Search results for "Chemical synthesi"
showing 10 items of 292 documents
Synthesis and biological evaluation of dehydroabietic acid derivatives.
2010
A series of C18-oxygenated derivatives of dehydroabietic acid were synthesized from commercial abietic acid and evaluated for their cytotoxic, antimycotic, and antiviral activities.
Synthesis of novel antimitotic agents based on 2-amino-3-aroyl-5-(hetero)arylethynyl thiophene derivatives
2011
Microtubules are dynamic structures that play a crucial role in cellular division and are recognized as an important target for cancer therapy. In search of new compounds with strong antiproliferative activity and simple molecular structure, a new series of 2-amino-3-(3',4',5'-trimethoxybenzoyl)-5-(hetero)aryl ethynyl thiophene derivatives was prepared by the Sonogashira coupling reaction of the corresponding 5-bromothiophenes with several (hetero)aryl acetylenes. When these compounds were analyzed in vitro for their inhibition of cell proliferation, the 2- and 3-thiophenyl acetylene derivatives were the most powerful compounds, both of which exerted cytostatic effects at submicromolar conc…
Fluorinated Heterocyclic Compounds. An Effective Strategy for the Synthesis of Fluorinated Z-Oximes of 3-Perfluoroalkyl-6-phenyl-2H-1,2,4-triazin- 5-…
2005
The reaction of 3-benzoyl-5-perfluoroalkyl-1,2,4-oxadiazoles with hydrazine has been investigated, evidencing the possibility of competitive reaction paths. Nucleophilic addition of the hydrazine to the electrophilic C(5) of the 1,2,4-oxadiazole ring, followed by ring opening and ring closure with enlargement, leads with high yield and in very mild experimental conditions to the formation of Z-oximes of 3-perfluoroalkyl-6-phenyl-2H-1,2,4-triazin-5-ones (11a-c) as major products of the reaction. In turn, the hydrazine can attack the electrophilic carbonyl carbon giving 4-perfluoroacylamino-5-phenyl-2H-1,2,3-triazoles (13a-c) through the well-known Boulton-Katritzky rearrangement of the inter…
Herbicidal activity of phosphonic and phosphinic acid analogues of glutamic and aspartic acids
1992
Phosphonic and phosphinic acid analogues of glutamic and aspartic acids were synthesized and screened for herbicidal activity on Lepidium sativum L. Depending on the chemical structure, they exhibited significant or moderate herbicidal activity against L. sativum roots (with some representatives being equipotent with phosphinothricin), while their influence on shoot growth was negligible. Cucumis sativus L. appeared to be more tolerant to these analogues. The origin of this selectivity remains to be determined.
Synthesis and herbicidal activity of isoxazole-substituted 1-aminoethylphosphonates and 1-hydroxyethylphosphonates
1994
Isoxazole‐substituted 1‐aminoethyl‐ and 1‐hydroxyethyiphosphonates were synthesized by a multi‐step procedure and were screened for herbicidal activity against Lepidium sativum L. and Cucumis sativus L. All the synthesized compounds exhibited notable herbicidal activity.
ChemInform Abstract: Chemoenzymatic-Chemical Synthesis of a (2-3)-Sialyl T Threonine Building Block and Its Application to the Synthesis of the N-Ter…
2010
Protection of all functional groups of the carbohydrate portion of the chemoenzymatically synthesized sialyl T threonine ester 1 (R=R1 =H, R2 =tBu, Fmoc=9-fluorenylmethoxycarbonyl) and subsequent acidolysis of the tert-butyl ester afforded the building block 2 (R=Ac, R1 =Me, R2 =H). The latter is a useful tool in the solid-phase synthesis of the N-terminal sequence 3 of the leukemia-associated leukosialin.
Synthesis of tritium labeled (�)-1-[2(triphenylmethoxy)ethyl]-3-piperidinecarboxylic acid: a possible compound to determine the efficacy of potential…
2000
(±)-1-[2-(Triphenyl[ 3 H]methoxy)ethyl]-3-piperidinecarboxylic acid ([ 3 H]SNAP-5114) with a specific activity of 40 Ci/mmol was prepared in a two step synthesis starting from ethyl (2-(4-hydroxyphenyl)bis(4-methoxyphenyl)methoxy)-ethyl)piperidine-3-carboxylate and [ 3 H]methyliodide with subsequent hydrolysis of the resulting ester with lithium hydroxide to yield the desired [ 3 H]SNAP-5114.
The synthesis and effect of fluorinated chalcone derivatives on nitric oxide production
2002
Abstract Dimethoxy- and trimethoxychalcone derivatives, with various patterns of fluorination, were synthesized and evaluated for their influence on nitric oxide production. Some of them, chalcones 1 , 5 , 7 , 10 , 11 and 17 , inhibited NO production with an IC 50 in the submicromolar range; 17 is especially noteworthy because of its potency (IC 50 30 nM). These effects were not the consequence of a direct inhibitory action on enzyme activity but the inhibition of enzyme expression.
Solid-phase synthesis and inhibitory effects of some pyrido[1,2-c]pyrimidine derivatives on leukocyte formations and experimental inflammation.
2001
A number of pyrido[1,2-c]pyrimidines bearing a nitrogen, oxygen, or sulfur functionality at C-1 were synthesized on solid-phase using the iminophosphorane methodology and tested for their effects on leukocyte functions in vitro and antiinflammatory activity. Compound 5c was found to be a strong scavenger of superoxide anion and an inhibitor of chemiluminescence induced by 12-O-tetradecanoylphorbol 13-acetate in human neutrophils. These pyrido[1,2-c]pyrimidines inhibited the generation of PGE(2) by COX-2 in RAW 264.7 macrophages stimulated with lipopolysaccharide. Compounds 7, 5f, 6, and 8 inhibited enzyme activity, whereas the remaining compounds also acted on the induction phase. In additi…
Synthesis of Lamellarin U and Lamellarin G Trimethyl Ether by Alkylation of a Deprotonated α-Aminonitrile
2008
1,2,3,4-Tetrahydroisoquinoline-1-carbonitriles can serve as starting materials for the one-pot synthesis of 5,6-dihydropyrrolo[2,1 a]isoquinolines and 1-benzyl-3,4-dihydroisoquinolines. The latter compounds were transformed to lamellarin G trimethyl ether and lamellarin U in short reaction sequences. This method allows the introduction of acid-sensitive protecting groups for the phenolic hydroxy functions which would be cleaved under the harsh conditions of the classical Bischler-Napieralski reaction.