Studies On The Activities Of Impatiens Balsamina L Stems And Isolation, Purification And Structure Identification Of The Antimicrobial Active Substances

In recent decades, the resistance and the potential harm to the human body which caused by the chemical preservatives becoming increasingly serious, developing natural preservatives has gain a great interest. In order to develop the new plant source preservatives, the antioxidant and antimicrobial activities of Impatiens balsamina L. were analyzed, the purification and structural identification of the main active compound were also carried out. The following results were obtained:1. The Impatiens balsamina L. stems were extracted with selected solvents with increasing polarity continuous extraction, and the petroleum ether, ether, chloroform, methanol and water extracts were obtained. The results showed that the extract had a more significant antimicrobial activity, in particular its antifungal activity. The ether extract had the most widely antimicrobial spectrum, and the petroleum ether had the strongest antimicrobial activity. But all the extracts had shown a weak antioxidant activity, which may be related to the destruction of phenolic compounds in herbs process.2. The95%ethanol crude extract of Impatiens balsamina L were separated into petroleum ether, ethyl acetate, butanol and water extracts by liquid-liquid extraction. The antimicrobial activity of the four extracts were determined to find the active site by the active tracking method and then by column silica gel-chromatography and gel filtration chromatography. At last the main active extract were isolated and purified, and its structure was identified to be2-methoxy-1,4-naphthoquinone by four spectral.3. The antimicrobial spectrum of2-methoxy-1,4-naphthoquinone isolated from Impatiens balsamina L. were determined. The results indicated that this compound had a good antimicrobial activity.