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Abadi A H - - 2001
Halomethylation of naproxene (1) occurs regioselectively in position 5 and subsequently--in situ or on treatment with silver nitrate--leads to naproxene-"dimers" with two naproxene units, 5,5'-connected through a ethenylene (3) and a methylene (4) bridge, respectively. Two of the new naproxene derivatives were screened for their cyclooxygenase inhibitory properties relative to ...
Korolev A M - - 2001
A facile preparation is described of 3-(indol-3-yl)-2-hydroxy-4-hydroxymethylcyclopent-2-enone and its N-derivatives in 15-40% yields by the degradation of ascorbigen or its N-derivatives in a warm solution of L-ascorbic acid through a sequential domino reaction. The same cyclopentenone derivatives were obtained in 30-40% yields by the condensation of (N-alkylindol-3-yl)glycolic acids with ascorbic ...
Nagashima Y - - 2001
Instead of tetrodotoxin, significant amounts of tetrodotoxin-related substances with no mouse lethality were detected in the nontoxic liver specimen of puffer fish, Takifugu xanthopterus. The tetrodotoxin-related substances, which were demonstrated to be tetrodotoxin derivatives by gas chromatography-mass spectrometry analysis, were similar to tetrodonic acid in HPLC but distinguishable from it ...
Cárdenas G - - 2001
Chitosan, poly-beta(1-->4)-2 amino-2-deoxy-D-Glucopyranose is a biopolymer obtained by extensive deacetylation of chitin [poly-beta(1-->4)-2-acetamide-2-deoxy-D-Glucopyranose], main constituent of crustacean shells. The present study was carried out using crab shells from nylon shrimps (Heterocarpus reedi). Despite the abundance of raw material in our environment, little work has been published in this field using ...
Emri T - - 2001
Both toxicity and penicillin productivity of the hydroxylated derivatives of phenylacetic acid (PA) and phenoxyacetic acid (POA) were highly dependent on the position of hydroxylation on the aromatic ring in Penicillium chrysogenum. Hydroxylation at position 2 diminished penicillin production but the compounds retained most of their toxicity. On the other ...
Taotafa U - - 2000
[structure:see text] Anionic facial amphiphiles have been prepared from cholic acid. These compounds offer antipodes of recently reported cationic amphiphiles derived from cholic acid. The synthesis of the anionic amphiphiles was accomplished in few steps from a common intermediate. In contrast to many other anionic facial amphiphiles, the cholic acid ...
Casini A - - 2000
A series of sulfonamides has been obtained by reaction of 4-isothiocyanatobenzenesulfonamide with amines, amino acids, and oligopeptides. The new thiourea derivatives showed strong affinities toward isozymes I, II, and IV of carbonic anhydrase (CA, EC 4.2.1.1). In vitro inhibitory power was good (in the low-nanomolar range) for the derivatives of ...
Berger Y - - 2000
Protoporphyrin IX (PpIX) is used as a photosensitizing agent in photodynamic detection and therapy (PDT) of cancer and is synthesized intracellularly from aminolevulinic acid (ALA) precursors. To evaluate means to specifically target ALA derivatives to defined cells, we have synthesized and characterized ethylene glycol esters and amino acid pseudodipeptide derivatives ...
Anisuzzaman A K - - 2000
The dimethyl derivatives of imazaquin, imazapyr, imazmethapyr, imazethapyr, 2-[4,5 dihydro-1, 4-dimethyl-4-(1-methylethyl)-5-oxo-1H-imidazol-2-yl]-5-methoxymethyl- 3-pyridine carboxylic acid, 2-[4,5-dihydro-1,4 -dimethyl-4-(1-methylethyl)-5-oxo-1H-imidazol-2-yl]-4-methyl benzoic acid, and 2-[4,5-dihydro-1,4-dimethyl-4-(1-methyl ethyl)-5-oxo-1H-imidazol-2-yl]-5-methyl benzoic acid were prepared and fully characterized. The availability of these derivatives has led to the development of efficient and multiresidue gas chromatographic methods for trace level analysis of ...
González Z - - 2000
A facile method for the formation of branched-chain sugar derivatives is described involving the reaction of lithium dianions and carboxylic acids with keto-sugar derivatives. Acetic, propanoic, phenylacetic, 3,3-dimethylacrylic, crotonic and sorbic acids were the acids used for the preparation of the lithium dianions, and glucose and fructose were used for ...
Moriguchi T - - 2000
This paper describes the design and synthesis of a new type of aminoacyl-adenylate analogue (aa-AMPN) having an N-acyl phosphoramidate linkage where the oxygen atom of the mixed anhydride bond of aminoacyl-adenylate (aa-AMP) is replaced by an amino group. This new type of aa-AMP analogue is expected to be useful as ...
Uchiyama T - - 2000
PURPOSE: The objective of this study is to examine the intestinal permeability of novel lipophilic derivatives of DADLE (Tyr-D-Ala-Gly-Phe-D-Leu), an enkephalin analogue, using isolated rat intestinal membranes. METHODS: The novel lipophilic derivatives of DADLE were synthesized by chemical modification with various fatty acids at the C terminus. The pharmacological activities ...
Sprott K T - - 2000
The preparation and utilization of C(2)-symmetric 1,4-diamines in the synthesis of amino acid-derived cyclic phosphonamides 1-3 are described. The 1,4-diamines are synthesized via three methods: (i) amino acid/fumaryl chloride coupling followed by amide reduction, (ii) amino acid/1,4-diamine coupling followed by amide reduction, and (iii) a template-supported ring-closing metathesis/hydrolysis sequence. The ...
Self W T - - 2000
Thiol-containing compounds, such as glutathione and cysteine, react with selenite under specific conditions to form selenotrisulfides. Previous studies have focused on isolation and characterization of intermolecular selenotrisulfides. This study describes the preparation and characterization of intramolecular selenotrisulfide derivatives of lipoic acid and lipoamide. These derivatives, after separation from other reaction ...
Hashimoto M - - 2000
4-[3-(Trifluoromethyl) diazirinyl] cinnamic acid derivatives were synthesized to elucidate properties of phenylalanine ammonia-lyase (PAL). 2-Methoxy and 2-biotinylated alkoxy compounds have inhibitory activity on the formation of phenylalanine from cinnamic acid. Specific photolabeling of the enzyme was detected using biotinylated derivatives without the use of radioisotopes. The results indicated that the ...
Saeki K - - 2000
Gallic acid derivatives with a lipophilic group (hydrogenated farnesyl gallate, lauryl gallate, gallic acid laurylamide and cholesteryl gallate) were examined for their ability to induce apoptosis in human monoblastic leukemia U937 cells. Farnesyl ester derivative is the most potent apoptosis inducer among the compounds examined. The results suggest that lipid ...
Krogh R - - 2000
Values of ID50 for a collection of structurally-related gallic acid derivatives have been employed to create a predictive quantitative structure-activity relationship (QSAR) which links structure to values of analgesic activity. The QSAR model developed has substantial predictive power for the design of novel gallic acid derivatives having improved analgesic potency.
Kett W C - - 2000
Conditions to effect the conversion of monosaccharide and disaccharide hydrazones to 1-glycosyl-3-methylpyrazol-5-ones were examined. The sugar pyrazolone derivatives were sensitive to oxidation, but high yields were achieved with 2,2,2-trifluoroethyl acetoacetate in mildly acidic solution. Azo coupling of the pyrazolones produced highly coloured azopyrazolone derivatives that prevented further degradation, and these ...
Di Nardo C - - 2000
Methanolysis of 2,4,6-tri-O-benzoyl-2,3-dibromo-3-deoxy-D-altrono-1,5-lactone gave methyl 3-bromo-3-deoxy-2,4,6-tri-O-benzoyl-alpha-D-ribo-hex-2-ulofuranosonat e (3) and the anomeric mixture of the analogous 4,6-di-O-benzoyl derivative, having HO-2 free. Compound 3 was subjected to debromination with tributyltin hydride and tributyltin deuteride in the presence of 2,2'-azo-bisisobutyronitrile affording, respectively, the corresponding derivatives of 3-deoxy-D-erythro-2-hexulosonic acid and its 3-deuterio analog. The ...
Dreher S D - - 2000
1,3-Diol synthons, protected as acetonides or benzylidene acetals, may be synthesized efficiently from homoallylic alcohols and acetone or benzaldehyde by oxymercuration of the derived hemiketals and hemiacetals with HgClOAc. The use of catalytic amounts of Yb(OTf)(3) is crucial to the success of the reaction, which was determined to be reversible.
Benderdour M - - 2000
Boric acid solution (3%) dramatically improves wound healing through action on the extracellular matrix, a finding that has been obtained in vitro. Consequently, investigations are presently underway to produce boronated compounds having a therapeutical effectiveness similar to that of boric acid. On the basis of experimental results obtained with boric ...
Mastrolorenzo A - - 2000
The screening of a series of arylsulfonylureido derivatives of amines (such as histamine, or dopamine), aliphatic/aromatic amino acids (such as Gly, beta-Ala, Val, Lys, Arg, Phe, Tyr, DOPA, etc.) and dipeptides (such as GlyGly, beta-AlaHis) led to the identification of three derivatives that possess tumor growth inhibitory properties against several ...
Clerici F - - 2000
A synthesis of the new oxazolone 2, functionalized with the ethoxycarbonyloxy group on methylenic carbon, is presented, starting from 4-hydroxymethylenoxazolone 1 and ethyl chlorocarbonate. Oxazolone 2 was reacted with cyclopentadiene in the presence of EtAlCl(2), giving the two diastereoisomeric cycloadducts exo-3 and endo-3 in a 70:30 ratio. Selective hydrolysis of ...
Czombos J - - 2000
Three strategies for the synthesis of the novel, doubly constrained, 3,4-methano-1,2,3,4-tetrahydroisoquinoline-3-carboxylic acid and its derivatives were evaluated. Only cyclocondensation of the mono(triphenyl)phosphonium salt derived from 1, 2-bis(bromomethyl)benzene with N-alkoxycarbonyloxamates in 1, 2-dimethoxyethane in the presence of potassium carbonate and subsequent cyclopropanation with dimethylsulfoxonium methylide in dimethyl sulfoxide furnished suitable O- ...
Ihmels H - - 2000
[reaction: see text] The fluorescence properties of selected derivatives of 6-methoxyanthracene-2-carboxylic acid were studied. The corresponding ester and oxazoline derivatives exhibit a moderate solvatochromism, which is caused by the donor-acceptor interplay. The fluorescence band shift and intensity of oxazoline 1f may be reversibly modulated by protonation or complexation with silver ...
Gallasch B A - - 2000
The previously unknown linoleic acid peroxidation product 9,12-dioxo-10(Z)-decenoic acid (Z5) was detected in lentil seed flour (Lens culinaris Medik.) by electron impact mass spectrometry (EI-MS) after derivatization with pentafluorobenzyl-hydroxylamine-hydrochloride, methylation of acidic groups with diazomethane, and protection of hydroxylic groups with N-methyl-N-trimethylsilyl-trifluoroacetamide. The structure of the natural product was confirmed ...
Xavier K B - - 2000
The operation of a novel glycolytic pathway was demonstrated in nongrowing cells of Thermococcus zilligii by analysis of the isotopic enrichment in the end products derived from fermentation of (13)C-labeled glucose. The new pathway involved the formation of formate, derived from C-1 in glucose, via cleavage of a six-carbon carboxylic ...
Wu T - - 2000
A novel method was used to obtain demethoxy amino-substituted hypocrellin derivatives. The reaction condition was mild and amino substitution occurred at position 2 or 11 of hypocrellins with high yield. The photophysical and photochemical properties of the amino-substituted hypocrellins derivatives were investigated, and their significantly enhanced red absorptivities and strong ...
Asami T - - 2000
Replacing the 4'-carbonyl group of abscisic acid with a methoxy group does not affect the abscisic acid (ABA)-like activities of the product in barley aleurone protoplasts, although the reduction of ABA to 4'-hydroxyl derivatives significantly reduces the ABA-like activity of the products. This suggests that methoxy derivatives of abscisic acid ...
Wilbur D S - - 2000
An investigation was conducted to determine the affect of structural variation of biotin conjugates on their dissociation rates from Av and SAv. This information was sought to help identify optimal biotin derivatives for in vivo applications. Fifteen biotin derivatives were conjugated with a cyanocobalamin (CN-Cbl) derivative for evaluation of their ...
Syrovets T - - 2000
Acetyl-boswellic acids (acetyl-BA) are pentacyclic triterpenes derived from the gum resin of frankincense. We have previously shown that these compounds are effective cytotoxic agents, acting through a mechanism that appears to involve the inhibition of topoisomerase activity. We have now investigated the mechanism of action of acetyl-BA and show that ...
Lee M K - - 2000
Asiatic acid, a triterpene of Centella asiatica (L.) Urban (Umbelliferae), has been patented as a treatment for dementia and an enhancer of cognition by the Hoechst Aktiengesellschaft (EP 0 383 171 A2). We modified the chemical structure of asiatic acid and obtained 36 derivatives of asiatic acid in an attempt ...
Sekine M - - 2000
A 2'-O-methyluridylic acid derivative 3 having a cyclic structure linked between the 5-position of the uracil residue and the 5'-phosphate group was synthesized. The NMR analysis suggests that this cyclouridylic acid derivative has exclusively the C3'-endo conformation that is in favor of duplex formation with RNA. Two oligonucleotides ¿pc3Um(pT)(9) and ...
Maier W - - 2000
Colonization of the roots of various tobacco species and cultivars (Nicotiana glauca Grah., N. longiflora Cav., N. rustica L., N. tabacum L., N. tabacum L. cv. Samsun NN, N. sanderae hort. Sander ex Wats.) as well as tomato plants (Lycopersicon esculentum L. cv. Moneymaker) by the arbuscular mycorrhizal fungus Glomus ...
Pellegrino L - - 2000
Residues of lysine-substituted AGEs (advanced glycosylation end-products) arising from the Maillard reaction and containing the carbon backbone of lactose or maltose, thus deriving from 1-desoxy-ketose degradation, were produced when casein was heated in the presence of the corresponding U14C labelled disaccharides. The enzymatic hydrolysates of the washed casein were purified ...
Bobrov M Y - - 2000
The hydrolysis of anandamide has been studied in mouse splenocytes using tritiated anandamide analogs labeled in the acyl- or ethanolamide parts of the molecule. [3H]Anandamide undergoes rapid (t(1/2) = 2.5 min) uptake and hydrolysis, yielding ethanolamine and arachidonic acid. The anandamide hydrolysis in splenocytes is sensitive to inhibition by phenylmethylsulfonyl ...
Dobosz M - - 2000
In the reaction of phenylacetic acid hydrazide or malonic acid hydrazide with isocyanates, new derivatives of semicarbazide were obtained [I-VIII]. Cyclization of these derivatives with a aqueous 2% sodium hydroxide led to the formation of new derivatives of delta 2-1,2,4-triazolin-5-one [IX-XVI]. Some of them were investigated pharmacologically on the central ...
Sobarzo-Sánchez E M - - 2000
(S)-(+)-Boldine (1) was brominated, chlorinated, and iodinated using molecular bromine in acetic acid or N-halosuccinimides in trifluoroacetic acid. Initial halogenation occurs at C-3, followed (in the cases of chlorine and bromine) by the less reactive C-8, to afford 3-haloboldines- and 3,8-dihaloboldines (2-5). Using a 2:1 ratio of N-iodosuccinimide to boldine, ...
Kiefelt M J - - 2000
Several C-9 modified N-acetylneuraminic acid derivatives have been synthesised and evaluated as substrates of N-acetylneuraminic acid aldolase. Simple C-9 acyl or ether modified derivatives of N-acetylneuraminic acid were found to be accepted as substrates by the enzyme, albeit being transformed more slowly than Neu5Ac itself. 1H NMR spectroscopy was used ...
Yokoyama M - - 2000
A stress-induced substance(s) (factor C) incubated with norepinephrine (NE) has strong flower-inducing activity in Lemna paucicostata. We isolated an essential component (FIF) of factor C, and clarified its chemical structure as 9-hydroxy-10-oxo-12(Z),15(Z)-octadecadienoic acid, an alpha-ketol derivative of linolenic acid, which is formed via 9-hydroperoxy linolenic acid. Synthesized FIF showed flower-inducing ...
Strigácová J - - 2000
The antimicrobial and morphogenetic effects of fourteen newly synthesized 2-substituted derivatives of quinoline-4-carboxylic acid and quinoline-4-carboxamide were studied using G+ and G- bacteria, yeasts and filamentous fungi. The highest antimicrobial effects were found with substituted quinoline-4-carboxylic acid derivatives. Quinoline-4-carboxamides only weakly influenced the growth of the tested microorganisms. Some derivatives ...
Talon R - - 2000
The growth and the effects of four species of staphylococci and six lactic acid bacteria (LAB) of the genus Carnobacterium, Lactobacillus and Pediococcus on unsaturated free fatty acids were studied. The strains were grown in complex medium supplemented either with oleic, linoleic or linolenic acids. Growth was followed and oxidation ...
Kanzaki H - - 2000
The cell-free extract of an albonoursin-producing strain, Streptomyces albulus KO-23, was found to catalyze the conversion of several cyclic dipeptides having Phe and aliphatic side chain-containing amino acid residues to the corresponding dehydro derivatives. 3Z-Benzylidene-6S-methyl-2,5-piperazinedione, 3Z-benzylidene-2,5-piperazinedione, and 3Z, 6Z-dibenzylidene-2,5-piperazinedione were prepared by this conversion system. Among the dehydro cyclic dipeptides ...
Chuiko AL - - 1999
Derivatives of aminomethylenebisphosphonic acids constitute a class of promising herbicides. Replacement of the amino group by hydroxyl, ureido, thioureido, or imino moieties leads to compounds of significant herbicidal properties. This indicates that protonated amino function is not a requirement for phytotoxic action of bisphosphonates.
Miketova P - - 1999
The mass spectral properties of 3,5- and 4,5-dicaffeoylquinic acids (DCQAs) and selected derivatives were examined using electron ionization (EI), fast atom bombardment (FAB) and electrospray ionization (ESI). EI analysis of the trimethylsilyl derivatives provides molecular mass (M(r)) information, but the spectrum is dominated by fragment ions of the caffeic acid ...
Kuroda N - - 1999
The preparation of three new types of phenylboronic acid derivatives and their evaluation as enhancers on the luminol-H(2)O(2)-horseradish peroxidase (HRP) chemiluminescence (CL) reaction are described. After optimizing the CL reaction conditions, the CL system was applied to the HRP determination. Among the three phenylboronic acid derivatives, i.e. 4-(4, 5-diphenyl-1H-imidazol-2-yl)phenylboronic acid ...
Petrusewicz J - - 1999
The action of acetylsalicylic acid, ticlopidine and a new pyrazine derivative HF90 selected in preliminary screenings (11, 18, 19) was studied by using the mouse antithrombotic assay according to DiMinno and Silver (22) and in vitro blood platelet aggregation method according to Born (23). Acute pulmonary thromboembolism was induced by ...
Mook-Jung I - - 1999
Asiaticoside (AS) derivatives were tested for potential protective effects against Abeta-induced cell death. Of the 28 AS derivatives tested, asiatic acid (AA), asiaticoside 6 (AS6), and SM2 showed strong inhibition of Abeta-induced death of B103 cells at 1 microM. The three AS derivatives were further tested for their effects on ...
Manna F - - 1999
Hyaluronic acid (HA) derivatives have been developed to try to enhance rheological properties of this molecule to make it suitable for various medical applications. The main dermatological application of HA derivatives is the augmentation of soft tissues, via injection into the dermis. HA derivatives are indicated for the correction of ...
Tremblay M R - - 1999
The C17-THP derivative of 7alpha-(11-azidoundecanyl)-estradiol (4) was synthesized and coupled to an aminomethyl resin via a photolabile o-nitrobenzyl linker. Reduction of the azide by the Staudinger reaction to its corresponding amine followed by acylation using four activated NFmoc protected amino acids gave a first level of diversity. Subsequent deprotection of ...
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