Phytochemicals, UPLC-QTOF-MS/MS analysis, potential acaricidal activity and molecular modeling of Datura metel grown in North-Eastern India

The present investigation emphasized exploitation of Datura metel L. for potential acaricidal activity. Extraction method suggested higher extraction efficiency with the use of 50 % methanol over aqueous medium. UPLC-QTOF-ESI-MS analysis of the extracts resulted tentative identification of eighteen tropane alkaloids such as tigloidin, hyoscyamine N-oxide, scopolamine N-oxide, hyocyamine, hydroxyapoatropine, tropinone, scopine, hyoscine, atropine, valtropine, ditigloyloxytropane, ditigloyloxytropanol, apohyoscine, tigloyloxytropane, norhyoscine, meteloidine, cuscohygrine and tropine in the aerial parts (EAP) and roots (ER). Further, nine phenolic acids such as gallic, protocatechuic, chlorogenic, vanillic, p-coumaric, ferulic, quinic, syringic, and sinapic acids along with fourteen flavonoids such as luteolin-7-glucoside, catechin-3-O-rhamnoside, kempferol-3,7-O-diglucoside, naringenin-6-β-D-glucopyranoside, quercetin 3-O-glucosyl-xyloside, apigenin-7-O-glucoside, flavonol-3-glucoside, luteolin, epicatechin, chrysoeriol, diadzein, genistein, hesperidin and hydroxycoumarin were also identified. Highest acaricidal activity was observed for ER showing LC₅₀ and LC₉₀ of 112.5 and 317.3 μg/mL after 48 h of exposure, respectively. Molecular modeling analysis revealed favourable interaction of tigloidine with UDP transferase of T. urticae through attractive charge, pi-alkyl, alkyl and conventional H bonds. Though, ER was found to be phytotoxic with the highest root growth inhibition in terms of IC₅₀ value of 131.2 and 184.9 μg/mL against Chenopodium album and Triticum aestivum, respectively. Being eco-benign natural products, Datura phytochemicals can serve as potential bio-acaricide, thereby, a smart delivery system could be developed comprising synergistic concoction of the alkaloid rich phytochemical fractions for efficient management of the notorious acarids.