Color development of proanthocyanidins in vanillin-hydrochloric acid reaction

The influence of proanthocyanidin (PA) structures contained in bark on color development in the vanillin-hydrochloric acid (V-HCl) method used widely as a quantitative method for measuring PA were examined. The maximal absorption wavelength was different in terms of the bark from which the PA was obtained. Phenyl nucleus (resorcinol, phloroglucinol) constituting the A-ring of PA reacts with vanillin to produce the color. The maximal absorption wavelengths of the solutions from synthesized procyanidin and profisetinidin were 500 and 540 nm, respectively, indicating that the color tone differs in the V-HCl method based on the hydroxylation patterns of the A-ring. The colored solution of (+)-catechin with vanillin was dialyzed, and the resulting product (C-VC) was analyzed by gel permeation chromatography and ¹H nuclear magnetic resonance. It was found that C-VC was a polymer complex consisting of 9mol (+)-catechin moieties and 10mol vanillin moieties. It was presumed that the cationized vanillin molecules that do not combine with (+)-catechin play an important role on color development in the presence of C-VC.This study was presented at the 44th and 45th Annual Meetings of The Japan Wood Research Society, Nara and Tokyo, April 1994 and April 1995     

Effect of salinity change and exposure time on the egg stages of two abalone species Haliotis discus discus and H. gigantea

Fisheries Science - The embryonic developmental response of two abalone species (disk abalone Haliotis discus discus, giant abalone Haliotis gigantea) to a drop in salinity with different exposure...     

Complementary DNA cloning and functional analysis of lycopene β-cyclase in the brown alga Undaria pinnatifida

Fisheries Science - To date, there is no functional evidence of the enzymes catalyzing carotenogenesis in brown algae. In this study, we have investigated the activity of brown algal lycopene...     

Development of a culture protocol for Rhodomonas sp. Hf-1 strain through laboratory trials

Fisheries Science - Rhodomonas sp. Hf-1 is a marine microalgal strain with a high nutritional value. In order to produce this microalga effectively and inexpensively in a hatchery, its production...     

Geographical and functional-morphological variations of the skull in the gray-bellied squirrel

The geographical variations of the skulls were osteometrically examined in the gray-bellied squirrel (Callosciurus caniceps) from the populations of Korat, Ranong, southernmost Thailand, and Terutau Island. The skull size was larger in northern population than in the southern population in the continental mainland. The zoogeographical influences of the Isthmus of Kra remained unclear, since the plots from Korat population were intermingled with those from southernmost Thailand population in the principal component charts. Although Korat population has been thought to belong to north group, we suggest that Ranong and southernmost Thailand populations may contain individuals from both north and south groups separated by the ancient Kra barrier. Terutau Island population was similar to southernmost Thailand population in skull size, although Terutau population has been isolated in the island and separated from the south group of the Isthmus of Kra. In the proportional analysis the interorbital space was narrower and the binocular sense has been well-developed in Terutau population. It suggests that this population has been highly adapted to arboreal behavior. In contrast, the skull with larger interorbital space was more adaptive for terrestrial life in Korat population. The canonical discriminant analysis could clearly separate the four populations in the scattergrams of discriminant scores.     

Impacts of short-term salinity and turbidity stress on the embryonic stage of red sea bream Pagrus major

Fisheries Science - Heavy rainfall can reduce salinity and increase turbidity in coastal waters, creating stressful conditions for the organisms found there, especially for the early stages of...     

Unique expression patterns of myosin heavy chain genes in the ductus arteriosus and uterus of rabbits.

In smooth muscle tissue, two smooth muscle myosin heavy chain (MHC) isoforms (SM1, SM2) and two non-muscle MHC isoforms (NMA, NMB) have been identified. The purpose of our study was to clarify whether smooth muscle MHC mRNA expression reflects the physiological and functional state of the muscle. We studied the expression pattern of MHC mRNAs, using the S1-nuclease mapping procedure, in functionally and morphologically changeable organs; the ductus arteriosus (DA) during development (25 and 29 days of gestation, and from 3-day-old neonates) and uteri from virgin, day-10 pregnant (P10) and day-29 pregnant (P29) rabbits. The results demonstrated that SM2 expression was greater in the fetal DA than in the fetal aortic and pulmonary arteries, but that it decreased significantly following closure of DA. In the gravid uterus, SM1 expression was significantly (P<0.05) strong compared to other MHC mRNAs from virgin to P10 rabbits. During pregnancy, NMB expression showed a tendency to increase until P10, and after P10, SM2 expression increased dramatically and NMB expression decreased to give almost a mirror image of the SM2 expression. Smooth muscle type (SM1, SM2) was significantly (P<0.05) strong compared to non-muscle type expression (NMA, NMB) at P29. These data suggest that smooth muscle MHC mRNA, especially SM2 expression reflects the physiological and functional state of the smooth muscle.     

Microbial metabolism in reduction process of paddy soils (Part 2)

The previous experiences^1-3) with incubation experiments of the soils under submargd condition indicated that the disappearance of molecular oxygen and nitrates occurred shortly after sub-emerging, and then the reduction of ferric iron proceeded, being followed by the reduction of sulfates and the formation of methane which nre caused by the activities of strict anaerobes. It was suggested from the above fact that the reduction process in the submarged soils was affected mainly by two factors: namely, the amount of reducible ferric iron and the soil organic matters which are avaiable as substrate for microbial metabolism.     

Bacterial canker of Maackia amurensis var. buergeri caused by a putative Pseudomonas syringae

A new disease of Maackia amurensis var. buergeri was recently found on the northern island of Hokkaido, Japan. Affected trees were heavily damaged and had cankers on both trunks and branches. After natural infection, a series of swellings on the bark surface developed longitudinally. These swellings burst and coalesced to become long cankers. It is proposed that the disease be designated ‘bacterial canker of Maackia’. The causal pathogen was isolated and characterized tentatively as Pseudomonas syringae on the basis of laboratory tests. Pathogenicity of the bacterium was confirmed by inoculation into the host.