Lignin acylated with acetate and/or p-coumarate is common in many herbaceous plants. Herein, the biomimetic oxidation of γ-acylated monolignols with Ag2O was studied to understand the effect of γ-acyl groups on monolignol polymerization. The oxidation of sinapyl acetate gave γ-acylated and α-acylated β-O-4 dimers in 71 and 9.5% yields, respectively. The oxidation of sinapyl p-coumarate produced γ-acylated
Mechanistic Study of the Biomimetic Synthesis of Flavonolignan Diastereoisomers in Milk Thistle
作者:Hanan S. Althagafy、Maria Elena Meza-Aviña、Nicholas H. Oberlies、Mitchell P. Croatt
DOI:10.1021/jo4011377
日期:2013.8.2
The mechanism for the biomimetic synthesis of flavonolignan diastereoisomers in milk thistle is proposed to proceed by single-electron oxidation of coniferyl alcohol, subsequent reaction with one of the oxygen atoms of taxifolin's catechol moiety, and finally, further oxidation to form four of the major components of silymarin: silybin A, silybin B, isosilybin A, and isosilybin B. This mechanism is significantly different from a previously proposed process that involves the coupling of two independently formed radicals.
Exploring Synthetic Dihydrobenzofuran and Benzofuran Neolignans as Antiprotozoal Agents against Trypanosoma cruzi
作者:Mariana C. Pagotti、Herbert J. Dias、Ana Carolina B. B. Candido、Thaís A. S. Oliveira、Alexandre Borges、Nicoli D. Oliveira、Carla D. Lopes、Renato P. Orenha、Renato L. T. Parreira、Antônio E. M. Crotti、Lizandra G. Magalhães
DOI:10.3390/pharmaceutics15030754
日期:——
drugs is important because the current treatments show limited effectiveness and high toxicity. In this work, eighteen dihydrobenzofuran-type neolignans (DBNs) and two benzofuran-type neolignans (BNs) were synthesized and evaluated against amastigote forms of two Trypanosoma cruzi strains. The in vitro cytotoxicity and hemolytic activity of the most active compounds were also evaluated and their relationships