Iridoids and Amino Acid Derivatives from the Paraguayan Crude Drug <i>Adenocalymma marginatum</i> (ysypó hû)

• Main Authors: Guillermo Schmeda-Hirschmann, Alberto Burgos-Edwards, Felipe Jiménez-Aspee, Daniel Mieres-Castro, Cristina Theoduloz, Lisa Pormetter, Ramon Fogel, Claudia Céspedes, Nelida Soria, Sintya Valdez
• Format: Article
• Language: English
• Published: MDPI AG 2020-01-01
• Series: Molecules
• Subjects: <i>adenocalymma marginatum</i>; bignoniaceae; counter-current chromatography; iridoids; amino acid derivatives; guarani medicine; paraguayan crude drug
• Online Access: https://www.mdpi.com/1420-3049/25/1/180

The crude drug ysyp&#243; h&#251; (<i>Adenocalymma marginatum</i> DC., Bignoniaceae) is used traditionally by the Guarani of Eastern Paraguayan as a male sexual enhancer. The aim of the present study was to identify the main constituents of the crude drug and to evaluate the in vitro inhibitory activity towards the enzyme phosphodiesterase-5 (PDE-5). The main compounds were isolated by counter-current chromatography (CCC). The metabolites were identified by spectroscopic and spectrometric means. The chemical profiling of the extracts was assessed by high-performance liquid chromatography coupled to mass spectrometry (HPLC-MS/MS). The crude extract and main isolated compounds were tested for their PDE-5 inhibitory activity using commercial kits. The iridoid theviridoside and 4-hydroxy-1-methylproline were isolated as the main constituent of the crude drug. Four chlortheviridoside hexoside derivatives were detected for the first time as natural products. Chemical profiling by HPLC-MS/MS led to the tentative identification of nine iridoids, six phenolics, and five amino acids. The crude extracts and main compounds were inactive towards PDE-5 at concentrations up to 500 &#181;g/mL. Iridoids and amino acid derivatives were the main compounds occurring in the Paraguayan crude drug. The potential of ysyp&#243; h&#251; as a male sexual enhancer cannot be discarded, since other mechanisms may be involved.