A sensitive and specific method for the quantitative determination of 6-mercaptopurine In plasma Is described. A variety of techniques was used to eliminate endogenous material which may Interfere with the assay. The limit of detection of the method Is 20 ng/mL.

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A gas chromatographic-mass spectrometric method was developed for determining 5-fluorouracil in plasma, using methylated thymine as an internal standard. 2 5-fluorouracil was extracted from plasma by a novel procedure which removed plasma components interfering with the sensitivity of the assay. The method included heating the plasma, washing with ether and extracting the drug under optimum conditions. 3 The sensitivity of the assay was 10 ng/ml plasma, sufficient to determine the low concentrations of 5-fluorouracil found in plasma during continuous infusion of the drug in patients receiving chemotherapy for cancer.

The antithrombosis e#ect of sesame seeds and flour cultured with various microorganisms was investigated by fluidity testing of human whole blood and inhibition of human platelet aggregation. Extracts in /*ῌ ethanol of sesame seeds contained sesamin and sesamolin but no sesaminol, and extracts of defatted flour showed no activity in these tests. However, extracts of flour cultured with Aspergillus niger (NRIC +,,,) as well as flour treated with two types of hydrolysis enzyme showed strong activity in both tests, while flours cultured with Asp. awamori, Asp. oryzae, and Bacillus natto showed weak or no e#ects. HPLC analysis of these specimens showed that sesame seed and flour contains considerable amounts of sesamin and sesamolin but no free sesaminol, while the products cultured with Asp. niger or treated with enzymes contains significant amounts of sesaminol derived from glucosides. It was also demonstrated in tests using pure samples of sesame lignans that sesaminol exhibited strong activity in both tests, while sesamin and sesamol showed only weak activity in the platelet aggregation test, indicating the necessity of the active phenol group and lignan structure in the development of antithrombosis activity. Citric acid, a by-product of incubation, appears to have a weak additional e#ect on sesaminol in high concentrations.