Application of Axial-haloketone Rule to Lactones

Antifungal activities were examined and compared for some 40 kinds of aliphatic and aromatic aldehydes, alcohols, phenolic compounds, ether compounds and hydrocarbons from essential oils and for some related compounds, using seven fungi.     

Micro-analysis of Amino Acids with Fluorescein-isothiocyanate

The separation and identification of fluorescein-thiocarbarnyl (FTC-) amino acid II were accomplished by one- and two-dimensional thin-layer chromatography. The authentic samples for identification of amino acids were synthesized with fluorescein-isothiocyanate II (FITC II) and 21 amino acids. These FTC-amino acids were studied spectrometrically.

For quantitative estimation of FTC-amino acids, the fluoroscopy was used. It was found that the fluorescence intensity was proportional to the concentration of FTC-amino acids in 2 pmole/ml to 20 nmole/ml range. Recovery of FTC-derivatives on silica gel plate was about 80%.     

Application of N-(9-Acridinyl)maleimide as a Fluorescent Detection Reagent of Cysteine and Related Thiols and Disulfide Compounds on Thin-layer Chromatogram

Fluctuations of pungent principles of hot pepper fruits (capsaicinoid), chlorophylls, carotenoid, and fresh fruit weight in Capsicum annuum var. annuum cv. Karayatsubusa at different growth stages after flowering were examined. Capsaicinoid was first detected 20 days after flowering, and reached maximal level around 40 days after flowering, then later decreased gradually. The capsaicinoid composition did not show any appreciable change throughout the stages after flowering. CAP and DC were the major components in all of the stages examined. By using radioisotopic technique, it was found that the main formation and accumulation sites of capsaicinoid are in the placenta of the fruits.     

The Mass Spectra of Thiohydantoins Derived from Some Amino Acids

One of the bound forms of vitamin B₆ occurring in rice bran was isolated in a faintly yellowish syrup by repeating ion-exchange and paper-partition chromatographic techniques. The behaviors of the isolate on thin-layer and Aminex A–5 column chromatograms were coincident with those of synthetic pyridoxine-β-d-glucoside which was obtained by Königs-Knorr condensation of α⁴,3-O-isopropylidene pyridoxine and 2,3,4,6-tetra-O-acetyl-α-d-glucopyranosyl bromide. On acid hydrolysis, the isolate gave pyridoxine and glucose. Glucose was proved to bind to the 5-hydroxymethyl group of pyridoxine, because the isolate did not react with 2,6-dichloroquinone chlorimide in the presence of boric acid. An equimolar amount of pyridoxine and d-glucose was produced with an equivalent consumption of the isolate by the action of β-glucosidase. No essential difference between the isolated and synthetic preparations could be detected in UV- and NMR-spectral features. Thus, the chemical structure of the isolate was identified as 5′-O-(β-d-glucopyranosyl) pyridoxine.     

Determination of Anomeric Configuration of Furanoside Derivatives by Carbon-13 NMR

A 24 kDa protein was isolated from tartary buckwheat seeds by using chromatography of Superdex 75 gel filtration and Resource Q ion-exchange column. SDS-PAGE and Sephacryl S-200 gel filtration were used to provide information about the molecular mass of the protein purified from tartary buckwheat. The protein was composed of 215 amino acid residues and showed strong IgE binding activity in an ELISA test to the sera colleted from two patients allergic to buckwheat. These results suggested that the purified 24 kDa protein from tartary buckwheat seeds was an important functional protein and was relatively specific for buckwheat-allergic patients. It should be a very useful tool in the diagnosis of buckwheat allergy in the future.     

Optical Rotatory Dispersion of Amino Acid Methylthiohydantoin

In order to clarify the postprandial glucose suppression via α-glucosidase (AGH) inhibitory action by natural compounds, flavonoids were examined in this study. Among the flavonoids (luteolin, kaempferol, chrysin, and galangin), luteolin showed the potent maltase inhibitory activity with the IC₅₀ of 2.3 mM, while less inhibitions were observed against sucrase. In addition, the effects of maltase inhibition by flavonoids were observed in the descending order of potency of luteolin>kaempferol>chrysin>galangin. Apparently, the AGH inhibition power greatly increased with the replacement of hydroxyl groups at 3′ and 4′-position of the B-ring. However, the inhibitory power of luteolin was poorer than a therapeutic drug (acarbose: IC₅₀; 430 nM). As a result of a single oral administration of maltose or sucrose (2 g/kg) in SD rats, no significant change in blood glucose level with the doses of 100 and 200 mg/kg of luteolin was observed. These findings strongly suggested that luteolin given at less than 200 mg/kg did not possess the ability to suppress the glucose production from carbohydrates through the inhibition of AGH action in the gut.     

Study on the Optical Rotatory Dispersion of Di-Peptides and its Application to the Recognition of Di-Peptides from Higher Peptides and Amino Acids

During the cource of the investigation of ribotidation of purine and pyrimidine bases by Brevibacterium ammoniagenes ATCC 6872, it was found that a large amount of uridine 5′-monophosphate (UMP) was accumulated in the culture broth when the organism was incubated in a medium containing uracil or orotic acid. The yields of UMP were 83% (4.8 mg/ml) from uracil and 100% (4.3 mg/ml) from orotic acid when each substrate was added at the concentration of 2 mg/ml.

Addition of 6-azauracil or 5-hydroxyuracil to the culture of the organism during cultivation led to the accumulation of both orotidine 5′-monophosphate (OMP) and UMP. The accumulation of OMP seemed to be due to the inhibition of OMP decarboxylase (E. C. 4.1.1.23) by the ribotide formed from each base. The OMP accumulation was enhanced by the addition of orotic acid in addition to 6-azauracil. When 6-azauracil was added to the medium before inoculation, UMP was predominantly accumulated, and when it was added after one day incubation, OMP was predominantly accumulated. A largest accumulation (3.6 mg/ml) of OMP was obtained when 6-azauracil was added on the 1st day and orotic acid was added on the 3rd day.

UMP and OMP accumulated in the medium were isolated from the cultured broth and identified by usual methods.     

A Comparative Study on the Analysis of Herbicide “Bromacil” Using ECD-gas Chromatography and Mass Fragmentography

Analysis methods of a herbicide “bromacil” were studied comparatively in soil and mandarin orange fruit. Bromacil content in tissue of mouse was also measured. Measurement was performed by gas chromatography with electron capture detector (ECD). Mass fragmentography was also studied, which was found to be useful for the residue analysis of this herbicide.     

Plant Growth Promoting Metabolites of Sclerotinia sclerotiorum

In the research on the plant growth regulators produced by phytopathogenic fungi, two active metabolites, sclerotinin A and B, in addition to sclerin have been isolated from the culture filtrate of S. sclerotiorum. Sclerotinin A and B have been shown to be 3,6,8-tri-hydroxy-3,4,5,7-tetramethyl-3,4-dihydroisocoumarin and 3,6,8-trihydroxy-3,5,7-trimethyl-3,4- dihydroisocoumarin, respectively.