Euphorbiane: A Novel Triterpenoid with an Unprecedented Skeleton from Euphorbia tirucalli

Euphorbiane ( 1 ), a novel triterpenoid exhibiting a unique skeleton, together with seven known compounds were isolated from the 95% EtOH extract of the fresh stems of Euphorbia tirucalli. The structure of 1 and relative stereochemistry were elucidated by extensive NMR and a single‐crystal X‐ray crystallographic analysis.     

Synthesis of 2‐Arylbenzoxazoles from Flash Vacuum Pyrolysis of 2‐Methoxy‐N‐(arenylidene)anilines

Flash vacuum pyrolysis of 2‐methoxy‐N‐(arenylidene)anilines 2a‐g at 700 °C and 1 × 10^‐2 Torr gave the corresponding 2‐arylbenzoxazoles 1a‐g .     

Combining Taguchi with fuzzy method on extended optimal design of miniature zoom optics with liquid lens

In this paper, the Taguchi method combined with fuzzy approach was applied to find the extended optimization for a multi-objective design of a miniature 2.5× zoom fold optics with liquid elements. Relative illuminance (RI) and modulation transfer function (MTF) were considered to be optimized. The experiments were simulated and the results were evaluated by the optical software tool CODE V. It was concluded that the method used in this research was successful in optimizing the values. In our proposed method, the appropriate weight of MTF and RI for the inputs of fuzzy controllers increased the MTF by 9.92%, but the RI only reduced by 0.19% in systematic wide-angle end, respectively.     

Stereoselective synthesis of hexahydroindoles and octahydrocyclohepta[b]pyrroles via gold(I)-catalyzed intramolecular 1,4-hydroamination of cyclic 1,3-dienes

The gold(I)-catalyzed intramolecular hydroamination of cyclohexa-1,3-dienes bearing an arylsulfonamide at the C-5 position proceeds in a 1,4-addition manner to afford hexahydroindole derivatives in a diastereoselective fashion and in good yields, whereas octahydrocyclohepta[b]pyrrole derivatives can be obtained from seven-membered ring substrates under the same reaction conditions. Coordination of the gold(I) species to the 1,3-diene at the double bond adjacent to the arylsulfonamide tether gave an η²-alkene gold complex. The anti-attack of the sulfonamide to the η²-alkene gold complex at the terminal position of the 1,3-diene resulted in the formation of the fused bicyclic ring with a newly formed Au-C bond at the allylic position. Allylic rearrangement of the η¹-allylgold complex followed by protodemetalation provided the fused heterobicyclic skeletons and regenerated the catalyst.     

Cyclic‐Disulfide‐Based Prodrugs for Cytosol‐Specific Drug Delivery

The cytosolic conversion of therapeutically relevant nucleosides into bioactive triphosphates is often hampered by the inefficiency of the first kinase‐mediated step. Nucleoside monophosphate prodrugs can be used to bypass this limitation. Herein we describe a novel cyclic‐disulfide class of nucleoside monophosphate prodrugs with a cytosol‐specific, reductive release trigger. The key event, a charge‐dissipating reduction‐triggered cyclodeesterification leads to robust cytosolic production of the cyclic 3′,5′‐monophosphate for downstream enzymatic processing. The antiviral competence of the platform was demonstrated with an O‐benzyl‐1,2‐dithiane‐4,5‐diol ester of 2′‐C‐methyluridine‐3′,5′‐phosphate. Both in vitro and in vivo comparison with the clinically efficacious ProTide prodrug of 2′‐deoxy‐2′‐α‐fluoro‐β‐C‐methyluridine is provided. The cytosolic specificity of the release allows for a wide range of potential applications, from tissue‐targeted drug delivery to intracellular imaging.     

Thermokinetic parameters analysis for 1,1-bis-(tert-butylperoxy)-3,3,5-trimethylcyclohexane at isothermal conditions for safety assessment

The rapid development of the petrochemical industry of Taiwan over the past four decades has resulted in a booming economy in Taiwan that drives derived industries to develop progressively. However, it has also caused many runaway reaction accidents, such as toxic gas release, fire, and explosion. It is crucial to eliminate those potential hazard factors which can induce consequent runaway reaction accidents during the life span of the manufacturing process. In response to this crucial issue, we performed a thermokinetic parameter analysis for 1,1-bis-(tert-butylperoxy)-3,3,5-trimethylcyclohexane at isothermal conditions to conduct a thermal safety assessment of chemical materials. The five isothermal temperatures, 90, 100, 110, 120, 130, and 140 °C, measured by DSC, were adopted in this study to calculate process safety parameters, including TMR_ad, T _NR, and SADT, which can be employed in process safety parameters for the manufacturing process. A novel, green kinetic approach accompanied with non-isothermal DSC results is used to derive thermokinetic parameters in safety protocol in this study.     

Trace Determination of Benzalkonium Chlorides in River and Wastewater by Capillary Electrophoresis following Solid‐Phase Extraction Coupled with Salting‐Out Extraction

Trace levels analysisbenzalkonium chlorides (BAKs) in river water and wastewater treatment plants (WWTP) effluents were determined by capillary electrophoresis (CE) following solid‐phase extraction (SPE) and salting‐out extraction. Salting‐out extraction using an appropriate ratio of sodium chloride (NaCl) and acetonitrile (ACN) mixed with concentrated SPE elutant was capable of providing more than 500‐fold enhancement in detection sensitivity. The ratios of ACN and NaCl for salting‐out extraction were investigated and optimized. Matrix interference was eliminated by salting‐out extraction. Limits of quantitation of BAK homologues were achieved at 0.1 μg/L in 250 mL water samples. Recoveries of BAKs in various spiked water samples ranged from 70% to 84% with relative standard deviation (RSD) less than 9%. Trace amounts of total BAKs were detected in river water and WWTP effluent samples ranging from 27 to 145 μg/L at the first time by CE.