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PubMedDate not supplied

Chromone glycosides from Knoxia corymbosa.

Four new chromone glycosides, corymbosins K1-K4 (3-6), together with two known compounds, noreugenin (1) and undulatoside A (2), were isolated from the whole plant of Knoxiacorymbosa (Rubiaceae). The structures of the new compounds were established through extensive NMR or X-ray spectroscopic analysis as 7-O-beta-D-allopyranosyl-5-hydroxy-2-methylchromone (corymbosin K1, 3), 7-O-beta-D-6-acetylglucopyranosyl-5-hydroxy-2-methylchromone (corymbosin K2, 4), 7-O-[6-O-(4-O-trans-caffeoyl-beta-D-allopyranosyl)]-beta-D-glucopyranosyl-5-hydroxy-2-methylchromone (corymbosin K3, 5) and 7-O-[6-O-(4-O-trans-feruloyl-beta-D-allopyranosyl)]-beta-D-glucopyranosyl-5-hydroxy-2- methylchromone (corymbosin K4, 6). Compounds 2-5 were subjected to test their immunomodulatory activity invitro.

Animals↗
PubMed2006

Antibacterial, antifungal and cytotoxic properties of some sulfonamide-derived chromones.

A series of antibacterial and antifungal sulfonamide (sulfanilamide, sulfaguanidine, sulfamethaxozole, 4-aminoethylbenzene-sulfonamide and 4-amino-6-trifluoromethyl-benzene-1,3-disulfonamide) derived chromones, previously reported as inhibitors of carbonic anhydrase, have been screened for in-vitro antibacterial activity against four Gram-negative (Escherichia coli, Pseudomonas aeruginosa, Salmonella typhi and Shigella flexener) and two Gram-positive (Bacillus subtilis and Staphylococcus aureus) bacterial strains, and for in-vitro antifungal activity against Trichophyton longifusus, Candida albicans, Aspergillus flavus, Microsporum canis, Fusarium solani, Candida glaberata. All compounds (1)-(5) showed significant antibacterial activity against all four Gram-negative species and both Gram-positive species. However, three of them, (1), (4) and (5), were found to be comparatively much more active compared to (2) and (3). Of these, (5) was found to be the most active one. For antifungal activity, generally compounds (1) and (2) showed significant activity against more than three strains whereas (3)-(5) also showed significant activity against varied fungal strains. In the brine shrimp bioassay for in-vitro cytotoxic properties, only two compounds, (4) and (5) displayed potent cytotoxic activity, LD50 = 2.732 x 10(-4)M) and LD50 = 2.290 x 10(-4)M) respectively, against Artemia salina.

Animals↗
PubMed2005

Chromones from Licania arianeae (Chrysobalanaceae).

The phytochemical studies of the leaves of Licania arianeae Prance (Crysobalanaceae) have led to the identification of ten new chromones, four 5,7-dihydroxy-2-alkylchromones, four 5,7-dihydroxy-6-chloro-2-alkylchromones and two 5,7-dihydroxy-6,8-dichloro-2-alkylchromones. The structures were established from IR, NMR and FAB-MS spectra data including 2D NMR experiments of natural substances and of the methyl derivatives.

Chromones↗
PubMed2006

Crystallization and preliminary crystallographic analysis of a novel plant type III polyketide synthase that produces pentaketide chromone.

Pentaketide chromone synthase (PCS) from Aloe arborescens is a novel plant-specific type III polyketide synthase that catalyzes the formation of 5,7-dihydroxy-2-methylchromone from five molecules of malonyl-CoA. Recombinant PCS expressed in Escherichia coli was crystallized by the hanging-drop vapour-diffusion method. The crystals belonged to space group P2(1), with unit-cell parameters a = 73.2, b = 88.4, c = 70.0 A, alpha = gamma = 90.0, beta = 95.6 degrees . Diffraction data were collected to 1.6 A resolution using synchrotron radiation at BL24XU of SPring-8.

Aloe↗
PubMed1981

Subpopulations of lymphocytes and lymphocyte transformation tests in atopic dermatitis: evaluation of a systemic treatment with a new chromone compound and comparison with a normal group.

In 28 adults patients with atopic dermatitis participating in a double-blind controlled clinical trial of systemic treatment with a new chromone compound, immune monitoring were performed with a number of in vitro tests. The parameters were phytohemagglutinin, pokeweed mitogen, concanavalin A, purified protein tuberculin derivative, Escherichia coli, Staphylococcus aureus, streptokinase/streptodornase, and allogene lymphocytes in a one-way mixed lymphocyte culture. No benefit could be proven for the drug in the clinical investigation or any change in the immunological tests during the trial. There was no demonstrable differences in the applied immunoparameters between mild and severe atopic dermatitis. The study group was compared with an age- and sex-matched control group and a general tendency to decreased T-cell function in the PHA, PWM, PPD and MLC tests together with a slightly increased HEAC percentage was found in the patients with atopic dermatitis.

Adult↗
PubMed1980

Clinical study of a new orally active chromone in asthma-proxicromil (FPL 57787).

The efficacy and safety of a new orally-active chromone, proxicromil, has been assessed in a single-blind controlled study in perennial extrinsic asthma. Patients entered into the study were currently requiring treatment with sodium cromoglycate (Intal; Lomudal) which was confirmed by deterioration of their asthma when changed to a placebo preparation of identical appearance. Proxicromil was administered for two consecutive 3-week periods using a dosage regimen of 18 mg twice per day for the first period followed by 18 mg four times per day for the second period. Patients improved during the 6 weeks' treatment with proxicromil. This improvement could be detected by the majority of patients by the end of the first week. When patient treatment was changed to a corresponding placebo for a final period of three weeks their asthma deteriorated. No abnormal laboratory findings of significance were detected on haematological, liver function or urinalysis examination. The side effects noted relate mainly to gastro-intestinal disturbances and generally were of a mild nature.

Adolescent↗
PubMed2003

Uncinoside A and B, two new antiviral chromone glycosides from Selaginella uncinata.

Five compounds have been isolated from the dried whole plants of Selaginella uncinata, two of them were new chromone glycosides, 5-hydroxy-2,6,8-trimethylchromone 7-O-beta-D-glucopyranoside (uncinoside A) and 5-acetoxyl-2,6,8-trimethylchromone 7-O-beta-D-glucopyranoside (uncinoside B). Their structures were elucidated by spectroscopic methods including one- and two-dimensional NMR techniques. The other three compounds were identified as 8-methyl eugenitol, amentoflavone and hinokiflavone. Uncinoside A and B showed potent antiviral activities against respiratory syncytial virus (RSV) with IC(50) value of 6.9 and 1.3 microg/ml, moderate antiviral activities against parainfluenza type 3 virus (PIV 3) with IC(50) value of 13.8 and 20.8 microg/ml, respectively.

Antiviral Agents↗
PubMed2006

Chromones from the branches of Harrisonia perforata.

Four new chromones, perforamone A, B, C, and D have been isolated together with six known compounds, peucenin-7-methyl ether, O-methylalloptaeroxylin, perforatic acid, eugenin, saikochromone A and greveichromenol, from the branches of Harrisonia perforata (Simaroubaceae). The structures were identified by spectroscopic data. The compounds were tested for antimycobacterial and antiplasmodial activities.

Animals↗
PubMed1979

Antiallergic action of 6-ethyl-3-(1h-tetrazol-5-YL) chromone (AA-344) on immediate hypersensitivity reaction in rats.

A newly synthesized compound, 6-ethyl-3-(1H-tetrazol-5-yl)chromone (AA-344) given intravenously or orally inhibited considerably the 72-hr passive cutaneous anaphylaxis (72-hr PCA) induced by IgE in rats. The antiallergic action of AA-344 was neither due to the antihistamine or antiserotonin effect nor was it mediated via adrenergic mechanisms. The results obtained in a double sensitization with two IgE antibodies suggest that AA-344 may not impair antigen-antibody combination but probably prevents the release of chemical mediators including histamine. This assumption was supported by observation that AA-344 inhibited a reduction in the skin histamine content caused by the 72-hr PCA, without effect on the compound 48/80-induced histamine reduction. AA-344 also partially inhibited the IgGa-mediated 3-hr PCA in rats. These results indicate that the inhibitory action of AA-344 on the immediate hypersensitivity reactions is due to prevention of the release of chemical mediators from the mast cells, by acting on some process in sequential events leading to the mediator release following antigen-antibody combination.

Adrenalectomy↗
PubMed1979

Inhibitory action of 6-ethyl-3-(1H-tetrazol-5-YL)chromone (AA-344) on IgE, IgGa- or chemical agent-induced histamine release from isolated rat mast cells.

The antiallergic action of 6-ethyl-3-(1H-tetrazol-5-yl)chromone (AA-344) was studied on isolated rat peritoneal mast cells. AA-344 clearly inhibited the IgE-mediated release of histamine caused by various concentrations of antigen and the 50% inhibitory concentration was 0.1 microM. On the IgGa-mediated release of histamine, a peak inhibition of AA-344 was observed at 10 microM. The histamine release induced by chemical agents such as concanavalin A, dextran and compound 48/80 was depressed by AA-344 at the range of 0.1--1 mM. The results obtained in this study indicate that the antiallergic action of AA-344 is due to selective inhibition on the immunological release of the chemical mediator from mast cells.

Animals↗
PubMed1979

Effect of 6-ethyl-3-(1H-tetrazol-5-yl)chromone (AA-344) on the immediate and delayed hypersensitivity reactions.

Effects of 6-ethyl-3-(1H-tetrazol-5-yl)chromone (AA-344) on the experimental models of the type I-IV allergic reactions were studied in comparison with those of disodium cromoglycate (DSCG), dexamethasone and other agents. AA-344 showed inhibitory effects on the homologous passive cutaneous anaphylaxis and the passive systemic anaphylaxis in guinea pigs. However, it had only a slight or little effect on the Forssman shock in guinea pigs, the complete-dependent cytolysis of mast cells in rats, the Arthus reaction in guinea pigs and the tuberculin reaction and the contact sensitivity in mice. DSCG was less effective, using these experimental models. Dexamethasone showed a suppressive effect on the type III and IV allergic reactions. The results indicate that AA-344 selectively suppresses the type I allergic reaction.

Animals↗
PubMed1984

The inhibition of substance P-induced histamine release from mast cells by 6, 7-dihydro-6, 8, 8, 10-tetramethyl-8H-pyrano-[3, 2-g] chromone-2-carboxylic acid (EAA).

In the presence of extracellular Ca2+, 6,7-dihydro-6,8,8, 10-tetramethyl-8H-pyrano [3, 2-g] chromone-2-carboxylic acid (EAA) had an inhibitory effect on the substance P-induced histamine release from rat peritoneal mast cells. Not only Ca2+ but also Mg2+, Sr2+ and Ba2+ were effective in enhancing the activity of EAA. Marked tachyphylaxis to EAA developed irrespective of the presence or absence of extracellular Ca2+. Cross-tachyphylaxis was observed between EAA and disodium cromoglycate (DSCG). These results indicate that the mode of action of EAA is similar, but not identical, with that of DSCG.

Animals↗
PubMed1979

Peroral chromones. A new way to treat allergic rhinitis?

Disodium chromoglycate (DSCG) is well documented in the topical treatment of allergic rhinitis. Its use does not lead to any major side effects. FPL 57579 is a new chromone compound which is well absorbed after oral administration. In a clinical trial, patients with allergic rhinitis underwent a nasal challenge before and after ingestion of FPL 57579. the effect on nasal airway resistance (NAR) was determined by rhinomanometry. In all cases there was a smaller increase in NAR after the intake of FPL 57579.

Administration, Oral↗
PubMed2002

The in vitro and in vivo effects of 2-(4-morpholinyl)-8-phenyl-chromone (LY294002), a specific inhibitor of phosphatidylinositol 3'-kinase, in human colon cancer cells.

PURPOSE: Phosphatidylinositol 3'-kinase (PI3K) and Akt/protein kinase B(PKB) allow for escape from apoptosis in various human cancer cells. We postulated that 2-(4-morpholinyl)-8-phenyl-chromone (LY294002), a PI3K inhibitor, should inactivate Akt/PKB, consequently inhibiting cell proliferation and inducing apoptosis in vitro and in vivo. EXPERIMENTAL DESIGN: Human colon cancer cell lines (DLD-1, LoVo, HCT15, and Colo205) and their mouse xenografts (DLD-1 and LoVo) were used in this study. The expression of phosphorylated Akt (Ser(473)) and apoptosis in cancer cells were determined by immunoblotting and immunohistochemistry. To evaluate the activity of caspase-3 in culturing cells, the caspase colorimetric assay was also performed. RESULTS: LY294002 demonstrated a remarkable growth-inhibitory and apoptosis-inducing effect in these colon cancer cell lines, with decreased expression of phosphorylated Akt (Ser(473)). However, there was a great discrepancy between the sensitivity for LY294002 and the level of expression of phosphorylated Akt. Although the LoVo and Colo205 cells exhibited high sensitivity to LY294002 with increased apoptosis, the DLD-1 and HCT15 cells did not show rapid induction of apoptosis. The caspase-3 activity was significantly high in the LoVo cells but not in the DLD-1 cells. In the experiments using mouse xenografts, we found that LY294002 administration in vivo also resulted in suppression of tumor growth and induction of apoptosis, especially in the LoVo tumors, and therefore showed remarkable effectiveness in the mouse peritonitis carcinomatosa model. CONCLUSIONS: PI3K-Akt/PKB plays an important role in colon cancer development and progression by helping to promote cell growth and allowing cells to escape apoptosis. These results propose the usefulness of LY294002 as an antitumoral agent for patients with colorectal cancer.

Animals↗
PubMed2003

[A new chromone glycoside from Cassia siamea lam].

AIM: To study the chemical constituents of the stem of Cassia siamea. METHODS: The compounds were isolated by chromatography on silica gel, and identified on the basis of spectral analysis. RESULTS: Five compounds were isolated and identified as: beta-sitosterol (I), sucrose (II), n-octacosanol (III), 2-methyl-5-(2'-hydroxypropyl)-7-hydroxy-chromone-2'-O-beta-D-glucopyranoside (IV) and piceatannol (V). CONCLUSION: Compound IV is a new compound. Compounds II, III and V were obtained from this plant for the first time.

Cassia↗
PubMed1992

Synthesis and in vitro activity of alkylaminoalkyloxy chromones on protoscoleces of Echinococcus multilocularis (Cestoda).

Twelve derivatives with alkylaminoalkyloxy chromone structures were synthesized and tested upon protoscoleces of Echinococcus multilocularis metacestode kept alive in vitro. Assays were performed with protoscoleces attached to the germinal layer in open and in closed vesicles. Compounds IVb and IIIe at the concentration of 0.1 mmol.L-1 killed 50% of the protoscoleces in open vesicles in 48 hours and compound IVb killed 100% of the protoscoleces in open vesicles within 96 hours at the same concentration. In closed vesicles after four days compound IVb killed all protoscoleces, compounds IIIe and IVd half of them, whereas in the controls all protoscoleces were alive. Trifluoperazine (TFP) was the reference compound; none of the new compounds showed better activity than TFP.

Animals↗