Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “TROPOLONES”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 595 records · Page 33Linked to original sources
PubMed2004

Biological activity of beta-dolabrin, gamma-thujaplicin, and 4-acetyltropolone, hinokitiol-related compounds.

Beta-dolabrin, gamma-thujaplicin, and 4-acetyltropolone, the components of Aomori Hiba (Thujopsis dolabrata SIEB. et ZUCC. var. hondai MAKINO), showed antifungal activity on seven kinds of plant-pathogenic fungi, antibacterial activity against two kinds of Legionella sp., and in vitro cytotoxic effect on murine P388 lymphocytic leukemia cell line. Firstly, beta-dolabrin, gamma-thujaplicin and 4-acetyltropolone had clear antifungal activity against seven kinds of plant-pathogenic fungi tested. In particular, beta-dolabrin and 4-acetyltropolone showed strong antifungal activity against Pythium aphanidermatum IFO 32440, with minimum inhibitory concentration (MIC) values of 6.0 microg/ml. Secondly, beta-dolabrin, gamma-thujaplicin and 4-acetyltropolone had obvious growth-inhibitory effect on two kinds of Legionella sp. 4-Acetyltropolone especially had strong antibacterial activity toward Legionella pneumophila SG 1, and its MIC value was 3.1 microg/ml. These three compounds showed cytotoxic effects against murine P388 lymphocytic leukemia cell line in vitro. The cytotoxic effect of three compounds in the murine P388 lymphocytic leukemia cell line were clear when cell growth was measured using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) method. At 48 h after treatment, gamma-thujaplicin and 4-acetyltropolone at 0.63 microg/ml inhibited cell growth of murine P388 lymphocytic leukemia by 85% and 65%, respectively. At the same time after treatment, the growth of the murine P388 lymphocytic leukemia cell line was completely suppressed by the three compounds at concentrations higher than 5.0 microg/ml. Among these three compounds, gamma-thujaplicin had the strongest cytotoxic activity on the growth of this tumor cell line in vitro.

Animals↗
PubMed2004

Biological activity of alpha-thujaplicin, the isomer of hinokitiol.

alpha-Thujaplicin, a minor component of Aomori Hiba (Thujopsis dolabrata SIEB. et ZUCC. var. hondai MAKINO), showed rather strong antifungal activity against seven kinds of plant-pathogenic fungi, their minimum inhibitory concentrations (MICs) being in the range of 12.0-50.0 microg/ml. alpha-Thujaplicin and hinokitiol (the major component of Aomori Hiba) also showed clear antibacterial activity against Legionella pneumophila SG 1 and L. pneumophila SG 3, and their MICs are in the range of 6.25-50 microg/ml. This compound showed strong insecticidal activity against Reticulitermes speratus [50%-lethal concentration (LC(50)): 0.02 g/m(2)], and it also had clear acaricidal activity against Dermatophagoides farinae (LC(50): 0.66 g/m(2)). At 24 h after treatment, alpha-thujaplicin at 0.63 microg/ml inhibited the cell growth of murine P388 lymphocytic leukemia by 78%, and its cytotoxic activity at a concentration higher than 0.63 microg/ml was as high as that of vincristine, used as a positive control. On the other hand, the cytotoxic effect of alpha-thujaplicin at 0.63 microg/ml was weaker than that of vinblastine. In this respect, the strong cytotoxic effect of alpha-thujaplicin on murine P388 lymphocytic leukemia cell line should be emphasized, considering that it has recently been found to be low in toxicity to mice.

Animals↗
PubMed2005

Inhibitory effects of 4-n-butylresorcinol on tyrosinase activity and melanin synthesis.

In this study, we investigated the effects of 4-n-butylresorcinol on melanogenesis in a spontaneously immortalized mouse melanocyte cell line, Mel-Ab. Our results show that 4-n-butylresorcinol significantly inhibits melanin synthesis in a concentration-dependent manner. In addition, it was also found to inhibit the activity of tyrosinase, the rate-limiting melanogenic enzyme. Several reports have indicated that the activation of extracellular signal-regulated kinase (ERK) or of Akt reduces melanin synthesis via microphthalmia-associated transcription factor (MITF) down-regulation. Accordingly, we examined the effects of 4-n-butylresorcinol on the ERK and Akt signaling pathways. 4-n-Butylresorcinol did not induce ERK, Akt activation, or MITF degradation, and had no effect on cAMP response element binding protein (CREB) phosphorylation, which stimulates MITF expression. In contrast, 4-n-butylresorcinol strongly reduced tyrosinase activity in a cell-free system. Moreover, 4-n-butylresorcinol showed an additive effect in combination with hinokitiol, which reduces MITF expression. These results show that the hypopigmentary effect of 4-n-butylresorcinol results from its direct inhibition of tyrosinase.

Animals↗
PubMed2006

Human metallothionein gene expression is upregulated by beta-thujaplicin: possible involvement of protein kinase C and reactive oxygen species.

Recently, we discovered that beta-thujaplicin (BT) induces metallothionein (MT) expression in mouse keratinocytes, both in vivo and in vitro. However, the molecular mechanisms by which BT exerts its biological effects have not been elucidated. The purpose of this study is to explore the signal transduction pathway involved in the MT mRNA induction by BT. Using a HaCaT keratinocyte cell line, Northern blotting was performed for analyzing the human MT-IIA mRNA expression levels in combination with BT and a number of protein kinase (PK) inhibitors including H7, HA1004 and a PKC-specific inhibitor chelerythrin. CAT assays with the MT-IIA gene promorter-CAT construct were conducted for examining the transcriptional regulation by BT of MT. A free radical scavenger N-acetylcysteine (NAC) was used for analyzing a role of oxidative stress for the MT gene induction by BT. BT increased MT-IIA gene transcript levels and CAT activity in a dose-dependent fashion in HaCaT cells. The increase in MT-IIA mRNA levels and CAT activity were completely suppressed by H7 but not by HA1004. In addition, chelerythrin prevented BT-inducible MT-IIA promoter activation. Furthermore, NAC suppressed BT-inducible MT-IIA promoter activation. These results demonstrate that BT is a potent activator of the MT-IIA gene promoter and that PKC activation and reactive oxygen species are implicated in BT-inducible MT-IIA gene expression. BT may be a useful tool for dissecting the signal transduction pathway mediating MT-IIA promoter activation.

Acetylcysteine↗
PubMed1993

Structures and solid state tautomeric forms of two novel antileukemic tropoloisoquinoline alkaloids, pareirubrines A and B, from Cissampelos pareira.

Two novel tropoloisoquinoline alkaloids, Pareirubrines A and B, have been isolated as antileukemic substances from Cissampelos pareira (Menispermaceae), together with the same skeleton alkaloids, grandirubrine and isoimerubrine. Their structures were elucidated by nuclear magnetic resonance (NMR) studies, and their solid state tautomeric forms were examined by X-ray crystallographic analysis.

Animals↗
PubMed1992

[Study on the development of biological-active compounds after the model of natural products].

In reviewing my lifework, I wish to summarize the results of studies on the development of new biological-active compounds. The following subjects are discussed: 1) syntheses and biological activities of benzoxazole derivatives, 2) structure-activity relationships of phyllodulcin, a natural sweetner, and 3,4-dihydroisocoumarins for sweetness, 3) syntheses and structure-activity relationships of spiro[isocoumarin-piperidine] analogs for antiallergic activity, 4) design, structure-activity relationships, and a mechanism of antitumor action of bistropolone derivatives, 5) design, structure-activity relationships of fused tetracyclic quinolines for antitumor activity.

Analgesics↗
PubMed1996

Negative chronotropic and inotropic effects of U-92032, a novel T-type Ca2+ channel blocker, on the isolated, blood-perfused dog atrium.

We investigated the effects of U-92032 ((7-((bis-4-fluorophenyl) methyl)-1-piperazinyl)-2-2(2-hydroxyethylamino)-4-(1-methylethyl)- 2,4, 6-cycloheptatrien-1-one), a novel T-type Ca2+ channel blocker, on sinus rate and atrial contractile force in the isolated, blood-perfused atrium of the dog. U-92032 (1 to 300 nmol) induced negative chronotropic and inotropic responses in a dose-dependent manner, and the percentage decrease in sinus rate was less than that in atrial contractile force. Atropine did not affect the negative responses to U-92032. These results suggest that U-92032, a T-type Ca2+ channel blocker, simultaneously decreases the sinus rate and atrial force as do L-type Ca2+ channel blockers in the isolated dog atrium.

Analysis of Variance↗
PubMed1990

The role of indium-labelled leukocyte imaging in pyrexia of unknown origin.

Indium-111-labeled white blood cell scanning is often used in the investigation of pyrexia of unknown origin (PUO) to locate an otherwise occult source of sepsis. From a series of 166 white blood cell studies performed for sepsis, 28 cases of true PUO were identified and reviewed. The sensitivity was 60% and specificity 70%, with a positive predictive value of 38% and negative predictive value of 90%. Only 11% of studies revealed a pyogenic cause for PUO. These results are discussed and the potential role of gallium scanning in PUO is raised.

Adult↗
PubMed2000

Identification of a compound in Chamaecyparis taiwanensis inhibiting the ice-nucleating activity of Pseudomonas fluorescens KUIN-1.

Inactivation of the ice-nucleating activity of Pseudomonas fluorescens KUIN-1 by compounds in the leaves from coniferous trees were investigated, and the inactivated material was identified. Intact cells of the strain KUIN-1 and the acetone or methanol extracts of leaves of various coniferous trees were allowed to react for 30 min at 18 degrees C. Antinucleation compounds were obtained from Chamaecyparis taiwanensis. When the acetone extract from the leaves of coniferous trees was added to the cell suspension (about 10(6) cells/ml) in 50 mM potassium phosphate buffer (pH 7.0), the ice nucleating temperature, T50, was significantly decreased (T50 < -5 degrees C). This inhibitor was isolated by using TLC, then identified as hinokitiol based on UV-VIS, IR, and mass spectral data. When intact cells of the strain KUIN-1 were incubated with hinokitiol, limonene, and alpha-pinene of the principal constituent of the leaves of coniferous trees in 50 mM potassium phosphate buffer (pH 7.0), the ice-nucleating activity decreased, but not in alpha-terpinene. Furthermore, the ice-nucleating activities from other ice-nucleating bacteria also decreased in the presence of hinokitiol. This inhibition was proportional to the concentration of hinokitinol. The pH and thermal stabilities of the ice-nucleating activity of the cells were changed by the addition of hinokitiol (10 mM).

Bicyclic Monoterpenes↗
PubMed2001

Production of beta-thujaplicin in Cupressus lusitanica suspension cultures fed with organic acids and monoterpenes.

Effects of some organic acids and monoterpenes on production of beta-thujaplicin were studied in Cupressus lusitanica suspension cultures. The fungal elicitor-induced biosynthesis of beta-thujaplicin was promoted by the feedings of malate, pyruvate, fumarate, succinate, and acetate. These results suggest some relationships between acetate/pyruvate metabolism and beta-thujaplicin biosynthesis, or between tricarboxylic acid cycle and beta-thujaplicin biosynthesis. Feedings of C. lusitanica suspension cultures with some monoterpenes inhibited elicitor-triggered beta-thujaplicin biosynthesis, but 2-carene and terpinyl acetate feedings significantly improved the beta-thujaplicin production of C. lusitanica suspension cultures. These results indicate a possible involvement of terpinyl acetate and 2-carene in beta-thujaplicin biosynthesis, as well as potential uses of these monoterpenes in large-scale beta-thujaplicin production.

Acids↗
PubMed2003

Generation of reactive oxygen species from Hinokitiol under near-UV irradiation.

Near-UV irradiation caused the decomposition of hinokitiol in an aqueous solution. During the photochemical reaction, the distinct electron spin resonance signal characteristic of the adduct of 5,5-dimethyl-1-pyrroline-N-oxide (DMPO) with the hydroxyl radical was accompanied by small signals corresponding to the adduct of DMPO with the superoxide anion radical. More than 95% of Escherichia coli cells were killed by the incubation with hinokitiol under near-UV irradiation by BLB fluorescent lamps. These results indicated the generation of reactive oxygen species during photochemical reaction of hinokitiol under near-UV irradiation.

Colony Count, Microbial↗
PubMed2005

Effects of beta-thujaplicin on anti-Malassezia pachydermatis remedy for canine otitis externa.

The antifungal activity of beta-thujaplicin was evaluated against 51 Malassezia pachydermatis strains isolated from canine ear canals with or without otitis externa. For comparison, sensitivity tests were performed on M. pachydermatis isolates for nystatin, ketoconazole, and terbinafine HCl, all clinically available antifungal agents. The minimal inhibition concentrations over 50% of the tested isolates (MIC50) were 3.13 microg/ml for beta-thujaplicin and nystatin, 0.016 microg/ml for ketoconazole, and 1.56 microg/ml for terbinafine HCl. The antifungal effect for M. pachydermatis of beta-thujaplicin compared favorably with commercial antifungal agents. None of the 51 M. pachydermatis isolates showed resistance against any of the tested antibiotics investigated in this study. Ten representative isolates of M. pachydermatis were subcultured for 30 generations at concentrations close to the MIC levels of beta-thujaplicin, nystatin, ketoconazole, and terbinafine HCl, and examined to determine whether they had acquired resistance to each drug. As a result, M. pachydermatis was found to achieve resistance more easily for ketoconazole and terbinafine HCl than for beta-thujaplicin or nystatin. The MIC50 of beta-thujaplicin did not change during the course of subculture, and it is thought that the potential development of a resistant strain is low, even with continuous infusion for otitis externa therapy. beta-Thujaplicin is an inexpensive and safe treatment with anti-inflammatory and deodorant effects that can be recommended as an effective remedy for canine otitis externa.

Animals↗
PubMed2006

Therapeutic effects of beta-thujaplicin eardrops on canine Malassezia-related otitis externa.

An eardrop solution of beta-thujaplicin was examined for therapeutic effects on canine Malassezia-related otitis externa. Half to one ml of beta-thujaplicin solution of 100 microg/ml including DMSO 2% was injected everyday into both external ear canals of 31 cases for test-of-cure agreement. Fifteen score phases were established from the symptoms and cerumen smear biopsy findings, and score changes were recorded at least once a week. The means of the second and the third inspection day scores decreased significantly more than the previous value of each. In addition, the numbers of yeast-like organisms clearly decreased. These results suggest that beta-thujaplicin eardrops are effective for Malassezia-related otitis externa in dogs.

Animals↗
PubMedDate not supplied

Comparison of tropane alkaloid spectra between Datura innoxia grown in Egypt and Bulgaria.

The alkaloid spectra of Datura innoxia plants grown in Egypt and Bulgaria were investigated by GC-MS. Thirty-eight alkaloids were detected in the roots, leaves and fruits of the plants. Five new alkaloids for D. innoxia are reported. Alkaloid spectra of Egyptian and Bulgarian plants differ significantly in respect to their alkaloid composition and main alkaloids accumulated in the plant organs.

Alkaloids↗