Purification Of Sapindus Saponins By Form Separation And Its Application In Antibacterial Detergent

Sapindus mukorossi that mainly grows in south of the Yangtze River can act as an ecological protection forest.Its pericarp contains a natural nonionic surfactant based on triterpenoid saponins,which of high practical value.Due to the excellent foaming,antibacterial and anti-tumor properties,Sapindus saponins have been widely used in environmentally friendly cosmetics,detergent raw materials and medicine.It is one of the research highlights to extract Sapindus saponins from the pericarp effectively.The emerging foam separation strategy has attracted growing attention because of the simple operation and low cost.Silver nanoparticles(AgNPs)with broad-spectrum bactericidal properties are widely used in antibacterial fabrics,medical device disinfection and detergents.Biological reduction method is a green method for preparing metal nanomaterials in recent years.The method has the advantages of mild reaction conditions,environmental-safety,as well as high biosafety.In this work,the advantages of Sapindus saponins and AgNPs are combined to prepare a antibacterial detergent.As a result,it can meet the standard of medical linen disinfection.Since Sapindus saponins have the ability of reducing the Ag precursor where Ag+can be reduced to AgNPs.Herein,Sapindus mukorossi extract,a reducing agent for AgNPs,was separated and purified by foam separation method.Then,the solution of Sapindus mukorossi and AgNPs with different sizes were obtained.And the antibacterial activity of such solution was preliminarily studied.Subsequently,such solution was added into the Sapindus saponins detergent product to prepare a Sapindus saponins-based antibacterial detergent.(1)Sapindus mukorossi was separated and purified by a foam separation device,and the efficiency of foam separation was evaluated by enrichment ratio and yield.Single factor experiments showed that the four factors of feed amount(A),gas flow rate(B),pH value(C)and temperature(D)had a great influence on the foam separation effect;The orthogonal experiment proved that the order of factors which influence the separation effect was:B>A>D>C.The foam separation conditions with a feed volume of 500 mL,a temperature of 40?,a pH of 4.5,and a gas flow rate of 0.15 L·min-1 are optimum.Meanwhile,the enrichment ratio was 1.2 and the yield is 48%.The critical micelle concentration(CMC)of Sapindus mukorossi was 36 mN·m-1.High performance liquid chromatography(HPLC)analysis showed the content of Sapindus mukorossi rising from 31.5%to 69.8%,indicating the feasibility of purifying Sapindus mukorossi by foam separation.(2)The purified Sapindus mukorossi foam solution was statically defoamed as a reducing agent for AgNPs.The particle size and morphology of AgNPs were characterized by UV-visible spectroscopy,XRD and TEM.The stability and antibacterial activity of the solution combined by Sapindus mukorossi and AgNPs are studied.The results showed that when the Sapindus mukorossi extract of was 20 mL,with a temperature of 80?,a pH of 4.5 and a heating time of 6.5 h,AgNPs with uniform dispersion and spherical structure can be achieved.It was found that the AgNPs were stable in the Sapindus mukorossi extract during one week.The MIC and MBC of AgNPs towards E.coli is 2.3 ppm and 15 ppm were determined,respectively,The MIC and MBC of AgNPs towards S.aureus was 3.5 ppm and 55 ppm.(3)Experimentally,the basic components of the detergent have no effect on the AgNPs;The third-party test report indicated that the specifications such as the detergency of the Sapindus mukorossi detergent and Sapindus mukorossi antibacterial detergent both met the national standard QB/T 1224-2012 "liquid detergent for clothing";The antibacterial rate of Sapindus mukorossi antibacterial detergent against Escherichia coli was above 99.97%,and the inhibition rate against Staphylococcus aureus was above 99.95%,meeting the national standard QB/T 2738-2012/7.3.3.