Ethyl linalool and diethyl phthalate from Pycnanthus angolensis (Welw.) Warb.

Abstract

Background: Pycnanthus angolensis (Welw.) Warb. belongs to the family, Myristiceae. Extracts of the plant are used in African ethno-medicine to treat diabetes, lumbago, wounds, arthritis, anemia, mouth-thrush, scabies, infertility and skin-fungal infections amongst many others. Flavonoids, terpenes, fatty acid derivatives and quinones had previously been isolated from different organs of the plant. Before now, very scanty literature exits on organic fractions from where specific compounds had been obtained. Objectives: To study the chemical and biological parameters of the ethyl acetate fraction obtained fractionation of crude ethanol extract of the leaves of Pycnanthus angolensis. Methodology: The leaves were to be extracted cold with 50 % ethanol and the obtained aqueous crude extract partitioned with ethyl acetate. Furthermore, the ethyl acetate fraction was to be subjected to silica gel column chromatography and the isolated compounds screened for both antibacterial and antifungal activities using the microbes namely, Staphylococcus aureus, Escherichia coli and Candida albicans. Results: Two isolates coded NG-2 (pale yellow compound; 62 mg; Rf. (0.53); [α]D20 (+3º); [n]D20 (1.4009) and NG-4c (off-white compound; 36 mg, Rf (0.24); [α]D20 (0º); [n]D20 (1.5006) whose identities have been revealed to be 3-ethoxy-3, 7-dimethyl-1, 6-octadiene (ethyl linalool) and diethyl phthalate (1, 2-benzenedicarboxylic acid diethyl ester) respectively using the MS and IR spectral techniques. Both NG-2 and NG-4c were strongly bacteriostatic against E. coli, but recorded no activity against S. aureus and C. albicans. Conclusion: The isolation of the two compounds is being reported for the first time from the ethyl acetate fraction of the plant. Hence, NG-2 and NG-4c would serve as chemotaxonomic markers for this species and the genus, Pycnanthus in general. Keywords: Pycnanthus angolensis; fraction; ethyl linalool; diethyl phthalate: antimicrobia