| Chalcone compound is an important intermediate for the synthesis of a series of flavonoids,widely exists in the medicinal plants of the nature such as safflower,licorice.As the chalcone molecule has a strong biological flexible,can be combined with a wide range of receptors,so it has extensive biological activities,such as antioxidant,antibacterial,antimalarial,anti-inflammatory,reducing blood lipid,anti ulcer,anti-tumor,antiviral,vascular relaxation etc.However,most Chalcone compounds have been limited in clinical application due to low bioavailability,instability and poor solubility in water.Cucurbiturils are a new type of host compounds with two hydrophilic carbonyl ports and one hydrophobic cage that can bind to drug molecules through cage interaction,hydrogen bonds,van der Waals forces and so on.Cucurbiturils are safe and innocent drug carriers that are able to improve drug solubility,stability and bioavailability and have shown superiority in drug delivery and drug analysis.In this paper,cucurbit[7]uril and cucurbit[8]uril were selected as host molecules,2'-hydroxy chalcone and cardamomin as guest molecules,focuses on the composition,characterization and properties of chalcone-cucurbit[7,8]uril supramolecular system.The stability,water solubility,antioxidant activity and in vitro release pathway of flavonoids have been studied.This paper includes the following contents:I: The host–guest interaction between cucurbit[7]uril(or cucurbit[8]uril)and 2'-hydroxy chalcone(CET)has been studied by means of UV/Vis spectrophotometry,fluorescence spectrophotometry.The results showed that CET formd a 1:1,1:2inclusion complex with Q[7] and Q[8],respectively;and the binding constants ofCET with Q[7] and Q[8],by UV absorption were 1.0248×106 and 8.9241×106,respectively;the binding constants of CET with Q[7] and Q[8] by fluorescence spectrum were 1.253×106 and 9.3625×106,respectively.The host guest inclusion was confirmed by IR and DTA.Phase solubility experiments showed that the solubility of CET could be increased 51 times by interacting with Q[7] [c(Q[7])=10-3mol/L],and increased 8.7times by interacting with Q[8] [c(Q[8])=10-4mol/L].A study of the evolution of UV absorption spectra with time showed that Q[7],Q[8] could significantly increase the stability of CET.Compared with CET,the stability of CET@Q[7] inclusion complex with the same concentration was increased by 3.5 times in the same solvent.The stability of CET@Q[8] inclusion compound was 6 times higher than that of CET.The antioxidant activity of CET@Q[7] and CET@Q[8] hve been tested by the ABTS method.The respective IC50 values of CET,CET@Q[7] and CET@Q[8]inclusion complex were 2.4×10–5mol/L,3.4×10–5mol/L and 2.7×10–5mol/L,respectively.And CET,CET@Q[7] and CET@Q[8] inclusion complex showed no antioxidant activity to DPPH.Study on the in vitro cumulative release showed that the cumulative release of CET@Q[7] in artificial gastric juice and in the artificial intestinal juice in 12 hours to reach 58.9% and 45.2%,respectively;was almost 1 times higher than that of CET.the cumulative release of CET@Q[8] in artificial gastric juice and in the artificial intestinal juice reached 35.6 % ? 61.3 % in 12 hours,respectively.was almost 1times higher than that of CET in artificial gastric juice.was almost 2 times higher than that of CET in the artificial intestinal juice.The CET@Q[7] and CET@Q[8] inclusion showed certain sustained release performance in artificial gastric juice and artificial intestinal juice.II: The host–guest interaction between cucurbit[7]uril(or cucurbit[8]uril)and Cardamomin(CAR)has been studied by means of UV/Vis spectrophotometry,fluorescence spectrophotometry.The results showed that CAR formd a 2:1 inclusion complex with Q[7] and Q[8],respectively;and the binding constants of CAR withQ[7] and Q[8],by UV absorption were 5.7962×106and 6.2475×106,respectively;the binding constants of CAR with Q[7] and Q[8] by fluorescence spectrum was were 3.9932×106 and 8.4713×106,respectively.The host guest inclusion was confirmed by IR and DTA.Phase solubility experiments showed that the solubility of CAR could be increased 38 times by interacting with Q[7] [c(Q[7])=10-3mol/L],the solubility of CAR hardly ever be increased by interacting with Q[8] [c(Q[8])=10-4mol/L].A study of the evolution of UV absorption spectra with time showed that Q[7],Q[8] could significantly increase the stability of CAR.Compared with CAR,the stability of CAR@Q[7] inclusion complex with the same concentration was increased by1 times in the same solvent.The stability of CAR @Q[8] inclusion compound was 1.7 times higher than that of CAR.The antioxidant activity of CAR,CAR@Q[7] and CAR@Q[8] inclusion complex have been tested by the DPPH method.The respective IC50 values of CAR,CAR@Q[7] and CAR @Q[8] inclusion complex were 1.85×10-5 mol/L,3.35×10-5mol/L,4.18×10-5 mol/L,respectively.And CAR,CAR@Q[7] and CAR@Q[8]inclusion complex show no antioxidant activity to ABTS. |
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