Phytochemical research of &lt;em&gt;Cordia rufescens&lt;/em&gt; A.DC

Ana Rita Silva,Carlos Arthur Veloso,Diego Igor Araújo,Emille Wannick Silva,Jociano Lins,Nikole Durand Trigueiro,Pedro Figueiredo,Vicente Carlos Costa

doi:10.3390/mol2net-04-05521

Abstract

Cordia rufescens A. DC, a small shrub in northeastern Brazil is popularly referred to as "old-growth" or "pigeon-claw". This plant is used in folk medicine as abortive, anti-inflammatory agent and in the treatment of dysmenorrhea and dyspesia (VALE et al., 2012). Thus, the need for a greater chemical and pharmacological knowledge of Cordia rufescens A.DC species was observed, necessitating a more in-depth study of the isolation and characterization of new compounds. The plant material (leaves) was collected in 2002 in the municipality of Cruz do Espírito Santo - PB and identified by Profa. Dr. Maria de Fátima Agra. The material was then oven dried with circulating air at an average temperature of 45 ° C, ground in a mechanical mill and subjected to steeping with 95% EtOH. The crude ethanolic extract (106.10 g) was dissolved in a methanol: water (7: 3 v / v) solution and partitioned with the following solvents: hexane, dichloromethane and ethyl acetate. An aliquot of the dichloromethane phase (7 g) was subjected to the chromatographic column (CC), using as a stationary phase silica gel, and as mobile phase hexane, ethyl acetate and methanol, with elution systems in increasing polarity order, obtaining 34 fractions. All fractions were submitted to analytical thin layer chromatography (ADCC) and analyzed and assembled according to their retention factors (Rfs) and after visualization in ultraviolet light. Fractions 2, 3 and 5 presented different retention factors and therefore were submitted to liquid chromatography of high efficiency in analytical scale, where fraction 5 was chosen to obtain a better resolution of the chromatogram in front of the others, being then submitted to the purification by HPLC on a semi-preparative scale that resulted in the identified substances 4-hydroxy-benzaldeído and 4 -hydroxy-3,5-dimethoxycinnamate, reported for the first time in the species under study.

Highlights

The genus Cordia L. has approximately 320 species, which are presented as trees, shrubs or herbs, having as main habituation to South America 1
Purification of fraction 5 by High Resolution Liquid Chromatography (HPLC) led to the isolation of two substances encoded as Crd-1 and Crd-7
The 1H NMR spectrum obtained at 400 MHz in CD3OD showed the presence of 3 signals, these two doublets being around δH 7.78 and 6.91 ppm both with J = 8.0 Hz corresponding to the ortho coupling between the hydrogens of the aromatic ring with a characteristic profile of pdisubstituted benzene, and a single with δH 9.75 ppm characteristic of hydrogen bound to aldehyde carbonyl

Summary

Introduction

The genus Cordia L. has approximately 320 species, which are presented as trees, shrubs or herbs, having as main habituation to South America 1. After analysis of the spectral data and comparisons with data described in the literature it was possible to identify that the compound Crd-1 is 4-hydroxy-benzaldehyde (Figure 1). The 13C NMR spectrum obtained at 100 MHz in CDCl3 showed the presence of 10 signals assigned to 13 carbons, being δc 14.34 assigned to methyl (C11); δc 56.32 and attributed to methoxylates (C-3 and C-5); δc 60.39 assigned to methylene carbon (C-10); δc 105.00 assigned to the methinic carbons (C-2 and C-6); δc 144.95 and 116.05 assigned to the olefinic carbons (C-7 and C-8, respectively); δc 137.05 assigned to nonhydrogenated carbon (C-1); δc 147.19 assigned to hydroxyl-bound carbon (C-4); and, δc 167.14 assigned to the ester carbonyl. After analysis of the spectral data and comparisons with data described in the literature it was possible to identify the Crd-7 compound as being ethyl 4hydroxy-3,5-dimethoxy cinnamate (Figure 2)

Materials and Methods

Conclusions