title: Flavonoids of Calligonum polygonoides and their cytotoxicity.
abstract: Context Calligonum polygonoides L. subsp. comosum L' Hér. (Polygonaceae), locally known as "arta", is a slow-growing small leafless desert shrub. Objective Isolation, structure elucidation and evaluation of cytotoxic activity of flavonoids from C. polygonoides aerial parts. Materials and methods Flavonoids in the hydroalcoholic extract of the of C. polygonoides were isolated and purified using column chromatography and preparative HPLC. The structures of the isolated flavonoids were elucidated on the basis of spectroscopic data including 2D NMR techniques. The cytotoxic activity of the isolated flavonoids (6.25, 25, 50 and 100 μg/mL) was evaluated against liver HepG2 and breast MCF-7 cancer cell lines using sulphorhodamine-B assay. Results A new flavonoid, kaempferol-3-O-β-D-(6″-n-butyl glucuronide) (1), and 13 known flavonoids, quercetin 3-O-β-D-(6″-n-butyl glucuronide) (2), kaempferol-3-O-β-D-(6″-methyl glucuronide) (3), quercetin-3-O-β-D-(6″-methyl glucuronide) (4), quercetin-3-O-glucuronide (5), kaempferol-3-O-glucuronide (6), quercetin-3-O-α-rhamnopyranoside (7), astragalin (8), quercetin-3-O-glucopyranoside (9), taxifolin (10), (+)-catechin (11), dehydrodicatechin A (12), quercetin (13), and kaempferol (14), were isolated from the aerial parts of C. polygonoides. Quercetin showed significant cytotoxic activity against HepG2 and MCF-7 cell lines with IC50 values of 4.88 and 0.87 μg/mL, respectively. Structure-activity relationships were analyzed by comparing IC50 values of several pairs of flavonoids differing in one structural element. Discussion and conclusion The activity against breast cancer cell lines decreased by glycosylation at C-3. The presence of 2,3-double bond in ring C, carbonyl group at C-4 and 3',4'-dihydroxy substituents in ring B are essential structural requirements for the cytotoxic activity against breast cancer cells.
authors.affiliation: a Department of Pharmacognosy, Faculty of Pharmacy , Beni-Suef University , Beni-Suef , Egypt ;
authors.forename: Hayam
authors.initials: H
authors.lastname: Ahmed
authors.affiliation: a Department of Pharmacognosy, Faculty of Pharmacy , Beni-Suef University , Beni-Suef , Egypt ;
authors.forename: Abeer
authors.initials: A
authors.lastname: Moawad
authors.affiliation: a Department of Pharmacognosy, Faculty of Pharmacy , Beni-Suef University , Beni-Suef , Egypt ;
authors.forename: Asmaa
authors.initials: A
authors.lastname: Owis
authors.affiliation: a Department of Pharmacognosy, Faculty of Pharmacy , Beni-Suef University , Beni-Suef , Egypt ;
authors.forename: Sameh
authors.initials: S
authors.lastname: AbouZid
authors.affiliation: b Division of Physiology, Department of Zoology, Faculty of Science , Beni-Suef University , BeniSuef , Egypt.
authors.forename: Osama
authors.initials: O
authors.lastname: Ahmed
mesh_terms: D000972:Antineoplastic Agents, Phytogenic / Q000302:isolation & purification / Q000494:pharmacology*; D001943:Breast Neoplasms / Q000188:drug therapy* / Q000473:pathology; D049109:Cell Proliferation / Q000187:drug effects; D002851:Chromatography, High Pressure Liquid; D004305:Dose-Response Relationship, Drug; D005260:Female; D005419:Flavonoids / Q000302:isolation & purification / Q000494:pharmacology*; D056945:Hep G2 Cells; D006801:Humans; D020128:Inhibitory Concentration 50; D008113:Liver Neoplasms / Q000188:drug therapy* / Q000473:pathology; D061986:MCF-7 Cells; D009682:Magnetic Resonance Spectroscopy; D015394:Molecular Structure; D008517:Phytotherapy; D035261:Plant Components, Aerial; D010936:Plant Extracts / Q000302:isolation & purification / Q000494:pharmacology*; D010946:Plants, Medicinal; D019664:Polygonaceae / Q000737:chemistry; D012997:Solvents / Q000737:chemistry; D013329:Structure-Activity Relationship
chemical_list: D000972:Antineoplastic Agents, Phytogenic; D005419:Flavonoids; D010936:Plant Extracts; D012997:Solvents
keywords: Breast cancer; SAR; kaempferol; quercetin