Analysis of phenmedipham in agricultural products by HPLC

An analytical method was developed for the determination of phenmedipham (PM) in agricultural products using reversed-phase high-performance liquid chromatography with UV detection. A sample was extracted with acetonitrile, and the acetonitrile layer was separated by salting-out. The acetonitrile phase was isolated and evaporated. The extract was dissolved in diethyl ether-hexane (1 : 1), and then cleaned up on a Florisil column. The column was washed with diethyl ether-hexane (1 : 1), and PM was eluted with acetone-hexane (3 : 7), and the eluate was evaporated. The residue was dissolved in acetone-hexane (2 : 8), and the sample solution was cleaned up on SAX/PSA cartridge. The SAX/PSA cartridge was washed with acetone-hexane (2 : 8), and PM was eluted with acetone-hexane (3 : 7). If required, the eluate of the Florisil column was cleaned up with SAX/PSA and ENVI-Carb/ NH2 cartridges. The SAX/PSA cartridge was washed with acetone-hexane (2 : 8), and connected to be ENVI-Carb/NH2 cartridge. The cartridges were washed with acetone-hexane (3 : 7), and then the SAX/PSA cartridge was removed. PM was eluted with acetonitrile-toluene (3 : 1) from the ENVI-Carb/NH2 cartridge. PM in the eluate was separated isocratically on an ODS column (4.6 mm i.d. x 150 mm, 5 microm) using acetonitrile-water (6 : 4) as a mobile phase (flow-rate 1.0 mL/min, temp. 40 degrees C), with monitoring at 235 nm. The calibration curve was linear from 0.005 microg/mL to 10 microg/mL of PM. The recoveries of PM from eight kinds of agricultural products spiked at levels of 0.1 and 0.02 microg/g were 80.8-98.7%. The determination limit was 0.01 microg/g.     

Identification of HLA-A24-restricted epitopes with high affinities to Hsp70 using peptide arrays

Heat shock protein 70 (Hsp70) family members are known as facilitators of immune responses by interacting with receptors on antigen-presenting cells leading to Hsp70-peptide uptake and antigen cross priming. Here, identification of human leukocyte antigen (HLA)-A24-restricted epitopes was achieved using peptide arrays for evaluation of their affinities to Hsp70 and HLA-A24 binding prediction tools. Using Hsp70 as the model antigen, the GYPVTNAVI and VFQHGKVEI peptides were identified as antigens. These peptides actually bound to HLA-A24 in the stabilization assay using T2-A*2402 cells, and induced a strong peptide-reactive cytotoxic T lymphocyte response in HLA-A24 transgenic mice after vaccination.     

Utilization of Lactoferrin as an Iron-Stabilizer for Soybean and Fish Oil

ABSTRACT: We investigated the oxidative stability of soybean oil and fish oil fortified with iron solubilized by lactoferrin (FeLF). Oxidative stability was evaluated by measuring the induction period of the Rancimat test. The induction time of soybean oil added FeCl₃ was decreased; however, that of added FeLF was not. This effect of lactoferrin was also observed in the iron-catalyzed oxidation offish oil at temperatures ranging from 50°C to 120°C, and at concentrations of iron ranging from 0 to 500 ppm. Thus, lactoferrin is considered useful as a natural iron stabilizer for food products containing polyunsaturated fatty acids.     

Pharmacological studies on basic ethers (R111 and R97) with antispasmodic activity

Pharmacological properties and acute toxicity of 2-tolyl 1-phenyl-3-(2-methylpiperidino) propyl ether methyl bromide (R111) and 2-chlorophenyl 1-phenyl-3-(2-methylpiperidino) propyl ether methyl iodide (R97) were examined. The results obtained were as follows: (1) In the analgesic effects, RIII and R97 inhibited markedly the acetic acid-induced writhing in mice, but in reducing pain induced by heat, R111 and R97 showed negative results. The local anesthetic effect of R111 was approximately equal to that of procaine. R111 and R97 showed no effects on spontaneous locomotion, the convulsion induced by strychnine or pentetrazol, and normal body temperature. (2) R111 and R97 antagonized acetylcholine, barium chloride, nicotine and serotonine-induced spasm, but not that of histamine and bradykinin. In particular they possessed marked anti-barium chloride activity, where their effects were 20 to 30 times more active than that of papaverine. (3) R111 and R97 indicated weak mydriatic activity. (4) R111 and R97 showed inhibitory effects on the pilocarpine-induced sialic secretion and the propulsive movements of the small intestine, but their inhibitory effects on the gastric secretion were relatively weak. (5) R111 and R97 displayed protective effects in Shay's ulcer, but had no curative effects on acetic acid ulcer. (6) R111 and R97 induced temporary reduction of arterial blood pressure and blood flow immediately after the administration of the test compounds in anesthetized rabbits. However, these agents induced no change in ECG, heart rate and respiration. (7) Intraperitoneally administered R111 and R97 were effective in inhibiting the carrageenin-induced edema in the hind paw of rats. From the above results, it may be considered that R111 and R97 have together strong cholinergic blocking and muscotropic antispasmodic effects, moreover, no significant effects on the central nervous system.     

Flaujeac factor deficiency. Reconstitution with highly purified bovine high molecular weight-kininogen and delineation of a new permeability-enhancing peptide released by plasma kallikrein from bovine high molecular weight-kininogen

Flaujeac trait is the functional deficiency of a plasma protein of the intrinsic coagulation, kinin-forming, and plasma fibrinolytic pathways. The Flaujeac factor in man has been isolated and tentatively identified as a kininogen of high molecular weight (HMW). Highly purified bovine HMW-kininogen, but not bovine low molecular weight kininogen, repaired Flaujeac factor deficiency. The two subspecies of this molecule, HMW-kininogen a and HMW-kininogen b, also corrected Flaujeac factor deficiency. When bovine HMW-kininogen was incubated with bovine plasma kallikrein, kinin-free HMW-kininogen, bradykinin, and a glycopeptide fragment (peptide 1-2; 12,584 daltons) were rapidly released. None of these fragmentation products corrected Flaujeac factor deficiency alone or in mixtures. The function of HMW-kininogen appeared to depend upon the structural integrity of the native molecule. When injected in concentrations of 2 pmol-8 nmol/0.1 ml, peptide 1-2 caused increased vascular permeability in rabbits, rats, or guinea pigs. The enhanced permeability was maximal within 1-2 min and terminated in 5-10 min, differing from that of bradykinin or histamine. Injected together in equimolar amounts, peptide 1-2 and bradykinin produced a synergistic permeability response which was immediate in onset as well as prolonged in duration. Peptide 1-2 is a rapidly acting, highly basic glyco-peptide which mediates increased vascular permeability in a complementary and synergistic manner with bradykinin.