A new sesquiterpene polyol ester was isolated from the leaves of Celastrus angulatus. Its structure was determined as 1 (beta), 2 (beta), 9 (a) -triacetoxy-8 (a) -((a) -hydroxyl-isobutyryloxy)-15-benzoyloxy-4 (a) -hyd...A new sesquiterpene polyol ester was isolated from the leaves of Celastrus angulatus. Its structure was determined as 1 (beta), 2 (beta), 9 (a) -triacetoxy-8 (a) -((a) -hydroxyl-isobutyryloxy)-15-benzoyloxy-4 (a) -hydroxy-dihydroagarofuran by means of NMR, MS and IR spectral analysis. Preliminary biological study on antitumor activity revealed that this compound showed strong nonselective cytotoxicity against four of the NCI panel cell lines.展开更多
In the organic Rankine cycle,the refrigerant inevitably interacts with the lubricating oil.This study investigates the interaction mechanism between the fourth-generation refrigerant R1336mzz(Z)and the polyol ester(PO...In the organic Rankine cycle,the refrigerant inevitably interacts with the lubricating oil.This study investigates the interaction mechanism between the fourth-generation refrigerant R1336mzz(Z)and the polyol ester(POE)which is a representative component of the lubricating oil,using molecular dynamics simulations.The research focuses on pentaerythritol ester(PEC)with medium to long chain lengths,specifically PEC9.Relevant parameters such as solubility parameters,diffusion coefficients,binding energies,and radial distribution functions were calculated to elucidate the interaction dynamics.The variation in solubility parameters suggests that the miscibility of PEC9 and R1336mzz(Z)diminishes as the number of PEC9 chains increases.Additionally,the compatibility between these two components deteriorates with rising temperature,which is accompanied by a reduction in their binding energy.The simulation results presented in this study offer theoretical insights into the behavior of refrigerant R1336mzz(Z)upon contact with lubricating oil during actual operation,as well as implications for the operational efficiency of the equipment.展开更多
Polyol esters of lubricating oil were synthesized by dipentaerythritol（di-PE）with n-Valeric acid,n-Hexanoic acid,n-Heptanoic acid and n-Caprylic acid（C5 to C8 carboxylic acids）under microwave radiation.The best sy...Polyol esters of lubricating oil were synthesized by dipentaerythritol（di-PE）with n-Valeric acid,n-Hexanoic acid,n-Heptanoic acid and n-Caprylic acid（C5 to C8 carboxylic acids）under microwave radiation.The best synthetical conditions of di-PE with C5 to C8 carboxylic acids were investigated under microwave radiation.The best molar ratio of C5 to C8 carboxylic acids vs di-PE was 8∶1.The best microwave power was between 300W and 320W.The best composite catalyst was selected,and the ratio of composite catalyst（vitriol oil vs P-Toluene Sulphonic acid）was from 1∶2.5 to 1∶3.0.The esterifiable temperatures of dipentaerythritol hexa-valerianate,dipentaerythritol hexa-caproate,dipentaerythritol hexa-heptylate,dipentaerythritol hexa-caprylate were respectively 114℃～116℃、126℃～128℃、134℃～136℃、140℃～142℃.The yields were at least 93% within 9～10min.The viscosity coefficients were determined by Ubbelohde viscosimeter at 31℃±0.05℃ and were respectively 66.4mm2/s,70.8mm2/s,75.3mm2/s,78.1mm2/s.With the increase of carbon atom number of carboxylic acids,the esterifiable temperatures and viscosities of 3a-3d gradually went up.The structures of 3a-3d were identified by 1H NMR,13C NMR and IR spectra.The refractive indexs of 3a-3d were determined with ZWA-J refractometer.This method is fast,efficient and high-yielding,and may provide a new researchful orientation for traditional technology improvement of esters lubricating oil.展开更多
文摘A new sesquiterpene polyol ester was isolated from the leaves of Celastrus angulatus. Its structure was determined as 1 (beta), 2 (beta), 9 (a) -triacetoxy-8 (a) -((a) -hydroxyl-isobutyryloxy)-15-benzoyloxy-4 (a) -hydroxy-dihydroagarofuran by means of NMR, MS and IR spectral analysis. Preliminary biological study on antitumor activity revealed that this compound showed strong nonselective cytotoxicity against four of the NCI panel cell lines.
基金supported by Hainan Provincial Natural Science Foundation of China(No.422CXTD509).
文摘In the organic Rankine cycle,the refrigerant inevitably interacts with the lubricating oil.This study investigates the interaction mechanism between the fourth-generation refrigerant R1336mzz(Z)and the polyol ester(POE)which is a representative component of the lubricating oil,using molecular dynamics simulations.The research focuses on pentaerythritol ester(PEC)with medium to long chain lengths,specifically PEC9.Relevant parameters such as solubility parameters,diffusion coefficients,binding energies,and radial distribution functions were calculated to elucidate the interaction dynamics.The variation in solubility parameters suggests that the miscibility of PEC9 and R1336mzz(Z)diminishes as the number of PEC9 chains increases.Additionally,the compatibility between these two components deteriorates with rising temperature,which is accompanied by a reduction in their binding energy.The simulation results presented in this study offer theoretical insights into the behavior of refrigerant R1336mzz(Z)upon contact with lubricating oil during actual operation,as well as implications for the operational efficiency of the equipment.
文摘Polyol esters of lubricating oil were synthesized by dipentaerythritol（di-PE）with n-Valeric acid,n-Hexanoic acid,n-Heptanoic acid and n-Caprylic acid（C5 to C8 carboxylic acids）under microwave radiation.The best synthetical conditions of di-PE with C5 to C8 carboxylic acids were investigated under microwave radiation.The best molar ratio of C5 to C8 carboxylic acids vs di-PE was 8∶1.The best microwave power was between 300W and 320W.The best composite catalyst was selected,and the ratio of composite catalyst（vitriol oil vs P-Toluene Sulphonic acid）was from 1∶2.5 to 1∶3.0.The esterifiable temperatures of dipentaerythritol hexa-valerianate,dipentaerythritol hexa-caproate,dipentaerythritol hexa-heptylate,dipentaerythritol hexa-caprylate were respectively 114℃～116℃、126℃～128℃、134℃～136℃、140℃～142℃.The yields were at least 93% within 9～10min.The viscosity coefficients were determined by Ubbelohde viscosimeter at 31℃±0.05℃ and were respectively 66.4mm2/s,70.8mm2/s,75.3mm2/s,78.1mm2/s.With the increase of carbon atom number of carboxylic acids,the esterifiable temperatures and viscosities of 3a-3d gradually went up.The structures of 3a-3d were identified by 1H NMR,13C NMR and IR spectra.The refractive indexs of 3a-3d were determined with ZWA-J refractometer.This method is fast,efficient and high-yielding,and may provide a new researchful orientation for traditional technology improvement of esters lubricating oil.
