4046-02-0Relevant articles and documents
Identification of 8-O-4/8-5(Cyclic)- and 8-8(Cyclic)/5-5-Coupled Dehydrotriferulic Acids, Naturally Occurring in Cell Walls of Mono- and Dicotyledonous Plants
Waterstraat, Martin,Bunzel, Diana,Bunzel, Mirko
, p. 7244 - 7250 (2016)
Besides ferulate dimers, higher oligomers of ferulic acid such as trimers and tetramers were previously demonstrated to occur in plant cell walls. This paper reports the identification of two new triferulic acids. 8-O-4/8-5(cyclic)-triferulic acid was synthesized from ethyl ferulate under oxidative conditions using copper(II)-tetramethylethylenediamine [CuCl(OH)-TMEDA] as a catalyst, whereas 8-8(cyclic)/5-5-triferulic acid was isolated (preparative size exclusion chromatography, reversed-phase HPLC) from saponified insoluble maize fiber. Structures of both trimers were unambiguously elucidated by high-resolution LC-ToF-MS/MS and one- (1H) and two-dimensional (HSQC, HMBC, COSY, NOESY) NMR spectroscopy. The newly described trimers were identified by LC-MS/MS in alkaline hydrolysates of insoluble fibers from maize, wheat, and sugar beet, indicating that ferulic acid cross-links between cell wall polymers are more diverse than previously recognized. Saponification experiments also suggest that the newly identified 8-O-4/8-5(cyclic)-triferulic acid is the naturally occurring precursor of the previously identified 8-O-4/8-5(noncyclic)-triferulic acid in plant cell walls.
Rapid syntheses of dehydrodiferulates via biomimetic radical coupling reactions of ethyl ferulate
Lu, Fachuang,Wei, Liping,Azarpira, Ali,Ralph, John
, p. 8272 - 8277 (2012)
Dehydrodimerization of ferulates in grass cell walls provides a pathway toward cross-linking polysaccharide chains limiting the digestibility of carbohydrates by ruminant bacteria and in general affecting the utilization of grass as a renewable bioresource. Analysis of dehydrodiferulates (henceforth termed diferulates) in plant cell walls is useful in the evaluation of the quality of dairy forages as animal feeds. Therefore, there has been considerable demand for quantities of diferulates as standards for such analyses. Described here are syntheses of diferulates from ethyl ferulate via biomimetic radical coupling reactions using the copper(II)-tetramethylethylenediamine [CuCl(OH)-TMEDA] complex as oxidant or catalyst. Although CuCl(OH)-TMEDA oxidation of ethyl ferulate in acetonitrile produced mixtures composed of 8-O-4-, 8-5-, 8-8- (cyclic and noncyclic), and 5-5-coupled diferulates, a catalyzed oxidation using CuCl(OH)-TMEDA as catalyst and oxygen as an oxidant resulted in better overall yields of such diferulates. Flash chromatographic fractionation allowed isolation of 8-8- and 5-5-coupled diferulates. 8-5-Diferulate coeluted with 8-O-4-diferulate but was separated from it via crystallization; the 8-O-4 diferulate left in the mother solution was isolated by rechromatography following a simple tetrabutylammonium fluoride treatment that converted 8-5-diferulate to another useful diferulate, 8-5-(noncyclic) diferulate. Therefore, six of the nine (5-5, 8-O-4, 8-5-c, 8-5-nc, 8-5-dc, 8-8-c, 8-8-nc, 8-8-THF, 4-O-5) diferulic acids that have to date been found in the alkaline hydrolysates of plant cell walls can be readily synthesized by the CuCl(OH)-TMEDA catalyzed aerobic oxidative coupling reaction and subsequent saponification described here.
First stereoselective and concise synthesis of rhoiptelol C
Purushotham Reddy, Sudina,Chinnababu, Baggu,Venkateswarlu, Yenamandra
, p. 999 - 1003 (2014)
The first concise stereoselective total synthesis of diarylheptanoid rhoiptelol C (1) was achieved from readily available vanillin. The synthesis involves Keck's asymmetric allylation, olefin cross metathesis, and Sharpless asymmetric dihydroxylation reaction as key steps. Copyright
Synthesis of Novel Antiviral Ferulic Acid-Eugenol and Isoeugenol Hybrids Using Various Link Reactions
Gan, Xiuhai,Wang, Zhengxing,Hu, Deyu
, p. 13724 - 13733 (2021/11/23)
To develop novel antiviral agents, some novel conjugates between ferulic acid and eugenol or isoeugenol were designed and synthesized by the link reaction. The antiviral activities of compounds were evaluated using the half leaf dead spot method. Bioassay results showed acceptable antiviral activities of some conjugates against the tobacco mosaic virus (TMV) and cucumber mosaic virus (CMV). Compounds A9, A10, E1, and E4 showed remarkable curative, protective, and inactivating effects on TMV and CMV at 500 μg mL-1. Notably, these compounds exhibited excellent protective effects on TMV and CMV. The EC50 values of compounds A9, A10, E1, and E4 against TMV were 180.5, 169.5, 211.4, and 135.5 μg mL-1, respectively, and those against CMV were 210.5, 239.1, 218.4, and 178.6 μg mL-1, respectively, which were superior to those of ferulic acid (471.5 and 489.2 μg mL-1), eugenol (456.3 and 463.2 μg mL-1), isoeugenol (478.4 and 487.5 μg mL-1), and ningnanmycin (246.5 and 286.6 μg mL-1). Then, the antiviral mechanisms of compound E4 were investigated by determining defensive enzyme activities and multi-omics analysis. The results indicated that compound E4 resisted the virus infection by enhancing defensive responses via inducing the accumulation of secondary metabolites from the phenylpropanoid biosynthesis pathway in tobacco.
First total syntheses of four natural bioactive glucosides
Xu, Guangya,Wu, Min,Yao, Zhongquan,Lou, Hongbin,Du, Weihong,Song, Mingwei,He, Yujiao,Dong, Hongbo
supporting information, p. 1266 - 1271 (2021/02/06)
The efficient total syntheses of four biologically interesting natural glucosides Ethylconiferin, Butylconiferin, 2’-Butoxyethylconiferin and Balajaponin B, have been achieved for the first time starting from commercially available Vanilline via concise reaction sequence of 8–10 steps with the overall yield of 26–41%. This work definitely laid the foundation for the further pharmacological study of this kind of natural compounds. Meanwhile, currently developed approach could be used as a general synthetic strategy for the syntheses of other monolignol glucosides and their derivatives, and provides an opportunity for further study of the structure-activity relationship of this kind of glucosides.
Ruthenium-catalyzed intramolecular arene C(sp2)-H amidation for synthesis of 3,4-dihydroquinolin-2(1 H)-ones
Au, Chi-Ming,Ling, Cho-Hon,Sun, Wenlong,Yu, Wing-Yiu
supporting information, p. 3310 - 3314 (2021/05/29)
We report the [Ru(p-cymene)(l-proline)Cl] ([Ru1])-catalyzed cyclization of 1,4,2-dioxazol-5-ones to form dihydroquinoline-2-ones in excellent yields with excellent regioselectivity via a formal intramolecular arene C(sp2)-H amidation. The reactions of the 2- and 4-substituted aryl dioxazolones proceeds initially through spirolactamization via electrophilic amidation at the arene site, which is para or ortho to the substituent. A Hammett correlation study showed that the spirolactamization is likely to occur by electrophilic nitrenoid attack at the arene, which is characterized by a negative ρ value of -0.73.
