Determination of endogenous peptides in the porcine brain: possible construction of peptidome,a fact database for endogenous peptides

Peptides play crucial roles in many physiological events. However, a database for endogenous peptides has not yet been developed, because the peptides are easily degraded by proteolytic enzymes during extraction and purification. In this study, we demonstrated that the data for endogenous peptides could be collected by minimizing the proteolytic degradation. We separated porcine brain peptides into 5250 fractions by 2-dimensional chromatography (first ion-exchange and second reversed-phase high-performance liquid chromatography), and 75 fractions of average peptide contents were analyzed in detail by mass spectrometers and a protein sequencer. Based on the analysis data obtained in this study, more than 10000 peptides were deduced to be detected, and more than 1000 peptides to be identified starting from 2 g of brain tissue. Thus, we deduce that it is possible to construct a database for endogenous peptides starting from a gram level of tissue by using 2-dimensional high-performance liquid chromatography coupled with a mass spectrometer.     

A critical stage in spermatogenesis for radiation-induced cell death in the medaka fish, Oryzias latipes

To ensure the high-fidelity transmission by reproductive cells of genetic information from generation to generation, cells have evolved surveillance systems to eliminate genomic lesions by inducing cell suicide and/or DNA repair. In this report, gamma-ray-induced cell death was investigated using the medaka fish, Oryzias latipes, because of the ease with which the differentiation stages of its spermatogenic cells can be identified. After 4.75 Gy gamma irradiation, the maximum rate of death of spermatogonial stem cells was observed at 18 h, and that of differentiating spermatogonia was at 12 h, followed by a peak in the extent of DNA fragmentation detected by the TUNEL assay. Dose-response curves for the death rate showed an obvious increase in the death rate for early-differentiating spermatogonia even after 0.11 Gy irradiation, whereas there were no such increases for spermatogonial stem cells and late-differentiating spermatogonia. In the male germ cells of this fish, the stage during spermatogenesis most sensitive to radiation-induced cell death is in early-differentiating spermatogonia, the immediate descendants of the stem cells. These spermatogonia may have a rigorous surveillance system for genomic lesions induced in spermatogonial stem cells.     

Encapsulation of shiitake (Lenthinus edodes) flavors by spray drying

Powdery encapsulation of shiitake flavors, extracted from dried shiitake, was investigated by spray drying. Flavor retention increased with an increase in drying air temperature and solid content, and decreased with an increase in dextrose equivalents of maltodextrin. A heat-treatment of the extract liquid made the lenthionine concentration increase, but did not influence the concentrations of the other flavors. The formation of lenthionine with heat-treatment could be described by the consecutive unimolecular-type first order reaction. Lenthionine content in a spray-dried powder prepared with the heated extracted liquid significantly increased. alpha-Cyclodextrin was the most suitable encapsulant of alpha-, beta-, and gamma-cyclodextrins to prepare the spray-dried powder, including lenthionine. The flavor retentions were markedly increased by using of alpha-cyclodextrin and maltodextrin in combination as an encapsulant.     

Synthesis of the sex pheromone of the citrus mealybug, Pseudococcus cryptus

The sex pheromone of the citrus mealybug (Pseudococcus cryptus), [(1R,3R)-3-isopropenyl-2,2-dimethylcyclobutyl]methyl 3-methyl-3-butenoate, was synthesized from (+)-alpha-pinene in five operational steps in a 43% overall yield. The synthetic pheromone was identical with the natural pheromone in (1)H-NMR and mass spectroscopic properties, and showed almost the same pheromonal activity as the natural pheromone.     

Effects of gamma-terpinene on lipid concentrations in serum using Triton WR1339-treated rats

We studied lipid metabolism to evaluate the effects of gamma-terpinene on suppression of increases in serum lipid concentrations using Triton WR1339-treated rats. At 6 hr after Triton WR1339 injection, the total cholesterol and triglyceride concentrations in the gamma-terpinene group underwent statistically significant decreases (18.3 and 30.3%, respectively) compared with those of the Triton-treated group.     

Simple synthesis of 5,9-dimethylated long-chain alkanes, the sex pheromones of leaf miner moths

Each stereoisomeric mixture of 5,9-dimethylpentadecane and 5,9-dimethylhexadecane, the major and the minor sex pheromone components of Perileucoptera coffeella, respectively, was synthesized in about 25% overall yield through 6 steps from beta-citronellol. 5,9-Dimethylheptadecane, the major sex pheromone component of Leucoptera malifoliella, was also synthesized analogously as a stereoisomeric mixture in a 22% overall yield.     

Preparation of (-)-periplanone D and its physical and spectroscopic properties

(-)-Periplanones C and D were obtained in reproducible yields by modifying reported procedures. Our synthetic sample of (-)-periplanone D showed somewhat different physical and spectroscopic properties from those reported in the literature.     

New route to enantiopure MalphaNP acid, a powerful resolution and chiral 1H NMR anisotropy reagent

MalphaNP acid (+/-)-1, 2-methoxy-2-(1-naphthyl)propionic acid, was enantioresolved by the use of phenylalaninol (S)-(-)-4; a diastereomeric mixture of amides formed from acid (+/-)-1 and amine (S)-(-)-4 was easily separated by fractional recrystallization and/or HPLC on silica gel, yielding amides (R;S)-(-)-5a and (S;S)-(+)-5b. Their absolute configurations were determined by X-ray crystallography by reference to the S configuration of the phenylalaninol moiety. Amide (R;S)-(-)-5a was converted to oxazoline (R;S)-(+)-8a, from which enantiopure MalphaNP acid (R)-(-)-1 was recovered. In a similar way, enantiopure MalphaNP acid (S)-(+)-1 was obtained from amide (S;S)-(+)-5b. These reactions provide a new route for the large-scale preparation of enantiopure MalphaNP acid, a powerful chiral reagent for the enantioresolution of alcohols and simultaneous determination of their absolute configurations by (1)H NMR anisotropy.