Chromatographic Investigation of Phytoconstituents in Milk Yam (Ipomoea digitata L.) Tubers

Objective: The present study is done with the aim of identifying the maturity stage of milk yam tuber containing maximum concentration of umbelliferone – a coumarin present in the tubers. Materials and Methods: Umbelliferone present in immature tubers (6 months after planting), overmature tubers (36 months after planting), and tubers at optimum maturity (21 months after planting) was assessed using high‑performance liquid chromatography (HPLC) and high‑performance thin‑layer chromatography (HPTLC) analysis. Results: HPLC and HPTLC techniques revealed the presence of umbelliferone and it was quantified to be higher in over mature tubers (0.44 and 0.42 µg/g, respectively), followed by optimally mature (0.31 and 0.22 µg/g, respectively) and immature tubers (0.20 and <0.11 µg/g, respectively). Conclusion: The study reveales that developmental stages affect umbelliferone concentration in milk yam tubers and it increased as the plant ages.