Phytochemical Profile of Makila (Litsea angulata) Wood Extracts and Their Potential for Bio-Based Wood Preservation against Subterranean Termites

Abstract

Subterranean termites pose a substantial threat to wood durability in tropical environments, highlighting the need to investigate sustainable, plant-derived wood-protection agents. This study characterised the qualitative phytochemical profiles of Makila (Litsea angulata) wood extracts obtained from basal, middle and upper stem sections and evaluated treatment-associated responses in meranti and samama wood following field exposure. Methanolic extracts were subjected to qualitative phytochemical screening, while treated and untreated wood specimens underwent a 30-day field graveyard test. Final oven-dry mass was evaluated descriptively and using separate one-way analyses of variance for each wood species. Saponins, tannins, alkaloids, triterpenoids and phenolic compounds were detected in all stem sections. Flavonoids were detected only in basal and middle sections, whereas steroids were not detected. No statistically significant differences in final oven-dry mass were observed among meranti treatments (p > 0.05). In contrast, samama exhibited significant between-treatment differences (p < 0.05), with the highest mean final mass recorded for specimens treated with upper-stem extract (69.49 g), compared with 51.59 g in untreated controls. These findings demonstrate stem-position-related variation in qualitative phytochemical detection and contrasting treatment-associated responses between the two wood substrates. Nevertheless, differences in final mass cannot independently establish preservative efficacy without accounting for initial specimen mass and potential treatment retention. Further investigations incorporating normalised mass loss, quantitative phytochemical characterisation and direct termite bioassays are therefore required. Makila wood extracts represent promising candidates for further investigation as locally sourced bio-based wood-protection agents.