Preparative-scale isolation of four anthocyanin components of black currant (Ribes nigrum L.) fruits

Four anthocyanin components of black currant, delphinidin 3-O-beta-rutinoside (D3R), cyanidin 3-O-beta-rutinoside (C3R), delphinidin 3-O-beta-glucoside (D3G), and cyanidin 3-O-beta-glucoside (C3G), were successfully isolated as crystalline forms on a preparative scale. In this process, selective hydrolysis of the glucosides (D3G and C3G) and rhamnosides (D3R and C3R) was achieved by treatment with beta-glucosidase and hesperidinase (alpha-rhamnosidase), respectively, to improve resolution of anthocyanin components. Especially, selective conversion of the rutinosides into glucosides made the amounts of D3G and C3G increase about 4- and 7-fold, respectively. D3R, C3R, D3G, and C3G were isolated from enzymatic hydrolysates of black currant anthocyanins through Amberlite XAD-7HP absorption followed by preparative HPLC separation, and their crystals were obtained as the flavylium chloride.

[A study of dental soldering. (10) The temperature distribution of infra-red soldering machine]

The purpose of this study is to measure the temperature distribution of focused energy by infra-red soldering machine. The result indicate following. 1. The three dimensional heating area is an ellipse shape, and soldering area is about 10 mm in diameter centering around the focus. 2. Temperature adjustment of INFRARED (NEY Co.) is to use Powerlevel, and of BEAMWERDER (YOSHIDA Co.) is adjusting the height of the turn table. 3. When soldering with focused energy with infra-red machine, it is adequate to solder at the focused level or the upper level, after pre-heating of the soldering objects at the lower level.

Application of encapsulated enzyme as a continuous packed-bed reactor

In the previous report, microencapsulation of lipase employing a (w/o)/w multiple phase emulsion technique, with 2:1 polystyrene (PS)-SBR mixture being used as a wall material, was proposed. Catalysis of the encapsulated enzyme was investigated, and the hydrolysis of triacetin (triglyceride of acetic acid) was successfully simulated by the reaction model based upon the Michaelis-Menten mechanism. Other factors affecting the mechanism such as the mass-transfer resistance of the substrate molecules through the wall and the decrease in pH due to the formation of acetic acid were also taken into consideration. In this report, the particular microcapsules were applied to the continuous tubular reactor system, essentially a packed column reactor, and longevity and mechanical strength of the microcapsules were fully demonstrated. The reaction model derived for a well-stirred batch reactor was also applicable to simulate the behaviour in the packed-column reactor as it was proved that there is no mass transfer resistance between the reactant stream and the surface of microcapsules. The observed data agreed quite well with the calculated values. Similarity of the behaviours of catalysis observed between two reactor systems was thoroughly confirmed. No leakage of the enzyme was detected after repeated usage over the duration of a few months, the temperature being maintained in the range between 293 and 323 K, and pH reset after each operation. Commercial feasibility of the microcapsules for the enzyme catalysis with substrates, small enough to permeate through the wall, was established by these fundamental investigations.

Immobilization of enzyme by microencapsulation and application of the encapsulated enzyme in the catalysis

Microencapsulation of lipase (Pseudomonas fluorescens) was carried out using (W/O)/W two-phase emulsion technique. Polystyrene (PS) and Styrene-Butadiene Rubber (SBR) were utilized as wall materials either separately or in mixture. A particular composition of 2:1 PS-SBR yielded homogeneous and tough wall structure, resilient to the impact and tight confinement of enzyme macromolecules. Performance of the encapsulated enzyme was evaluated employing the hydrolysis of triacetin (triglyceride of acetic acid) as a model substrate of the enzyme catalysis. A mathematical model was developed to simulate the behaviour of hydrolysis, which was derived under the assumption that the diffusion of small molecules (substrate and products) through the wall of microcapsules plays a dominant role to the reaction rate. Inhibition of the reaction by the decreasing pH due to the release of acetic acid was also taken into account. The calculated values agreed quite well with the observed data.

Effects of p-chloromercuribenzene sulfonate on the uptake of D- and L-leucines in Ehrlich ascites tumor cells

In order to ascertain the significance of the hydrophobic region in the carrier protein responsible for the D-leucine transport reported previously, the effects of p-chloromercuribenzene sulfonate (PCMBS) were investigated on the transport of D- and L-leucines in Ehrlich ascites tumor cells. The uptake of D-leucine in the presence of PCMBS was inhibited more strongly than that of L-leucine. Km values for D-leucine uptake increased with increasing concentration of PCMBS, while those for L-leucine showed only a little increase. D-Leucine uptake was restored considerably from the PCMBS inhibition by washing with buffer, whereas L-leucine uptake was only slightly affected. The inhibition of D-leucine exit by PCMBS was also higher than that of L-leucine. These results suggest that the binding site of PCMBS for the carrier protein of Ehrlich cells is involved in its hydrophobic region that would be more significant for the binding of alkyl side chain D-leucine than that of L-leucine.