Bioguided Isolation and Antiproliferative Activity of Constituents from Smilax korthalsii A.D.C. Leaves

Ethyl acetate extract of Smilax korthalsii A.D.C. leaves exhibited antiproliferative activity on leukaemia carcinoma K562, hepatic liver cancer cells WRL and colorectal carcinoma with IC₅₀ of 125.20, 46.10 and 160.00 μM respectively. Isolation of the bioactive ethyl acetate extract of Smilax korthalsii A.D.C. leaves gave eight compounds; 3β‐hydroxyspirost‐5‐ene (diosgenin), 1 , β‐sitosterol, 2 , lup‐5,11,20‐trien‐23‐ol, 3 , uneicos‐9‐enoic acid, 4 , ethylheptadecan‐17‐oic‐9‐enoate, 5 , cis‐octadec‐9‐enoic acid, 6 , hexadec9‐enoic acid, 7 and 11‐methyltridec‐12‐en‐1‐ol, 8 . The isolated compounds were tested against four human cancer cell lines: leukaemia carcinoma, K‐562; hepatic liver cancer cells, WRL; colorectal carcinoma, COLO; and breast carcinoma, MCF‐7 using the MTT assay. Diosgenin 1 exhibited significant antiproliferative activity against all four cell lines (IC₅₀; K562=6.25, WRL=14.34, COLO=38.00, MCF‐7=12.40 μM), while compounds 3, 6 and 7 inhibited the growth of K‐562 at 20, 50 and 100 μM concentrations with IC₅₀ of 90.20, 75.92 and 50.72 μM respectively. Other isolated compounds also showed cytotoxic properties against K‐562, WRL and COLO, but showed low inhibition of MCF‐7.     

Bioassay Guided Isolation and Identification of a Cytotoxic Compound from Azadirachta indica Leaves

This study aimed to investigate the structural features of the isolated flavonol glycoside, which might behave as a cytotoxic compound. The hexane, chloroform, ethyl acetate, and aqueous fractions of an 80% methanol solution of Neem (Azadirachta indica) (Family: Meliaceae) leaves were subjected to a cytotoxicity bioassay against brine shrimp, Artemia salina. The ethyl acetate fraction exhibited the highest cytotoxic effect, supported by the lowest lethal concentration, a LC₅₀ value of 1.35±0.40 ppm. A compound, Quercetin 3‐O‐β‐D‐glucopyranoside, was isolated from the most toxic fraction of the ethyl acetate via preparative liquid chromatography and then identified via ultraviolet‐visible (UV‐Vis), infrared (IR), mass spectrum (MS) and nuclear magnetic resonance (NMR) analyses. The compound was further confirmed by physical state, color, solubility, and melting point determination. The cytotoxic results suggest that the leaf ethyl acetate fraction consists of toxic compounds, which point towards the isolation of Quercetin 3‐O‐β‐D‐glucopyranoside.