A novel high-performance anion-exchange chromatographic method for the analysis of carrageenans and agars containing 3,6-anhydrogalactose.

A novel method has been developed to determine the sugar composition of 3,6-anhydrogalactose-containing polysaccharides, such as carrageenan and agar. The method is based on reductive hydrolysis with a methylmorpholine-borane complex in the presence of acid and subsequent high-performance anion-exchange chromatography analysis of the alditols without any derivatization. The method was validated by 13C NMR analysis of six carrageenans and three agars and by a previously used method based on derivatization to alditol acetates and gas-liquid chromatography analysis. The new method was found to be superior to the gas-liquid chromatography method as the analysis time was less than half. Also it was found to be more accurate and reproducible and no derivatization was required. The analysis of the six different carrageenan samples revealed that homogeneous mu- and nu-carrageenan, theoretically without 3,6-anhydrogalactose residues, cannot be isolated from red seaweeds. Consequently, the question arose if mu- and nu-carrageenans at all are present in seaweeds and if the current hypotheses regarding biosynthesis of carrageenans in the seaweeds are correct. The data demonstrated that carrageenans are highly complex natural polysaccharides, which are more irregular than assumed hitherto. The new analytical technique will permit elucidation of the detailed structure of seaweed polysaccharides and determination of their structure-property relationships.

Penetration of rufloxacin into human prostatic tissue and fluid.

The penetration of rufloxacin into prostatic tissue and prostatic fluid was investigated in 16 patients undergoing elective transurethral prostate resection. Rufloxacin 400 mg was given orally approximately 16 h before surgery with a further dose of 200 mg approximately 5 h before surgery. Sampling was inadequate in three patients. One patient reported transient flushing and headache after the first dose of rufloxacin and was hence withdrawn from the study. In the remaining 12 evaluable patients, the mean ratios of rufloxacin concentrations (determined by HPLC) in prostatic tissue and fluid to the plasma concentration were 1.9 and 1.5, respectively. There were no significant differences between the tissue penetration ratios in different parts of the prostate. The levels of rufloxacin found in prostate tissue and fluid, in this study, exceeded the MICs for most micro-organisms causing chronic bacterial prostatitis.

Automated analysis of mitomycin C in body fluids by high-performance liquid chromatography with on-line sample pre-treatment.

A fully automated liquid chromatographic system for the bioanalysis of mitomycin C has been described. The isolation of the analyte from the biological matrix (plasma, ascites and urine) is performed using a continuous-flow system equipped with a dialysis membrane in order to remove proteins. The samples are concentrated on a reversed-phase pre-column and subsequently introduced on to a reversed-phase analytical column by applying column-switching techniques. The drug is detected by absorbance measurements at 360 nm. Using the described system up to 100 samples a day can be analysed with determination limits of the order of 1 ng/ml, with a linear dynamic range of at least three decades for plasma and urine samples. The procedure was applied to pharmacokinetic studies of ovarian cancer patients treated intraperitoneally with mitomycin C.