title: Bioactive steroidal saponins from Agave offoyana flowers.
abstract: Bioguided studies of flowers of Agave offoyana allowed the isolation of five steroidal saponins never described previously, Magueyosides A-E (1-5), along with six known steroidal saponins (6-11). The structures of compounds were determined as (25R)-spirost-5-en-2α,3β-diol-12-one 3-O-{β-d-xylopyranosyl-(1→3)-O-β-d-glucopyranosyl-(1→2)-O-[β-d-xylopyranosyl-(1→3)]-O-β-d-glucopyranosyl-(1→4)-O-β-d-galactopyranoside} (1), (25R)-spirost-5-en-2α,3β-diol-12-one 3-O-{β-d-glucopyranosyl-(1→2)-O-[β-d-xylopyranosyl-(1→3)]-O-β-d-glucopyranosyl-(1→4)-O-β-d-galactopyranoside} (2), (25R)-spirost-5-en-2α,3β,12β-triol 3-O-{β-d-glucopyranosyl-(1→2)-O-[β-d-xylopyranosyl-(1→3)]-O-β-d-glucopyranosyl-(1→4)-O-β-d-galactopyranoside} (3), (25R)-5α-spirostan-2α,3β-diol-12-one 3-O-{β-d-xylopyranosyl-(1→3)-O-β-d-glucopyranosyl-(1→2)-O-[β-d-xylopyranosyl-(1→3)]-O-β-d-glucopyranosyl-(1→4)-O-β-d-galactopyranoside} (4), and (25R)-5α-spirostan-2α,3β-diol-9(11)-en-12-one 3-O-{β-d-xylopyranosyl-(1→3)-O-β-d-glucopyranosyl-(1→2)-O-[β-d-xylopyranosyl-(1→3)]-O-β-d-glucopyranosyl-(1→4)-O-β-d-galactopyranoside} (5), by comprehensive spectroscopic analysis, including one- and two-dimensional NMR techniques, mass spectrometry and chemical methods. The bioactivities of the isolated compounds on the standard target species Lactuca sativa were evaluated. A dose-dependent phytotoxicity and low dose stimulation were observed.
authors.affiliation: Grupo de Alelopatía, Departamento de Química Orgánica, Facultad de Ciencias, Universidad de Cádiz, C/República Saharaui, s/n, 11510 Puerto Real, Cádiz, Spain; Department of Biochemistry, Institute of Soil Science and Plant Cultivation, State Research Institute, ul. Czartoryskich 8, 24-100 Puławy, Poland.
authors.forename: Andy J
authors.initials: AJ
authors.lastname: Pérez
authors.forename: Juan M
authors.initials: JM
authors.lastname: Calle
authors.forename: Ana M
authors.initials: AM
authors.lastname: Simonet
authors.forename: José O
authors.initials: JO
authors.lastname: Guerra
authors.forename: Anna
authors.initials: A
authors.lastname: Stochmal
authors.forename: Francisco A
authors.initials: FA
authors.lastname: Macías
mesh_terms: D027882:Agave / Q000737:chemistry*; D035264:Flowers / Q000737:chemistry; D018545:Lactuca / Q000187:drug effects; D015394:Molecular Structure; D010936:Plant Extracts / Q000737:chemistry / Q000494:pharmacology*; D012503:Saponins / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*
chemical_list: D010936:Plant Extracts; D012503:Saponins
keywords: Agave offoyana; Phytotoxic activity; Steroidal saponins; Structural elucidation; Structure–activity relationship