Simultaneous Extraction Of Flavonoids And Essential Oils From Ficus Carica L. Leaves And Their Activities

Ficus carica,also known as "Ying Riguo",is a flowering plant of Ficus genus in Moraceae family.It has elegant tree form and good ornamental value.The fruits and leaves from Ficus Carica L.can be used as medicine,which has the functions of strengthening stomach and clearing intestines,detoxifying swelling,antioxidant,anti-inflammatory and anti-virus.At present,only the fruits of Ficus Carica L.were utilized,but the leaves from Ficus Carica L.have not been effectively utilized.In this study,the flavonoids and volatile oil in Ficus carica leaves were extracted using a novel ionic liquid based ultrasonical and microwave simultaneous distillation extraction(IL-UMASDE)using Ficus carica leaves as raw material,and the extraction parameters were optimized by response surface method.The components and content of flavonoid from Ficus carica leaves were detected by HPLC,and the chemical components and relative content of volatile oils were detected by GC-MS.Furthermore,flavonoids were enriched and purified by macroporous adsorption resin,and their antioxidant capacity was investigated by FRAP,DPPH and ABTS methods.The antibacterial activity of volatile oil against staphylococcus aureus,escherichia coli,pseudomonas aeruginosa and bacillus subtilis was evaluated.The research results are as follows:1.Flavonoid and volatile oil in Ficus carica leaf were extracted using IL-UMASDE.The extraction process condition was optimized by single factor experiment and BBD response surface analysis and the optimal extraction condition for flavonoids and volatile oil is:ionic liquids with 0.35 mol/L 1-butyl 3 methyl bromide imidazole([C4MIM]Br),liquid-solid ratio 30 mL/g,extracting time of 16 min,microwave power 530 w.Under the optimal extraction parameters,the yield of quercetin,rutin,kaempferol,isorhamnetin,and the volatile oil is respectively 8.70 mg/g,5.72 mg/g,11.28 mg/g,6.49 mg/g and 0.32%.2.Macroporous resin was used to enrich and purify the flavonoids.Six kinds of macroporous resins(X-5,AB-8,NKA-9,D101,LAS-10,HPD400)with different polarities were selected.By measuring their adsorption capacity and resolution rate,it was found that D101,X-5 and AB-8 had strong enrichment capacity.Thus,D101,X-5 and AB-8 were selected for dynamic adsorption-desorption tests,and the recovery of total flavonoids was calculated.The best adsorption resin was chosed as AB-8 resin.In succession,the dynamic adsorption and desorption conditions of AB-8 resin were optimized:the flow rate of the sample solution was 3 BV/h and the volume of the sample was 4 BV;the desorption conditions were 80%ethanol as the desorbent,the flow rate of the desorbent was 6 BV/h and the volume of the desorbent was 9 BV.Under the above conditions,the recovery rate of total flavonoids from Ficus carica leaves by AB-8 resin was 84.55%.After enrichment with AB-8 resin,the contents of four flavonoids(rutin,quercetin,kaempferol and isorhamnetin)in Ficus carica leaves extract were 38.54 mg/g(rutin),24.08 mg/g(quercetin),47.83 mg/g(kaempferol),28.43 mg/g(isorhamnetin),respectively,which were 4.43,4.21,4.24 4.38 times compared with those without be treated by resin.3.The antioxidant activity of flavonoid extract from Ficus carica leaf was investigated.The antioxidant capacity of the FRAP assay was determined by the concentration of FeSO4 standard solution.At the sample concentration of 0.3 mg/mL,the antioxidant capacity of tested four flavonoids:quercetin(3.64 mg/mL)>kaempferol(3.14 mg/mL)>isorhamnetin(2.56 mg/mL)>rutin(2.14 mg/mL)and>Ficus carica leaf extract(1.984 mg/mL).The ECso values of quercetin(0.22 mg/mL)>Vc(0.31 mg/mL)>isorhamnetin(0.41 mg/mL)>kaempferol(0.55 mg/mL)>rutin(0.75 mg/mL)and>Ficus carica leaf extract(1.85 mg/mL)were calculated by DPPH method for the evaluation of antioxidant capacity.When the antioxidant capacity was evaluated by ABTS method,the ECso values of the extracts and the four flavonoids were:rutin(0.22 mg/mL)>quercetin(0.24 mg/mL)>isorhamnetin(0.31 mg/mL)>kaempferol(0.36 mg/mL)>Vc(0.89 mg/mL)>Ficus carica leaf extract(0.9 mg/mL).4.The antimicrobial activity of volatile oil from Ficus carica leaf was investigated.The results showed that the volatile oil from Ficus carica leaves had certain antimicrobial activity,and its inhibitory effect on Gram-positive bacteria was stronger than that on Gram-negative bacteria.The minimum inhibitory concentrations of volatile oil from Ficus carica leaf against Staphylococcus aureus,Bacillus subtilis,Escherichia coli and Pseudomonas aeruginosa were 125,62.5,125 and 250 ml/mL,respectively.In conclusion,the IL-UMASDE proposed in this study provides a new method for extracting flavonoids and volatile oils from Fig leaves.Furthermore,the flavonoids were enriched and their antioxidant activities were studied.At the same time,the antimicrobial activities of volatile oils were also studied.The research results provide a basis for comprehensive exploitation and utilization of Ficus carica leaves.