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1.
Scand J Rheumatol ; 47(5): 364-370, 2018 09.
Article in English | MEDLINE | ID: mdl-29804492

ABSTRACT

OBJECTIVE: To prospectively investigate the effect of tocilizumab (TCZ) on the levels of N-terminal pro-brain natriuretic peptide (NT-proBNP), as a predictor of congestive heart failure (CHF) in patients with active rheumatoid arthritis (RA). METHOD: Seventy patients with RA (median age 59 years, 86% female) free of cardiovascular disease were treated with TCZ and followed for 24 weeks. The NT-proBNP levels were measured at baseline and week 24. Thirty healthy controls were included for comparison of normal NT-proBNP levels with those of RA patients. RESULTS: The NT-proBNP level was significantly higher in patients with RA than in controls (median 42.5 pg/mL vs 109.0 pg/mL, p < 0.001). NT-proBNP levels decreased by 63% over the 24 weeks of TCZ treatment. Multiple linear regression analysis indicated that the percentage change in the NT-proBNP level was significantly associated with that of the Simplified Disease Activity Index (ß = 0.356, p = 0.014), even after adjusting for the levels of rheumatoid factor, duration of RA, age, and anti-cyclic citrullinated peptide antibody. CONCLUSION: TCZ decreased the NT-proBNP level in patients with RA without preceding cardiovascular disease and CHF. TCZ may have a cardioprotective effect in those with active RA.


Subject(s)
Antibodies, Monoclonal, Humanized/therapeutic use , Arthritis, Rheumatoid/drug therapy , Heart Failure/prevention & control , Natriuretic Peptide, Brain/blood , Peptide Fragments/blood , Adult , Aged , Arthritis, Rheumatoid/blood , Arthritis, Rheumatoid/complications , Female , Heart Failure/blood , Heart Failure/etiology , Humans , Male , Middle Aged , Prospective Studies
3.
Vet Comp Oncol ; 15(3): 731-739, 2017 Sep.
Article in English | MEDLINE | ID: mdl-26766288

ABSTRACT

5-Aminolevulinic acid (5-ALA) is widely used in photodynamic detection (PDD) and therapy. We evaluated the pharmacokinetics of 5-ALA-induced porphyrins and its effectiveness in PDD in dogs with mammary gland tumours (MGTs) following oral administration. Healthy dogs and those with MGTs (nine each) were orally administered 4 mg kg-1 5-ALA. Protoporphyrin IX (PpIX) was not detected in the plasma of healthy dogs but it peaked in dogs with MGT at 2 h after 5-ALA administration. In the PDD study, 16 dogs with MGT were orally administered 40 mg kg-1 5-ALA, and MGT but not normal tissue showed red fluorescence after 2-4 h. Photon counts were 6635-63 890 and 59-4011 (median, 19 943 and 919) for MGT and non-tumour tissues, respectively. Cell density strongly correlated with PpIX photon counts of MGT tissue of the dogs (R = 0.743, P = 0.0009). We suggest that 5-ALA-PDD might be an effective diagnostic tool for MGTs.


Subject(s)
Aminolevulinic Acid/pharmacology , Dog Diseases/diagnosis , Mammary Neoplasms, Animal/diagnosis , Photosensitizing Agents/pharmacology , Spectrometry, Fluorescence/veterinary , Administration, Oral , Aminolevulinic Acid/administration & dosage , Animals , Dogs , Female , Photosensitizing Agents/administration & dosage , Porphyrins/metabolism
4.
Anticancer Res ; 20(5A): 2951-4, 2000.
Article in English | MEDLINE | ID: mdl-11062706

ABSTRACT

Among 11 benzothiepins/benzoxepins, 4-chloro-3,4-dihydro-2-(2-oxo-2-phenylethyl)-1-benzothiepin-5-(2H)-one [1] showed the highest cytotoxicity against human oral squamous cell carcinoma HSC-2 cells, followed by 2,3-dihydro-2-(2-oxopropyl)-2-phenyl-1-benzoxepin [2]. Popular antioxidants, such as N-acetyl-L-cysteine and sodium ascorbate significantly reduced the cytotoxic activity of [1] but not that of [2]. Compound [1] induced internucleosomal DNA fragmentation in human promyelocytic leukemic HL-60 cell line, but produced large DNA fragmentation in human oral tumor cell lines (HSC-2, HSG). Compounds [1] and doxorubicin additively reduced the viable cell number of HSC-2 cells. These data, taken together with their tumor specific action, demonstrate for the first time, the medicinal efficacy of benzothiepins/benzoxepins.


Subject(s)
Antineoplastic Agents/pharmacology , Antioxidants/pharmacology , Benzothiepins/pharmacology , Benzoxepins/pharmacology , Copper , Ferric Compounds , Apoptosis/drug effects , Benzothiepins/chemistry , Benzoxepins/chemistry , Carcinoma, Squamous Cell , Cell Survival/drug effects , DNA Fragmentation/drug effects , Doxorubicin/pharmacology , Drug Synergism , HL-60 Cells , Humans , Metals , Molecular Structure , Mouth Neoplasms , Salivary Gland Neoplasms , Tumor Cells, Cultured
5.
Anticancer Res ; 18(1A): 425-8, 1998.
Article in English | MEDLINE | ID: mdl-9568113

ABSTRACT

The radical modulating activity of 2-methoxy-4-(2-propenyl)phenol (eugenol), 2-t-butyl-4-methoxy-phenol (BHA), and their dimers (bis-eugenol, bis-BHA) was investigated, using ESR spectroscopy. Eugenol produced radicals in alkaline solutions, and enhanced the radical intensity of both sodium-L-ascorbate and sodium 5,6-benzylidene-L-ascorbate. BHA has similar, but slightly lower activity, and their dimers were inactive. Their ability to scavenge the superoxide anion (O2-), generated by hypoxanthine and xanthine oxidase reaction, was in the order of eugenol > bis-eugenol > BHA > bis-BHA. The relative radical intensity among these compounds was paralleled by their cytotoxic activity. The present study demonstrates that eugenol and BHA were very reactive with radicals and their reactivity was considerably reduced by dimerization. The applicability of the dimerized eugenol in dentistry was discussed.


Subject(s)
Butylated Hydroxyanisole/chemistry , Eugenol/chemistry , Free Radical Scavengers , Ascorbic Acid/chemistry , Electron Spin Resonance Spectroscopy , Free Radicals , Superoxides/chemistry
6.
Anticancer Res ; 21(5): 3371-5, 2001.
Article in English | MEDLINE | ID: mdl-11848496

ABSTRACT

A total of 23 newly-synthesized 2-aminomethylene-3(2H)-benzofuranone and structurally-related compounds were compared for their cytotoxic activity against both normal (human gingival fibroblast HGF) and tumor cells (human oral squamous cell lines HSC-2, HSC-3 and human salivary gland tumor cells HSG). There was a significant variability of drug sensitivity among the oral tumor cell lines. In general, HSC-2 cells were the most sensitive, followed by HSG cells, while HSC-3 cells were the most resistant. HGF normal cells were highly resistant to all compounds, suggesting their tumor-specific cytotoxic action. The cytotoxic activity of the compounds with morpholine, 1-methylpiperazine or piperidine structure was generally elevated by the introduction of fluorine, but not chlorine and methoxy functional groups, to the benzofuranone structure, whereas that of compounds attached by 1-phenylpiperazine or 1-(2-pyridyl)piperazine was rather reduced. The most active compounds induced internucleosomal DNA fragmentation in human promyelocytic leukemia HL-60 cells, but not in HSG, further confirming that oral tumor cell lines are resistant to DNase digestion.


Subject(s)
Antineoplastic Agents/pharmacology , Benzofurans/pharmacology , Carcinoma, Squamous Cell/drug therapy , Mouth Neoplasms/drug therapy , Antineoplastic Agents/chemical synthesis , Antineoplastic Agents/chemistry , Benzofurans/chemical synthesis , Benzofurans/chemistry , Drug Screening Assays, Antitumor , Fibroblasts/drug effects , Gingiva/cytology , Gingiva/drug effects , Humans , Piperidines/chemical synthesis , Piperidines/chemistry , Piperidines/pharmacology , Salivary Gland Neoplasms/drug therapy , Structure-Activity Relationship , Tumor Cells, Cultured
7.
Anticancer Res ; 21(2A): 1081-6, 2001.
Article in English | MEDLINE | ID: mdl-11396143

ABSTRACT

A total of 24 benzoylimidazoles and structurally-related compounds were investigated for their cytotoxic activity against oral tumor cells and normal gingival fibroblast. Compound 23 (5-(2-hydroxylbenzoyl)-2-phenylimidazole) showed the highest cytotoxic activity against both human oral tumor cell lines (human squamous cell carcinoma HSC-2, human salivary gland tumor HSG) and normal human gingival fibroblast (HGF). Compounds 7 (2-(2-hydroxybenzoyl)benz imidazo[2,1-b]thiazole), 14 (1,3-diethyl-5-(2-hydroxybenzoyl)-4-imidazoline-2-thione) and 18 (5-(2-hydroxy-4-methoxybenzoyl)-3-methyl-2-methylimino-4-thiazoline) showed slightly lower cytotoxic activity, but higher tumor-specific cytotoxic action. The cytotoxic activity of compound 23 was significantly reduced by CuCl2, but not by CoCl2, FeCl3, or by antioxidants (N-acetyl-L-cysteine, sodium ascorbate, catalase). Compound 23 did not show any detectable oxidation potential (determined by NO monitor). Agarose gel electrophoresis demonstrated that compound 23 induced DNA fragmentation in human promyelocytic leukemia cells HL-60, but not in HSG cells. These data suggested that the response to compound 23 might be different from cell to cell.


Subject(s)
Antineoplastic Agents/pharmacology , Imidazoles/pharmacology , Antineoplastic Agents/chemistry , Antioxidants/pharmacology , Carcinoma, Squamous Cell , DNA Fragmentation , Drug Screening Assays, Antitumor , HL-60 Cells , Humans , Imidazoles/chemistry , Metals , Molecular Structure , Mouth Neoplasms , Salivary Gland Neoplasms , Tumor Cells, Cultured
8.
Anticancer Res ; 20(4): 2519-24, 2000.
Article in English | MEDLINE | ID: mdl-10953321

ABSTRACT

To investigate the possible link between radicals and cytotoxicity of eugenol-related compounds, dimer compounds were synthesized from eugenol (4-allyl-2-methoxyphenol) or isoeugenol (4-propenyl-2-methoxyphenol): bis-eugenol (3,3'-dimethoxy-5,5'-di-2-propenyl-1,1'-biphenyl-2,2'-diol); dehydrodiisoeugenol (2-(3-methoxy-4-hydroxyphenyl)-3-methyl-5-(1-propenyl)-7-methoxy-2,3- dihydrobenzofuran) and alpha-di-isoeugenol (r-l-ethyl-5-hydroxy-t-3-(4-hydroxy-3-methoxyphenyl)-6-methoxy-c-2- methylindane). Both the cytotoxic activity and the DNA synthesis inhibitory activity of these compounds against a salivary gland tumor cell line (HSG) and normal human gingival fibroblast (HGF) were decreased in the order of: dehydrodiisoeugenol, alpha-di-isoeugenol > isoeugenol > eugenol > bis-eugenol. Electron spin resonance (ESR) spectroscopy showed that dehydrodiisoeugenol, alpha-di-isoeugenol and eugenol, but not isoeugenol and bis-eugenol, produced phenoxyl radicals under alkaline condition (pH > 9.5). However, benzyl radicals were produced during the dimerization of isoeugenol to dehydrodiisoeugenol. The radical intensity of alpha-di- and dehydrodiisoeugenol appeared at relatively later incubation time than eugenol, suggesting that their phenoxyl radical was more stable than that of eugenol. Such a phenoxyl radical is produced by scavenging free radicals, during the inhibition of lipid peroxidation. Higher cytotoxic activity of isoeugenol dimers was thought to be induced by interaction with cell membranes via the lipophilic radical. The present study supports the notion that relative cytotoxicity of chemicals can be evaluated by measuring the radical intensity using ESR.


Subject(s)
Antineoplastic Agents/pharmacology , Eugenol/analogs & derivatives , Eugenol/pharmacology , Cell Line , DNA/biosynthesis , Electron Spin Resonance Spectroscopy , Fibroblasts/drug effects , Free Radicals , Humans , Salivary Gland Neoplasms/pathology
9.
Anticancer Res ; 21(4A): 2629-32, 2001.
Article in English | MEDLINE | ID: mdl-11724331

ABSTRACT

A total of 11 newly synthesized benzothiepins and structurally-related compounds were investigated for cytotoxic activity against both normal and tumor cells. All these compounds showed higher cytotoxic activity against three human oral tumor cell lines (HSC-2, HSC-3, HSG) than against normal human gingival fibroblast (HGF), suggesting tumor-specific cytotoxic action. In general, 3,4-dihydro-1-benzothiepin-5(2H)-ones [1-6] showed higher cytotoxic activity than 2,3-dihydro-1-benzothiepins [7-11]. Compounds 4 (4-bromo-3,4-dihydro-2-(2-oxo-2-phenylethyl)-1-benzothiepin-5(2H)-one), 5 (4-bromo-3,4-dihydro-2-(2-oxopropyl)-1-benzothiepin-5(2H)-one) and 6 (4-bromo-3,4-dihydro-2-[1-(methoxycarbonyl)-1-methylethyl]-1-benzothiepin-5(2H)-one), showed higher cytotoxic activity than compounds 1, 2 and 3, respectively, which had Cl instead of Br at C-4 position. Agarose gel electrophoresis demonstrated that these compounds induced large DNA fragments in oral tumor cells, whereas they produced smear pattern of smaller DNA fragments in human promyelocytic leukemia cells HL-60. These data suggest the medicinal efficacy of benzothiepins.


Subject(s)
Antineoplastic Agents/toxicity , Benzothiepins/toxicity , Mouth Neoplasms/drug therapy , Antineoplastic Agents/chemical synthesis , Benzothiepins/chemical synthesis , Carcinoma, Squamous Cell/drug therapy , Drug Screening Assays, Antitumor , Fibroblasts/cytology , Fibroblasts/drug effects , Gingiva/cytology , Gingiva/drug effects , HL-60 Cells/drug effects , Humans , Salivary Gland Neoplasms/drug therapy , Structure-Activity Relationship , Tumor Cells, Cultured
10.
Anticancer Res ; 20(5A): 2955-60, 2000.
Article in English | MEDLINE | ID: mdl-11062707

ABSTRACT

The ability of nine synthetic eugenol-related compounds to scavenge O2- (generated by the hypoxanthine-xanthine oxidase reaction) was compared with their radical generation and cytotoxic activity. ESR spectroscopy showed that eugenol (4-allyl-2-methoxyphenol), 2-allyl-4-methoxyphenol, 2-allyl-4-t-butylphenol and 2,4-dimethoxyphenol efficiently scavenged O2- and produced radicals under alkaline conditions. 2-allyl-4-t-butylphenol showed the highest cytotoxic activity and DNA-synthesis inhibitory activity, possibly due to the hydrophobic radical reactivity. 2-allyl-4-methoxyphenol and 2,4-dimethoxyphenol showed higher antioxidant activity than 3-t-butyl-4-hydroxyanisol (BHA), but all these compounds showed comparable cytotoxic activity with each other. These findings suggest a possible link between the cytotoxic activity and radical generation/scavenging activity in eugenol-related compounds.


Subject(s)
Antineoplastic Agents/pharmacology , Antioxidants/pharmacology , Eugenol/analogs & derivatives , Free Radical Scavengers/pharmacology , Antineoplastic Agents/chemical synthesis , Antineoplastic Agents/metabolism , Antioxidants/chemical synthesis , Antioxidants/metabolism , Eugenol/chemical synthesis , Eugenol/metabolism , Free Radical Scavengers/chemical synthesis , Free Radical Scavengers/metabolism , Free Radicals , Humans , Salivary Gland Neoplasms , Superoxides , Tumor Cells, Cultured
11.
Anticancer Res ; 19(5B): 3947-52, 1999.
Article in English | MEDLINE | ID: mdl-10628336

ABSTRACT

The radical intensity of BHA (4-Hydroxy-3-t-butylanisole) and its dimer (3,3'-Di-t-butyl-5,5'-dimethoxy-1,1'-biphenyl-2,2'-diol, Bis-BHA) were compared with their cytotoxic activity. ESR spectroscopy showed that BHA produced characteristic five peaks of radicals under alkaline conditions (pH > 9.5). At higher pH, BHA radical rapidly disappeared, and progressively transformed into new radical species, as detected by the splitting of the ESR signal. BHA showed higher cytotoxic activity against salivary gland tumor cell line than against normal human gingival fibroblast. On the other hand, Bis-BHA did not produce any detectable amounts of radicals at wide ranges of pH, corresponding with its weaker cytotoxic activity as compared with BHA. BHA scavenged DPPH (1,1-Diphenyl-2-picrylhydrazyl) radical and superoxide anion, more efficiently than Bis-BHA. The present study demonstrated that BHA is more cytotoxic, produces higher amounts of radicals and more efficiently scavenges various radical species, as compared with Bis-BHA. This suggests the possible link between the cytotoxic activity and radical generation/scavenging activity in BHA-derived compounds.


Subject(s)
Antioxidants/chemistry , Butylated Hydroxyanisole/chemistry , Butylated Hydroxyanisole/pharmacology , Free Radical Scavengers/chemistry , Picrates , Aspirin/pharmacology , Bepridil/analogs & derivatives , Bepridil/pharmacology , Biphenyl Compounds , Butylated Hydroxyanisole/analogs & derivatives , Child , Dose-Response Relationship, Drug , Electron Spin Resonance Spectroscopy , Female , Fibroblasts/metabolism , Free Radicals/chemistry , Gingiva/metabolism , Humans , Hydrogen-Ion Concentration , Kinetics , Models, Chemical , Salivary Gland Neoplasms/drug therapy , Time Factors , Tumor Cells, Cultured
12.
J Dent ; 27(4): 291-5, 1999 May.
Article in English | MEDLINE | ID: mdl-10193107

ABSTRACT

OBJECTIVES: To assess the usefulness of dimerized eugenol (bis-eugenol) in dentistry, the physical properties of zinc oxide eugenol cement (ZOE) with bis-eugenol and the cytotoxicity of bis-eugenol were studied. METHODS: Setting time, compressive strength, solubility and disintegration of ZOE cement with bis-eugenol according to the specifications of JDMAS315 were evaluated. The cytotoxicity of bis-eugenol and eugenol toward two different cell types, HGF (a primary culture of human gingival fibroblast) and HSG (a human epidermoid carcinoma cell line derived from a salivary gland) was evaluated by the MTT test and in terms of cell survival. RESULTS: Addition of bis-eugenol to ZOE did not decrease the physical properties when employed at the ratio of 9:1 or 6:1 (liquid ND:bis-eugenol, w/w). Bis-eugenol was less toxic than eugenol in the cell culture tests. CONCLUSIONS: The results of this assay demonstrated that bis-eugenol is useful in ZOE.


Subject(s)
Eugenol/chemistry , Zinc Oxide-Eugenol Cement/chemistry , Adenocarcinoma , Cell Survival/drug effects , Cells, Cultured , Chemical Phenomena , Chemistry, Physical , Dose-Response Relationship, Drug , Drug Combinations , Eugenol/toxicity , Fibroblasts/drug effects , Gingiva/cytology , Gingiva/drug effects , Humans , Salivary Gland Neoplasms , Tumor Cells, Cultured , Zinc Oxide-Eugenol Cement/toxicity
13.
Yakugaku Zasshi ; 115(4): 307-17, 1995 Apr.
Article in Japanese | MEDLINE | ID: mdl-7602497

ABSTRACT

It was found that (+/-)ethyl 2-[2-(3-hydroxypropyl)-4-oxocyclohexylidene]-propionate (1), (+/-)ethyl 2-[2-(3-hydroxypropyl)-4,5-dimethoxyphenyl]propionate (2) and (+/-)3-[2-(3-hydroxypropyl)-4,5-dimethoxyphenyl]-2-butanone (3) had excellent antiulcer activities. In order to study structure-activity relationships, (+/-)2-[(3-hydroxypropyl)phenyl]cyclopentanone derivatives (4, 5) and (+/-)2-[(3-hydroxypropyl)phenyl]cyclopentanol derivatives (6, 7) were synthesized and tested for antiulcer activities. As a result, (+/-)2-[2-(3-hydroxypropyl)-4-methoxy-5-(2- piperidinoethoxy)phenyl]cyclopentanone (5k) exhibited potent antiulcer activities.


Subject(s)
1-Propanol/chemical synthesis , Anti-Ulcer Agents/chemical synthesis , Benzhydryl Compounds/chemical synthesis , 1-Propanol/chemistry , 1-Propanol/pharmacology , Animals , Anti-Ulcer Agents/chemistry , Anti-Ulcer Agents/pharmacology , Benzhydryl Compounds/chemistry , Benzhydryl Compounds/pharmacology , Rats , Rats, Sprague-Dawley , Structure-Activity Relationship
14.
Yakugaku Zasshi ; 115(4): 318-28, 1995 Apr.
Article in Japanese | MEDLINE | ID: mdl-7602498

ABSTRACT

It was found that (+/-)ethyl 2-[2-(3-hydroxypropyl)-4-oxocyclohexylidene-propionate (1), (+/-)ethyl 2-[2-(3-hydroxypropyl)-4,5-dimethoxyphenyl]propionate (2), (+/-)3-[2-(3-hydroxypropyl)-4,5-dimethoxyphenyl]-2-butanone (3) and (+/-)2-[2-(3-hydroxypropyl)-4-methoxy-5-(2- piperidinoethoxy)phenyl]cyclopentanone (4) had potent antiulcer activities. In order to study structure-activity relationships, (+/-)3-[(3-hydroxypropyl)phenoxy]-2-butanone derivatives (5, 6) were synthesized and tested for antiulcer activities. Among them, (+/-)3-[2-(3-hydroxypropyl)-4-methoxy-5-[3-(4- methylpiperidino)propoxy]phenoxy]-2-butanone.3/2 oxalate (6k) was selected as a preferred antiulcer agent.


Subject(s)
1-Propanol/chemical synthesis , Anti-Ulcer Agents/chemical synthesis , Benzhydryl Compounds/chemical synthesis , 1-Propanol/pharmacology , Animals , Anti-Ulcer Agents/chemistry , Anti-Ulcer Agents/pharmacology , Benzhydryl Compounds/pharmacology , Rats , Rats, Sprague-Dawley , Structure-Activity Relationship
15.
Yakugaku Zasshi ; 114(12): 995-1004, 1994 Dec.
Article in Japanese | MEDLINE | ID: mdl-7869239

ABSTRACT

It was found that gamma-irigermanal, obtained from the methanol extract of root of Iris germanica, exhibited a potent antiulcer activity. Therefore, this compound was selected as a lead-compound, and related compounds were synthesized and tested for antiulcer activities. It was found that (+/-) ethyl 2-[2-(3-hydroxypropyl)-4-oxocyclohexylidene]- propionate (1) had excellent antiulcer activities. Then phenylpropanol derivatives, obtained by changing from cyclohexane ring of 1 to benzene ring, were synthesized and tested for antiulcer activities in order to study structure activity relationships. As a result, (+/-) ethyl 2-[2-(3-hydroxypropyl)-4,5-dimethoxy-phenyl]propionate (2b) and (+/-) 3-[2-(3-hydroxypropyl)-4,5-dimethoxyphenyl]-2-butanone (5) were shown to have antiulcer activities.


Subject(s)
1-Propanol/chemical synthesis , Anti-Ulcer Agents/chemical synthesis , 1-Propanol/pharmacology , Animals , Anti-Ulcer Agents/pharmacology , Propanols , Rats , Rats, Sprague-Dawley , Stomach Ulcer/drug therapy , Structure-Activity Relationship
16.
Yakugaku Zasshi ; 114(12): 980-94, 1994 Dec.
Article in Japanese | MEDLINE | ID: mdl-7869238

ABSTRACT

The antiulcer activities of 59 methanol and aqueous extracts obtained from 59 crude drugs on the ethanol-HCl-induced ulceration in rats were investigated. Among them 15 extracts were selected and they were further examined for their effects on indomethacin-, aspirin- and the water-immersion stress-induced ulcer. From these results, the methanol extract of root of Iris germanica was found to, show potent antiulcer activities. The above methanol extract was separated into 3 portions by solvent extraction, and the ether soluble portion was fractionated into 5 fractions (1 to 5) by chromatography. Fractions 4 and 5 showed significant antiulcer activities. Fraction 4 was further purified and the obtained gamma-irigermanal exhibited a potent antiulcer activity. However, further investigations are required to understand the mechanism.


Subject(s)
Anti-Ulcer Agents/pharmacology , Drugs, Chinese Herbal/pharmacology , Stomach Ulcer/drug therapy , Animals , Disease Models, Animal , Gastric Acid/metabolism , Methanol , Mice , Mice, Inbred ICR , Rats , Rats, Sprague-Dawley , Water
20.
Chem Pharm Bull (Tokyo) ; 49(5): 657-8, 2001 May.
Article in English | MEDLINE | ID: mdl-11383629

ABSTRACT

The treatment of cyclopropanes having donor and acceptor substituents at the vicinal positions on the cyclopropane ring with a Lewis acid readily generates a 1,3-zwitterion, which reacted with allylsilanes to produce cycloadducts and allylic products. It was found that the yield of the cycloadduct depends on the steric demand of the alkyl substituents on the silicon atom.


Subject(s)
Allyl Compounds/chemistry , Cyclopropanes/chemistry , Silanes/chemistry , Cyclization , Indicators and Reagents , Stereoisomerism
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