Anti-fungal activity and preliminary active components separation from ethanol extracts in Saffron (Crocus sativus L.) lateral buds

Saffron (Crocus sativus L.) is renowned for the active compounds contained in its stigmas, which are used in traditional medicine and as a spice. However, although the stigmas are well above the average yield, the lateral buds of saffron are usually discarded in saffron culturing. In order to expand saffron resource utilization, this study assessed the anti-fungal activities of saffron lateral bud ethanol extracts on six common food-borne pathogenic fungi, as well as investigated the stability of these activities under various heat and pH conditions. Furthermore, the active anti-fungal components of ethyl acetate phase were preliminarily separated by silica gel column chromatography technology and its major chemical constituents were investigated by HPLC-MS/MS. Results revealed that the ethyl acetate phase of saffron lateral bud ethanol extracts elicited a remarkable anti fungal effect against the tested fungi, especially Aspergillus niger (83.47 %) and Trichoderma viride (79.93 %). Moreover, these inhibitory effects were stable in neutral and acidic pH ranges at temperatures < 100 degrees C. The ethyl acetate phase can further be separated into eight fractions by silica gel column chromatography, of which fraction 6 (F6) had the strongest anti-fungal effect by anti-fungal activity evaluation in vitro. HPLC-MS/MS analysis showed that the major compounds of F6 mostly belonged to polyphenols. To summarize, these findings demonstrated that saffron lateral buds are a potentially efficient and affordable source of natural preservatives for use in food.

Automated summary

The study demonstrated that saffron lateral bud ethanol extracts have significant anti-fungal activities against common food-borne pathogenic fungi, especially against Aspergillus niger and Trichoderma viride. These inhibitory effects were stable in neutral and acidic pH ranges. The separation of the ethyl acetate phase revealed that fraction 6 had the strongest anti-fungal effect, with major compounds belonging to polyphenols.