Effect of solvent polarity on extractive yield and phytochemical composition of three under-utilized Cameroonian hardwoods

The commercial exploitation of Cameroonian timber resources remains concentrated on a limited number of well-known hardwood species, increasing pressure on mature forest stands while many potentially valuable species remain under-utilized. This study investigated the influence of solvent polarity on extractive yield and phytochemical composition of three lesser-used Cameroonian hardwoods: Okan (Cylicodiscus gabunensis), Dabema (Piptadeniastrum africanum) , and Kotibe (Nesogordonia papaverifera). Heartwood samples were extracted using four solvents of differing polarity acetone, methanol, ethanol, and distilled water. Extractive yield was determined gravimetrically, while qualitative phytochemical screening was conducted to identify major classes of secondary metabolites. Extraction experiments were performed in triplicate, and the effects of solvent type, species, and their interaction were evaluated using two-way analysis of variance (ANOVA). Organic solvents, particularly acetone and methanol, produced significantly higher extractive yields than ethanol and distilled water (p < 0.05). Among the species studied, C. gabunensis consistently exhibited the highest extractive yields, followed by P. africanum, whereas N. papaverifera showed comparatively lower values. Phytochemical screening indicated that phenolic compounds and tannins predominated across species, especially in semi-polar solvent extracts, while saponins were weakly present or absent. The combined assessment of extractive yield and phytochemical composition reveals substantial chemical potential in under-utilized Cameroonian hardwoods, particularly Okan and Dabema. These findings support their potential use in natural wood preservation, bio-based coatings, and other sustainable material applications, contributing to reduced pressure on heavily exploited commercial species and improved forest resource management.