Effects of a lysophosphatidylcholine and a phosphatidylcholine on the morphology of taurocholic acid-based mixed micelles as determined by small-angle X-ray scattering

We previously showed that Caco-2 cell absorption of β-carotene from taurocholic acid (TA)-based mixed micelles differed depending on the composition of the micelles. In this study, the shapes and sizes of TA-based mixed micelles, that is, mixed micelles of TA, 1-oleoyl-rac-glycerol (MG), oleic acid (OLA), and either 1-palmitoyl-sn-glycero-3-phosphocholine (MPPC; i.e., a lysophospholipid) or 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC; i.e., a phospholipid) (60:3:1:0.75–12) were determined by using small-angle X-ray scattering (SAXS). We found that increasing the ratio of MPPC in mixed micelles of TA, MG, OLA, and MPPC was responsible for the previously observed enhanced β-carotene absorption by Caco-2 cells and changed the micelle shape from core–shell spherical to core–shell ellipsoidal. In contrast, increasing the ratio of POPC in mixed micelles of TA, MG, OLA, and POPC was responsible for the suppressed β-carotene absorption by the cells, changed the micelle shape from core–shell spherical to core–shell ellipsoidal to core–shell cylindrical, and caused a rapid increase in micelle volume. These results will be useful for understanding the mechanisms that mediate β-carotene absorption by cells and for developing technologies to improve the intestinal absorption of lipophilic components of drugs and nutrients.     

Synthesis of epigallocatechin trimer, (epigallocatechin)2-epicatechin,and (epigallocatechin)2-catechin via a Lewis acid mediated one-pot condensation and their antitumor activities in prostate cancer cells

Syntheses of epigallocatechin trimer, (epigallocatechin)₂-epicatechin and (epigallocatechin)₂-catechin were achieved. The key condensation to form the proanthocyanidin trimer derivatives was accomplished in a one-pot procedure using a dimeric epigallocatechin electrophile, which was prepared in situ by self-condensation of an epigallocatechin derivative, and an epigallocatechin, epicatechin, or catechin derivative as the nucleophile in the presence of a Lewis acid. The epigallocatechin monomer to trimer compounds containing a pyrogallol group significantly suppressed cell proliferation in PC-3 prostate cancer cells.     

Formation and Characterization of Reversed Micelles Composed of Phospholipids and Fatty Acids

The formation of reversed micellar systems composed of phosphatidylcholine (PC) and fatty acid was newly demonstrated by a significant increase in water content in the organic ethyl oleate phase when the micelles were prepared by the contact method. The solubilized water concentration in the reversed micellar organic phase reached 3 wt%. The new systems are expected to be used as highly biocompatible reversed micellar systems. The structure of the reversed micelles composed of PC and oleic acid was characterized by determining the water concentration and by small-angle X-ray scattering analysis. The reversed micelles composed of PC and oleic acid formed in ethyl oleate were spherical. The radius of gyration was between 30 and 50 Å. The size of the reversed micelles decreased with an increase in the oleic acid concentration and was independent of the PC concentration. Experimental results indicated that the structure of the reversed micellar system was determined by the oleic acid concentration. An increase in the PC concentration caused an increase in the number of reversed micelles of the same size. These reversed micellar systems are expected to be used as solubilization media in pharmaceutical and food industries because they are not toxic.     

Efficient synthesis of (±)-8,14-cedranoxide using electrochemical method as a key step

(±)-8,14-Cedranoxide has been synthesized starting from 3,4-dimethoxyphenol, wherein 6-acetoxymethyl-2,6-dimethyl-9-methoxytricyclo[5.3.1.0^1,5]undec-9-en-8,11-dione as a key intermediate has been produced efficiently by means of electrochemical methods.     

Improved accuracy for Raman spectroscopic determination of polyethylene property by optimization of measurement temperature and elucidation of its origin by multiple perturbation two-dimensional correlation spectroscopy

A novel strategy is demonstrated to improve the accuracy for determination of polyethylene (PE) density using Raman spectroscopy by optimizing the temperature of sample measurement. Spectral features associated with the conformation change of the polymer induced by temperature may provide valuable information to quantify important polymer properties such as density. To evaluate possible existence of an optimal temperature providing improved quantitative accuracy, Raman spectra of PE pellets with different densities were collected at eight different temperatures from 30 to 100 °C at 10 °C intervals. Using the spectral datasets collected at each temperature, partial least squares (PLS) models were developed using the reference PE density values determined by a standard density gradient method at 23 °C. Interestingly, the most accurate determination of density was realized at 70 °C. Multiple perturbation two-dimensional (MP2D) correlation analysis and differential scanning calorimetry (DSC) were used to examine the origin of improved accuracy at 70 °C. From these analyses, the pre-melt behavior of the PE samples was identified below their melting temperatures. Structural variations induced at the pre-melt stages enhance Raman spectral selectivity among the samples, thereby providing more accurate determination of PE density. The MP2D correlation analysis revealed the unforeseen thermal behavior of PE samples and successfully explained the improved accuracy at 70 °C.     

Total synthesis of mycestericin A

The first total synthesis of mycestericin A (1) starting from tartrates is described. The Overman rearrangement of an allylic trichloroacetimidate generated a tetra-substituted carbon with nitrogen, and subsequent stereoselective transformations afforded the highly functionalized vinyl iodide. The cross-coupling of the vinyl iodide with a chiral organozinc species under Negishi conditions, followed by deprotection, completed the total synthesis of 1.     

Reactions of 1,2‐dihydro‐4H‐3,1‐benzothiazine‐2,4‐dithiones (trithioisatoic anhydrides) with N‐substituted benzylamines and trialkyl phosphites

Reactions of 1,2‐dihydro‐4H‐3,1‐benzothiazine‐2,4‐dithiones (trithioisatoic anhydrides) 3 with N‐substi‐tuted benzylamines 9 gave 1,2‐dihydroquinazoline‐4‐thiones 10 , o‐thioureidodithiobenzoic acid 11 , o‐aminothiobenzamides 12 , 2‐amino‐3,1‐benzothiazine‐4‐thiones 13 , or quinazoline‐2,4‐dithiones 14 , depending on the kinds of amine and the reaction solvent. On the other hand, reaction of 3 with trialkyl phosphites afforded dialkyl (1,2‐dihydro‐2‐thioxo‐4H‐3,1‐benzothiazin‐4‐yl)phosphonates 18 .     

New Layered Double Hydroxide, Zn–Ti LDH : Preparation and Intercalation Reactions

The layered double hydroxide (LDH) well known for its abilityto intercalate anionic compounds has been prepared conventionallyonly with bivalent and trivalent cations. In this study, Zn–Ti LDH consisting of bivalent and tetravalent cations was prepared, andreacted with organic monocarboxylic, dicarboxylic and aromatic acidsat high or room temperature. XRD patterns of the prepared LDH(Zn–Ti-CO₃) showed that interlayer spacing of the LDH was 0.67 nm. The value was small compared to the usual LDH (Zn–Al–CO₃)of 0.76 nm in the case of carbonate anion as the guest. Also, DTA,TG and DTG analysis indicated that the electrostatic force betweenthe layers and carbonate anions increased where the carbonate anionsin Zn–Ti LDH decomposed at 255 °C while those inZn–Al–CO₃ decomposed at 230–240 °C.