Salicin-based phenolic glycosides（PGs） are important defensive substances against herbivore feeding and have good bioactivities. In this work, a novel approach for the synthesis of salicin-based PGs has been develop...Salicin-based phenolic glycosides（PGs） are important defensive substances against herbivore feeding and have good bioactivities. In this work, a novel approach for the synthesis of salicin-based PGs has been developed, by which PGs of 2＇-O-acetylsaliein（5a）, 3＇-O-acetylsalicin（gb） and 3＇-O-benzoylsalicin（Sd） were hemisynthesized. The effects of acylation reagent, solvent and temperature on the regioselective acylation of 2＇- or 3＇-hydroxyl groups of salicin mediated by dibutyltin oxide were investigated. The optimal conditions under which the best regioselectivity reached for 5a-5d were discovered, respectively. Moreover, a tentative tin-oxygen coordination mechanism was put forward to explain the different regioselectivities shown under different conditions.展开更多
The regioselective acylation of unprotected phenylethyl glucoside withcinnamoyl chloride leads to 6-OH cin-namoylated glucoside. In this manner, thirteen phenylpropanoidglycoside analogs were designed and prepared. Th...The regioselective acylation of unprotected phenylethyl glucoside withcinnamoyl chloride leads to 6-OH cin-namoylated glucoside. In this manner, thirteen phenylpropanoidglycoside analogs were designed and prepared. Their structure was confirmed by ~1H NMR and ^(13)CNMR spectra.展开更多
A series of novel coumarin glycoside esters（1-9） was synthesized through the acylation reaction of 4-methylcoumarin-7-O-β-D-glucoside（11） with different long chain fatty acids catalyzed by lipase in organic mediu...A series of novel coumarin glycoside esters（1-9） was synthesized through the acylation reaction of 4-methylcoumarin-7-O-β-D-glucoside（11） with different long chain fatty acids catalyzed by lipase in organic medium. The acylation occurred regioselectively at the 6＇-OH of glycosyl moiety. The enzymatic synthesis was optimized to achieve 54%-70% yield using immobilized lipase（Novozym 435, 10 mg/mL） as catalyst and acetone and pyri- dine（9：1, volume ratio, water content〈1%） as solvent with an acyl donor/coumarin glycoside molar ratio of 10：1 at a temperature of 40--50 ℃ for 96 h. All the synthesized compounds were confirmed.展开更多
基金Supported by the National Natural Science Foundation of China（No.31270861/C050204）, the Agricultural Science and Technology Innovation Project of Shaanxi Province, China（No.2012 NKC01-12） and the Talent Start-up Fund of Northwest Sci-tech University of Agriculture and Forestry University, China.
文摘Salicin-based phenolic glycosides（PGs） are important defensive substances against herbivore feeding and have good bioactivities. In this work, a novel approach for the synthesis of salicin-based PGs has been developed, by which PGs of 2＇-O-acetylsaliein（5a）, 3＇-O-acetylsalicin（gb） and 3＇-O-benzoylsalicin（Sd） were hemisynthesized. The effects of acylation reagent, solvent and temperature on the regioselective acylation of 2＇- or 3＇-hydroxyl groups of salicin mediated by dibutyltin oxide were investigated. The optimal conditions under which the best regioselectivity reached for 5a-5d were discovered, respectively. Moreover, a tentative tin-oxygen coordination mechanism was put forward to explain the different regioselectivities shown under different conditions.
文摘The regioselective acylation of unprotected phenylethyl glucoside withcinnamoyl chloride leads to 6-OH cin-namoylated glucoside. In this manner, thirteen phenylpropanoidglycoside analogs were designed and prepared. Their structure was confirmed by ~1H NMR and ^(13)CNMR spectra.
基金Supported by the National Natural Science Foundation of China（Nos.21342015, J1210040） and the Hunan Provincial Natu- ral Science Foundation, China（No. 14JJ2048）.
文摘A series of novel coumarin glycoside esters（1-9） was synthesized through the acylation reaction of 4-methylcoumarin-7-O-β-D-glucoside（11） with different long chain fatty acids catalyzed by lipase in organic medium. The acylation occurred regioselectively at the 6＇-OH of glycosyl moiety. The enzymatic synthesis was optimized to achieve 54%-70% yield using immobilized lipase（Novozym 435, 10 mg/mL） as catalyst and acetone and pyri- dine（9：1, volume ratio, water content〈1%） as solvent with an acyl donor/coumarin glycoside molar ratio of 10：1 at a temperature of 40--50 ℃ for 96 h. All the synthesized compounds were confirmed.
