Studies on the sclerotia of Aspergillus sclerotioniger and the alkaloid extracted

In the present study the sclerotia of different Aspergilli (Aspergillus sclerotioniger, A. sclerotiorum, A. candidus, A. flavus, A. piperis, A. ochraceus, A. robustus, A. sepultus, A. petrakii, A. melleus, A. parasiticus and A. sclerotii carbonarius) were examined for the presence of alkaloids in their formed sclerotia separately where, A. sclerotioniger exhibited the best result. Accordingly, the culture conditions (temperature, pH, carbon source, nitrogen source and carbon/ nitrogen (C/N) ratio were optimized for the formation of sclerotia by A. sclerotioniger. The best weight of sclerotia was achieved at temperature 30°C, PH 6, maltose as carbon source, KNO₃ as nitrogen source and (C/N) ratio of 43.33.

The total alkaloids content of A. sclerotioniger sclerotia was detected using Van Urk’s reagent and recording the optical density on spectrophotometer at 580 nm, then separated on thin layer chromatography (TLC). The separated alkaloid was defined using the percentage of carbon, hydrogen and nitrogen (CHN) percentage, as well as ultraviolet (UV) spectrum, nuclear magnetic resonance (H1NMR) analysis, gas spectroscopy mass spectral analysis (GC-MS mass) and infrared (IR) analysis. The alkaloid was found to be a member of indole alkaloids and was defined as chloro derivative of aflavinine.