We describe a novel method for determining serum triglycerides, in which an enzymatic hydrolysis replaces the more commonly used saponification procedure. Under the conditions of the assay, the enzymatic hydrolysis can be completed in less than 10 min by the combined action of a microbial lipase and a protease. We have been able to demonstrate complete hydrolysis of triglycerides by thin-layer chromatography of the reaction products, by recovery of glycerol from sera of known triglycerides content, and by comparison of triglyceride assays on a number of sera assayed by our method vs. the AutoAnalyzer procedure. The hydrolysis is directly coupled to the enzymatic determination of glycerol, and is followed through absorbance changes at 340 nm. The assay is simple, rapid, and requires only 50 µl or less of sample. Because the enzymes used do not release glycerol from other compounds in serum, the hydrolysis can be considered specific for triglycerides.

Two new sulfur-containing pyrimidine nucleotides have been isolated from hydrolyzates of Escherichia coli transfer RNA. The structures, 2-thiocytosine and 5-methylaminomethyl-2-thiouracil, have been assigned to the bases as a result of study of ultraviolet and mass spectra. An acid-degradation product, S-methylamino-methyluracil, has been synthesized and is identical to that derived from the natural product.

The cytokinin, N(6)-(Delta(2)-isopentenyl) adenosine occurs in the soluble RNA of yeast and mammalian tissue and has now been detected in plant soluble RNA. A hydroxylated derivative of this cytokinin 6-(cis-4-hydroxy-3-methylbut-2-enylamino)-9-,beta-D-ribofuranosylpurine has also been identified as a constituent of plant soluble RNA.

We describe a direct colorimetric assay for alpha-amylase, with 2-chloro-4-nitrophenyl-alpha-maltotrioside as substrate. Both human pancreatic and salivary amylase split this substrate without the use of helper enzymes, yielding free 2-chloro-4-nitrophenol, which is monitored at 405 nm. The performance of this reagent compares well with that of Pantrak Amylase (Behring Diagnostics) for both serum and urine samples. The reagent is very stable in dry powder form and is stable for one month at 2 to 8 degrees C after reconstitution. Because of the rapid color development and linear kinetics (less than 30 s), the assay is easily automated. Results can be obtained in less than 5 min.

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