Use of Group Contribution Methods, Hansen’s Solubility Theory and Microsoft Excel in Solvents Selection for Extraction of Natural Products

Abstract

Usually, Hansen’s theory and the COSMO continuous solvation models have been used for the selection
of solvents related to a solute, using the HSPiP and COSMO-RS computational tools, respectively. Those tools are not
always available to many researchers; for this reason, Microsoft Excel (ME) has been used for the estimation of good
solvents in the extraction of natural products of high value and interesting for the food, pharmaceutical and cosmetic
industries. This method is applicable to cases where there is little, or practically no information about the compound of
interest, for which functional group contribution methods are used, among them, the Joback method for the estimation of
properties necessary for the determination of solubility models, and Van Krevelen method for the initial estimation of the
Hansen solubility parameters for solubility estimates, the Flory-Hugging model is used, from which and its classification,
according to the North American Pharmacopeia, the good and bad solvents are defined in the selected database for
the final estimation of Hansen’s parameters and the solubility region. The methodology was validated with ten study
cases reported in the literature. The results of this study showed that other green solvents, not reported in the literature
consulted, are suggested as good solvents for polyphenols, such as diacetone alcohol, diethylene glycol monobutyl ether
and tetrahydrofurfuryl alcohol. In the consulted literature there are no references on the use of a structured methodology
in Microsoft Excel (ME) for the estimation of good solvents for the extraction of natural products from the estimation
of solubility with existing models. All the consulted papers refer the use of various professional computer programs for
this purpose, specifically HSPiP, and COSMO-RS, which are not accessible to all researchers. With these estimates and
an initial classification based on pharmacopoeia criteria, a first classification of good and bad solvents is made, which is
refined by means of optimization methods in ME.