2150-38-1Relevant articles and documents
Kopsirachin, ein ungewoehnliches Alkaloid aus der Apocynaceae Kopsia dasyrachis Ridl.
Homberger, Katharina,Hesse, Manfred
, p. 237 - 248 (1984)
From the leaves of Kopsia dasyrachis Ridl, a new typ of alkaloid, kopsirachine (1) built up from catechin (2) and skytanthine (3) has been isoled.The structure elucidation is based on spectral and chemical evidence.Oxidative cleavage of its derivative 4 with KMnO4 afforded veratric acid which was identified as its methylester by comparison with an authentic sample.Pyrolysis of 1 yielded δ-skythanthine (3).The stereochemistry of the skythanthine substrituents in 1 could not yet be estabilished.
Tyrosinase Inhibitor from Black Rice Bran
Miyazawa, Mitsuo,Oshima, Teruo,Koshio, Katsuya,Itsuzaki, Yumi,Anzai, Jun
, p. 6953 - 6956 (2003)
The inhibitor of tyrosinase activity in black rice bran was investigated. The methanol extract from black rice bran was re-extracted with hexane, chloroform, ethyl acetate, or water. The ethyl acetate extract had the most potent inhibition against tyrosinase activity by 80.5% at a concentration of 0. 4 mg/mL. Inhibitory compound in the ethyl acetate fraction was isolated by silica gel column chromatography, and identified as protocatechuic acid methyl ester (compound 1) by GC, GC-MS, IR, and 1H and 13C NMR spectroscopy. Compound 1 inhibited 75.4% of tyrosinase activity at a concentration of 0.50 μmol/mL. ID50 (50% inhibition dose) value of compound 1 was 0.28 μmol/mL. To study the structure-activity relationship, protocatechuic acid (2), vanillic acid (3), vanillic acid methyl ester (4), isovanillic acid (5), isovanillic acid methyl ester (6), veratric acid (7), and veratric acid methyl ester (8) were also assayed.
Novel arylcarbamate-N-acylhydrazones derivatives as promising BuChE inhibitors: Design, synthesis, molecular modeling and biological evaluation
Yamazaki, Diego A.S.,Rozada, Andrew M.F.,Baréa, Paula,Reis, Elaine C.,Basso, Ernani A.,Sarragiotto, Maria Helena,Seixas, Flávio A.V.,Gauze, Gisele F.
, (2021/01/18)
A novel series of arylcarbamate-N-acylhydrazones derivatives have been designed and synthesized as potential anti-cholinesterase agents. In vitro studies revealed that these compounds demonstrated selective for butyrylcholinesterase (BuChE) with potent inhibitory activity. The compounds 10a-d, 12b and 12d were the most potent BuChE inhibitors with IC50 values of 0.07–2.07 μM, highlighting the compound 10c (IC50 = 0.07 μM) which showed inhibitory activity 50 times greater than the reference drug donepezil (IC50 = 3.54 μM). The activity data indicates that the position of the carbamate group in the aromatic ring has a greater influence on the inhibitory activity of the derivatives. The enzyme kinetics studies indicate that the compound 10c has a non-competitive inhibition against BuChE with Ki value of 0.097 mM. Molecular modeling studies corroborated the in vitro inhibitory mode of interaction and show that compound 10c is stabilized into hBuChE by strong hydrogen bond interaction with Tyr128, π-π stacking interaction with Trp82 and CH?O interactions with His438, Gly121 and Glu197. Based on these data, compound 10c was identified as low-cost promising candidate for a drug prototype for AD treatment.
Polyhydroxybenzoic acid derivatives as potential new antimalarial agents
Degotte, Gilles,Francotte, Pierre,Pirotte, Bernard,Frédérich, Michel
, (2021/08/07)
With more than 200 million cases and 400,000 related deaths, malaria remains one of the deadliest infectious diseases of 2021. Unfortunately, despite the availability of efficient treatments, we have observed an increase in people infected with malaria since 2015 (from 211 million in 2015 to 229 million in 2019). This trend could partially be due to the development of resistance to all the current drugs. Therefore, there is an urgent need for new alternatives. We have, thus, selected common natural scaffolds, polyhydroxybenzoic acids, and synthesized a library of derivatives to better understand the structure–activity relationships explaining their antiplasmodial effect. Only gallic acid derivatives showed a noticeable potential for further developments. Indeed, they showed a selective inhibitory effect on Plasmodium (IC50 ~20 μM, SI > 5) often associated with interesting water solubility. Moreover, this has confirmed the critical importance of free phenolic functions (pyrogallol moiety) for the antimalarial effect. Methyl 4-benzoxy-3,5-dihydroxybenzoate (39) has, for the first time, been recognized as a potential lead for future research because of its marked inhibitory activity against Plasmodium falciparum and its significant hydrosolubility (3.72 mM).
Palladium-Catalyzed Chlorocarbonylation of Aryl (Pseudo)Halides Through In Situ Generation of Carbon Monoxide
Bismuto, Alessandro,Boehm, Philip,Morandi, Bill,Roediger, Sven
supporting information, p. 17887 - 17896 (2020/08/19)
An efficient palladium-catalyzed chlorocarbonylation of aryl (pseudo)halides that gives access to a wide range of carboxylic acid derivatives has been developed. The use of butyryl chloride as a combined CO and Cl source eludes the need for toxic, gaseous carbon monoxide, thus facilitating the synthesis of high-value products from readily available aryl (pseudo)halides. The combination of palladium(0), Xantphos, and an amine base is essential to promote this broadly applicable catalytic reaction. Overall, this reaction provides access to a great variety of carbonyl-containing products through in situ transformation of the generated aroyl chloride. Combined experimental and computational studies support a reaction mechanism involving in situ generation of CO.