A series of hexadeoxyribonucleotides (6-mers), d(TGGGAG), substituted with a variety of aromatic groups at the 5'-end were synthesized and tested for anti-human immunodeficiency virus type 1 (HIV-1) activity. While unmodified d(TGGGAG) (31) had no anti-HIV-1 activity, compound 23 with a 3,4-di(benzyloxy)benzyl (DBB) group at the 5'-end potently inhibited the HIV-1IIIB-induced cytopathicity of MT-4 cells in vitro (IC50 = 0.37 microM) without cytotoxicity up to 40 microM. A thermal denaturation study on the 5'-end-substituted 6-mers by means of the circular dichroism (CD) spectra demonstrated that the aromatic substituent attached at the 5'-end of the 6-mer strongly enhanced the formation of a parallel helical structure consisting of four strands (quadruplex). On the contrary, compound 36, in which one of the guanosines of 23 was replaced by a thymidine, did not form a quadruplex, thus exhibiting no anti-HIV-1 activity. Moreover, both compound 15, with a tert-butyldiphenylsilyl group solely at its 3'-end, and compound 21, with a relatively small substituent, a benzyl group, at the 5'-end, formed quadruplexes but had no anti-HIV-1 activity. These findings led us to the conclusion that both the quadruplex structure and the aromatic substituent with adequate size at the 5'-end are crucial for the interaction of the 5'-end-substituted 6-mers with the V3 loop as well as the CD4 binding site on viral gp120, resulting in anti-HIV-1 activity.

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We clarified that photo-irradiation of young green barley from three different light sources, natural light, 100% red light-emitting diodes (R-LEDs), and a mixture of 90% red-LEDs + 10% blue-LEDs (RB-LEDs), had significantly different results in growth degree (weight and height) and in components of young green barley. Barley that has sprouted for 15 days after germination did not show any apparent difference in height in response to irradiation by the three tested light sources, but by the 20 th day of sprouting the height showed a positive effect by R-LEDs irradiation. By 15 days of sprouting the barley had achieved the heaviest weight by natural light irradiation, while the barley irradiated by R-LEDs had made remarkable progress at 20 days of sprouting. On the other hand, the irradiation by RB-LEDs showed a suppressive tendency after 15 days or more. The amino acid content, as indicated by dry weight conversion, was greatest in the barley irradiated by RB-LEDs, followed by R-LEDs, and natural light, which showed that LEDs irradiation is effective. In addition, four cyanogenic glucosides were isolated, identified, and quantified, as they are components frequently assessed in barley research. With regard to vitamin E, R-LEDs irradiation increased γ-tocopherol. Our results indicate that irradiation by LEDs would be effective for the enhancement of the functionality of young green barley.

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We investigated the mechanical nature of multiply hydrogen-bonded systems by means of ab initio quantum chemical calculations, and we derived a set of force constants to reproduce the anisotropic vibration modes of such systems. Twenty multiply hydrogen-bonded molecular dimers were selected for evaluation of the stiffness of their hydrogen bonds. By means of a multivariate analysis, the principal values of the stiffness tensor were divided into the contributions from each hydrogen bond. Force constants in the stretching directions were estimated to be 20.2 and 11.5 N m(-1) for NH...O and NH...N pairs, respectively. The obtained parameter set was used to reconstruct the various intermolecular vibration motions, and reasonable values in the low-frequency (ca. terahertz) region were obtained. Comparison of the multivariate analysis with the normal-mode analysis suggested that the off-diagonal terms for the transverse and rotational motions may appreciably contribute to the coupling of those basic motions.

Treading barley ("Mugifumi" in Japanese) is a barley culturing process that is unique and indispensable in Japan. Generally, roller machines or human feet are used to tread young barley several times (Figure 1). As a model examination, a stainless steel instrument was used for treading barley in this study (Figure 2(a)). Treading damages plants and decreases growth, such as the height and weight of aerial parts, which then recover gradually. In our study, the total amino acid contents increased with the treading stress. The treading stress induced a 1.7-fold increase in aspartic acid contents and an approximately 1.6-fold increase in glutamic acid, proline, cystine, and methionine contents. Isolation and purification suggested that the main components of the methanol-eluted fraction from the young green barley were six known phenolic compounds. Saponarin and lutonarin were the main components. The saponarin content was about 160 mg/g (methanol-soluble fraction) at 10 days after germination. We found that the higher antioxidant activity was due to the increased lutonarin/saponarin ratio from 10% to 24%. Therefore, our results suggest that treading stress is useful for young green barley.

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