The breakage activities of aromatic reductones, such as catecholamines, on homopolyribo-nucleotides were investigated by gel electrophoretic methods. A comparison of poly C breakage activities of aromatic reductones in the presence of Cu²⁺ revealed that epinephrine had the strongest effect, followed by the order, dopamine, norepinephrine, pyrocatechol and dopa. Adrenochrome had no breakage activity. The pattern of molecular distribution of homopolyribonucleotide fragments produced by treatment with the aromatic reductone-Cu²⁺ mixture suggested that the cleavage of homopolyribonucleotide strands by aromatic reductones occurred at random.
The mean breakage number on poly C induced by the epinephrine-Cu²⁺ mixture increased with reaction time. The breakage reaction was remarkably enhanced depending on the concentration of epinephrine and Cu²⁺. In the absence of Cu²⁺ no detectable cleavage occurred. The cleavage reaction proceeded quickly at pH 7 but was weakened in both the acidic and alkaline pH regions. Among various kinds of metallic ions, Cu²⁺ exhibited an overwhelmingly strong effect on the catalysis of the breakage reaction.
Although Ni²⁺, Co²⁺, Mg²⁺ and Fe³⁺ also had weak effects, Fe²⁺ Mn²⁺, Zn²⁺ and Pb²⁺ had no detectable effects. All homopolyribonucleotides used were broken by the epinephrine-Cu²⁺ mixture but the sensibility to the breakage was weakened in the order of poly C, poly U, poly A and poly G, in accordance with the degree of epinephrine oxidation at later reaction periods.
The breakage of poly C by the epinephrine-Cu²⁺ mixture was suppressed by the co-existence of cytosin or adenine, suggesting that nucleic acid components can regulate the degree of nucleic acid scission by aromatic reductones through the regulation of the oxidation reaction of aromatic reductones in the presence of Cu²⁺.

View full abstract

Myosins from various vertebrate species were heat-denatured. The resulting aggregates were dissolved by boiling with 8 M urea-0.5% 2-mercaptoethanol and dialyzed against water. The dialyzate turned to a transparent gel. The gel melted on heating, but set to gel again on cooling. The gel was reproduced on rehydrating the once dehydrated gel. Heat-denaturation of the starting myosin did not affect the elasticity of the product. The solubilized gel showed the same electrophoretic pattern as that of intact myosin and showed two bands that were due to a myosin heavy chain and light chain in the elution pattern. The reduced viscosity of the solubilized gel increased, as the myosin concentration in the dialyzate increased.

View full abstract

Our previous work demonstrated that rat intestinal flora and several species of intestinal bacteria degraded aflatoxin B₁ (AF B₁). In the study here, a combination culture was prepared of Proteus mirabilis Y 2 plus Streptococcus sp. Y 5, in the presence of AF B₁, to clarify the relationship between microbial cell growth and degradation of the toxin. The extent of the degradation in late stationary phase was 31% at 48 hr and 54% at 72 hr.
Using the 72 hr culture of Escherichia coli Y 8 and flora C, the AF B₁-degrading activity was determined in the chloroform extract of the culture filtrate (Step I) and in the solution of the solid matter from the extract once dried up (Step II). Both in the presence and absence of AF B₁, the degradation in Step II was always higher than that in Step I. During stock of the flora, activity of the degradation of AF B₁ was weakened.
Fresh florae H and K, having highly degrading potency, was added to stocked flora C. The presence of the substance responsible for degradation in the bacterial cell and in the filtrate of the 72 hr culture was sought by measuring the AF B₁ just after mixing with chloroform extract (Process A) and after evaporation (Process B). For comparison, the culture of E. coli Y 8 was processed in the same way. Degradation of AF B₁ by the cell extract was low in both Process A and B with a maximum of 12.6% (flora H) and a minimum of 3.0% (E. coli Y 8), whereas degradation of AF B₁ by the extract of the culture filtrate was high in flora H and K with about 50% in Process A and more than 90% in Process B.
These results may indicate that the substance responsible for AF B₁ degradation is present in the culture filtrate of the intestinal flora, and its function is intensified in the evaporating process.

View full abstract

Three trithiolanes, one dithiin, one thiazole and three thialdines were identified by gas chromatography with FPD in the two tested species. These compounds were found in precooked E. superba, but their compositions differed quantitatively in the cooked samples. S. lucens had much less heterocyclic compounds with ethyl substituent than E. superba. This tendency was most remarkable among thialdine derivatives. Ethyl thialdines are formed by condensation of ammonia, hydrogen sulfide and aldehydes containing propanal. Propanal was scarcely found in S. lucens by TLC, and this explains the difference in the amounts of ethyl substituted sulfur compounds between E. superba and S. lucens and seemed to characterize their respective cooked odor.

View full abstract

1 D-5-O-(α-D-Galactopyranosyl)-4-O-methyl-myo-inositol and 4-O-methyl-myo-inositol were found in seeds of four leguminous species of three genera [Cassia obtusifolia L., Vigna angularis Ohwi et Ohashi, Vigna unguiculata Walp. and Lablab purpureus Sweet] out of ca. 60 examined species from 20 families. However, these low-molecular weight carbohydrates were not detected in two other species from the above genera [Cassia mimosoides L. subsp. nomame Ohashi and Vigna mungo Hepper]. These inositol derivatives were also not found in two species of Phaseolus, which is regarded as being more closely related to Vigna than Lablab.

View full abstract

Volatile isothiocyanates obtained from the edible parts of four varieties of cruciferous vegetables introduced from China were investigated by GC and GC-MS analyses. The relative amounts of volatile isothiocyanates were compared with amounts obtained by similar procedures from edible parts of three Japanese cruciferous vegetables.
In three Chinese crucifers, namely, Saishin (Brassica campestris L. var. parachinensis), Pakchoi (B. campestris L. var. chinensis), and Kotaisai (B. campestris L. var. campestris), a relatively high concentration of 4-pentenyl isothiocyanate was found, whereas two Japanese varieties, Chisuzikyo-mizuna and Mibuna (both B. campestris L. var. Japonica) had relatively large amounts of 3-butenyl isothiocyanate. Kairan (B. oleracea L. var. albaglabra), a variety of Chinese kale, had relatively high concentrations of 3-butenyl and allyl isothio-cyanates. Yukizirotaina, a Japanese cruciferous vegetable which is considered to come of the Pakchoi strain, contained relatively large amounts of 3-butenyl and 4-pentenyl isothiocyanates. 2-Phene-thyl cyanide was also identified in all volatile samples examined. 3-Butenyl and 4-pentenyl cyanides were not separated by the GC and GC-MS procedures used in the present study.

View full abstract