Inorganic and organic chemical constituents of trona, alum and palm ash: Potential alternatives to conventional antifungal drugs?

Abstract

There is high demand for the development of novel, effective, clinically safe and affordable antifungal agents to manage the ever emerging and re-emerging fungal infections. Natural compounds may be a source of novel chemical structures for development of antimicrobials. The aim of this study was to determine the inorganic and organic chemical constituents of trona, alum and palm ash; as potential alternatives to conventional antifungal drugs. The fungal isolates were obtained from high vaginal swab samples of patients suffering from vulvo-vaginal candidiasis. The isolates were identified based on their macroscopic, physiological, biochemical and molecular characteristics. The minimal inhibitory concentration (MIC) and minimal fungicidal concentrations (MFC) of the test agents were determined using the broth dilution method. Gas chromatography-mass spectroscopy (GC-MS) was used to determine the organic constituents; while x-ray fluorescence spectroscopy, for inorganic constituents. The isolates include Candida albicans, C. tropicalis, C. glabrata and C. parapsilosis. The MIC and MFC of alum against the isolates ranged from 12.50 mg/ml to 50 mg/ml, trona (6.25 mg/ml to 100 mg/ml) and palm ash (100 mg/ml to 200 mg/ml). Alum comprises oxides of sulphur (44.5 %), aluminium (14.49 %) while lead, arsenic and nickel all accounted for <0.0010 %. The naturally occurring fatty acids include vaccenic acid (40.39 %), decanoic acid (13.21 %) and linoelaidic acid (9.84 %). Trona comprises of sulphur (2.14 %), chlorine (5.8 %), potassium (1.7 %), lead (0 %), arsenic and nickel (<0.003 %); while the organic constituents include linoelaidic acid (32.99 %), nonanoic acid (14.81 %) and decanoic acid (6.8 %). The inorganic components of palm ash include potassium (28.8 %), sulphur (3.4 %), calcium (2.8 %) and chlorine (15 %) while the heavy metals all accounted for <0.0007 %. The organic constituents were urea (8.65 %) and fatty acids (<6 %). The antimicrobial properties of the natural compounds were probably due to their various organic and inorganic constituents; thus, could serve as potential raw materials in antifungal drugs production.