Phytochemical, Nematicidal, and Aphidicidal Studies of the Leaves of <i>Cannabis sativa</i> L.

Phytochemical analysis of Cannabis sativa leaves led to the identification of seven cannabinoids [cannabidiol (58.10–62.84%), cannabicitran (0.39–7.97%), cannabinol (1.41–6.9%), cannabidivarol (1.93–3.25%), cannabicyclol (2.65–3.14%), Δ9-tetrahydrocannabinol (2.66–2.80%), Δ9-tetrahydrocannabivarin (0.13–2.63%)] and four sesquiterpenoids [caryophyllene oxide (1.41–3.26%), β-caryophyllene (1.41–2.32%), α-bisabolol (0.42–1.87%), and humulene epoxide II (0.3–0.87%)] in its hexane extract by GC-MS. Six pure compounds were also isolated from its methanolic extract and were identified as l-quebrachitol (1), sucrose (2), rel-(2S,3S,4R,16E)-2-[(2′R)-2′-hydroxy-nonadecanoylamino]-heneicosadec-16-ene-1,3,4-triol (3), β-sitosterol-3-O-β-d-glucoside (4), stigmasterol (5), and cannabispirone (6) by FT-IR, NMR, and MS studies. The hexane (CSH) and methanolic (CSM) extracts of cannabis leaves showed dose dependent nematicidal activity against Meloidogyne incognita (LC50, 271.13 and 122.68 ppm) and fewer galls (9.33 ± 0.67 to 16.33 ± 0.88 galls/root) in the roots under pot conditions as compared to the untreated control (29.67 ± 1.45). In silico molecular docking studies revealed variable degrees of binding affinity (−4.1 to −10.5 kcal/mol) of various components toward the four different target sites of M. incognita. The methanolic extract exhibited aphidicidal activity against wheat aphids, Rhopalosiphum maidis and Sitobion avenae (LC50 = 0.987% and 0.953%). Compound (3) was isolated for the first time from the genus Cannabis.