Characterization of new thioacidolysis products of sinapyl aldehyde and coniferyl aldehyde

To elucidate the chemical structure ofp-hydroxycinnamyl aldehyde moieties of abnormal angiosperm lignins of cinnamyl alcohol dehydrogenase down-regulated plants, sinapyl and coniferyl aldehydes were subjected to thioacidolysis. and the products were analyzed by gas chromatograph-mass spectrometer (GC-MS). The chromatograms indicated that two pairs of new isomeric compounds were released during thioacidolysis of sinapyl and coniferyl aldehydes, respectively, together with the previously found products. These products were also found in the thioacidolysis products of dehydrogenation polymer incorporatingp-hydroxycinnamyl aldehydes. The new compounds had the novel indane structure in that they position of the side chain was linked to an aromatic ring. In the case of sinapyl aldehyde, these isomer compounds were the main products, which indicated different reactivities of sinapyl and coniferyl aldehydes during thioacidolysis.Part of this paper was presented at the TAPPI Pulping Conference. Nashville, October 1996; and the 41st Lignin Symposium, Nagoya. October 1996     

Contribution of lignin to the reactivity of wood in chemical modifications I: influence of delignification on acetylation

In order to examine the contribution of wood components to the acetylation of wood, we acetylated wood meal that had been partially delignified. The results were analyzed in terms of the reaction kinetics. The first-order rate equation was successfully adjusted to the weight gain data. The rate constant for acetylation initially increased with progress of lignin elimination and then turned to decrease; the apparent activation energy showed the reverse tendency and ranged from about 90 to 130 kJ/mol. These results suggest that lignin elimination brings not only separation of lignin but also drastic change of the chemical and/or physical structure in the residual lignin, and this affects the reactivity of wood meal as a whole. The ultimate weight gain estimated by the regression of the rate equation showed a minimum when lignin was moderately eliminated, which was explained in terms of enhanced reactivity of lignin and lower accessibility for holocellulose than predicted. The equilibrium moisture content had a maximum when lignin was moderately eliminated. This tendency is the opposite of that observed for the ultimate weight gain, and suggests that the sites for acetylation do not always correspond to those for moisture adsorption. Part of this report was presented at the 54th Annual Meeting of the Japan Wood Research Society, Sapporo, August 2004     

Contribution of lignin to the reactivity of wood in chemical modifications II: influence of delignification on reaction with vaporous formaldehyde

Participation of lignin in the reaction between vapor-phase formaldehyde and wood was examined by using gradually delignified wood meal. A fi rst-order rate equation was successfully applied to the weight gain data. From the estimated reaction parameters such as rate constant, k, and ultimate weight gain, a, the reactivity toward formaldehyde was discussed among wood components, and compared with that for acetylation. k decreased monotonously with progress of the elimination of lignin, suggesting that the reaction rate of lignin is dominant over that of whole wood, and the decrease in the ratio of lignin retarded the reaction of wood as a whole. On the other hand, a increased with decreasing lignin content. This may be attributable to the enhanced reactivity of the remaining lignin due to some structural changes and to the increase in the number of reactive sites in polysaccharides as a result of their exposure accompanying the elimination of lignin. The dependencies of k and a on the lignin content were not similar to the case for acetylation, probably because of the difference in the reaction phase. In vapor-phase formaldehyde treatment, the remaining lignin reacts as it is, whereas in liquid-phase acetylation it would undergo rearrangement or swelling of the structure in the reaction solution.     

Photodiscoloration of western hemlock (Tsuga heterophylla) sapwood III Early stage of photodiscoloration reaction with lignans

The reaction during the early stage of photodiscoloration of constituents in western hemlock [Tsuga heterophylla (Raf. Sarg., Pinaceae] sapwood was investigated with chemical methods. The main photodiscoloring constituents, hydroxymatairesinol, allohydroxymatairesinol, -conidendrin, and oxomatairesinol, were used as substrates for light-irradiation experiments in vitro. The structures of photodiscoloration reaction products were elucidated by isolation and instrumental analyses and/or co-high-performance liquid chromatography analyses with authentic specimens. The experiment was undertaken to distinguish each series of liquid phases using chloroform, water (both including a trace of methanol), and methanol, and the solid phase. The reaction products allohydroxymatairesi (2), oxomatairesinol (3), -conidendrin (4), allo-7-methoxymatairesinol (5), 7-methoxymatairesinol (6), and vanillin (7) were isolated or detected in the reaction mixture of a hydroxymatairesinol system. The reaction products hydroxymatairesinol (1), 3, 4, 5, 6, and 7 were confirmed in the reaction system of allohydroxymatairesinol, which was an epimer of hydroxymatairesinol. Product 3 was confirmed from the -conidendrin system, and reaction product 7 was confirmed from oxomatairesinol. The photodiscoloration reaction of western hemlock sapwood could be initiated by the formation of phenoxy radicals from the respective constituents. The reaction was then presumed to progress via formation of a quinonemethide intermediate in many of them. It was suggested that the reactive species, such as phenoxy radical or quinonemethide intermediate, formed by lightirradiation might be converted to quinone derivatives and colored oligomers. Products 1, 2, 3, 4, and 7, formed from substrates such as hydroxymatairesinol, allohydroxymatairesinol, -conidendrin, and oxomatairesinol, were the same as the original metabolic constituents of western hemlock. Therefore it was concluded that the photodiscoloration of western hemlock depends not on the quantitative level of a few respective metabolites but, rather, on the coexistence of many metabolites.Part of this paper was presented at the 46th Annual Meeting of Japan Wood Research Society at Kumamoto, April 1996     

Production of calcium maintenance factor Stanniocalcin-1 (STC1) by the equine endometrium during the early pregnant period

A factor responsible for progression to pregnancy establishment in the mare has not been definitively characterized. To identify factors possibly involved in the establishment of equine pregnancy, the endometrium was collected from day 13 (day 0=day of ovulation) cyclic and day 13, 19 and 25 pregnant animals. From initial subtractive hybridization studies, a calcium regulating factor, Stanniocalcin-1 (STC1) mRNA, was found as a candidate molecule expressed uniquely in the pregnant endometrium. Endometrial expression of STC1 mRNA was noted on day 19 and was markedly increased in the day 25 gravid endometrium. STC1 protein was found in the extracts of day 25 gravid endometrium and immunochemically localized in the uterine glands. In addition, STC1 protein was detected in uterine flushing media collected from day 25 pregnant mares. High concentrations of estradiol-17 β (E(2)) were detected in day 25 conceptuses. E(2) levels were much higher in the gravid endometrium than in other regions, whereas progesterone levels did not differ among the samples from different endometrial regions. Expression of STC1 mRNA, however, was not significantly upregulated in cultured endometrial explants treated with various concentrations of E(2) (0.01-100 ng/ml) with or without 10 ng/ml progesterone. These results indicate that an increase in STC1 expression appears to coincide with capsule disappearance in the conceptus, and suggest that STC1 from the uterine glands likely plays a role in conceptus development during the pregnancy establishment period in the mare.     

Prokinetic effect of the 5-HT4R agonist mosapride on canine gastric motility

We assessed prokinetic action of gastroprokinetic agent, mosapride in dogs. Open-label cross-over study. Six healthy beagles were administered single oral mosapride at doses of 0.5, 0.75, 1, and 2 mg/kg 30 min prior to feeding, followed by 1-week interval. The motility index (MI) of gastric contraction was ultrasonographically evaluated by change rate of antral area and contraction number. Significant increases in MI were observed at doses of 0.75 mg/kg (mean ± SEM, 11.11 ± 0.19), 1 mg/kg (11.65 ± 0.34), and 2 mg/kg (12.04 ± 0.34), compared with that of the control (9.37 ± 0.51). Mosapride administration (2.0 mg/kg, BID) for 1 week had no adverse effects on blood tests or health of the animals. In conclusion, 0.75 to 2 mg/kg of mosapride produces gastric prokinetic actions without adverse effects.     

Homozygosity of single nucleotide polymorphisms in the 3′ region of the canine estrogen receptor 1 gene is greater in Toy Poodles than in Miniature Dachshunds and Chihuahuas

Differences in the distribution of single nucleotide polymorphisms (SNPs) and haplotypes in the estrogen receptor α gene (ESR1) were examined in Miniature Dachshunds (n = 48), Chihuahuas (n = 20) and Toy Poodles (n = 18). Five DNA fragments located in the 40‐kb region at the 3′ end of ESR1 were amplified by polymerase chain reaction and were directly sequenced. We compared allele, genotype and estimated haplotype frequencies at each SNP in the 3′ end of ESR1 for these three breeds of small dog. The frequency of the major allele and the genotype frequency of the major allele homozygotes, were significantly higher in Toy Poodles for five SNPs (SNP #5, #14–17) than in Miniature Dachshunds, and significantly higher in Toy Poodles than Chihuahuas for three SNPs (SNP #15–17). A common haplotype block was identified in an approximately 20‐kb region encompassing four SNPs (SNPs # 14–17). The frequencies of the most abundant estimated haplotype (GTTG) and GTTG homozygotes were significantly higher in Toy Poodles than in the other two breeds. These results imply that homozygosity for the allele, genotype and haplotype distribution within the block at the 3′ end of ESR1 is greater in Toy Poodles than in Miniature Dachshunds and Chihuahuas.