Study On The Saponification Of Astaxanthin Ester Compounds And The Separation And Identification Of Other Compounds In Calendula Officinalis

The Adonis aestivalis L.is an annual herbaceous plant of the genus Ranunculus,Ranunculaceae and the genus Calendula,which contains astaxanthin with extremely high antioxidant activity.Therefore,the extraction of astaxanthin and other natural compounds from the Adonis aestivalis L.has attracted great attraction from researchers.Astaxanthin has strong antioxidant activity and mainly extracted from Haematococcus pluvialis and other aquatic plants and less research from terrestrial plants.The Adonis aestivalis L.as a source of astaxanthin terrestrial plant,has great potential for research and study.In this paper,the terrestrial plants Adonis aestivalis L.was taken as the research object,and the crude extracts were extracted by organic solvent.Then,the saponification reaction conditions were optimized for the extracted astaxanthin derivatives.As a result,the optimal saponification conditions obtained by TLC detection were:20 mg crude extract used of 7 mL of dichloromethane:0.5%NaOH methanol solution=1:3 was saponification solvent,temperature was 25^oC,saponification for 1 h.Under the optimal saponification conditions,fatty acid composition of the samples were analyzed,the main type was C18:3 unsaturated fatty acid compounds.Finally,the free astaxanthin was isolated by preparative thin layer chromtography?pTLC?and identified by nuclear magnetic resonance technique and its content was measured at 0.513%?in dried flower?.Meanwhile,the crude extracts extracted from the Adonis aestivalis L.were isolated and identified,14 monomeric compounds were obtained,including two autocatalytic products of astaxanthin?AA 1-2?,four flavonoids compounds?AA 3-6?,three steroid compounds?AA 7-9?,one lignan compound?AA 10?,two simple compounds?AA 11-12?,two fatty acid compounds?AA 13-14?,of which AA 1 was a new compound and its production was speculated.Besides,the DPPH scavenging free radical activity and antibacterial activity of some of the isolated compounds were tested.The free radical scavenging activity of flavonoids were stronger,the IC₅₀0 values of the compounds AA 3,AA 4 and AA 6 were 10,8 and 50?g/mL respectively.In the antibacterial activity test,compounds AA 3,AA 4 and AA 6 have antibacterial activity against Escherichia coli,Aeromonas hydrophila,Vibrio harveyi,Vibrio parahaemolyticus and Vibrio anguillarum;the compound AA 1 against Escherichia coli,Ceratobasidium cornigerum and Penicillium digitatum showed a certain antibacterial activity;and the compound AA 2showed certain antibacterial activity to Escherichia coli and Penicillium digitatum.The results of this study indicated that the content of astaxanthin was higher in the Adonis aestivalis L.,and the extraction and separation methods were simple and feasible,which is a source of astaxanthin with potential for development.Besides,the saponification conditions of astaxanthin esters were reasonably rationally optimized,and the optimum conditions were obtained.Furthermore,the other compounds contained in the Adonis aestivalis L.were isolated and identified,and some of them were studied and analyzed with the bioactivity which provides a scientific basis of planting and application.