures were identified using 1D and 2D NMR and mass spectrometry. Meanwhile, their cytotoxic activity was tested on MCF-7, A549, KB, KB-VIN, and MDA-MB-231 cancer cells using the sulforhodamine B (SRB) assay. The research results revealed that compounds (1) stigmasta-5,22,25-trien-3β-ol, (2) 6-nonadecenoic acid, and (3) 6,9-nonadecadienoic acid, methyl ester was discovered in this plant for the first time. The fingerprinting profile of the PCP extracts and compounds showed resonance at δH 5.33 ppm (m, 1H) and δH 5.24 ppm (m, 1H). PCA of the 12 samples with eigenvalues > 1 explained 91% of the data and exhibited a normal distribution. The score plot was influenced by PC1 (82.2%) and PC2 (10.5%). The loading plot and CA combined with the linearity of (1), (2), and (3) with respect to the variation in extracts had determination coefficients (R² = 0.7550 - 0.9288) and similarities (78.26% - 98.98%). Cytotoxicity activity showed weak growth inhibition (> 89.6%) in all tested cancer cell types. In conclusion, 1H NMR spectrum and chemometrics detects the fingerprinting profile of Pagoda extract variations, clustering extracts, identifying marker compounds, and potential for cytotoxicity studies in cancer cells.