621-23-8Relevant articles and documents
Efficient 1H nuclear magnetic resonance method for improved quality control analyses of Ginkgo constituents
Li, Chia-Ying,Lin, Chun-Hua,Wu, Chia-Che,Lee, Kuo-Hsiung,Wu, Tian-Shung
, p. 3721 - 3725 (2004)
We developed an analytical method using 1H nuclear magnetic resonance (NMR) spectrometry to resolve analytical problems with Ginkgo. After a simple hydrolysis step, an NMR analysis of the terpene trilactone H-12 signals and the flavonol aglycone H-2′ (or H-2′/6′ for kaempferol) signals was performed. By comparing the solvent effects on the resolution of these signals, methanol-d4-benzene-d6 (65:35) was selected as the optimal 1H NMR solvent. The amounts of terpene lactones and flavonol aglycones in various commercial Ginkgo products and Ginkgo leaves were determined. This newly developed 1H NMR method enables the simultaneous analysis of terpene trilactones and flavonols and allows simple, rapid quantification of these compounds in pharmaceutical Ginkgo preparations.
Scandium trifluoromethanesulphonate as an active catalyst in the decarbonylation of aromatic aldehydes
Castellani, Carla Bisi,Carugo, Oliviero,Giusti, Manuel,Leopizzi, Claudia,Perotti, Angelo,Invernizzi, Anna Gamba,Vidari, Giovanni
, p. 11045 - 11052 (1996)
Scandium trifluoromethanesulphonate efficiently catalyzes the decarbonylation of 2,4,6-trimethoxybenzaldehyde (1) which, on heating in MeOH solution, is deformylated neatly and completely in a few minutes, yielding 1,3,5 trimethoxybenzene and methyl formate. The reaction was studied by UV and NMR spectroscopy, which gave evidence for the reaction mechanism. Aromatic aldehydes less electron rich than 1 were decarbonylated more sluggishly. The unique catalytic properties of Sc(OTf)3 were compared with other non transition metal triflates.
Methylation with Dimethyl Carbonate/Dimethyl Sulfide Mixtures: An Integrated Process without Addition of Acid/Base and Formation of Residual Salts
Chan, Bun,Lui, Matthew Y.,Lui, Yuen Wai
, (2022/01/08)
Dimethyl sulfide, a major byproduct of the Kraft pulping process, was used as an inexpensive and sustainable catalyst/co-reagent (methyl donor) for various methylations with dimethyl carbonate (as both reagent and solvent), which afforded excellent yields of O-methylated phenols and benzoic acids, and mono-C-methylated arylacetonitriles. Furthermore, these products could be isolated using a remarkably straightforward workup and purification procedure, realized by dimethyl sulfide‘s neutral and distillable nature and the absence of residual salts. The likely mechanisms of these methylations were elucidated using experimental and theoretical methods, which revealed that the key step involves the generation of a highly reactive trimethylsulfonium methylcarbonate intermediate. The phenol methylation process represents a rare example of a Williamson-type reaction that occurs without the addition of a Br?nsted base.
Catalytic SNAr Hydroxylation and Alkoxylation of Aryl Fluorides
Kang, Qi-Kai,Li, Ke,Li, Yuntong,Lin, Yunzhi,Shi, Hang,Xu, Lun
supporting information, p. 20391 - 20399 (2021/08/13)
Nucleophilic aromatic substitution (SNAr) is a powerful strategy for incorporating a heteroatom into an aromatic ring by displacement of a leaving group with a nucleophile, but this method is limited to electron-deficient arenes. We have now established a reliable method for accessing phenols and phenyl alkyl ethers via catalytic SNAr reactions. The method is applicable to a broad array of electron-rich and neutral aryl fluorides, which are inert under classical SNAr conditions. Although the mechanism of SNAr reactions involving metal arene complexes is hypothesized to involve a stepwise pathway (addition followed by elimination), experimental data that support this hypothesis is still under exploration. Mechanistic studies and DFT calculations suggest either a stepwise or stepwise-like energy profile. Notably, we isolated a rhodium η5-cyclohexadienyl complex intermediate with an sp3-hybridized carbon bearing both a nucleophile and a leaving group.
Preparation method of trimethylphloroglucinol
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Paragraph 0029-0043, (2021/09/21)
The invention discloses a preparation method of trimethylphloroglucinol. According to the invention, phloroglucinol is taken as a raw material, and sulfuric acid is adopted to catalyze a first-step reaction, so operation is simpler and more convenient, reaction byproducts are reduced, and damage to production equipment is reduced; and a reaction product obtained in the first-step reaction and dimethyl carbonate are subjected to a second-step methylation reaction, and dimethyl carbonate is non-toxic and non-corrosive, so production safety is greatly improved, the method is green and environment-friendly, and the quality and yield of a final finished product are improved. The method solves the problem of low safety in the production process of existing trimethylphloroglucinol preparation methods, avoids the use of strong corrosive reagents such as hydrochloric acid, and adopts dimethyl carbonate to replace a highly toxic reagent, namely dimethyl sulfate.
Facile C-S Bond Cleavage of Aryl Sulfoxides Promoted by Bronsted Acid
Brutiu, Bogdan R.,Klose, Immo,Maulide, Nuno
supporting information, p. 488 - 490 (2021/03/09)
A method for the Bronsted acid promoted desulfination of aryl sulfoxides is presented. In the presence of a thiol, electron-rich sulfoxides undergo C-S bond cleavage to give the corresponding protodesulfinated arenes and disulfides.
Synthesis method of high-purity phloroglucinol compound
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Paragraph 0018, (2021/06/09)
The invention discloses a one-step chemical catalytic synthesis method of high-purity phloroglucinol by taking 3,5-dichlorophenol as a starting material and taking strong base and a catalyst as auxiliary materials. Through the method, the phloroglucinol compound with high molar yield, high purity and low cost can be effectively synthesized.
Phloroglucinol derivatives as anti-tumor agents: synthesis, biological activity evaluation and molecular docking studies
Jin, Xiaobao,Lai, Qingfu,Lai, Weihong,Li, Ming,Ye, Lianbao,Zhang, Fuli
, (2021/12/02)
Phloroglucinol compounds isolated from Dryopteris fragrans (L.) Schott showed a variety of biological activities, such as anticancer and anti-inflammatory. In this study, we have made a number of modifications around the scaffold of phloroglucinol and synthesized phloroglucinol derivatives A1–A9, B1–B9, and C1–C3. We synthesized these compounds and investigated their effect on four human cancer cell lines (A-549, MCF-7, Hela, HepG2 cell lines) via MTT assay in vitro. The results revealed that all compounds exhibited certain antiproliferative activities on cancer cell lines and excellent inhibitory effects on MCF-7, in which compound C2 was the best with the IC50 value of 18.49 μM, exceeding that of 5-fluorouracil. Moreover, the cell apoptosis test showed that compound C2 induced apoptosis in a concentration-dependent manner. Furthermore, the results of molecular docking analysis explained the probable interaction between the active compounds and active sites of target protein 4I22 and 1OG5. [Figure not available: see fulltext.]
Development of a novel nitric oxide (NO) production inhibitor with potential therapeutic effect on chronic inflammation
Chen, Lijuan,Fan, Tiantian,Lei, Xiangui,Teichmann, Alexander Tobias,Wang, Amu,Wang, Chao,Wei, Zhe,Wieland, Frank Heinrich,Yang, Youzhe,Yin, Jinxiang,Zhou, Li,Zhu, Yue
, (2020/03/24)
Inflammation is a complex biological response to stimuli. Activated macrophages induced excessively release of pro-inflammatory cytokines and mediators such as endogenous radical nitric oxide (NO) play a significant role in the progression of multiple inflammatory diseases. Both natural and synthetic chalcones possess a wide range of bioactivities. In this work, thirty-nine chalcones and three related compounds, including several novel ones, based on bioactive kava chalcones were designed, synthesized and their inhibitory effects on NO production in RAW 264.7 cells were evaluated. The novel compound (E)-1-(2′-hydroxy-4′,6′-dimethoxyphenyl)-3-(3-methoxy-4-(3-morpholinopropoxy)phenyl)prop-2-en-1-one (53) exhibited a better inhibitory activity (84.0%) on NO production at 10 μM (IC50 = 6.4 μM) with the lowest cytotoxicity (IC50 > 80 μM) among the tested compounds. Besides, western blot analysis indicated that compound 53 was a potent down-regulator of inducible nitric oxide synthase (iNOS) protein. Docking study revealed that compound 53 also can dock into the active site of iNOS. Furthermore, at the dose of 10 mg/kg/day, compound 53 could both significantly suppress the progression of inflammation on collagen-induced arthritis (CIA) and adjuvant-induced arthritis (AIA) models. In addition, the structure-activity relationship (SAR) of the kava chalcones based analogs was also depicted.
SYNTHESIS OF MORIN AND MORIN DERIVATIVES
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Paragraph 0031; 0033, (2020/11/24)
The invention relates to a method for directly producing morin derivatives and high-purity morin of formula (I). The invention also relates to morin derivatives and high-purity morin that can be obtained using the claimed method.
