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.

Saponins of Agave: Chemistry and bioactivity

“…The majority of the extraction procedures for saponins of Agave involve classical methods such as Soxhlet extraction (Wilkomirski et al, 1975) and maceration (Chen et al, 2011;Eskander et al, 2010;Perez et al, 2013Perez et al, , 2014Yokosuka and Mimaki, 2007). The choice of the extraction solvents is also limited as the saponins dissolve in polar solvents only.…”

“…subcerulata (leaves) Blunden et al (1980b) A. cocui (leaves) Blunden et al (1980b) Sharma and Khanna (1980) A. filifera (leaves) Blunden et al (1978) A. avellanidens (leaves) Blunden et al (1980b) A. cerulata (leaves) Blunden et al (1980b) A. cerulata ssp. subcerulata (leaves) Blunden et al (1980b) A. cocui (leaves) Blunden et al (1980b) A. canatala (leaves) A. wightii (leaves) Khanna et al (1979) 16 (25S)-5a-Spirostan-3-one (Neotigogenone) A. sisalana (leaves) Tsung et al (1976a) 17 (25R)-5b-Spirostan-3b-ol (Smilagenin) A. lecheguilia (leaves) Blunden et al (1980a);de Rodriguez et al (2006) A. haynaldii (leaves) Blunden et al (1978) A. rigidissima (leaves) Blunden et al (1978) A. ghiesbrechtii (leaves) Blunden et al (1974) 18 (25S)-5b-Spirostan-3b-ol (Sarsasapogenin) A. attenuata (leaves) Blunden et al (1978); Mendes et al (2004) A. lophantha (leaves) Bedour et al (1979) 19 (25R)-5b-Spirostan-3b,6a-diol (Ruizgenin) A. lecheguilia (leaves) Blunden et al (1980a) (25S)-5a-Cholestane-3b,16b,22b,26-tetrol (Agavegenin D) A. americana (leaves) Jin et al (2004a) methanol (or ethanol)-water combinations (Perez et al, 2013(Perez et al, , 2014Yu et al, 2011) are generally employed for extraction. The choice of solvent also depends upon the probability of artifact formation.…”

Mass Spectrometry-Based Metabolomics of Agave Sap (Agave salmiana) after Its Inoculation with Microorganisms Isolated from Agave Sap Concentrate Selected to Enhance Anticancer Activity

“…Mass spectra analysis of compound 2 showed that two kammogenin glycosides were co-eluting. These saponins exhibited characteristic ions at m/z 1217.51 ([M + Na] + ) and 1085.48 ([M + Na] + ), and both were isolated previously from flowers of A. offoyana and identified as magueyoside A and magueyoside B, respectively [16]. Similarly, at the retention time of compound 4, two kammogenin glycosides were found.…”

“…Concentrations were reported as µg PE/mg extract. For saponin characterization, extracted ion chromatograms were analyzed considering the exact masses reported for saponins and sapogenins, as well as their fragmentation patterns (±0.05 units) using the Analyst QS 1.1 software (Applied Biosystems) [6,7,16].…”

“…Data analysis was conducted using PCA to select the ions that generated more variability among samples. Metabolites that were related to the decrease in viability were characterized by their retention times and mass spectra and compared with previous literature reports [6,7,16], and the Metlin database [17].…”