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Biomedical subjects

I Kubo

Publications and source records attributed to I Kubo.

At least 55 records · Page 3Linked to original sources
PubMed1995

Structural functions of antimicrobial long-chain alcohols and phenols.

Antimicrobial activity of a series of long-chain alcohols and common naturally occurring alcohols were tested against 15 selected microorganisms in order to gain new insights into their structural functions. The maximum activity seems to depend on the hydrophobic chain length from the hydrophilic hydroxyl group, and also the microorganisms being tested. The results obtained with the alcohols exhibit a generally applicable rule to many other compounds.

Alcohols↗
PubMed1995

Tyrosinase inhibitors from Bolivian medicinal plants.

Bioassay-guided fractionation monitored by mushroom tyrosinase (EC 1.14.18.1) activity, afforded six inhibitors from three Bolivian medicinal plants, Buddleia coriacea, Gnaphalium cheiranthifolium, and Scheelea princeps. These inhibitors, which are all known phenolic compounds, inhibited the oxidation of L-3,4-dihydroxyphenylalanine (L-DOPA) mediated by a mushroom tyrosinase.

Basidiomycota↗
PubMed1995

Enantioselective biotransformation of 1-isopropylnaphthalene in rabbits.

1-Isopropylnaphthalene (1) was administered orally to rabbits and the following eight metabolites, 2-(1-naphthyl)-2-propanol (7), 2-(1-naphthyl)-1-propanol (8: R/S = 83:17), 2-(1-naphthyl)-1,2-propanediol (9:R/S = 40:60), 4-isopropyl-1,2-naphthoquinone (10), 4-isopropyl-1-naphthol (11), 4-isopropyl-2-naphthol (12), 5-isopropyl-2-naphthol (13), and 2-(1-naphthyl)propanoic acid (14') as its methyl ester (14: R/S = 52:48), were isolated from urine. Among them, three metabolites (8, 9, and 14), possessing an asymmetric carbon atom in the molecule, were formed enantioselectively and five metabolites (7, 10, 11, 12, and 13) were formed regioselectively. The presumed metabolic pathways of 1-isopropylnaphthalene (1) in rabbits leading to these metabolites are discussed.

Administration, Oral↗
PubMed1994

Double perfusion system for coronary angioplasty at the origin of the main vessel.

For the treatment of stenosis near the origin of either the left anterior descending artery or the left circumflex artery, one autoperfusion catheter was used to dilate the lesion while another was used to maintain perfusion of the nonstenosed vessel, which would normally suffer from a decrease in blood flow. This technique was applied to nine procedures in six patients. The balloon could be inflated for more than 60 sec in all cases. Satisfactory dilation was achieved without a significant decrease of systemic blood pressure during the procedure.

Angioplasty, Balloon, Coronary↗
PubMed1994

Structural basis for bitterness based on Rabdosia diterpenes.

Bitterness of naturally occurring substances seems to be due to a balance between the "bitter unit" and the hydrophobic portions of the molecule. The study based on the Rabdosia diterpenes indicates that the bitter unit consists of a proton donor DH group and a proton acceptor A group. In addition to this DH-A unit, an A-A unit may also be possible. The bitter compounds could enter the molecular structure of the receptor site with the bitter unit oriented into the aqueous phase by hydrogen bonding and the hydrophobic portion aligned into the lipid phase by dispersion forces.

Animals↗
PubMed1994

Naturally occurring antiacne agents.

Antibacterial activity of various secondary metabolites from plants against Propionibacterium acnes was tested. In addition, the study of combinations of compounds to enhance the total activity against this follicular bacterium was investigated. A series of long-chain alcohols was studied in great detail to gain new insights into the role of the hydrophobic alkyl groups in the activity.

Acne Vulgaris↗
PubMed1994

Tyrosinase inhibitors from Anacardium occidentale fruits.

Anacardic acids, 2-methylcardols, and cardols isolated from various parts of the cashew [Anacardium occidentale] (Anacardiaceae) fruit have been found to exhibit tyrosinase inhibitory activity. Kinetic studies with the two principal active compounds, 6-[8(Z),11(Z),14-pentadecatrienyl]salicylic acid and 5-[8(Z),11(Z),14-pentadecatrienyl]resorcinol, have indicated that both of these phenolic compounds exhibit characteristic competitive inhibition of the oxidation of L-3,4-dihydroxyphenylalanine (L-DOPA) by mushroom tyrosinase.

Anacardic Acids↗
PubMed1994

Antimicrobial agents from Heterotheca inuloides.

By bioassay directed fractionation, four sesquiterpenoids 1-4 were isolated as antimicrobial agents from the dried flowers of Heterotheca inuloides, a Mexican medicinal plant locally known as "arnica". 7-Hydroxy-3,4-dihydrocadalin (3) and 7-hydroxycadalin (4) exhibited potent antibacterial activity against Gram-positive bacteria with minimum inhibitory concentrations (MICs) ranging from 6.25 to 12.5 micrograms/ml. Notably, 7-hydroxy-3,4-dihydrocadalin showed bactericidal activity against methicillin-resistant Staphylococcus aureus (MRSA) with a minimum bactericidal concentration (MBC) of 12.5 micrograms/ml.

Anti-Bacterial Agents↗
PubMed1993

Combination effects of antifungal nagilactones against Candida albicans and two other fungi with phenylpropanoids.

Antifungal activity of three nagilactones isolated from the root bark of Podocarpus nagi (Podocarpaceae), alone and in combination with a variety of phenylpropanoids, was investigated against three fungi, Candida albicans, Saccharomyces cerevisiae, and Pityrosporum ovale. Nagilactone E [2], the most abundant norditerpene dilactone, showed moderate to weak activity against these fungi. This activity was dramatically enhanced by several naturally occurring phenylpropanoids such as anethole [5] and isosafrole. For example, anethole enhanced the activity of nagilactone E as much as 128-fold for C. albicans, decreasing the MIC of this nagilactone from 800 to 6.25 micrograms/ml.

Amphotericin B↗
PubMed1993

Percutaneous transluminal coronary angioplasty for acute myocardial infarction.

Between 1986 and 1991, direct coronary angioplasty was attempted in 79 patients. The procedure was successful in 76 patients (96%), unsuccessful without complications in 2 patients, and major complications occurred in 1 patient (ventricular fibrillation and cardiogenic shock). Reperfusion was obtained from 1 to 7.5 hours (mean: 3.3 +/- 1.3 hours) after the onset of chest pain. Among the 76 successfully dilated patients, there was one cardiac death and 68 had predischarge angiography (64 patent, 2 stenosed, and 2 occluded). Although only 33 of the 58 patients (57%) angiographically followed after discharge showed persistence of primary patency, 52 of the 57 (91%) followed further obtained final patency when angioplasty was repeated up to 4 times. These results indicate that direct angioplasty in the community hospital setting can achieve a high primary success rate and a low reocclusion rate.

Adult↗
PubMed1993

[Clinical efficacy of coronary angioplasty for totally occluded lesions in recent transmural myocardial infarction].

Percutaneous coronary angioplasty was used to treat the occlusive lesions responsible for prior myocardial infarction occurring 1-8 weeks previously. Angioplasty was successful in 31 of 33 patients' lesions. Follow-up angiography showed dilated lesions were patent (0-50% diameter stenosis) in 10 patients, mildly stenosed (51-74%) in 3, severely stenosed (75-90%) in 10, subtotally occluded in 2, totally occluded in 5 and one was lost to follow-up. By repeating angioplasty up to two times, the lesions became patent in 23 patients, mildly stenosed in one, totally occluded in 4, and 3 were lost to follow-up. Measuring the left ventricular function in 22 patients with patent lesions and one with mildly stenosed lesion showed the left ventricular ejection fraction was improved from 60 +/- 13.1 to 69 +/- 11.6% (p < 0.00005), and hypokinetic areas (from 18 +/- 15.1% of left ventricular wall to 11 +/- 9.9%, p < 0.05) and an akinetic area (from 11 +/- 12.5% to 4 +/- 7.3%, p < 0.002) were decreased. The findings indicate that angioplasty for totally occluded lesions within 12 weeks of infarction achieves satisfactory lesion patency and functional recovery of the infarcted myocardium.

Angioplasty, Balloon, Coronary↗
PubMed1993

[Ticlopidine may prevent subtotal or total occlusion of dilated lesions after percutaneous coronary angioplasty].

The efficacy of ticlopidine and probucol plus oryzanol for reducing restenosis after dilation was examined in 151 patients with 229 stenotic lesions treated by coronary angioplasty after complete resolution of associated acute myocardial infarction, unstable angina, and variant angina. The stenotic lesions were 90% or less in diameter and less than 10 mm in length, and residual stenosis was 40% or less after treatment. Patients were randomly assigned to receive no medication, ticlopidine (200 mg daily) and/or probucol (1,000 mg daily) plus oryzanol (300 mg daily). One hundred forty-six patients with 220 dilated lesions were examined angiographically to evaluate restenosis. The medications achieved no clear reduction in restenosis, but subtotal or total reocclusion occurred in 6 of 102 patients not receiving ticlopidine, and in none of 118 patients receiving ticlopidine (p < 0.008). Ticlopidine may prevent subtotal or total reocclusion in dilated lesions.

Angioplasty, Balloon, Coronary↗
PubMed1992

Potentiation of antifungal activity of sesquiterpene dialdehydes against Candida albicans and two other fungi.

The antifungal activity of two drimane sesquiterpene dialdehydes, polygodial (1) and warburganal (2), alone and in combination with several other substances, was examined against three fungi, Candida albicans, Saccharomyces cerevisiae and Pityrosporum ovale employing a broth dilution method. Anethole significantly synergized the activity of the two sesquiterpenoids against C. albicans and S. cerevisiae; however, it had only an additive effect against P. ovale. By contrast, two antioxidants, ascorbic acid (vitamin C) and BHA (butylated hydroxyanisole), noticeably enhanced the activity of the sesquiterpenoids against P. ovale, but had no effect against C. albicans and S. cerevisiae.

Allylbenzene Derivatives↗
PubMed1992

Coronary angiography using 4-French preformed catheters--percutaneous brachial approach.

4-French performed catheter systems were developed for coronary angiography. After several new technical features were introduced, these catheters were applied in 384 outpatients between January 1989 and December 1989. Diagnostic coronary angiography was performed in all cases without major complications. In the left coronary artery, 4.0 cm left Judkins catheters were generally used; however, 3.5 cm left Judkins catheters were used if the patient was < or = 164 cm tall and left Amplatz catheters were employed for those > or = 165 cm tall. Although 4.0 cm right Judkins catheters were mainly used for right coronary arteries, there were no predictive factors for subsequent catheter selection. This technique is believed to be suited to meet the increasing demand for coronary angiography.

Adult↗
PubMed1992

Antimicrobial agents from Licaria puchuri-major and their synergistic effect with polygodial.

The resistance of the seeds of Licaria puchuri-major (Lauraceae) to decomposition in nature seems to be due largely to chemical defense, since its n-hexane extract contains antimicrobial principles in quantity, with a broad antimicrobial spectrum. In order to identify the active principles, the n-hexane extract was steam-distilled to yield a distillate and a residue. Subsequent bioassay indicated that the distillate retained the original broad antimicrobial activity, while the residue exhibited almost no activity. Gc-ms analysis showed that the distillate contained four phenolic compounds, seven monoterpenes, and one sesquiterpene. In contrast, the residue contained, almost exclusively, lauric acid. In the detailed antimicrobial assay with the pure compounds identified, most of them showed broad, but moderate, antimicrobial activity. Some of the components identified in the distillate were combined with polygodial [1] in order to enhance their antifungal activity. Unexpectedly, while polygodial did not synergize the antifungal activity of any of the compounds tested, the antifungal activity of polygodial was significantly increased when combined with aromatic substances such as anethole, safrole, or methyleugenol.

Antifungal Agents↗
PubMed1992

Antibacterial activity of crinitol and its potentiation.

An acyclic diterpene alcohol, crinitol [1], was identified in a marine brown alga, Sargassum tortile, as the principal antibacterial agent against Gram-positive bacteria, among which Propionibacterium acnes was most sensitive and, Staphylococcus aureus was least. To enhance its activity, crinitol was combined with several antioxidants, which presumably retard oxidative destruction of this molecule which possesses two easily oxidizable allylic alcohol groups. Two synthetic antioxidants, BHA (butylated hydroxyanisole) and BHT (butylated hydroxytoluene), significantly enhanced the activity of crinitol, especially against Streptococcus mutans. Interestingly, crinitol also synergized BHT and BHA against this cariogenic bacterium.

Anti-Bacterial Agents↗
PubMed1992

Molluscicidal acridone alkaloids from Angostura paniculata: isolation, structures, and synthesis.

Two novel acridone alkaloids, cuspanine [1] and cusculine [2], were isolated from the CH2Cl2 extract of the leaves of Angostura paniculata (Rutaceae). Their structures were established as 1-hydroxy-2,3,5,6-tetramethoxy-9-acridone for 1 and 1,2,3,5,6-pentamethoxy-9-acridone for 2 by means of spectroscopic studies, in particular nmr. These structural assignments were confirmed by synthesis, using a direct metallation method as a key reaction. Both alkaloids exhibited moderate molluscicidal activity against an aquatic snail, Biomphalaria glabrata, and cytotoxicity against several types of carcinoma cell lines.

Acridines↗