5614
Ann Gamal Boulis Kirolos
A Phytochemical and Biological Study Ulmus pumila L. Cultivated in Egypt
cytotoxic potential, leafy branches, lipoid profiling, phytochemical screening, phytoconstituents, radical scavenging activity, stem bark, TLC analysis, Ulmus pumila L.
Ulmus pumila L., a member of family Ulmaceae, is successfully grown in Egypt. Genus Ulmus is renowned for its cytotoxic terpenoids. The current study aimed to investigate the locally cultivated plant as a potential source of cytotoxic constituents that could be employed in the pharmaceutical industries. Reports on either the phytoconstituents of the aforementioned species or its evidence-based biological activities were rare or completely lacking, thus granting a great interest in its intensive phytochemical and biological investigation. The methanol extracts of the stem bark and leafy branches of the investigated species were subjected to phytochemical screening, TLC investigation, and quantitative estimation of the major constituents. The composition of the lipoidal matter of both was examined via GC/MS analysis. The dichloromethane fraction of the methanol extract of the stem bark and the ethyl acetate fraction of the methanol extract of the leafy branches were selected for intensive phytochemical investigation based on available literature on genus Ulmus, TLC analysis of the various fractions, and total phenolic, flavonoid, and terpenoid/steroid contents of the total extracts. Repeated chromatographic fractionation of the dichloromethane fraction of the methanol extract of the stem bark yielded six isolates identified as Friedelin, 3β-acetoxyurs-11-en-13β,28-olide, 3β-O-acetyl ursolic acid contaminated with 3β-O-acetyl oleanolic acid, a mixture of β-Sitosterol and Stigmasterol, Betulinic acid, and a mixture of Methyl ursolate and Methyl oleanolate. Among these, 3β-acetoxyurs-11-en-13β, 28-olide, 3β-O-acetyl ursolic acid, 3β-O-acetyl oleanolic acid, Methyl ursolate, and Methyl oleanolate were reported for the first time in genus Ulmus; and Betulinic acid was reported for the first time in Ulmus pumila L. Repeated chromatographic fractionation of the ethyl acetate fraction of the methanol extract of the leafy branches yielded three isolates identified as Kaempferol-3-Orutinoside, a mixture of Quercetin-3-O-β-D-glucopyranoside and Quercetin-3-O-βD-galactopyranoside, and 3,4-Dihyroxycinnamic acid. Quercetin-3-O-β-Dgalactopyranoside was reported for the first time in genus Ulmus; while Kaempferol3-O-rutinoside was reported for the first time in Ulmus pumila L. Evaluation of the cytotoxic potential of the crude methanol extract of the stem bark, along with the isolated triterpenoids, revealed that the crude extract (IC50 = 29.54 ± 0.05 μg/ml), as well as Betulinic acid (IC50 = 22.39 ± 0.09 μM), and Methyl ursolate and/or Methyl oleanolate (IC50 = 50.71 ± 0.18 μM) possess in-vitro cytotoxic activities against MCF-7 (human breast adenocarcinoma) cell line. It was also demonstrated that 3β-acetoxyurs-11-en-13β,28-olide (IC50 = 78.98 ± 0.07 μM), 3β-O-acetyl ursolic acid and/or 3β-O-acetyl oleanolic acid (IC50 = 48.91 ± 0.12 μM), Betulinic acid (IC50 = 22.29 ± 0.05 μM), and Methyl ursolate and/or Methyl oleanolate (IC50 = 52.96 ± 0.07 μM) exhibit remarkable in-vitro cytotoxic activities against HCT-116 (human colorectal carcinoma) cell line. In addition, it was found that Betulinic acid possesses an in-vitro cytotoxic potential against A549 (Human pulmonary adenocarcinoma) cell line (IC50 = 42.33 ± 0.06 μM). Evaluation of the antioxidant potential of the ethyl acetate fraction of the methanol extract of the leafy branches, using DPPH assay, revealed that it possesses a mild radical scavenging activity (IC50 = 95.92 ± 2.88 µg/ml).
2020
M.Sc
Cairo
Pharmacy