Identification of the monobrominated derivative of Acid Red 52 (Food Red No. 106) in pickled vegetables.

Two unknown dyes (purple and purplish-red) were detected by TLC in two pickled vegetable (sakura-zuke daikon) samples containing Acid Red 52 (AR) and New Coccine as food colorants. HPLC with diode-array detection and LC/MS analyses suggested that the purple dye is monobrominated AR and the purplish-red dye is its N-desethyl derivative, which would be generated mainly during sample preparation. For the identification of the purple dye, a reference compound was prepared by bromination of AR followed by isolation of the monobrominated AR, the structure of which was elucidated as 4'-brominated AR (4'BrAR) by LC/ToF-MS and (1)H-NMR spectroscopy. The purple dye was confirmed as 4'BrAR by comparison of its retention time, ultraviolet-visible spectrum and mass spectrum with those of the prepared reference compound. To our knowledge, this is the first report of the detection of 4'BrAR in foods.

Identification of indicator components for the discrimination of Cassia plants in health teas and development of analytical method for the components.

Components that could be used as indicators for the discrimination of senna (Cassia angustifolia) from other cassia plants contained in health teas were identified, and an analytical method for the components was developed. Our results revealed two components in senna that were not found in other Cassia spp. widely used in health teas, such as C. alata, C. corymbosa, C. obtusifolia, and C. occidentalis. Structural elucidation of the two components showed that they were isorhamnetin-3-O-gentiobioside and tinnevellin glucoside. We analyzed commercial health teas using the HPLC method developed in this study. The two indicator components were detected at 366 nm using an RP C18 column and gradient elution with a mixture of water and acetonitrile (with formic acid), as the mobile phase. Our analytical method by HPLC enabled the differentiation of senna from other Cassia plants present in health teas in which sennosides A and B were detected. Moreover, this method allowed us to predict the parts of senna in health teas from the amounts of isorhamnetin-3-O-gentiobioside and tinnevellin glucoside contained in the teas.

[Analysis of the chemical drugs among structural isomer].

Drugs that have a pharmacological effect similar to legal drugs such as narcotics and stimulants are available in the market and widely used. 5-methoxy-N,N-di-iso-propyl-tryptamine (5MeO-DIPT) and alpha-methyl-tryptamine (AMT) were categorized as narcotics and were specified as legal drugs in April 2005, and also 2,5-dimethoxy-4-n-propylthiophenethylamine (4C-T-7) and N-methyl-alpha-ethyl-3,4-methylenedioxy-phenethylamine (MBDB) were categorized as narcotics and were specified as legal drugs in April 2006, in Japan. We are analyzing these chemical drugs by investigating the market research. It is recognized that during the analysis of chemical drugs, drugs that resemble a structural isomer of a target substance, such as 5MeO-DIPT and 5-methoxy-N,N-di-n-propyl-tryptamine (5MeO-DPT) or 4C-T-7 and 2,5-dimethoxy-4-iso-propylthiophenethylamine (4C-T-4), should be distinguished. The results of TLC, IR, GC-MS and HPLC analyses were compared. 5MeO-DIPT and 5MeO-DPT could be distinguished by TLC and HPLC analyses, but not by IR and GC-MS analysis. The drugs 4-hydroxy-N-methyl-N-iso-propyl-tryptamine (4HO-MIPT) and 4-hydroxy-N,N-di-ethyl-tryptamine (4HO-DET) or could not be distinguished. Moreover, the isomers of 4-hydroxy-N-methyl-N-n-propyl-tryptamine (4HO-MPT) was not found to be present. Thus, we have demonstrated that the chemical drug could be distinguished from each other, and we have also shown that NMR data is essential for the analysis.

Hydrophobic scale: a second parameter to elucidating various specific ligand-protein interactions.

In the sequence Fourier analysis (SFA) of specific interactions such as those between fibroblast growth factors (FGFs)/FGF receptors (FGFRs), bone morphogenetic proteins (BMPs)/BMP receptors (BMPRs), or tumor repressor protein p53/mouse double minute 2 homolog (MDM2), the characteristic frequency peak(s) could be observed with the hydrophobic scale for 20 amino acids as well as 4 nucleotides as the physicochemical parameter, but not successfully with the absolute electronegativity scale. This result implies that these two independent scales should be appropriately selected in various specific ligand-protein interactions, though the critical difference has to be determined.

Genetic diversity and structure of urban populations of Pieris butterflies assessed using amplified fragment length polymorphism.

Conservation programs in urban ecosystems need to determine the genetic background in populations of urban dwellers. We examined the genetic diversity and structure of Pieris rapae and P. melete using AFLP markers, and compared them between species and between urban and rural environments. As a result: (i). in both species, there was no reduction in genetic diversity within urban populations by direct comparison of diversity measurements, although the analysis of molecular variance suggested significant reductions in the variance within seasonal subpopulations in urban populations; (ii). P. rapae retained greater genetic diversity within species and populations; (iii). populations of both species showed significant genetic differentiation, and P. melete was more strongly subdivided; (iv). in both species, geographically close populations did not cluster with one another in the upgma analysis; (v). there was no genetic isolation due to geographical distance in either species; (vi). the genetic composition of seasonal subpopulations differed in urban populations of both species, and the genetic distances among subpopulations were correlated with seasonal differences in P. rapae and with temporal differences in P. melete. These results indicate that the genetic diversity in urban populations of both species was reduced at times, but was maintained by dispersal from genetically differentiated populations. Differences in the ability and mode of dispersal in the two species may be reflected in the degree of population subdivision and patterns of seasonal change in the genetic composition.

A new application of sequence Fourier analysis to specific ligand-protein interactions.

A frequency (or sequence)-dependent rule seems to be conserved in a simple and concerted interaction of various human proteins.

Analysis of the peptides (Prp106-126, MSI-78A, and Oxaldie 1) with the same biological activity by discrete Fourier transform: toward a selection rule in ligand-receptor interaction.

Here, we first report a novel method in which the "desired cross-spectrum" of the peptides Prp106-126, MSI-78A, and oxaldie 1 with the same biological activities is obtained by the multiplication of two cross-spectra derived from the RNA sequence and from the cognate amino acid sequence by discrete Fourier transform (DFT), respectively. Based on a well-known method reported previously, we investigated the cross-spectrum by the multiplication of two of three desired cross-spectra. As a result, we found that one prominent peak occurring in the three cross-spectra showed the same frequency when a binary scale was used as a parameter of nucleotide or amino acid in the analysis. Moreover, we examined the relationship between a binary scale and other physicochemical ones. Almost the same results could be reproduced when the absolute electronegativity scale (or the absolute hardness one) was used, but not in the case of the hydrophobic or electron-ion interacting potential scale reported previously. This indicates that either the absolute electronegativity scale (or the absolute hardness one) or a binary scale, or both is very useful in extracting the information desired for various proteins by the present method from the amino acid and the RNA sequence.