Rutin Derivatives Research Articles

Enzymatic formation of 4G-.ALPHA.-D-glucopyranosyl-rutin.

A water-soluble derivative of rutin was found to be formed in a high yield from dextrin and rutin in 50% methanol by the successive actions of Bacillus stearothermophilus cyclomaltodextrin glucanotransferase and Rhizopus sp. glucoamylase. The derivative was isolated from the reaction mixture by paper chromatography, Toyopearl HW-40S column chromatography, lyophilization, and successive treatment with methanol and ethanol, and then obtained as yellowish needle crystals [232-235°C, decomp. 16D +65.3° (c = 3.77, H2O)]. The compound was identified as 4G-α-Dglucopyranosyl-rutin on the basis of the various experimental results, viz., UV, IR, 1H-NMR, and 13C-NMR spectra, products by hydrolysis with acid and with α- and β-glucosidases. The solubility of the compound in water was about 30×103 times higher than that of rutin.

Role of antigen structure in the regulation of IgE isotype expression.

Tobacco glycoprotein (TGP) is a glycoprotein containing rutin-like polyphenol groups that is purified from cured tobacco leaves and can be detected in condensates of tobacco smoke. One-third of normal humans have been shown to manifest immediate, IgE-mediated, wheal and flare reactions to an intradermal injection of TGP. Rutin-like moieties are also found in a wide variety of vegetable foods. The possible importance of sensitivity to TGP in the pathogenesis of the vascular and pulmonary complications of tobacco smoking has stimulated us to study the immune response of mice to TGP and the role of rutin groups in influencing isotype expression. A series of three intradermal injections of TGP elicits a long-lasting IgE antibody response in mice. However, no hemagglutinating antibodies are produced. Similarly, immunization with a rutin derivative of bovine serum albumin stimulates IgE antibodies to bovine serum albumin but little hemagglutinating antibodies. In contrast, mice injected in the same manner with bovine serum albumin produce both IgE and hemagglutinating antibodies. Thus, the rutin moiety is implicated as exerting a regulatory effect on isotype expression by suppressing the production of serum antibodies of isotypes other than IgE. The immunization procedure employed (which involves an initial injection of 100 micrograms of antigen in phosphate-buffered saline, followed, at monthly intervals, by two intradermal injections of 100 micrograms of antigen precipitated on alum) apparently fails to stimulate the normal "down-regulation" of the IgE response so that a persisting high-titered response is obtained.

The effect of rutin-N-mustard on the survival of NK/Ly ascites tumour-bearing mice.

A newly synthetized rutin derivative, rutin-N-mustard, showed a marked antiproliferative effect on NK/Ly ascites tumour cells in vivo. When administered i.p. or i.v., this compound increased the survival time of the animals, but oral administration had no such effect. The drug was not able to kill the tumour cells, since the chromium release from the rutin-N-mustard-treated tumour cells was the same as in the case of the controls. Tumour growth was completely inhibited in the animals when the cells were pretreated with 100 mg/kg rutin-N-mustard before transplantation. The results also showed that rutin-N-mustard has little effect on the xenogenization of NK/Ly tumour cells. We presume that the antiproliferative action of rutin-N-mustard is due to its alkylating activity.

Studies on the haemolytic action of amphiphilic substances in vitro: Inhibition by O-(β-hydroxyethyl)-rutosides

the water soluble rutin derivative O-(β-hydroxyethyl)rutosides (HR) † was found to inhibit the haemolytic action of a variety of amphiphilic substances on human red blood cells, without causing haemolysis by itself. the effect of HR on haemolysis caused by aescin, digitonin, cetyltrimethyl-ammonium bromide, sodium dodecyl sulfate, polidocanol, sodium deoxycholate, chiorpromazine, promethazine, and thiazinamium was investigated in vitro. The antihaemolytic potency of HR was detennined for each haemolysin and expressed as the AH 50, which is the concentration necessary to reduce 50 per cent haemolysis to 25 per cent. the biphasic behavior of the unsperific haemolysins in hypotonic buffer solution was studied in the presence and absence of 2 × 10 −2 M HR. Both the stabilizing and the destabilizing part of the curve were shifted to higher concentrations, with the exception of sodium deoxycholate, where only the destabilizing part was affected. Two possible mechanisms are discussed: (1) the unspecific, hydrophobic interaction of HR with the single haemolysins resulting in complex formation, and (2) the protection of the membrane by competition of the inhibitor with the haemolysin for the binding site.