2491-20-5Relevant articles and documents
Development of a prodrug of salicylic acid, salicylic Acid-L-alanine conjugate, utilizing hydrolysis by rabbit intestinal microorganisms
Nakamura,Tagami,Nishida,Sasaki
, p. 295 - 299 (1992)
The hydrolysis of salicylic acid-L-alanine conjugate (salicyl-L-alanine) following oral, intravenous, intracaecal and rectal administration (60, 10, 5 and 5 mg kg-1 respectively: salicylic acid equivalent) was examined in rabbits. Salicylic acid was detected in the blood 2 h after oral administration of salicyl-L-alanine and reached a maximum concentration at 10 h, whereas salicyl-L-alanine was rapidly eliminated. In contrast, unchanged salicyl-L-alanine only was found following intravenous administration of salicyl-L-alanine, suggesting that presystemic de-conjugation of salicyl-L-alanine was involved. The intestinal mucosal de-conjugation of salicyl-L-alanine was not recognized in the in-situ intestinal sac preparation with complete mesenteric venous blood collection. Immediate and very extensive salicylic acid formation in the caecum was found following intracaecal administration of salicyl-L-alanine. After oral pretreatment of rabbits with kanamycin sulphate, a significant inhibition of salicylic acid formation following intracaecal administration of salicyl-L-alanine was observed, indicating that the intestinal microorganisms were responsible for the biotransformation of salicyl-L-alanine. In-vitro incubation of salicyl-L-alanine with gut contents showed that the major source of its hydrolysis was the hind gut. Consequently, the blood concentration of salicylic acid was prolonged extensively following rectal administration of salicyl-L-alanine, suggesting the usefulness of salicyl-L-alanine as a prodrug of salicylic acid.
Three new metabolites from the endophytic fungus Climacocystis montana isolated from the root bark of Paeonia ostia
Zhang, Pei-liang,Wang, Gang,Liu, Jin-song,Xu, Feng-qing,Zhao, Zhen-zhu,Wang, Wen-xiang,Wang, Ju-tao,Wang, Guo-kai,Wu, Pei-yun
, p. 50 - 54 (2018)
Two new pyridine derivatives climacomontaninates A–B (1–2), and a new sesquiterpenoid derivative climacomontanetate (3), together with twelve known compounds (4–15) were isolated from the culture extract of the fungal strain Climacocystis montana from the root bark of Paeonia ostii. The structures of these compounds were determined through spectroscopic methods such as NMR and HRMS. Moreover, we expound the absolute configuration of 1 using the organic synthesis method. The cytotoxicity against five human cancer cell lines of new compounds were evaluated by SRB assay.
Triazolyl-donor-acceptor chromophore-decorated unnatural amino acids and peptides: FRET events in a β-turn conformation
Bag, Subhendu Sekhar,Jana, Subhashis,Yashmeen, Afsana,Senthilkumar,Bag, Raghunath
, p. 433 - 435 (2014)
The β-turn conformation and FRET process were established in the designed tripeptide containing fluorescent triazolyl donor and acceptor-decorated unnatural amino acids separated by a natural alanine.
Novel emissive bio-inspired non-proteinogenic coumarin-Alanine amino acid: Fluorescent probe for polyfunctional systems
Oliveira, Elisabete,Capelo, José Luis,Lima, Jo?o Carlos,Lodeiro, Carlos
, p. 1779 - 1790 (2012)
Two new bio-inspired non-proteinogenic compounds L1 and L2, containing coumarin and/or acridine chromophores and bearing as spacer an alanine amino acid were successfully synthesized and fully characterized by elemental analysis, 1H and 13
Design and synthesis of hydrophobic and chiral anions from amino acids as precursor for functional ionic liquids
Fukumoto, Kenta,Ohno, Hiroyuki
, p. 3081 - 3083 (2006)
Hydrophobic ionic liquids composed of tetrabutylphosphonium cation and chiral anions derived from amino acids modified with trifluoromethane sulfonyl groups have been synthesized using a simple method. The Royal Society of Chemistry 2006.
Multiple alkylation and mapping of the active site of α-chymotrypsin by carbonium ions generated with active-site-directed enzyme-activated nitrosoamide substrates
White,Li,Cousins,Roswell
, p. 1956 - 1961 (1990)
The inhibition of α-chymotrypsin with 13C-enriched alanine- and phenylalanine-based N-nitrosoamides, as active-site-directed and enzyme-activated inhibitors, results in the alkylation (benzylation) of side chains and also of the amide linkages of the protein backbone (both at O and N). 13C NMR spectra of the denatured inhibited enzyme (in Gdn.HCl) indicate that alkylation has occurred at O, N, S, and C sites. 13C NMR spectra of the amino acid mixtures from fully hydrolyzed inhibited enzymes show that the pattern of alkylation is strikingly different for inhibitions by the alanine- and phenylalanine-based inhibitors. In the case of the phenylalanine-based inhibitor, approximately equally intense signals are observed at 52.32, 51.31, 36.78, and 32.91 ppm, while with the alanine-based inhibitor, a major signal appears at 52.35 ppm, with minor signals appearing at 36.83 and 32.9 ppm. Chromatographic and NMR evidence is presented to indicate that the 52.32-52.35-ppm signal stems from N-benzylglycine. The chemical shift data suggest that the 51.31-ppm signal stems from N-benzylserine and the 36.78-36.83-ppm signal from S-benzylcysteine. Mechanisms are presented to account for the formation of those products.
Hydrogen-Borrowing Alkylation of 1,2-Amino Alcohols in the Synthesis of Enantioenriched γ-Aminobutyric Acids
Hall, Christopher J. J.,Goundry, William R. F.,Donohoe, Timothy J.
supporting information, p. 6981 - 6985 (2021/03/01)
For the first time we have been able to employ enantiopure 1,2-amino alcohols derived from abundant amino acids in C?C bond-forming hydrogen-borrowing alkylation reactions. These reactions are facilitated by the use of the aryl ketone Ph*COMe. Racemisation of the amine stereocentre during alkylation can be prevented by the use of sub-stoichiometric base and protection of the nitrogen with a sterically hindered triphenylmethane (trityl) or benzyl group. The Ph* and trityl groups are readily cleaved in one pot to give γ-aminobutyric acid (GABA) products as their HCl salts without further purification. Both steps may be performed in sequence without isolation of the hydrogen-borrowing intermediate, removing the need for column chromatography.
Two-Dimensional Barriers for Probing Conformational Shifts in Macrocycles
Kobori, Shinya,Huh, Sungjoon,Appavoo, Solomon D.,Yudin, Andrei K.
supporting information, p. 5166 - 5171 (2021/05/04)
We describe the development and use of composite two-dimensional barriers in macrocyclic backbones. These tunable constructs derive their mode of action from heterocyclic rearrangements. The Boulton-Katritzky reaction has been identified as a particularly versatile means to effect a composite barrier, allowing the examination of the influence of heterocycle translocation on conformation. Kinetic studies using 1H NMR have revealed that the in-plane atom movement is fast in 17, 18, 19-membered rings but slows down in 16-membered rings. The analysis by NMR and MD simulation experiments is consistent with the maintenance of rare cis-amide motifs during conformational interconversion. Taken together, our investigation demonstrates that heterocyclic rearrangement reactions can be used to control macrocyclic backbones and provides fundamental insights that may be applicable to the development of a wide range of other conformational control elements.