23518-30-1Relevant articles and documents
Continuous flow study of isoeugenol to vanillin: A bio-based iron oxide catalyst
Filiciotto, Layla,Márquez-Medina, María Dolores,Pineda, Antonio,Balu, Alina M.,Romero, Antonio A.,Angelici, Carlo,de Jong, Ed,van der Waal, Jan C.,Luque, Rafael
, p. 281 - 290 (2019/12/25)
The use of a biorefinery co-product, such as humins, in combination with an iron precursor in a solvent-free method yields a catalytic material with potential use in selective oxidative cleavage reactions. In particular, this catalyst was found active in the hydrogen-peroxide assisted oxidation of a naturally extracted molecule, isoeugenol, to high added-value flavouring agent, vanillin. By carrying out the reaction in continuous flow, not only a better understanding of the reaction mechanism and of the catalyst deactivation can be achieved, but also important insights for optimised conditions can be developed. The findings of this paper could pave the way to a more sustainable process for the production of a valuable food and perfume additive, vanillin.
(±)-trans-2-phenyl-2,3-dihydrobenzofurans as leishmanicidal agents: Synthesis, in vitro evaluation and SAR analysis
Bernal, Freddy A.,Gerhards, Marcel,Kaiser, Marcel,Wünsch, Bernhard,Schmidt, Thomas J.
, (2020/08/06)
Leishmaniasis, a neglected tropical disease caused by parasites of the genus Leishmania, causes a serious burden of disease around the world, represents a threat to the life of millions of people, and therefore is a major public health problem. More effective and non-toxic new treatments are required, especially for visceral leishmaniasis, the most severe form of the disease. On the backdrop that dihydrobenzofurans have previously shown antileishmanial activity, we present here the synthesis of a set of seventy trans-2-phenyl-2,3-dihydrobenzofurans and evaluation of their in vitro activity against Leishmania donovani as well as a discussion of structure-activity relationships. Compounds 8m-o and 8r displayed the highest potency (IC50 4.6). Nonetheless, structural optimization as further requirement was inferred from the high clearance of the most potent compound (8m) observed during determination in vitro of its metabolic stability. On the other hand, chiral separation of 8m and subsequent biological evaluation of its enantiomers demonstrated no effect of chirality on activity and cytotoxicity. Holistic analysis of in silico ADME-like properties and ligand efficiency metrics by a simple scoring function estimating druglikeness highlighted compounds 16c, 18 and 23 as promising candidates for further development. Overall, the potential of trans-2-phenyl-2,3-dihydrobenzofurans as leishmanicidal agents was confirmed.
Task-Specific Catalyst Development for Lignin-First Biorefinery toward Hemicellulose Retention or Feedstock Extension
Qiu, Shi,Guo, Xuan,Huang, Yong,Fang, Yunming,Tan, Tianwei
, p. 944 - 954 (2019/01/08)
A catalytic reductive fractionation method for lignocellulosic biomass, termed lignin-first biorefinery, has emerged, which emphasises preferential depolymerization of the protolignin. However, in most studies, the lignin-first biorefinery is only effective for hardwood that has a high syringyl/guaiacol (S/G) ratio of lignin building blocks, and the degradation of hemicellulose also takes place simultaneously to a certain degree. In this study, two task-specific catalysts were developed to realize hemicellulose retention and feedstock extension through the development of an objective performance–structure relationship. It is found that MoxC/carbon nanotube (CNT) is highly selective in the cleavage of bonds between carbohydrates and lignin and ether bonds in lignin during the catalytic reductive fractionation of hardwood, leading to a carbohydrate (both cellulose and hemicellulose) retention degree in the solid product close to the theoretical maximum and a delignification degree as high as 98.1 %. Ru/CMK-3 is demonstrated to be effective in the catalytic reductive fractionation of softwood and grass, resulting from its weak acidity and high mesoporosity.
Synthesis and characterization of di-μ-oxidovanadium(V), oxidoperoxido-vanadium(V) and polymer supported dioxidovanadium(V) complexes and catalytic oxidation of isoeugenol
Maurya, Mannar R.,Uprety, Bhawna,Chaudhary, Nikita,Avecilla, Fernando
, p. 230 - 238 (2015/06/30)
The tridentate ONN donor ligand, Hbzpy-fah (I) (Hbzpy-fah = Schiff base derived from 2-benzoylpyridine and 2-furoylhydrazide) upon reaction with [VIVO(acac)2] in methanol followed by aerial oxidation give a dinuclear complex, [{VVO(bzpy-fah)}2(μ-O)2] (1) having [{VVO}2(μ-O)2]2+ core. Treatment of 1 with H2O2 in methanol results in the formation of dinuclear peroxido complex, [{VVO(bzpy-fah)}2(μ-O2)2] (2). The molecular structure of 2 was determined by single-crystal X-ray diffraction, confirming the ONN binding mode of I and μ-bis(peroxido) with side-on coordination. Reaction of 1 with imidazolomethylpolystyrene cross-linked with 5% divinylbenzene (PS-im) in DMF gives the polymer-supported complex 3 (abbreviated as PS-im[VVO2(bzpy-fah)]) which was characterized by field-emission scanning electron micrographs (FE-SEM) as well as energy dispersive X-ray (EDAX), atomic force microscopy (AFM) and thermal analysis along with usual spectroscopic techniques. Complexes 1 and 3 have been used as catalyst precursors for the oxidation of isoeugenol in the presence of aqueous H2O2 as oxidant and gave vanillin, vanillic acid and dehydrodiisoeugenol. The polymer-supported complex showed higher conversion than its neat counterpart. This has also allowed for recyclable catalytic system with increased catalyst lifetime and thus proved to be better over the homogeneous counterpart.
Radical synthesis of tetrameric lignin model compound
Ouyang, Xin-Ping,Yang, Yun,Zhu, Guo-Dian,Qiu, Xue-Qing
, p. 980 - 982 (2015/08/18)
Abstract The lack of suitable lignin model compound limits the understanding of the characteristics of lignin, and hence hinders the efficient utilization of this kind of bioresource. A tetramer phenolic lignin model compound composed of 5-5, α-O-4 and β-
Selective Activation of C=C Bond in Sustainable Phenolic Compounds from Lignin via Photooxidation: Experiment and Density Functional Theory Calculations
Zielinski, Morgan,Burke, Luke A.,Samokhvalov, Alexander
, p. 1332 - 1339 (2015/11/10)
Lignocellulosic biomass can be converted to high-value phenolic compounds, such as food additives, antioxidants, fragrances and fine chemicals. We investigated photochemical and heterogeneous photocatalytic oxidation of two isomeric phenolic compounds from lignin, isoeugenol and eugenol, in several nonprotic solvents, for the first time by experiment and the density functional theory (DFT) calculations. Photooxidation was conducted under ambient conditions using air, near-UV light and commercial P25 TiO2 photocatalyst, and the products were determined by TLC, UV-Vis absorption spectroscopy, HPLC-UV and HPLC-MS. Photochemical and photocatalytic oxidation of isoeugenol proceeds via the mild oxidative "dimerization" to produce the lignan dehydrodiisoeugenol (DHDIE), while photooxidation of eugenol does not proceed. The DFT calculations suggest a radical stepwise mechanism for the oxidative "dimerization" of isoeugenol to DHDIE as was calculated for the first time.
Oxidovanadium(iv) and dioxidovanadium(v) complexes of hydrazones of 2-benzoylpyridine and their catalytic applications
Maurya, Mannar R.,Chaudhary, Nikita,Avecilla, Fernando,Ad?o, Pedro,Costa Pessoa, Jo?o
, p. 1211 - 1232 (2015/02/02)
Reactions between the tridentate ONN donor ligands, Hbzpy-tch (I) and Hbzpy-inh (II), with [VIVO(acac)2] in dry methanol give two different types of complexes, [VIVO(acac)(bzpy-tch)] (1) and [VIVO(OMe)(bzpy-inh)] (2), respectively. Irrespective of their nature in methanol upon aerial oxidation and precipitation both yield dinuclear [{VVO(bzpy-tch)}2(μ-O)2] (3) and [{VVO(bzpy-inh)}2(μ-O)2] (4). Treatment of 1 or 2 in methanol with H2O2 yields the oxidomonoperoxidovanadium(v) complexes [{VVO(bzpy-tch)}2(μ-O2)2] (5) and [VVO(O2)(bzpy-inh)] (6). Reactions of 3 and 4 with imidazolomethylpolystyrene cross-linked with 5% divinylbenzene (PS-im) in DMF give the polymer-supported PS-im[VVO2(bzpy-inh)] (7) and PS-im[VVO2(bzpy-tch)] (8). The compounds are characterized by various spectroscopic techniques and compounds 7 and 8 were also analyzed by thermal, atomic force microscopy (AFM), field-emission scanning electron micrographs (FE-SEM) as well as energy dispersive X-ray (EDAX) studies. The molecular structures of 3-5 and of [VVO(O2)(bzpy-inh)(H2O)]·0.5MeOH (6a) were determined by single-crystal X-ray diffraction, confirming the μ-bis(O) and ONN binding mode in the dinuclear complexes 3 and 4, as well as the side-on coordination of the peroxido ligand in 5 and 6a. The polymer-grafted compounds 7 and 8 were used for the catalytic oxidation of isoeugenol using aqueous H2O2 as an oxidant. The intermediate peroxido species, expected to be involved during catalytic action, were also generated from solutions of 1-4 and studied by UV-Vis and 51V NMR. The catalytic activity of the several systems was tested and the polymer-supported versions showed higher conversions than their neat counterparts. The polymer-supported complexes allow for recyclable catalytic systems, thus providing additional advantages over their homogeneous counterparts in terms of increased catalyst lifetime and easier separation from the reaction mixture. This journal is
Cerium ammonium nitrate-mediated the oxidative dimerization of p-alkenylphenols: A new synthesis of substituted (±)-trans- dihydrobenzofurans
Chen, Po-Yuan,Wu, Yi-Hua,Hsu, Mon-Huei,Wang, Tzu-Pin,Wang, Eng-Chi
, p. 653 - 657 (2013/07/27)
A new method for the preparation of substituted dihydrobenzofurans is described. The p-alkenylphenols, mediated by cerium ammonium nitrate (CAN), undergo the oxidative dimerization to generate substituted dihydrobenzofurans including (±)-conocarpan, (±)-licarin A, (±)-acuminatin, as well as their related substituted dihydrobenzofurans.
USE OF DIHYDRODEHYDRODIISOEUGENOL AND PREPARATIONS COMPRISING DIHYDRODEHYDRODIISOEUGENOL
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Paragraph 0192; 0193, (2013/05/08)
This invention relates to cosmetic and pharmaceutical preparations comprising (i) a diastereomer or a mixture of two or more diastereomers of the compound of formula (I) or (ii) a salt of a diastereomer or of a mixture of two or more diastereomers of the compound of formula (I) or (iii) a mixture of two or more salts of a diastereomer or of a mixture of two or more diastereomers of the compound of formula (I), a diastereomer, salt or a mixture as defined above as a drug for topical application and/or for the treatment of lipoatrophy; the non-therapeutic use of a diastereomer, salt or a mixture as defined above for the prevention, treatment or reduction of skin aging, especially skin wrinkles; the use of a diastereomer, salt or a mixture as defined above for the production of an orally administered non-pharmaceutical preparation.
Anodic oxidation on a boron-doped diamond electrode mediated by methoxy radicals
Sumi, Takenori,Saitoh, Tsuyoshi,Natsui, Keisuke,Yamamoto, Takashi,Atobe, Mahito,Einaga, Yasuaki,Nishiyama, Shigeru
supporting information; experimental part, p. 5443 - 5446 (2012/07/14)
Direct evidence: The existence of methoxy radical species formed during an anodic oxidation in MeOH on a boron-doped diamond (BDD) electrode was confirmed by ESR spectroscopy. Effective production of a neolignan, licarinA, was accomplished by the BDD-medi
