The methods described two decades ago (l-3) for the isolation of crystalline stercobilin or urobilin from feces or urine are relatively slow and cumbersome. It is often desirable to obtain a few mg of crystalline material quickly, either to permit determination of the preponderant type (whether stercobilin, urobilin, or d-urobilin) or calibration of a quantitative method. More recently, the stu...

Recent studies have revealed that various derivatives of 2,4-diaminopyrimidine exhibit profound biochemical reactivity. For example, nearly all 2,4-diaminopyrimidines and their condensed ring systems inhibit the growth of LactobaciZZus casei with folic acid (1). 2,4-Diamino&p-chlorophenoxypyrimidine was found to be a potent antimalarial in that it was active against Plasmodium gallinaceum infec...

A facile synthesis of the C4-substituted isoquinolines 5a-c and 6a-c is described. Commercially available 4-bromoisoquinoline is converted to the alpha,beta-unsaturated esters 8 and 10 on treatment with the appropriate acrylate ester under Heck reaction conditions. The saturated amides 5a-c were obtained from the reaction of ester 9 with the requisite primary amine. Similarly the unsaturated an...

The extensible byssus is produced by the foot of bivalve animals, including the pearl oyster Pinctada fucata, and enables them to attach to hard underwater surfaces. However, the mechanism of their extensibility is not well understood. To understand this mechanism, we analyzed the ultrastructure, composition and mechanical properties of the P. fucata byssus using electron microscopy, elemental ...

Preliminary investigations in South Africa into determining the resistance of sugarcane varieties to red rot (Glomerella tucumanensis) by means of an inoculation procedure, conducted in 1988-89, showed promise. Results of these trials, together with findings from industry-wide red rot surveys in the late 1980s, were used to provide a preliminary ranking of a number of released varieties. Variet...

It is now well established that glycine is a direct nitrogenous precursor of hemoglobin protoporphyrin in rats (l), rabbits (Z), dogs (3), and humans (4), of coproporphyrin I in dogs and humans (3, 5), of uroporphyrin I in humans (5), and of stercobilin in humans (5, 6). It is well known that lead intoxication in rabbits is associated with prompt and marked increases of urinary coproporphyrin I...