Chemical analysis (high-performance liquid chromatography) and bioassay demonstrated the presence of compounds that seem to be components of the Ixodes scapularis arrestment pheromone. Only two purines, guanine and xanthine, were found in acidified saline extracts made from cast skins after molting of fed nymphs, fed larvae, and fecal/excretory exudates deposited by unfed adults on substrates i...

Nitric oxide (NO) is important physiologically as a gaseous messenger in the central nervous system;1 its level is also associated with several disease states.2 The concentration of NO in these cases is in the nanomolar range; therefore accurate and direct detection of NO at these levels is important. NO is also a decomposition product of several explosives3 so detection of trace amounts of exp...

A kinetic characterization of the regulation of purified soluble guanylate cyclase from bovine lung by protoporphyrin M and hematin is reported. Purified guanylate cyclase was isolated with heme and had specific activities @mol of cGMP/min/mg of protein) of 0.1-0.2 and 0.3-0.6 in the presence of excess MgGTP and MnGTP, respectively, in the absence of added activators. Protoporphyrin IX, nitric ...

Background: The genus Eryngium, Apiaceae is widely distributed in the world and used traditional medicine for different therapeutic purposes. Eryngium thyrsoideum was investigated due to a lack of phytochemical studies on probable bioactivities its compounds. Methods: aerial parts plant were extracted using n-hexane, dichloromethane, methanol (MeOH) by soxhlet method. MeOH extract exposed C18 S...

A series of analogues of cryptolepine (1) have been synthesized and evaluated for their in vitro antiplasmodial and cytotoxic properties. The IC(50) values of several compounds (11a, 11k-m, 11o, 13) against Plasmodium falciparum (strain K1) were <0.1 muM, 5-10-fold lower than that of 1 but their cytotoxicities were only 2-4 times greater than that of 1. Compounds with a halogen in the quinoline...