title: Antiproliferative terpenoids from almond hulls (Prunus dulcis): identification and structure-activity relationships.
abstract: Bioassay-guided fractionation of the EtOAc crude extract from Sicilian almond hulls, a waste material from Prunus dulcis crop, allowed identification of 10 constituents, isolated as pure compounds (1-5, 7, and 10) or unseparable mixtures (5 + 6 and 8 + 9). All compounds were subjected to spectroscopic analysis and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide bioassay on MCF-7 human breast cancer cells. In addition to the main components oleanolic (1), ursolic (2), and betulinic (3) acids, the 2-hydroxy analogues alphitolic (4), corosolic (5), and maslinic (6) acids, as well as the related aldehydes, namely, betulinic (7), oleanolic (8), and ursolic (9), were identified. From a more polar fraction, the beta-sitosterol 3-O-glucoside (10) was also identified. A sample of commercially available betulin (11) was also included in bioassays as further support to a structure-activity relationship study. Betulinic acid showed antiproliferative activity toward MCF-7 cells (GI50 = 0.27 microM), higher than the anticancer drug 5-fluorouracil.
authors.affiliation: Dipartimento di Scienze Chimiche, Università di Catania, Viale A. Doria 6, 95125 Catania, Italy.
authors.forename: Vincenzo
authors.initials: V
authors.lastname: Amico
authors.forename: Vincenza
authors.initials: V
authors.lastname: Barresi
authors.forename: Daniele
authors.initials: D
authors.lastname: Condorelli
authors.forename: Carmela
authors.initials: C
authors.lastname: Spatafora
authors.forename: Corrado
authors.initials: C
authors.lastname: Tringali
mesh_terms: D000970:Antineoplastic Agents; D001943:Breast Neoplasms; D002455:Cell Division / Q000187:drug effects*; D006801:Humans; D009682:Magnetic Resonance Spectroscopy; D053978:Pentacyclic Triterpenes; D027861:Prunus / Q000737:chemistry*; D012639:Seeds / Q000737:chemistry*; D013329:Structure-Activity Relationship; D013729:Terpenes / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology*; D014315:Triterpenes / Q000494:pharmacology; D000094062:Betulinic Acid
chemical_list: D000970:Antineoplastic Agents; D053978:Pentacyclic Triterpenes; D013729:Terpenes; D014315:Triterpenes; D000094062:Betulinic Acid