Iminosugars from Baphia pubescens Hook (Fabaceae) as a potential source of antidiabetic phytopharmaceuticals

Baphia pubescens Hook (Fabaceae) is a shrub or small tree found in the tropical regions of Africa. Locally, the leaves and seedpods of Baphia species are used as a vegetable or spice and also for treating various ailments including inflammation, pain and diarrhoea [1], but ethnobotanical literature does not list these plants amongst those traditionally used for the treatment and management of diabetes.

Previous phytochemical investigation has shown that plants belonging to this genus of legumes are rich in iminosugars. These compounds closely resemble sugars structurally and mimic them along metabolic pathways. Iminosugars often show digestive enzyme inhibition and thus have a therapeutic potential in managing diabetes (by helping to stabilise blood glucose levels) [2].

This research focuses on the isolation and purification of iminosugars from Baphia pubescens by ion exchange chromatography and aims to establish whether HPCCC (high performance counter current chromatography) could offer an alternative method for isolation.

An ethanolic extract (50 % vol:vol) of whole seed pods, prepared and fractionated using ion exchange resins, yielded several iminosugar compounds and two related glycosides. A method of isolation by HPCCC is currently being developed.

As iminosugars previously isolated from Baphia nitida have demonstrated significant glycosidase inhibition (e. g. 1-deoxynojirimycin (DNJ)) [2], Baphia pubescens may serve well as a potential source of antidiabetic phytopharmaceuticals.

• References

• 1 Ogunwa TH, Fasimoye RY, Sholanke DR, Ademoye TA, Ilesanmi OC, Awe OB. et al. Compositional studies of Baphia pubescens (Urohun) leaves. Asian J Nat Appl Sci 2016; 5: 53-62
• 2 Kato A, Kato N, Miyauchi S, Minoshima Y, Adachi I, Ikeda K. et al. Iminosugars from Baphia nitida Lodd. Phytochemistry 2008; 69: 1261-1265