Steroid, Triterpenoid and Phenylpropanoid From Stereospermum Suaveolens (Roxb.) DC Growing in Bangladesh

The study was carried out to investigate the composition of natural compounds of methanol extract of leaf and stem bark of Stereospermum suaveolens (Roxb.) DC by repeated chromatographic separation and purification processes over silica gel. The phytochemical investigation resulted in the isolation of a total of three compounds, which were identified as stigmasterol (1), β-amyrin (2) and 4-methoxycinnamic acid (3). The chemical structures of the isolated compounds were elucidated by analyses of their physical properties, acquired 1H NMR data and comparison with published reports. Among these, compounds 2 and 3 are first report of their isolation from this plant species. Bangladesh J. Bot. 50(4): 1191-1194, 2021 (December)

The thermodynamic study of p-methoxycinnamic acid inclusion complex formation, using β-cyclodextrin and hydroxypropyl-β-cyclodextrin

Objectives Cyclodextrin’s ability to form an inclusion complex with a guest molecule is a function of two factors. The first is steric and depends on the relative size of cyclodextrin cavity to the guest molecule, while the second is the thermodynamic interaction between the different system components. This study therefore aims to determine the effect of β-cyclodextrin and hydroxypropyl-β-cyclodextrin as complex formers, on thermodynamic parameter values (ΔH, ΔG, and ΔS) in the formation of inclusion complex with p-methoxycinnamic acid (pMCA). Methods The pMCA complex formation with β-cyclodextrin or hydroxypropyl-β-cyclodextrin was determined in 0.02 pH 4.0 M acetate buffer and 0.02 M pH 7.0 phosphate buffer, with a 0.2 µ value at 32, 37, and 42 ± 0.5 °C. This experiment was carried out in a waterbath shaker until a saturated solution was obtained. Subsequently, pMCA concentration was determined using UV spectrophotometer at the maximum pMCA wavelength, at each pH. Results The result showed pMCA formed inclusion complex with β-cyclodextrin or hydroxypropyl-β-cyclodextrin and exhibited increased solubility with increase in β-cyclodextrin or hydroxypropyl-β-cyclodextrin concentration. This temperature rise led to a decrease in the complex’s constant stability (K). Furthermore, the interaction showed a negative enthalpy (∆H<0) and is a spontaneous processes (∆G<0). At pH 4.0, an increase in the system’s entropy occurred (∆S>0), however, at pH 7.0, the system’s entropy decreased (∆S<0). Conclusions The rise in pMCA solubility with increase in cyclodextrin solution concentration indicates an inclusion complex has been formed, and is supported by thermodynamic data.

Recent Developments in Therapeutic and Nutraceutical Applications of p-Methoxycinnamic Acid from Plant Origin

The p-methoxycinnamic acid (p-MCA) is one of the most studied phenylpropanoids with high importance not only in the wide spectrum of therapeutic activities but also its potential application for the food industry. This natural compound derived from plants exhibits a wide range of biologically useful properties; therefore, during the last two decades it has been extensively tested for therapeutic and nutraceutical applications. This article presents the natural sources of p-MCA, its metabolism, pharmacokinetic properties, and safety of its application. The possibilities of using this dietary bioactive compound as a nutraceutical agent that may be used as functional food ingredient playing a vital role in the prevention and treatment of many chronic diseases is also discussed. We present the antidiabetic, anticancer, antimicrobial, hepato-, and neuroprotective activities of p-MCA and methods of its lipophilization that have been developed so far to increase its industrial application and bioavailability in the biological systems.

Optimization of Plant Extract Purification Procedure for Rapid Screening Analysis of Sixteen Phenolics by Liquid Chromatography

A solid-phase extraction (SPE) procedure was developed for simultaneous monitoring of sixteen different phenolics of various polarity, quantified by high-performance liquid chromatography (HPLC). The procedure allowed screening the accumulation of intermediates in different metabolic pathways that play a crucial role in plant physiology and/or are beneficial for human health. Metabolites mostly involved in phenylpropanoid, shikimate, and polyketide pathways comprise chlorogenic acid, gentisic acid, vanillic acid, caffeic acid, protocatechuic acid, ferulic acid, rutin, quercetin, epicatechin, gallic acid, sinapic acid, p-coumaric acid, o-coumaric acid, vanillin; two rarely quantified metabolites, 2,5-dimethoxybenzoic acid and 4-methoxycinnamic acid, were included as well. The procedure offered low cost, good overall efficiency, and applicability in laboratories with standard laboratory equipment. SPE recoveries were up to 99.8% at various concentration levels. The method allowed for routine analysis of compounds with a wide range of polarity within a single run, while its applicability was demonstrated for various model plant species (tobacco, wheat, and soybean), as well as different tissue types (shoots and roots).