Some contributions to the application of LC-NMR, LC-MS, and LC-CD to the biosynthesis of isoquinoline alkaloids using callus cultures.

Hyphenated spectroscopic techniques in combination with a special extraction and work-up of plant calli cultures of Berberidaceae, Fumariaceae, and Papaveraceae families, e.g., enabled us to get deeper insight into the sequential biochemical conversions of precursors into simple isoquinoline- and protoberberine-alkaloids and their follow-up-products with different skeletons.

Evidence of covalent interaction of fumaric acid esters with sulfhydryl groups in peptides.

Fumaric acid esters, namely dimethylfumarate, have been used for the treatment of psoriasis for many years. Still, their mode of action is not fully clear. Because addition of nucleophiles to the double bonds of fumarates can occur (Michael analogous addition), a study of the interaction of fumarates with cysteine and cysteine-containing peptides possessing nucleophilic sulfhydryl group was carried out.

LC-NMR and LC-MS analysis of 2,3,10,11-oxygenated protoberberine metabolites in Corydalis cell cultures.

The metabolism of 2,3,10,11-oxygenated protoberberine alkaloids was studied in cell cultures of Corydalis species. Without prior isolation, the structures of the metabolites were determined by LC-MS and LC-NMR analyses. Tetrahydropseudocoptisine alpha-N-metho salt, pseudoprotopine, and pseudomuramine were identified for the first time, and preliminary evidence for metabolic pathways to the formation of these alkaloids were obtained.

Dimethylfumarate inhibits tumor-necrosis-factor-induced CD62E expression in an NF-kappa B-dependent manner.

Fumaric acid esters are thought to improve psoriasis by altering leukocyte, keratinocyte, and/or endothelial functions. To determine specificity, kinetics, and molecular mechanisms of different fumaric acid esters in their ability to inhibit endothelial cell activation, we analyzed CD62E and CD54 expression in endothelial cells in vivo and in vitro. In lesional skin of psoriatic patients, oral fumaric acid ester treatment resulted in a marked reduction of CD62E but not CD54 expression on dermal microvessels.

Simple isoquinoline and benzylisoquinoline alkaloids as potential antimicrobial, antimalarial, cytotoxic, and anti-HIV agents.

Twenty-six simple isoquinolines and 21 benzylisoquinolines were tested for antimicrobial, antimalarial, cytotoxic, and anti-HIV activities. Some simple isoquinoline alkaloids were significantly active in each assay, and may be useful as lead compounds for developing potential chemotherapeutic agents. These compounds include 13 (antimicrobial), 25, 26, and 42 (antimalarial), 13 and 25 (cytotoxic), and 28 and 29 (anti-HIV).

In vitro cytotoxicity of the protoberberine-type alkaloids.

In vitro cytotoxic activities of 24 quaternary protoberberine alkaloids related to berberine have been evaluated using a human cancer cell line panel coupled with a drug sensitivity database. Extending the alkyl chain at position 8 or 13 strongly influenced the cytotoxic activity, that is, relative lipophilicity as well as the size of the substituent affects cytotoxicity. The highest level of activity was observed in 8- or 13-hexyl-substituted derivatives of berberine.

A new steroidal alkaloid from the roots of Cynanchum caudatum.

A new steroidal alkaloid, 12-O-nicotinoylsarcostin, gagamine (1), was isolated from the roots of Cynanchum caudatum Max. (Asclepiadaceae), together with a known alkaloid, gagaminine (2). Their structures were established using spectroscopic methods, some 13C-NMR data of 2 have to be revised.

Medicinal plants from nepal: evaluation as inhibitors of leukotriene biosynthesis.

The methanolic extracts of 25 different Nepalese medicinal plants were tested for their activity to inhibit the biosynthesis of leukotriene B(4) in bovine polymorphonuclear leukocytes. The selected indigenous plants are used in traditional herb remedies to treat inflammatory diseases such as asthma, bronchitis, rheumatism, and skin disorders presumed to be mediated by leukotrienes. The leaves of Zanthoxylum nepalensis were shown to be the most potent inhibitor with an IC(50) value of 11 microgram/ml.

Potential antipsoriatic agents: lapacho compounds as potent inhibitors of HaCaT cell growth.

A number of lapacho compounds, representing the most common constituents of the inner bark of Tabebuia impetiginosa, together with some synthetic analogues, were evaluated in vitro against the growth of the human keratinocyte cell line HaCaT. With an IC(50) value of 0.7 microM, beta-lapachone (4) displayed activity comparable to that of the antipsoriatic drug anthralin.

Synthesis of enantiomerically pure (-)-(S)-brevicolline.

(-)-(S)-Brevicolline (1) and related beta-carbolines were synthesized using an enantiomerically pure Michael-acceptor synthon (3). Subsequent Pictet-Spengler reaction afforded the tetrahydro-beta-carboline skeleton, which, in turn, was transformed to the beta-carboline by catalytic dehydrogenation.

Antimicrobial activity of 8-alkyl- and 8-phenyl-substituted berberines and their 12-bromo derivatives.

The 8-alkyl- (3-6), 8-phenyl- (7), 12-bromo- (8), 8-alkyl-12-bromo- (9-12), and 12-bromo-8-phenyl- (13) berberine derivatives were prepared and tested for their antimicrobial activity in vitro to evaluate structure-activity relationships. Introduction of the alkyl or phenyl group and the bromine atom into the C-8 and C-12 positions of berberine (1), respectively, led to significant increases of the antimicrobial activity. In both the 8-alkyl- and 8-alkyl-12-bromo-berberines (3-6 and 9-12, respectively), the antibacterial activity increased as the length of the aliphatic chain increased.

Anthranoid free radicals found in pseudomelanosis coli.

Pseudomelanosis coli occurs after prolonged intake a anthranoids. After discontinuation of intake the pigmentation disappears apparently without noxious effects, including carcinogenicity and genotoxicity. We are presenting ESR spectra of pseudomelanosis coli specimen, compared to ESR spectra of pigmented skin scales taken from psoriatic patients treated topically with anthralin, and with ESR spectra of anthralin brown material formed in vitro.

Antipsoriatic anthrones with modulated redox properties. 3. 10-thio-substituted 1,8-dihydroxy-9(10H)-anthracenones as inhibitors of keratinocyte growth, 5-lipoxygenase, and the formation of 12(S)-HETE in mouse epidermis.

The synthesis of a series of 1,8-dihydroxy-9(10H)-anthracenones bearing sulfur-linked substituents in the 10-position is described. These compounds were evaluated for their ability to inhibit the growth of the human keratinocyte cell line HaCaT and the 5- and 12-lipoxygenase enzymes in bovine polymorphonuclear leukocytes and mouse epidermal homogenate, respectively. In addition, the following redox properties of the compounds were determined: reactivity against 2,2-diphenyl-1-picrylhydrazyl, generation of hydroxyl radicals as measured by deoxyribose degradation, and inhibition of lipid peroxidation in model membranes.

Syntheses of Anthracenones. 3. Revised Preparative Route to 10-Benzoyl-1,8-dihydroxy-9(10H)-anthracenones.

The acylation of anthralin (1,8-dihydroxy-9(10H)-anthracenone) with acetylsalicylic acid chloride in toluene and collidine was found to give the O-acylated product, rather than 10-(acetylsalicyl)anthralin. A procedure is described for benzoylation of anthralin in the 10-position which involves reaction of 1,8-diacetoxy-9(10H)-anthracenone with benzoyl chloride and sodium hydride in THF followed by hydrolysis of an intermediate enol ester. Furthermore, when benzoyl chloride and DMF were used for the acylation of anthralin, a Vilsmeier-type reaction was observed leading to a novel enamine derivative of anthralin which was hydrolyzed or benzoylated to an enol or enol ester, respectively.

Syntheses of Anthracenones. 2. Preparation of 1,8-Dimethoxy- (Dimethylanthralin) and 4,5-Dihydroxy-9(10H)-anthracenone (Isoanthralin): A Revision.

The reduction of 1,8-dimethoxyanthracenedione with zinc dust and aqueous ammonia gives a mixture of 1,8-dimethoxyanthracene and 4,5-dimethoxy-9(10H)-anthracenone, rather than the isomeric 1,8-dimethoxy-9(10H)-anthracenone (dimethylanthralin). This isomer was obtained exclusively using SnCl(2) in HCl and acetic acid as reducing agent at room temperature. The structure was confirmed to exist as the tautomeric 1,8-dimethoxy-9-hydroxyanthracene.

Syntheses of Anthracenones. 1. Sodium Dithionite Reduction of peri-Substituted Anthracenediones.

The reaction of peri-substituted anthracenediones with sodium dithionite in dimethylformamide and water has been investigated. The system selectively reduces the carbonyl group flanked by the peri substituents of the anthracenediones to give the corresponding 4,5-disubstituted 9(10H)-anthracenones and thus provides a route to anthracenones which are otherwise difficult to obtain. Many functional groups can be tolerated, the reaction is compatible with the presence of peri alkoxy groups and unsaturated side chains of the starting anthracenediones, and the reduction does not go beyond the anthracenone stage.

Modification of DNA bases by anthralin and related compounds.

Modification of bases in calf thymus DNA by treatment with the antipsoriatic drug anthralin was studied. The products of DNA bases were identified and their yields measured by gas chromatography-mass spectrometry with selected ion monitoring. Treatment of calf thymus DNA with anthralin significantly enhanced the amount of modified bases above control levels.

1,3-Diphenylpropane-1,3-diamines, VI): DNA-interaction, estrogen receptor affinity, and cytostatic activity of 1,3-diphenylpropane-1,3-diamine-Pt(II) complexes.

The Pt(II) complexes of 1,3-diphenylpropane-1,3-diamines (part IV2)) were tested for DNA interaction (UV-difference spectroscopy, Tables 1 and 2), for affinity to the estrogen receptor (calf uterus cytosol; scarcely any affinity), and for cytostatic activity at estrogen independent MDA-MB 231 cells (Tables 3 and 4) and estrogen dependent MCF-7 cells (Tables 5 and 6). The data are compared with those reported for the analogous 1,2-diphenylethane-1,2-diamine-Pt(II) complexes: most probably, the cytostatic activity is not mediated by the estrogen receptor.

Reduction of nitroxides by anthralin and some of its derivatives.

In DMSO solution, anthralin and its C-10 monosubstituted derivatives reduce nitroxides to the corresponding hydroxylamine derivatives, which are not further transformed. The reaction rate depends on the solvent used, the nitroxide, and the structure of the reducer. It is faster in DMSO than in DMF, piperidine type of nitroxides are reduced faster than the pyrrolidine type, and the substitution on C-10 of anthralin has a significant influence on the reaction rate.

Treatment of psoriasis with anthrones-chemical principles, biochemical aspects, and approaches to the design of novel derivatives.

Antipsoriatic anthrones are probably the most commonly used topical agents in the treatment of psoriasis. There is growing evidence that the biochemical basis for their mechanism of action at the molecular level is related to their redox activity leading to the production of active oxygen species, which include singlet oxygen, superoxide anion radical, and hydroxyl radical. These species are involved in a variety of oxidative effects affecting cellular targets that have been implicated both in the mode of action and the skin-irritating properties of antipsoriatic anthrones: interaction with DNA, inhibition of various enzyme systems associated with cell proliferation and inflammation, such as glucose-6-phosphate dehydrogenase and inflammation, such as glucose-6-phosphate dehydrogenase and 5-lipoxygenase, and destruction of membrane lipids.

Dibenzo[a,f]quinolizines: syntheses and cytostatic activity in estrogen-sensitive tumor cells.

A number of methoxy-substituted 7,11b,12,13-tetrahydro-6H-dibenzo-[a,f]quinolizines with short alkyl groups in position 6 or 12 were synthesized by the Bischler-Napieralski reaction using the appropriate starting material followed by a second ring closure reaction involving a base-generated benzyne intermediate. The methoxy functions in positions 2 or 3 and 9 were cleaved with BBr3 and the free hydroxy groups converted into the acetates. The enantiomers of two of these derivatives were separated by liquid chromatography on triacetylcellulose.

Antipsoriatic anthrones with modulated redox properties. 1. Novel 10-substituted 1,8-dihydroxy-9(10H)-anthracenones as inhibitors of 5-lipoxygenase.

The syntheses, the biological evaluation, and the structure-activity relationships of a novel series of 1,8-dihydroxy-9(10H)-anthracenones bearing acyl-, alkyl-, or alkylidene-linked aromatic substituents in the 10-position are described. The phenylacyl and phenylalkylidene analogs were far more potent inhibitors of 5-lipoxygenase (5-LO) from bovine polymorphonuclear leukocytes (IC50 values in the 10(-7) M range) than the antipsoriatic drug anthralin, whereas phenylalkyl analogs were only weak inhibitors. Among the active compounds were both potent generators of hydroxyl radicals, as determined by deoxyribose degradation, and strong reducers of the stable free radical 2,2-diphenyl-1-picrylhydrazyl (DPPH).

High-performance liquid chromatographic analysis of cyclosporine A in human skin.

A three-dimensional high-performance liquid chromatography (HPLC) method is described for the determination of cyclosporine A in human skin. The method allows to determine at least 3 ng cyclosporine A in 10 mg skin (total sample amount needed) and is suitable for cyclosporine A level monitoring in the skin of psoriatic patients.

Alkaloids of Cynanchum vincetoxicum: efficacy against MDA-MB-231 mammary carcinoma cells.

Alkaloids 1-4 from Cynanchum vincetoxicum (asclepiadaceae) (Scheme 1) do not have affinity to the oestrogen receptor but they inhibit the growth of the hormone-independent mammary carcinoma cells MDA-MB-231 (Fig. 1) and bind to nucleosides and nucleotides (Table 1). Intercalation was not observed.