## 3 Results and Discussion
### Solubility Prediction  
Due to the complex nature of the sample matrix and diverse chemical characteristics of its constituents, there is no single standard method that can be used to extract or separate every bioactive natural product from plant material. Solvent extraction is the most commonly used method of extraction. Trends in green chemistry have pushed the focus towards the use of 'green' solvents. Thus, simple alcohols, ethanol and methanol, as universal solvents, are commonly chosen as extraction solvents. Alcohols, ethanol and methanol, as universal solvents, are commonly chosen as extraction solvents [31]. Due to  
Figure 5: Superimposed ATR-FTIR spectra of (**a**) an isolated compound from combined 13–19 fractions from ethanol extract and oleanolic acid standard (dashed line), and (**b**) s compound isolated from the fractions 18–20 from the ethyl acetate extract and maslinic acid standard (dashed line).  
methanol toxicity [32], ethanol is commonly selected as a green solvent with low toxicity for phytochemical studies. Guided by the law of similarity and intermiscibility (like dissolves like), the extraction of organic components from plant materials is directly related to the polarity of the extraction solvent, which should match the polarity of targeted compounds (solute). The polarity of the solvent and the solubility of the targeted compound in the solvent must be considered. In general, solutes whose polarity matches that of the solvent will generally be soluble in the solvent. Thus, solubility is a key parameter when selecting a solvent for separation processes and can be used to screen for possible candidates. Calculated solubility and solubility-related parameters are often related to the ionic and electronic characteristics of a molecule, while polarity of a molecule can be described by its dipole moment. The ability for a solvent to dissolve various compounds depends primarily on its polarity. Calculated solubility parameter, dipole moment, and hydrophilic surface area of ethyl acetate were found to match to those of oleanolic, unsolic and mashinic acids (Table 1).  
The three-dimensional Hansen solubility parameter (HSP) is a three component solubility parameter, a combination of dispersion, polarity and hydrogen bonding values (\(\delta\)D, \(\delta\)P, and \(\delta\)H). This combination gives a vector in 3D space that describes a radius of interaction sphere \(R\) of a molecule [33]. HSPs are useful for predicting solvent-solute affinity. They have been widely used to predict the solubility of polymers in different solvents and their compatibility with other polymers [34]. Dipole moment is a measure of the distribution and strength of partial charges in a molecule. Molecular Modelling Pro(r) 5.1 (ChemSW, Fairfield, CA, USA) was used to calculate the dipole moment from the partial charges of the individual atoms using semi-empirical quantum chemistry methods. Hydrophobic Surface Area, or HSA descriptors, were designed to measure molecular size related to solvent-accessible surface area of hydrophobic and hydrophilic features. Hydrophilicity or hydrophobicity are essential when dealing with liquids and miscibility. Log \(P\) values, could not be used to match solubilities. The log \(P\) value for a compound is the logarithm of the partition coefficient (\(P\)). The partition coefficient (\(P\)) is the ratio of a compound's solubility in an organic (oil) phase to its solubility in aqueous phase. Thus, log \(P\) values do not directly correlate with solubility.