Chemical Compositions of Lonchocarpus cyanescens Benth., (Fabaceae)—Case Study of Its Volatile Oils, and Two Triterpenoids

Leaf and stem essential oils of Lonchocarpus cyanescens Benth., (Fabaceae) were obtained by hydro-distillation, using all-glass apparatus adapted to British Pharmacopeia specifications with yields of 0.03% and 0.17% respectively. The oils were investigated by GC and GC-MS analyses. Results show seven compounds were responsible for 90.4% of leaf; eleven compounds responsible for 97.6% of stem volatile oils. Phytol (62.5%) and hexadecanoic acid (12.4%) dominate the leaf oil; octadecenoic (24.1%) and hexadecanoic acids (17.2%) are predominant in the stem oil. Phytochemical screening of stem, leaf, and root methanol extracts of Lonchocarpus cyanescens reveal presence of following seven classes of metabolites: saponin, tannin, steroid, terpenoid, cardiac glycosides, phlobatannins and flavonoids. Partitioning of methanol extract from dried leaf of it with ethylacetate gave fraction, which was chromatographed using gradient elution. TLC with high Rf was used in monitoring elution. Two white crystalline solids eluted at 5% and 10% ethylethanoate in hexane, were re-crystallized and characterized. They were subjected to Infra-Red spectra, mass spectrometry (ESI technique), H and C-NMR analyses, which confirmed they are triterpenoids. Above mentioned metabolites may be responsible for literature acclaimed bio-activities L. cyanescens display [anti-inflammatory, anti-arthritic, anti-microbial effects]. This paper presents details of above results which are new in literature.