<scp>GC</scp> – <scp>MS</scp> Characterisation, In Vitro Bioactivities, <i>In Silico</i> Molecular Docking and <scp>ADMET</scp> Studies of Phytoconstituents From <i>Rytigynia umbellulata</i> (Hiern) Robyns Essential Oils

Abstract

ABSTRACT Rytigynia umbellulata (Hiern) Robyns is often deciduous and has many folkloric uses, such as anti‐malaria and anti‐diabetic. This study investigated the essential oil constituents of Rytigynia umbellulata leaf and stem, along with their antioxidant and cytotoxic activities as well as investigating in silico molecular docking and ADMET studies of phytoconstituents. The essential oils were extracted using hydrodistillation and gas chromatography–mass spectrometry (GC–MS) for identification and characterisation. In silico studies were performed using AutoDock Vina in the PyRx workspace. The antioxidant activity of the volatile oils was evaluated using the 2,2′–diphenyl–1–picrylhydrazyl radical (DPPH*) method, while the brine shrimp lethality test determined cytotoxic potential. The GC–MS analyses revealed 11 and 13 compounds in the leaves and stem essential oils of R. umbellulata , representing 98.5% and 95.1% of the total oil contents, with phytol (73.5%) and pentadecanal (55.1%) as the most abundant components, respectively. The essential oils showed significant antioxidant activity with a 69.03% ± 0.41% inhibition. The in silico studies supported the cytotoxicity potential of the essential oils with the highest binding affinity and attributed the strongest inhibitory activity to β ‐Gurjunene and Acorenone with respect to the reference standard, doxorubicin, for both the target proteins. Acorenone, pentadecanal and phytol present significantly lower probabilities of AMES toxicity (0.163), Human Hepatotoxicity (0.156), and Carcinogenicity (0.195) compared to doxorubicin, indicating a safer profile in these critical areas. Phytoconstituents of the leaf and stem essential oil of R. umbellulata might be linked to the free radical scavenging and cytotoxic potential observed in this study.