Stereochemistry of cis- and trans-hinokiresinol and their estrogen-like activity

Naturally occurring phenylpropanoids, hinokiresinol (trans-hinokiresinol) and nyasol (cis-hinokiresinol) were found to possess appreciable estrogen receptor binding activity. Strong differences in activity were observed between the geometrical isomers and enantiomers. Among these, (3S)-cis-hinokiresinol displayed the highest activity, one order of magnitude greater than the activity of genistein. Furthermore, cis- and trans-hinokiresinol stimulated the proliferation of estrogen-dependent T47D breast cancer cells, and their stimulatory effects were blocked by an estrogen antagonist, indicating that the compounds are estrogen agonists. In addition, the absolute configuration of C-3 in (+)-cis-hinokiresinol has been assigned as S by comparison with the circular dichroism spectra of the hydrogenated products prepared from cis and trans ((3S)-trans-hinokiresinol: previously assigned) isomers. These results incidentally provide us with an unambiguous answer to contradictory reports regarding the assignment of the full stereochemisry of cis- and trans-hinokiresinol that have existed in the literature for more than two decades.     

Mannich-type reaction with trifluoromethylated N,O-hemiacetal: facile preparation of beta-amino-beta-trifluoromethyl carbonyl compounds

On treatment of silyl enolates and an N,O-hemiacetal, derived from trifluoroacetaldehyde ethyl hemiacetal and p-anisidine, with GaCl(3) (0.2 equiv) and C(6)H(5)COCl (0.2 equiv) in propionitrile, Mannich-type reaction took place smoothly to afford beta-amino-beta-trifluoromethyl carbonyl compounds in high yields.     

Esterification of Tertiary Amides: Remarkable Additive Effects of Potassium Alkoxides for Generating Hetero Manganese–Potassium Dinuclear Active Species

A catalyst system of mononuclear manganese precursor 3 combined with potassium alkoxide served as a superior catalyst compared with our previously reported manganese homodinuclear catalyst 2 a for esterification of not only tertiary aryl amides, but also tertiary aliphatic amides. On the basis of stoichiometric reactions of 3 and potassium alkoxide salt, kinetic studies, and density functional theory (DFT) calculations, we clarified a plausible reaction mechanism in which in situ generated manganese–potassium heterodinuclear species cooperatively activates the carbonyl moiety of the amide and the OH moiety of the alcohols. We also revealed details of the reaction mechanism of our previous manganese homodinuclear system 2 a , and we found that the activation free energy (ΔG^≠) for the manganese–potassium heterodinuclear complex catalyzed esterification of amides is lower than that for the manganese homodinuclear system, which was consistent with the experimental results. We further applied our catalyst system to deprotect the acetyl moiety of primary and secondary amines.     

Similar dissection of sets

In 1994, Martin Gardner stated a set of questions concerning the dissection of a square or an equilateral triangle in three similar parts. Meanwhile, Gardner’s questions have been generalized and some of them are already solved. In the present paper, we solve more of his questions and treat them in a much more general context. Let \({D\subset \mathbb{R}^d}\) be a given set and let f ₁, . . . , f _k be injective continuous mappings. Does there exist a set X such that \({D = X \cup f_1(X) \cup \cdots \cup f_k(X)}\) is satisfied with a non-overlapping union? We will prove that such a set X exists for certain choices of D and {f ₁, . . . , f _k }. The solutions X will often turn out to be attractors of iterated function systems with condensation in the sense of Barnsley. Coming back to Gardner’s setting, we use our theory to prove that an equilateral triangle can be dissected in three similar copies whose areas have ratio 1 : 1 : a for \({a \ge (3+\sqrt{5})/2}\).     

Effects of the Thermal Environment on Articular Chondrocyte Metabolism: A Fundamental Study to Facilitate Establishment of an Effective Thermotherapy for Osteoarthritis

Aim: To facilitate establishment of an effective thermotherapy for osteoarthritis (OA), we investigated the effects of the thermal environment on articular chondrocyte metabolism in vitro. Methods: Chondrocytes were isolated from porcine knee joints, and cultured at 32°C, 37°C and 41°C. Cell proliferation and viability were assessed at Days 2, 4 and 8. In addition, TdT-mediated dUTP nick end labeling (TUNEL) assay was performed at Day 3 to determine the proportion of apoptotic chondrocytes. Analysis of genes specific for factors related to the cartilage extracellular matrix (ECM), cartilage destruction, and cartilage protection was performed at Day 2. Furthermore, evaluation of heat stress tolerance, and heat shock protein 70 (HSP70) mRNA expression and protein synthesis was performed at Day 2 and 3, respectively. Results: Cell proliferation was more at 37°C than at 32°C and 41°C. Cell viability and the number of TUNEL-positive cells were not affected until Day 8 and 3, respectively. The expression of the ECM-related genes was up-regulated at higher temperature. The expression of MMP13, a type II collagen destructive enzyme, and that of TIMP1 and TIMP2, which are MMP inhibitors, were up-regulated at higher temperatures. Finally, the chondrocytes cultured at 41°C may acquire heat stress tolerance, in part, due to the up-regulation of HSP70, and may inhibit apoptosis induced by various stresses, which is observed in OA. Conclusions: The thermal environment affects articular chondrocyte metabolism, and a heat stimulus of approximately 41°C could enhance chondrocyte anabolism and induce heat stress tolerance.     

Electrical orientation behaviour of a nematic liquid crystal with negative dielectric anisotropy above the microelectrodes

Factors for the electrical orientation on interdigitated microelectrodes deposited on a substrate, a microdielectrometric sensor (or a sensor), were discussed experimentally using a model nematic liquid crystal with negative dielectric anisotropy. The electrical orientation behaviour of the nematic liquid crystal was investigated using microdielectrometry and polarised optical microscopy. The experimental results were discussed in relation to electric-field line, surface topology, anchoring of the liquid crystalline molecules to the microelectrodes, and transversal rotation of a rode-like molecule of the liquid crystal with negative dielectric anisotropy.     

Determination of particle-associated hydroxynitropyrenes with correction for chemical degradation on a quartz fibre filter during high volume air sampling

A correction method for the determination of atmospheric monohydroxylated derivatives of 1-nitropyrene (hydroxy-1-nitropyrenes, OHNPs) based on their degradation rates during high volume air sampling was established. OHNPs adsorbed directly on a quartz fibre filter (QFF) or on airborne particles collected on a QFF were exposed to ambient air passively or actively in a high volume air sampling system. The influence of ozone flux and exposure time on the degree of degradation of OHNPs was investigated. Up to 50% of OHNPs degraded over 1 h of exposure to ambient air containing ～60 ppbv of ozone in the active system. The degradation rate constants of OHNPs were found to correlate with the number of ozone molecules passing through the QFF in a unit time (N_O3) during high volume air sampling. The chemical loss of OHNPs under high volume air sampling conditions was successfully evaluated by the exposure time and the pseudo-first-order rate constant for OHNP degradation estimated from the correlation with N_O3. Concentrations of 3-, 6-, and 8-hydroxy-1-nitropyrenes in airborne particles collected in Osaka, Japan were determined using the established correction method.     

Mild Deprotection of Methyl,Benzyl, Methoxymethyl,Methylthiomethyl, Methoxyethoxymethyl,and β-(Trimethylsilyl)-ethoxymethyl Esters with AlCl3-N,N-dimethylaniline

Methyl, benzyl, methoxymethyl, methylthiomethyl, methoxyethoxymethyl, and β-(trimethylsilyl)ethoxymethyl esters could be cleaved readily under mild conditions on treatment with AlCl₃-N,N-dimethylaniline in CH₂Cl₂ to give parent carboxylic acids in high yields.     

Radial transport characteristics of fast ions due to energetic-particle modes inside the last closed-flux surface in the compact helical system

The internal behavior of fast ions interacting with magnetohydrodynamic bursts excited by energetic ions has been experimentally investigated in the compact helical system. The resonant convective oscillation of fast ions was identified inside the last closed-flux surface during an energetic-particle mode (EPM) burst. The phase difference between the fast-ion oscillation and the EPM, indicating the coupling strength between them, remains a certain value during the EPM burst and drives an anomalous transport of fast ions.     

Refractive index behavior in phosphate glass from the view point of B3+ and Al3+ coordination

Higher refractive index and higher Abbe value were obtained simultaneously at B₂O₃/Al₂O₃ = 1 in the system of 65P₂O₅–xAl₂O₃–(20 ? x)B₂O₃–10CaO–5Li₂O, although the refractive index generally shows a positive correlation with the dispersion. We investigated the molar volume and the molar refraction by Lorentz–Lorenz’s formula and also studied the coordination number of ¹¹B and ²⁷Al by MAS NMR. By the replacement of Al₂O₃ with B₂O₃, the molar refraction constantly decreased, but the molar volume was minimized at B₂O₃/Al₂O₃ = 1. The refractive index behavior of the glasses was mainly determined by the molar volume in the system. The coordination number of B³⁺ was only IV and it did not change if the composition was changed. On the other hand the coordinations IV, V and VI were observed for Al³⁺. The ratio of Al³⁺(VI) was maximized at B₂O₃/Al₂O₃ = 1. It is considered that the higher coordination of Al³⁺ brings the improvement of the packing and it leads to high refractive index.