New Truxinic and Truxillic Acid Sucrose Diesters From the Leaves of Trigonostemon honbaensis

A new δ-truxinic acid sucrose diester and a new ε-truxillic acid sucrose diester (named trigohonbanosides E and F) were isolated from the leaves of Trigonostemon honbaensis. Their chemical structures were determined by extensive analysis of their HR-ESI-MS and NMR spectra. At a concentration of 20 µM, trigohonbanosides E and F exhibited weak inhibitory effects on NO production in LPS-activated RAW264.7 cells with inhibitory percentages of 22.7% ± 1.1% and 18.5% ± 1.4%, respectively.

Electric Volume Resistivity for Biopolyimide Using 4,4′-Diamino-α-truxillic acid and 1,2,3,4-Cyclobutanetetracarboxylic dianhydride

Biopolyimides poly(ATA-CBDA), made from of 4,4′-diamino-α-truxillic acid dimethyl ester (ATA) and 1,2,3,4-cyclobutanetetracarboxylic dianhydride (CBDA), is synthesized and measured its electric volume resistivity at various experimental conditions. The effects of film size, thickness, drying time, and the electric field strength on electric resistivity are investigated and compared with polyimide (Kapton). The electric resistivity for all polyimide and biopolyimide are distributed in the range of 1015–1016 Ωcm, which shows that biopolyimide has high electrical insulation as well as polyimide. The electric resistivity strongly depends on film thickness, which suggests that electric resistivity is a function of electric field strength. The critical electric field for polyimide and biopolyimide films are determined to be 5.8 × 107 V/m and 3.2 × 107 V/m, respectively. Humidity was found to strongly affect the electric resistivity; ~1016 Ωcm at 34% RH and ~1013 Ωcm at 60% RH for both polyimide and biopolyimide films.

Fluorinated and Bio-Based Polyamides with High Transparencies and Low Yellowness Index

Bio-based polyamides with high transparency and low yellowness were synthesized using 4,4′-bis(trifluoroacetamido)-α-truxillic acid (ATA-F1) and 4,4′-bis(pentafluoropropionamido)-α-truxillic acid (ATA-F2) as a fluoroalkylated aromatic dicarboxylic acid, and various aromatic diamines. The introduction of fluorine side chains improved the transparency of the polyamide film, and suppressed its yellowness. On the other hand, water repellency, which should be a general characteristic of the fluorinated polymers, was not observed. By using ATA-F1 and various aromatic diamines, aromatic and fluorinated polyamides were obtained. In addition, these also demonstrated a high transparency and a low yellowness index. The heat resistance properties of all the obtained polyamides was over 250 °C, and the characteristics of the bio-based polyamides from 4-aminocinnamic acid derivatives were retained.

Crystal chemistry and photomechanical behavior of 3,4-dimethoxycinnamic acid: correlation between maximum yield in the solid-state topochemical reaction and cooperative molecular motion

A new monoclinic polymorph, form II (P21/c,Z= 4), has been isolated for 3,4-dimethoxycinnamic acid (DMCA). Its solid-state 2 + 2 photoreaction to the corresponding α-truxillic acid is different from that of the first polymorph, the triclinic form I (P\bar 1,Z= 4) that was reported in 1984. The crystal structures of the two forms are rather different. The two polymorphs also exhibit different photomechanical properties. Form I exhibits photosalient behavior but this effect is absent in form II. These properties can be explained on the basis of the crystal packing in the two forms. The nanoindentation technique is used to shed further insights into these structure−property relationships. A faster photoreaction in form I and a higher yield in form II are rationalized on the basis of the mechanical properties of the individual crystal forms. It is suggested that both Schmidt-type and Kaupp-type topochemistry are applicable for the solid-statetrans-cinnamic acid photodimerization reaction. Form I of DMCA is more plastic and seems to react under Kaupp-type conditions with maximum molecular movements. Form II is more brittle, and its interlocked structure seems to favor Schmidt-type topochemistry with minimum molecular movement.