A survey of the total aminopeptidase activity of bovine, porcine, and chicken skeletal muscles at neutral pH was done, using the β-naphythylamide derivatives of nine amino acids. DEAE-cellulose column chromatography of the muscle extract found at least four types of aminopeptidases in bovine muscle and six types of aminopeptidases in porcine and chicken muscles. Aminopeptidase B and aminopeptidase C were commonly recognized in bovine, porcine, and chicken muscles. Hydrolase H was recognized in porcine and chicken muscles. Aminopeptidase C and hydrolase H had high activity against almost all substrates. The substrate specificities of both enzymes were fairly compatible with the pattern of free amino acids which increased during the storage of bovine, porcine, and chicken meats [Agric. Biol. Chem. 52, 2323 (1988)], indicating that aminopeptidase C and hydrolase H are responsible for the increment of free amino acids during aging of these muscles.

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Phosphatidylglycerol (PG) is a phospholipid characteristic of chloroplasts of higher plants. Molecular species of PG isolated from leaves of 7 Citrus species were examined and grouped into 5 classes. More than 90% of the total molecules were of the prokaryotic type synthesized in chloroplasts. Fatty acid compositions (sn-1/sn-2) of the major molecular species were 18:1/16:1 (26-47% of the total molecules), 18:1/16:0 (11-35%), and 16:0/16:1 (10-22%), which were all prokaryotic. Molecular species with 18:1 at sn-1 were characteristic of Citrus leaf PG. Unsaturated prokaryotic molecular species of (18:1, 18:2, and 18:3)1(16:0 and 16:1) accounted for 65-82%, and saturated ones of (16:0 and 18:0)/(16:0 and 16:1) for 19-32%.

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A sensitive near-infrared detection system with improvements was used to study the quenching of the steady-estate luminescence of singlet molecular oxygen at 1270 nm. Stern-Vohner plots which were linear up to 80% quenching by luminol of the ¹O₂ generated by rose bengal yielded rate constants of 9.30 × 10⁸ and 1.40 × 10⁹ M^-1 sec^-1 for the quenching of ¹Q₂ in pH 7.1 and pH 10.1 buffer solutions (25 HIM). Quenching rate constants of ¹O₂ by superoxide dismutase and Cypridina luciferin analogues, 2-methyl-6-phenyl- and 2-methyl-6-[p-[2-[sodium 3-carboxylato-4-(6-hydroxy-3-xanthenon-9-yl)-phenylthioureylene]ethyleneoxy]phenyl]-3, 7-dihydroimidazo[1, 2-a]pyrazin-3-one (CLA and FCLA) were measured similarly as 2.73 × 10⁹, 6.30 × 10⁸ and 8.00 × 10⁸ M^-1 sec^-1 in the pH 7.1 buffer solutions, respectively.

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Factors affecting the genetic stability of cycloheximide-kabicidin resistant segregants as non-parental type segregants generated from fusants between cycloheximide 500 μg/ml resistant strains derived from A. oryzae IFO 5239 and kabicidin 240μg/ml resistant segregants derived from A. niger IFO 4407 were investigated. There were two types of cycloheximide-kabicidin resistant segregants. One type was the heterokaryons and the other type contained fused nuclei. Almost all colonies were unstable heterokaryons, and balanced heterokaryons were not seen. This was considered to be caused by the difference of growth rates between parental strains although A. oryzae are multinuclear by nature. It was suspected that the difference of growth rates between two strains in colonies were caused by the decrease in medium pH owing to higher acid production of A. niger.

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Enzyme hydrolysis of soluble starch by free β-amylase and pullulanase for the production of maltose was done by the simultaneous use of a stirred tank reactor and an ultrafiltration membrane. Higher conversions of starch to maltose were obtained in the permeates than that in a batch reaction. Using the basic mass balance and rate equations, concentrations of maltose, maltotriose, and substrate in the retentates and permeates could be simulated effectively. More than 99.9% of enzyme was found to be rejected by the membrane. The obtained volumetric productivities were several times higher than those reported in other systems. This system was found to have high maltose productivity with a short mean residence time, being easily controlled by transmembrane pressure.

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Four recombinant plasmids coding for human lymphotoxin (LT) were constructed with genomic DNA (gDNA) or cDNA sequences. The simian virus 40 (SV40) early region, which contains the early promoter, an intron of the small-t-antigen-encoding gene, and polyadenylation signal sequences, was used for transcriptional and post-transcriptional regulatory elements in the construction of these plasmids. Two of them contained gDNA and the other two contained cDNA. One of the gDNA plasmids and one of the cDNA plasmids carry the SV40 intron between the structural gene and polyadenylation signal. Transient and stable gene expression levels of these plasmids in Chinese hamster ovary (CHO) cells were measured by assaying the secreted LT.
The plasmid carrying gDNA without the SV40 intron was expressed more efficiently than the other three plasmids in both transient and stable gene expression assays.

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Cubes of 2% agar gel, with side lengths (2L) of 1, 2, 3, 5, 7 and 10cm, were soaked in a 0.1 M sodium chloride solution at 25°C. After soaking for 0-75 hr (f), the amounts of sodium chloride and water in the gel were measured, and the mean concentration of the sodium chloride in the gel cube was calculated. The ratio of the mean concentration to the boundary concentration (C_r) depended on the value of t/L². The value for the apparent diffusion coefficient (D_app), which was yielded by substituting the values of t/L² and Cr into the solution of the diffusion equation, depended on t/L² and C_r, and reached the maximum value (1.03 × 10^-5 cm²/sec) at about C_r = 0.6. The relationship between C_r and D_appt/L² which is shown in this paper, can be applied to the diffusion of any substance in various food materials other than agar gels or sodium chloride.

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γ-Glutamylmethylamide (γ-GMA) synthetase was detected in crude extracts of Methylophaga sp. AA-30, but neither methylamine dehydrogenase nor N-methylglutamate dehydrogenase was observed. A large amount of γ-GMA was accumulated in the cells when the growth on methanol-methylamine was inhibited with iodoacetate, but the accumulation was not observed in the cells grown on methanol-(NH₄)₂SO₄. It is thought that γ-GMA is a metabolic intermediate of the methylamine-dissimilating pathway in the bacterium. In addition, γ-GMA-dissimilating enzymes were found in methylamine-grown cells. The enzymes, which consisted of H protein and L protein, required α-ketoglutaric acid, Mg²⁺ or Mn²⁺, and ammonia as a cofactor. Although the enzyme catalyzed the formation of glutamate from γ-GMA, it did not catalyze the formation of N-methylglutamate. Consequently, in this bacterium, methylamine seems to be metabolized through a different pathway from the N-methylglutamate pathway.

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A simple and rapid colorimetric method for the measurement of the freshness of fish meat was developed using a nucleoside oxidase-catalyzed oxidative coupling reaction. Fish freshness can be expressed by the K₁ value according to the following equation¹):
K₁(%) = 100(HxR + Hx)/(IMP + HxR + Hx).
To measure the K₁ value, hypoxanthine (Hx) and inosine-5'-monophosphate (IMP) were converted to inosine (HxR) by nucleoside phosphorylase and alkaline phosphatase, respectively, and then HxR was oxidized by nucleoside oxidase in the presence of N-ethyl-N-(2-hydroxy-3-sulfopropyl)-3, 5-dimethoxy aniline sodium salt (DAOS) and 4-aminoantipyrine. The amount of colored substance formed was proportional to the amounts of these compounds. One assay was completed within 10min and good comparative results were obtained between the K₁ value from the proposed method and from the HPLC method. A method for measuring HxR, Hx, and IMP ratios was also developed.

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Formation of quinoprotein methanol dehydrogrnase (MDH) in Methylobacillus glycogenes, an obligate methylotroph, was strictly controlled by calcium (Ca) in the culture medium. Both the growth of the organism and the total enzyme activity of MDH were also repressed at less than 1 ppm of Ca, although specific activity of MDH showed a similar level. Ca in MDH was replaced with other metals during cultivation of M. glycogenes. When strontium (Sr) chloride was fed instead of CaCl₂, Ca in MDH was completely replaced by Sr and showed a specific activity over ten times higher than Ca-containing MDH, although there was no appreciable increase in the MDH content in cells cultured in Sr medium. Methanol oxidase activity was also elevated in the cells that were cultured in the medium with Sr.

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L-Phenylalanine ammonia-lyase was crystallized for the first time from a cell-free extract of Rhodosporidium toruloides IFO 0559. Heat treatment at 50°C for 5min was a smart step for enzyme purification. Column chromatographies with DEAE-cellulose and hydroxyapatite, and gel filtration on a Sephadex G-200 column were used in the subsequent purification. The enzyme was purified to a homogeneous state and crystallized as fine needles with ammonium sulfate. The crystalline enzyme was pure by both analytical ultracentrifugation and polyacrylamide gel electrophoresis. The enzyme had a 8.2 s sedimentation velocity. The molecular weight of the enzyme was 165, 000 by the dual methods of sedimentation equilibrium and gel filtration. The enzyme was composed of two identical subunits with a molecular weight of 80, 000.

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A simple and rapid procedure for the preparation of milk fat globule membrane (MFGM) is proposed. The membrane fragments released from bovine milk fat globules were recovered as MFGM by acidification at pH 4.8 and centrifugation (AC-MFGM). The yield, gross compositions, enzymatic activities, and electrophoretic properties of the resultant MFGM were compared with those of MFGMs recovered by ultracentrifugation (UC-MFGM) and by salting out (SA-MFGM). The different methods for recovering MFGM had significant effects principally on the lipid content and protein composition of MFGM. Of the three MFGMs, AC-MFGM had a moderate lipid content, while UC-MFGM had the lowest and SA-MFGM the highest. High activities of marker enzymes for plasma membrane in AC- and UC-MFGM were retained but not in SA-MFGM. Glycoproteins PAS-6 and -7 were preferentially released from UC-MFGM. The pH was a factor in causing the release of these glycoproteins. The release of PAS-6 and -7 was also ascertained by the decrease in UC-MFGM of proteins extractable with 1 M KC1 and 8 M urea. The yield of MFGM was influenced mostly by the smaller fat globules and releasable protein and, consequently, was low in UC-MFGM, moderate in AC-MFGM, and high in SA-MFGM. Acidification to the isoelectric point was the easiest method for recovering MFGM, and resultant AC-MFGM had advantages over both the UC- and SA-MFGMs.

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During experiments on protoplast fusion of complementary auxotrophic mutants (194 and 11M-21) of Streptomyces antibioticus for strain improvement, the clones (typified by F-40) regenerated on minimal regeneration medium (MRM) were found to be prototrophs, and to produce an antibiotic different from those produced by the parent strain. The protoplast regeneration of each parent was examined as a negative control experiment.
In the regenerated clones of 194, half of them produced actinomveins similar to those produced by the original mutant 194, but others (typified by R-20) seemed to produce antibiotics similar to those produced by F-40. In the taxonomic characterization of morphological, cultural, and physiological properties of each strain, F-40, R-20, and the parent mutant 194 had no significant differences with a few exceptions. The problem here is whether the antibiotic of R-20 is the same as that of F-40, which was first isolated and found to be a peptide antibiotic different from actinomycins, with activity against Gram-negative and Gram-positive bacteria.

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A restriction endonuclease, designated as Dmal, was purified from cell-free extracts of Deleya marina IAM 14114 by streptomycin treatment, ammonium sulfate fractionation and two steps of chromatographies on heparin-Sepharose CL-6B and Mono Q (HR 5/5, FPLC). The purified enzyme was homogeneous on SDS-polyacrylamide gel disk electrophoresis and a ligation-recutting test. The relative molecular mass measurements of the purified enzyme gave 28, 000 daltons by SDS-polyacrylamide gel disk electrophoresis and 56, 000 daltons by gel filtration. These data indicated that the purified enzyme (56, 000 daltons) has a dimeric structure composed of two 28, 000-dalton subunits. The isoelectric point was 5.5. The purified enzyme worked best at 37°C in a reaction mixture (50 μl) containing 1.0 μg λADNA, 10 mM Tris-HCl, 7 mM 2-mercaptoethanol, 7 mM MgCl₂ and 100 mM NaCl (pH 7.5). The enzyme was stable up to 55°C and between pH 7.0 and 9.0. The purified enzyme recognizes the palindromic hexanucleotide DNA sequence 5'-CAGCTG-3', cuts between G and C and produces a flush end (isoschizomer of PvuII).

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To study the behavior of Bifidobacterium toward oxygen, oxygen uptake was investigated in detail. The cells of Bifidohacterial strains absorbed considerable amounts of oxygen. The exogenous oxygen uptake activity changed depending upon the period of incubation. Bifidobacterial cells also had high endogenous oxygen uptake, which was, in B. longum strains, as high as about 80% of the exogenous oxygen uptake activity. Bifidobacterial cells accumulated considerable amounts of polysaccharide, which was associated with cellular growth. By incubating the cultivated cells in a glucose-free medium, the endogenous oxygen uptake activity was decreased with a decrease of intracellular polysaccharide. Therefore it was postulated that the high endogenous oxygen uptake activity of Bifidobacterium was owing to the metabolism of intracellular polysaccharide. The enzymatic activity, which was involved in the mechanism of oxygen uptake, was also investigated.

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Streptomyces griseus and bacteriophage B were used for an assay system detecting antibacteriophage antibiotics. Streptomyces sp. RK-1441 was found to produce antibacteriophage antibiotics, RK-1441A and B, which are pyrrolo[1, 4]benzodiazepine group antibiotics related to neothramycin. Both RK-1441A and B had antibacteriophage activity. The former showed antimicrobial activity on a hypersensitive strain of E. coli for antitumor antibiotics, but the later did not show the activity. Restriction enzyme assay suggested that RK-1441A formed adducts with guanine residues in DNA strands. RK-1441B was not active in vitro, but it might be converted to the active form in host organisms.

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Antibacteriophage antibiotics, RK-1441A and B, related to neothramycin were isolated from the culture broth of Streptomyces sp. and their structures were deduced from spectroscopic analyses. The structure of RK-1441A was 8, 11-dihydroxy-3, 7-dimethoxy-5-oxo-1H-pyrr61o[2, 11c:1, 4]benzodiazepine. RK-1441B is a tautomeric mixture at C-3 of the structure, 3, 8, 11-trihydroxy-7-methoxy-5-oxo1H-pyrrolo[2, 1-c:1, 4]benzodiazepine.

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Polysaccharides extracted from Himematsutake, the fruiting body of Agaricus blazei Murill with hot water were fractionated and purified by ethanol precipitation, ion-exchange chromatography, gel-filtration, affinity chromatography, etc.
A total of 17 polysaccharide samples thus obtained were given an antitumor activity test (Sarcoma 180/mice i.p. p.o. method) and traces of their activities through the fractionation and purification processes were found.
FI₀-a-β, FA-1-a-α, FA-1-a-β, and FA-2-b-β, were obtained as water soluble polysaccharides fractions having great antitumor activities.
Analyses of physico-chemical properties and IR- and NMR-spectra of these active fractions showed that their main components were: FI₀-a-β, (1→6)-; (1→3)-β-D-glucan; FA-1-a-α, acidic (1→6)-; (1→4)-α-D-glucan; FA-1-a-β, acidic (1→6)-; (1→3)-α-D-glucan; and FA-2-b-β, acidic RNA-protein complex.

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After extraction of a hot-water-soluble polysaccharide (FI) from the fruiting bodies of Himematsutake (Agaricus blazei Murill), water-insoluble polysaccharides were obtained by successive extraction with 1% ammonium oxalate solution (FII), 5% sodium hydroxide solution (Fill and FIV), 20% sodium hydroxide solution (FV), and 5% lithium chloride-dimethylacetamide solution (FVI) in that order. These water-insoluble fractions were further fractionated by ethanol precipitation, gel-filtration, etc. Polysaccharides, polysaccharide-protein complexes, and chitin substances thus obtained were assayed for their antitumor activities using the Sarcoma 180/mice i.p., p.o. method.
The heteroglycan-protein complexes, FH-a, -b and -c, obtained from FII had weak antitomor activities.
A remarkable antitumor activity was found in a glycoprotein, FIII-2-b, fractionated and purified from Fill. The polysaccharide portion of this polysaccharide-protein complex (polysaccharide, 50.2% and protein, 43.3% each on a weight basis) consisted of (1-*6)-β-D-glucan, and its protein portion was rich in Asx, Glx, Ala, Leu, and Pro.
A high antitumor activity was found in a xyloglucan-protein complex, FIV-2-b, fractionated and purified from FIV.
Antitumor activity was found also in a glucoxylan, FV-2-a, obtained from FV.
No significant antitumor activity was found in a chitin substance, FVI.

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Lipase-catalyzed enantioselective hydrolysis of the acetic ester of racemic α-cyano-3-phenoxybenzyl alcohol (CPBA) was examined to prepare (S)-CPBA. Most of the lipases tested hydrolyzed (S)-CPBA acetate preferentially, while Candida cylindracea lipase favored (R)-CPBA acetate. Enantioselective hydrolysis by Arthrobacter lipase gave the optically pure (S)-CPBA in the reaction mixture of pH 4.0. The kinetic studies showed that (R)-CPBA acetate reacted as a competitive inhibitor. The Arthrobacter lipase solution in the water/oil biphasic reaction system could be used repeatedly. The lipase immobilized to resins had insufficient activity or low operational stability for the repeated batch reaction. The unhydrolyzed (R)-CPBA acetate was racemized by heating with triethylamine and could be reused as the substrate of the enzymatic hydrolysis. A chemico-enzymatic process for the preparation of (S)-CPBA was developed based on these studies.

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The interfacial adsorptivity of lysophosphatidylcholine (LPC) was investigated in relation to formation of stable emulsions and interaction of LPC on lipoproteins. The proportion of adsorbed LPC on the interface was measured by using the quantitative interaction between free LPC in an aqueous phase and multilamellar vesicle PC (MLV-PC) that was added after emulsification. Moreover, the effects of free fatty acid on the adsorptivity of LPC were measured by the decrease of LPC-fatty acid vesicles after emulsification. The line widths of ³¹P-NMR spectra broadened and mean diameters of droplets decreased with the increase of absorptivity. Thus, the restriction of headgroup motional freedom of LPC was correlated with the interaction between LPC and triacylglycerol or free fatty acid on the interface, and the adsorptivity and interaction varied with the fatty acid composition of oil phase and with the emulsifying temperature.

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D-Fructose dehydrogenase was immobilized behind a dialysis membrane on a carbon paste electrode containing p-benzoquinone. The electrode showed a current response to D-fructose due to the p-benzoquinone-mediated bioelectrocatalytic oxidation of D-fructose. The dependence of the current response on the potential applied to the electrode, pH of the solution, and temperature was studied. On this basis, measurements of D-fructose were done at 0.5 V vs. Ag/AgCl, pH 4.5 and 25°C using the fructose dehydrogenase-modified carbon paste electrode. D-Fructose in fruits was measured by this electrode method, in which the interference from L-ascorbic acid was taken into account. A method of elimination of the interference, which uses ascorbate oxidase, is also described.

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Inhibitory effects of green tea poly phenols on glucan synthesis by glucosyltransferases of Streptococcus mutans MT8148 and Streptococcus sobrinus 6715DP and on sucrose-dependent adherence of the bacterial cells were examined in vitro. The glucan synthesis by the bacterial glucosyltransferase was strongly inhibited by (-)-epicatechin gallate (ECg) and (-)-epigallocatechin gallate (EGCg), the main components of the tea polyphenols. It was also demonstrated that ECg and EGCg interfered with the sucrose-dependent adherence of those bacterial cells at much smaller concentrations than those which were needed to inhibit the growth of the bacteria.

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A plant glycosphingolipid, O-(β-D-mannopyranosyl)-(1→4)-O-(β-D-glucopyranosyl)-(1→1)-(2S, 3S, 4R)-4-hydroxy-N-tetracosanoylsphinganine 1, and the stereoisomer, O-(α-D-mannopyranosyl)-(1→4)-O-(β-D-glucophranosyl)-(1→1)-(2S, 3S, 4R)-4-hydroxy-N-tetracosanoylsphinganine 6, were synthesized in a stereo- and regio-controlled way.

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Microphotometric and linear viscoelastometric observations were done for various samples of mochi cake prepared by a kneading or a stamping method. The former was done at a magnification of 10. The latter was done at a frequency between 3.1 and 3.3×10^-4 radian/sec and at a temperature between 30 and 90°C. In both observations, differences were recognized among samples. However, quantitative interpretation seemed to be difficult using microphotometry. It was found that viscoelastic characterization of mochi cake should be done above the gelatinizing temperature. It was concluded that the combination of microphotometry and viscoelastometry in linear region allowed us to characterize mochi cake. Each of them only, however, was insufficient for the characterization.

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The apparent viscosity development after onset of steady shear flow was measured at 90°C for the various samples of mochi cake prepared by a kneading or a stamping method. The typical mochi cake samples showed clear stress overshoot phenomena. The results agreed well with those in a sensory test. This indicates the present nonlinear viscoelastometry is very effective for characterization of mochi cake.

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The effects of ethanol feeding on the tryptophan-niacin metabolism were investigated in rats. Male rats of the Wistar strain (3 weeks old) were fed with a 20% casein diet and 15% ethanol ad libitum for 56 days. Urine samples were collected every week during the experimental period. Urinary excretion of N¹-methylnicotinamide (MNA) was always higher in the ethanol-fed group than in the control group, but urinary excretion of its oxidized metabolites N¹-methyl-2-pyridone-5-carboxamide (2-Py) and N¹-methyl-4-pyridone-3-carboxamide (4-Py) was always lower. Therefore, the ratio of (2-Py+4-Py)/MNA excretion was lower in the ethanol-fed group than in the control group. The rats were killed on day 57 and liver enzyme activities involved in the tryptophan-niacin metabolism were also measured. Tryptophan oxygenase, kynureninase, nicotinamide mononucleotide adenylyltransferase, NAD⁺ synthetase, and nicotinamide methyltransferase activities were similar in both groups, but, 2-Py-forming MNA oxidase and 4-Py-forming MNA oxidase activities in the ethanol-fed group were 43% and 18% of the control, respectively. Therefore, the increase in MNA excretion and the decrease in the ratio of (2-Py+4-Py)/MNA excretion might be attributed to the inhibition of the two MNA oxidase activities by ethanol feeding. Furthermore, it happened to be found that this excretion ratio also increased with growth up to nine weeks and this change was attributed to the increased reaction MNA→4-Py with growth.

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The toxicity of dimethyl sulfoxide (Me₂SO) was examined in HeLa cells cultured at 37°C for up to 72 hr. The growth of the cells was measured by a colorimetric method with the use of 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT), which gave good correlation between the cell number and the color development from the reduction of MTT under suitable conditions. When the initial number of cells was 3 × 10⁴/ml, Me₂SO at 1% or less had no apparent effect on prolifiration for up to 48 hr of incubation, but in longer incubations, cell growth was repressed. When the initial number of cells was 3 × 10⁵/ml, the effect of Me₂SO was similar.

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The complete amino acid sequence of luffin-a has been determined. Twenty-two peptides were isolated from the tryptic digest of luffin-a and sequenced employing the DABITC/PITC double coupling method. Overlaping of these peptides was achieved by analyzing the chymotryptic peptides or CNBr-fragments of luffin-a and their S. aureus V8 protease peptides. Luffin-a consists of 248 amino acid residues and its relative molecular mass is calculated to be 27, 021 Da, excluding the attached sugar chains reasoned to be present at each Asn residue of positions 28, 33, 77, 84, 206, and 227. A comparison with the sequence of ricin A-chain showed 33% sequence identity indicating that these proteins are homologous.

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Uracil auxotrophic mutants were constructed from the sake yeasts K-701 and K-901 by successive URA3 gene disruption. First, as sake yeast is diploid, one URA3 gene was disrupted with pURA38 (ΔURA3 SMR1) and the heterozygous disruptant was isolated on an SM (sulfometuron methyl) plate. The other URA3 gene was disrupted with pURA36 (ΔURA3) and homozygous URA3 disruptants were isolated on FOA (5-fluoro-orotic acid) plate on which only URA3 mutants can grow. Direct URA3 gene disruption with pURA36 (ΔURA3) was also done and the uracil auxotrophic mutant was isolated. Four types of URA3 disruptants were isolated, two of which had no bacterial DNA.
A tryptophan auxotrophic mutant was constructed from one of the URA3 disruptant using pTRP14 (ΔTRP1 URA3) by gene disruption. This TRP1 disruptant was also lacking bacterial DNA.
Laboratory scale sake brewing using the auxotrophic mutants showed that these strains are very useful as recipient strains for molecular breeding of sake yeasts.

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An enantioselective Michael addition of thiophenols to 2-cyclohexen-1-one was performed with catalysts of γ-amino alcohols that were synthesized from D-glucose. A linear relationship between the optical yield of this Michael addition and the specific rotation of the γ-amino alcohol catalysts was clearly observed.

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δ-Tocopherol was reacted with an alkylperoxyl radical at 37°C in benzene. 2, 2'-Azobis(2, 4-dimethylvaleronitrile) was used to generate the alkylperoxyl radical. The reaction products of δ-tocopherol were isolated and characterized. There were δ-tocored, four stereoisomers of 8a(1-cyano-l, 3-dimethyl)butylperoxy-δ-tocopherone, a mixture of four stereoisomers of 8a-(1-cyano1, 3-dimethyl)butylperoxy-5-(δ-tocopheroxy)-δ-tocopherone, 5-(δ-tocopheroxy)-δ-tocopherol, a mixture of four stereoisomers of 8a-(1-cyano-l, 3-dimethyl)butylperoxy-5-[(5-(δ-tocopheroxy)-δ-tocopheroxy]-δ-tocopherone, and 5-[(5-(δ-tocopheroxy)-δ-tocopheroxy]-δ-tocopherol. From the reaction products of δ-tocopherol and its dimer, a possible mechanism for the reaction of δ-tocopherol with peroxyl radicals was discussed.

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