Effect of Hemicellulose on the Wet Tensile Strength of Kozo Paper.

Kozo paper, usu-mino-gami, is frequently used as the first back lining paper of hanging scrolls in order to support the main paper with a painting or a work of calligraphy on it. To dye it an appropriate color, paper is often treated with an alkali mordant solution. However, current kozo paper products have received such comments from conservators that wet tensile strength is weak and hard to handle. Therefore, improving the wet tensile strength of kozo paper is required. In previous papers, the effect of the sheet forming method, cooking condition, and parenchyma cell content between fibers on the wet tensile strength of kozo paper has been investigated. In this paper, the effect of glucuronoxylan, the main component of hardwood hemicellulose on the wet tensile strength of kozo paper was investigated. The wet tensile strength of kozo paper, when made in different cooking conditions, was evaluated using the Finch device. Glucuronoxylan content in fiber was analyzed using GC-FID. According to the results, it has been proved that glucuronoxylan content (with a xylan to glucan molar ratio of 4.43% to 5.16%) itself contributes to the wet tensile strength of the kozo sheet. Therefore, to increase the wet tensile strength of kozo paper, it is recommended to cook under milder conditions, thus retaining a higher amount of glucuronoxylan in the pulp.

Age-specific values of Access anti-Müllerian hormone immunoassay carried out on Japanese patients with infertility: a retrospective large-scale study.

BACKGROUND: The ovarian reserve in women is known to correlate with anti-Müllerian hormone (AMH) levels, and currently the latest, third-generation, fully-automated AMH immunoassays, such as Access and Cobas, are beginning to be used for measuring AMH levels. However, the age-specific reference values obtained for AMH levels have been based on samples from an American population, measured using first-generation immunoassays. In this study, we attempted to determine the age-specific AMH reference values based on a large set of samples taken from Japanese infertile women measured by Access so that they could be used by infertility centers treating Japanese and those with similar racial and life-style characteristics. METHODS: The study included 5483 Japanese patients who enrolled in infertility treatment programs at two in-vitro fertilization centers, Shimbashi YUME Clinic and Natural ART Clinic Nihombashi in Tokyo, and who had their serum AMH levels measured between December 2015 and November 2017 by Access. Each patient was represented only once in the study. The mean, median, and standard deviation values were obtained from the measured values for single-year intervals from 28 through 48 years of age (21 age groups in total). The 3D-fitted curve of age-specific mean and median values measured by Access was obtained by regression analysis. RESULTS: The mean and median values decreased with advancing age (mean: R2 = 0.9864; median: R2 = 0.9926). In all age groups, the mean values were higher than the median values; however, the differences between these values decreased with increasing age. CONCLUSIONS: The age-specific AMH reference values measured by Access in this study may serve as a useful diagnostic marker in infertility centers, especially those treating Japanese patients or patients with similar characteristics.

Enantioselective synthesis of 2-methyl-1,2-syn- and 2-methyl-1,2-anti-3-butenediols via allene hydroboration-aldehyde allylboration reaction sequences.

The hydroboration of allene 7 with ((d)Ipc)(2)BH at 0 degrees C provides the kinetic allylborane 12Z with >20:1 selectivity. However, when the hydroboration is performed at 85 degrees C, the kinetically formed allylborane isomerizes to give the thermodynamic allylborane 12E with >or=12:1 selectivity. Subsequent treatment of 12Z or 12E with aldehydes at -78 degrees C, followed by oxidative workup, provides the 2-methyl-1,2-diols 8 and 9 in good yield and with 80-92% e.e.

Studies on the synthesis of apoptolidin A. 1. Synthesis of the C(1)-C(11) fragment.

A synthesis of the C(1)-C(11) fragment of apoptolidin A has been accomplished by a convergent route involving the stereoselective glycosidation of 9 and the Suzuki cross-coupling reaction of bromodienoate 7 and the vinylborane generated via chemoselective hydroboration of diyne 6 with diisopinocampheylborane.

Studies on the synthesis of apoptolidin A. 2. Synthesis of the disaccharide unit.

Disaccharide 3 correspoinding to the disaccharide unit of apoptolidin A has been synthesized via the regio- and stereoselective TBS-OTf-promoted beta-glycosidation reaction of 2,6-dideoxy-2-iodo-beta-glucopyranosyl acetate (5) and p-methoxybenzyl 2,6-dideoxy-2-iodo-3-C-methyl-alpha-mannopyranoside (11).

Stereostructure of luminamicin, an anaerobic antibiotic, via molecular dynamics, NMR spectroscopy, and the modified Mosher method.

The absolute stereostructure of luminamicin, an anaerobic antibiotic, has been determined by using conformational analysis via high-temperature molecular dynamics, NMR spectroscopy, and the modified Mosher method. It was found that luminamicin has the S, S, R, R, R, R, S, S, S, R, and S configurations at C2, C4, C7, C9, C10, C11, C12, C13, C16, C28, and C29, respectively. This configuration is the same as that found in nodusmicin, which has a chemical structure quite similar to luminamicin. The structure of luminamicin consists of three different rings, i.e., a decalin ring, a 10-membered macrolactone ring, and a 14-membered macrolactone ring. The resulting three-dimensional structure of luminamicin shows an interesting feature in that the maleic anhydride functionality in conjugation with the enol ether group of the 14-membered macrolactone is nearly perpendicular to the plane of the other two rings.

The first total synthesis of (+/-)-arisugacin A, a potent, orally bioavailable inhibitor of acetylcholinesterase.

The first convergent total synthesis of (+/-)-arisugacin A was accomplished by stereoselective construction of the arisugacin skeleton via a Knoevenagel-type reaction of an alpha,beta-unsaturated aldehyde with a 4-hydroxy 2-pyrone and stereoselective dihydroxylation followed by deoxygenation.