title: Structure and cytotoxic activity of sesquiterpene glycoside esters from Calendula officinalis L.: Studies on the conformation of viridiflorol.
abstract: Topic applications of Calendula officinalis L. lipophilic extracts are used in phytotherapy to relieve skin inflammatory conditions whereas infusions are used as a remedy for gastric complaints. Such a different usage might be explained by some cytotoxicity of lipophilic extracts at gastric level but little is known about this. Therefore, we screened the CH2Cl2 extract from the flowers of C. officinalis by MTT and LDH assays in human epithelial gastric cells AGS. This bioassay-oriented approach led to the isolation of several sesquiterpene glycosides which were structurally characterized by spectroscopic measurements, chemical reactions and MM calculations. The conformational preferences of viridiflorol fucoside were established and a previously assigned stereochemistry was revised. The compounds 1a, 2a and 3f showed comparably high cytotoxicity in the MTT assays, whereas the effect on LDH release was lower. Our study provides new insights on the composition of C. officinalis extracts of medium polarity and identifies the main compounds that could be responsible for cytotoxic effects at gastric level.
authors.affiliation: Laboratory of Bioorganic Chemistry, Department of Physics, Università degli Studi di Trento, 38123 Trento, Italy. Electronic address: michele.dambrosio@unitn.it.
authors.forename: Michele
authors.initials: M
authors.lastname: D'Ambrosio
authors.affiliation: Laboratory of Bioorganic Chemistry, Department of Physics, Università degli Studi di Trento, 38123 Trento, Italy.
authors.forename: Alexandru
authors.initials: A
authors.lastname: Ciocarlan
authors.affiliation: Laboratory of Pharmacognosy, Department of Pharmacological and Biomolecular Sciences, Università degli Studi di Milano, 20133 Milan, Italy.
authors.forename: Elisa
authors.initials: E
authors.lastname: Colombo
authors.affiliation: Laboratory of Bioorganic Chemistry, Department of Physics, Università degli Studi di Trento, 38123 Trento, Italy.
authors.forename: Antonio
authors.initials: A
authors.lastname: Guerriero
authors.affiliation: Dipartimento di Farmacia, Università degli Studi di Salerno, 84084 Fisciano (SA), Italy.
authors.forename: Cosimo
authors.initials: C
authors.lastname: Pizza
authors.affiliation: Laboratory of Pharmacognosy, Department of Pharmacological and Biomolecular Sciences, Università degli Studi di Milano, 20133 Milan, Italy.
authors.forename: Enrico
authors.initials: E
authors.lastname: Sangiovanni
authors.affiliation: Laboratory of Pharmacognosy, Department of Pharmacological and Biomolecular Sciences, Università degli Studi di Milano, 20133 Milan, Italy.
authors.forename: Mario
authors.initials: M
authors.lastname: Dell'Agli
mesh_terms: D020838:Calendula / Q000737:chemistry*; D002301:Cardiac Glycosides / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology*; D004952:Esters; D035264:Flowers / Q000737:chemistry; D006027:Glycosides / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology*; D006801:Humans; D007770:L-Lactate Dehydrogenase / Q000378:metabolism*; D015394:Molecular Structure; D019906:Nuclear Magnetic Resonance, Biomolecular; D008517:Phytotherapy; D010936:Plant Extracts / Q000737:chemistry / Q000494:pharmacology; D012717:Sesquiterpenes / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology*; D013237:Stereoisomerism; D013729:Terpenes / Q000737:chemistry*
chemical_list: D002301:Cardiac Glycosides; D004952:Esters; D006027:Glycosides; D010936:Plant Extracts; D012717:Sesquiterpenes; D013729:Terpenes; C421806:ledol; D007770:L-Lactate Dehydrogenase; C552080:viridiflorol
keywords: Calendula officinalis; Ledol; Marigold; Officinoside D; Sesquiterpene glycoside; Viridiflorol; α-Elemol; β-Eudesmol