Abstract

PHYSICO-CHEMICAL, ANALYTICAL AND ANTIMICROBIAL STUDIES OF NOVEL SOPHOROLIPIDS SYNTHESIZED USING CETYL ALCOHOL.

Parul Dubey, Kaliaperumal Selvaraj, Asmita Prabhune*

ABSTRACT

We have synthesized novel sophorolipids (sophorolipids derived from cetyl alcohol, SLCA), by supplementing non-pathogenic yeast Candida bombicola (ATCC 22214), with glucose and cetyl alcohol as hydrophilic and lipophilic carbon source, respectively. Physicochemical characterization performed to ascertain the effectiveness of SLCA as a biosurfactant, revealed that it significantly lowered the surface tension of water to 31.349 mN/m with critical micelle concentration of 104 mg/L. Characterization and structure identification via techniques like thin layer chromatography, Fourier transform infrared spectroscopy and liquid chromatography high resolution mass spectrometry (LC-HRMS) confirmed the incorporation of already hydroxylated lipidic carbon source, cetyl alcohol in sophorolipid molecule. The mixture comprised of the two major forms, which possessed terminal methyl and –CH2OH group respectively, thus indicating that role of cytochrome P450 monooxygenase enzyme has been ruled out partially and not completely. Applicability of these novel sophorolipids as a safe and effective therapeutic alternative to existing antibacterial agent was found remarkable. Interestingly, unlike other sophorolipids SLCA completely inhibited the growth of both Escherichia coli and Staphylococcus aureus at the same and relatively low concentration (300 μg/mL). These interesting findings add a new facet to the known range of sophorolipids that can be explored for potential applications in diverse industries.

Keywords: Sophorolipids, cetyl alcohol, Candida bombicola, surface tension, LC-HRMS, antibacterial.