[Purification of enramycin by macroporous resin adsorption and reversed phase chromatography purification].

Enramycin is a polypeptide antibiotic and new, safe animal feed additive. A new purification process was developed, based on pre-purification by macroporous resin and refining by reversed phase chromatography. AB-8 macroporous resin was used for the pre-purification process of enramycin, with an elution buffer of 0.012 mol/L aqueous HCl solution-methanol (50: 50, V/V). Then, enramycin a and enramycin b were separated effectively by C18 reversed phase chromatography, with a elution buffer of 0.05 mol/L aqueous KH2PO4 solution-acetonitrile (70: 30, V/V, pH 4.5). The purities of enramycin a and enramycin b were up to 98.5% and 98.0%, respectively. The yield reached 29.2%. This study would provide a useful reference for the preparation of enramycin a and enramycin b with a high purity.

Fourier Transform Infrared Spectrometry and Magnetic Resonance Spectrometry for the Diagnosis of Colorectal Cancer / 中国微创外科杂志

Objective To analyze ex vivo samples of colorectal cancers by Fourier transform infrared spectrometry and magnetic resonance spectrometry,and to explore the feasibility to diagnose the tumor by using the methods in clinic.Methods From March 2007 to April 2008,fresh samples colorectal mucosa and carcinoma were obtained from 47 patients.The regimens were examined pathologically and then analyzed by Fourier transform infrared spectrometry and magnetic resonance spectrometry.The accuracy of the spectrometrical results was determined by comparing with the pathological results.Results The accuracy of the Fourier transform infrared spectrometry and magnetic resonance spectrometry was 94.7%(89/94)and 97.8%(45/46),respectively,while the sensitivity was 93.6%(44/47)and 100%(23/23),specificity was 95.7%(45/47)and 95.7%(22/23),false positive rate was 4.3%(2/47)and 4.3%(1/23),false negative rate was 6.4%(3/47)and 0%(0/23),positive prognostic value was 95.7%(44/46)and 95.8%(23/24),and the negative prognostic value was 93.8%(45/48)and 100%(22/22).ConclusionsBenign and malignant colorectal tissues can be identified quickly and accurately by Fourier transform infrared spectrometry and magnetic resonance spectrometry.The methods,which are minimally invasive,could be a potential diagnosing tool for colorectal cancer at an early stage.