Predicted real solubility (– log x₂) and the level of hydrophilic-lipophilic balance (HLB_Requ.) of phytochemicals contained in extracts isolated from linden inflorescence (Tiliae flos) with solvents of diversified polarity (ε_M)

Abstract

Summary Introduction: The broad spectrum of pharmacological properties of linden inflorescence extracts results from polarity and the level of hydrophilic-lipophilic balance of solvents (medium) used to separate compatible phytochemical structures with the expected pharmacotherapeutic profile. Objective: The use of the general Hildebrand-Scatchard-Fedors theory of solubility to calculate the predicted solubility of classes of phytochemicals contained in linden inflorescences (Tiliae flos) and the indication of those structures which, due to their high solubility in the medium, are responsible for the profile of pharmacological activity. Material and methods: The Hildebrand, Scatchard equation, supported with computational technique proposed by Fedors, allows calculation of the solubility parameters of the extraction medium. Despite application reservations, it is a fundamental tool for estimating the predictable solubility of phytochemicals in real solution. Results: The structure of phytochemicals isolated from linden inflorescences (Tiliae flos) owing to the use of solvents of significantly diversified polarity (–dielectric constant – εM) was the basis for calculating the molar evaporation energy – ΣΔEi (cal/mol) and molar volume – ΣΔVi (cm3/mol) by Fedors method, which are fundamental quantities necessary to estimate the solubility parameter – δ1/2 and required solubility level of hydrophilic-lipophilic balance – HLBRequ. Conclusions: Results of the presented research indicate that basing on the parameters characterizing the structure of phytochemicals and the calculated ideal (–logxi2) and predicted real (– log x2) solubility, it is possible – using the general Hildebrand-Scatchard-Fedors theory of solubility – to choose selectively the cascade of extraction media in order to distinguish in the plant material chemical and structural individuals of different polarity.