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PDF file, 162K, AR mRNA levels are unaffected upon treatment with VPC-3022 and VPC-3033. Total RNA was extracted after treatment of LNCaP and MDV3100-resistant cells with VPC-3022 and VPC-3033 for 24 hours at the indicated concentrations in the presence of 0.1 nM R1881. Quantitative RT-PCR analysis of AR expression was performed and normalized to 18S rRNA levels. Error bars indicate standard deviation.

PDF file, 122K.

PDF file, 2136K, (A) Effect of VPC-3022 on AR activity in HeLa-AR cells in the presence of cyclohexamide. HeLa-AR cells were treated with serially-diluted concentrations of VPC-3022 (0 - 100 ?M) with or without 10 ?M of cyclohexamide for 8 hours, and then lysed with passive lysis buffer. (B) AR degradation caused by VPC-3031 and VPC-3041 in HeLa-AR cells. HeLa-AR cells were treated by VPC-3031 and VPC-3041 at different concentrations in the presence of 0.1 nM R1881.

PDF file, 1976K, (A) Inhibition of in vitro polymerization of tubulin at 37 {degree sign}C by various concentrations of VPC-3033; turbidity was recorded at 360 nM.The steady-state tubulin assembly level in the absence of inhibitor was set at 100%. (B) IC50 values were determined by sigmoidal fitting of the plot of the steady state levels of tubulin assembly (taken after 45 min) aginst drug concentration and represent the concentration for 50% inhibition of the maximum tubulin polymerization level.

PDF file, 3480K, The binding pose of DHT (A) and VPC-3022 with AR by molecular docking (B) and binding pose of VPC-3022 with AR after 10 ns molecular dynamics (C); RMSD values of the protein backbone, protein-ligand, ligand in the 10 ns molecular dynamics for AR-DHT (D) and AR-VPC-3022 (E).

The human androgen receptor plays a major role in the development and progression of prostate cancer and represents a well-established drug target. All clinically approved androgen receptor antagonists possess similar chemical structures and exhibit the same mode of action on the androgen receptor. Although initially effective, resistance to these androgen receptor antagonists usually develops and the cancer quickly progresses to castration-resistant and metastatic states. Yet even in these late-stage patients, the androgen receptor is critical for the progression of the disease. Thus, there is a continuing need for novel chemical classes of androgen receptor antagonists that could help overcome the problem of resistance. In this study, we implemented and used the synergetic combination of virtual and experimental screening to discover a number of new 10-benzylidene-10H-anthracen-9-ones that not only effectively inhibit androgen receptor transcriptional activity, but also induce almost complete degradation of the androgen receptor. Of these 10-benzylidene-10H-anthracen-9-one analogues, a lead compound (VPC-3033) was identified that showed strong androgen displacement potency, effectively inhibited androgen receptor transcriptional activity, and possesses a profound ability to cause degradation of androgen receptor. Notably, VPC-3033 exhibited significant activity against prostate cancer cells that have already developed resistance to the second-generation antiandrogen enzalutamide (formerly known as MDV3100). VPC-3033 also showed strong antiandrogen receptor activity in the LNCaP in vivo xenograft model. These results provide a foundation for the development of a new class of androgen receptor antagonists that can help address the problem of antiandrogen resistance in prostate cancer. Mol Cancer Ther; 12(11); 2425–35. ©2013 AACR.

PDF file, 109K, Inhibition of VPC-3022 against wild-type AR in HeLa-AR cells. HeLa-AR cells transfected with ARR3tk-luciferase reporter were treated with VPC-3022 for 24 hours in various concentrations in the presence of 0.1 nM R1881. Error bars indicate standard deviation.

As part of our continuing search for potent inhibitors of tubulin polymerization, two novel series of 42 10-(4-phenylpiperazine-1-carbonyl)acridin-9(10H)-ones and N-benzoylated acridones were synthesized on the basis of a retrosynthetic approach. All newly synthesized compounds were tested for antiproliferative activity and interaction with tubulin. Several analogs potently inhibited tumor cell growth. Among the compounds tested, 10-(4-(3-methoxyphenyl)piperazine-1-carbonyl)acridin-9(10H)-one (17c) exhibited excellent growth inhibitory effects on 93 tumor cell lines, with an average GI50 value of 5.4 nM. We were able to show that the strong cytotoxic effects are caused by disruption of tubulin polymerization, as supported by the EBI (N,N'-Ethylenebis(iodoacetamide)) assay and the fact that the most potent inhibitors of cancer cell growth turned out to be the most efficacious tubulin polymerization inhibitors. Potencies were nearly comparable or superior to those of the antimitotic reference compounds. Closely related to this, the most active analogs inhibited cell cycling at the G2/M phase at concentrations down to 30 nM and induced apoptosis in K562 leukemia cells. We believe that our work not only proves the excellent suitability of the acridone scaffold for the design of potent tubulin polymerization inhibitors but also enables synthetic access to further potentially interesting N-acylated acridones.

The androgen receptor (AR) is a hormone-activated transcription factor that regulates the development and progression of prostate cancer (PCa) and represents one of the most well-established drug targets. Currently clinically approved small molecule inhibitors of AR, such as enzalutamide, are built upon a common chemical scaffold that interacts with the AR by the same mechanism of action. These inhibitors eventually fail due to the emergence of drug-resistance in the form of AR mutations and expression of truncated AR splice variants (e.g. AR-V7) that are constitutively active, signalling the progression of the castration-resistant state of the disease. The urgent need therefore continues for novel classes of AR inhibitors that can overcome drug resistance, especially since AR signalling remains important even in late-stage advanced PCa. Previously, we identified a collection of 10-benzylidene-10H-anthracen-9-ones that effectively inhibit AR transcriptional activity, induce AR degradation and display some ability to block recruitment of hormones to the receptor. In the current work, we extended the analysis of the lead compounds, and used methods of both ligand- and structure-based drug design to develop a panel of novel 10-benzylidene-10H-anthracen-9-one derivatives capable of suppressing transcriptional activity and protein expression levels of both full length- and AR-V7 truncated forms of human androgen receptor. Importantly, the developed compounds efficiently inhibited the growth of AR-V7 dependent prostate cancer cell-lines which are completely resistant to all current anti-androgens.

Novel analogues of oxadiazole-substituted naphtho[2,3-b]thiophene-4,9-diones were synthesized in which the tricyclic quinone skeleton was systematically replaced with simpler moieties, such as structures with fewer rings and open-chain forms, while the oxadiazole ring was maintained. In addition, variants of the original 1,2,4-oxadiazole ring were explored. Overall, the complete three-ring quinone was essential for potent suppression of human keratinocyte hyperproliferation, whereas analogous anthraquinones were inactive. Also, the oxadiazole ring per se was not sufficient to elicit activity. However, rearrangement of the heteroatom positions in the oxadiazole ring resulted in highly potent inhibitors with compound 24b being the most potent analogue of this series showing an IC50 in the nanomolar range. Furthermore, experiments in isolated enzymatic assays as well as in the keratinocyte-based hyperproliferation assay did not support a major role of redox cycling in the mode of action of the compounds.

We report here a series of 27 10-(4-phenylpiperazin-1-yl)methanones derived from tricyclic heterocycles which were screened for effects on tumor cell growth, inhibition of tubulin polymerization, and induction of cell cycle arrest. Several analogues, among them the 10-(4-(3-methoxyphenyl)piperazine-1-carbonyl)-10H-phenoxazine-3-carbonitrile (16o), showed excellent antiproliferative properties, with low nanomolar GI50 values (16o, mean GI50 of 3.3 nM) against a large number (93) of cancer cell lines. Fifteen compounds potently inhibited tubulin polymerization. Analysis of cell cycle by flow cytometry revealed that inhibition of tumor cell growth was related to an induction of G2/M phase cell cycle blockade. Western blotting and molecular docking studies suggested that these compounds bind efficiently to β-tubulin at the colchicine binding site. Our studies demonstrate the suitability of the phenoxazine and phenothiazine core and also of the phenylpiperazine moiety for the development of novel and potent tu...

A series of 8-chloronaphtho[2,3-b]thiophene-4,9-diones and also some 8-bromo analogues were prepared. The compounds were evaluated for their potencies to suppress keratinocyte hyperproliferation using the human keratinocyte line HaCaT as the primary test system. Structure-activity relationship studies revealed that replacement of the phenolic group of an earlier series with an 8-halogen atom retained the inhibitory potency against keratinocyte hyperproliferation with IC50 values in the submicromolar range. 8-Chloro-substitution led to inhibitors that were more potent than their bromo analogues. Concomitantly, halo-substitution eliminated membrane-damaging properties as assessed by LDH release from the cytoplasm of the keratinocytes which, in contrast, were induced by the corresponding phenolic analogues. Finally, selective compounds were characterized for their ability to participate in redox cycling to generate superoxide in enzymatic and keratinocyte-based studies.

The basic structure of linearly anellated lapacho quinones, naphtho[2,3-b]furan-4,9-dione (7), was modified in the search for novel agents against keratinocyte hyperproliferation. The synthesis and structure–activity relationships of several heterocycle-fused naphthoquinones as well as a full range of 2- and 7-substituted derivatives of one of these, 8-hydroxynaphtho[2,3-b]thiophene-4,9-dione (8a), are described. Out of a total of 71 analogues, particularly 2-thenoyl-substituted 26l, 2-nicotinoyl-substituted 26m, and 2-oxadiazole-substituted 35a compared favorably with the antipsoriatic agent anthralin. Their potency for suppression of keratinocyte hyperproliferation, which was evaluated using HaCaT cells as a model, was combined with comparably low membrane-damaging effects toward keratinocytes, as established by the release of lactate dehydrogenase activity from the cytoplasm of the cells. With respect to the mechanism of action, redox activation of lapacho quinones by one- and two-electron reduction in...

The human androgen receptor plays a major role in the development and progression of prostate cancer and represents a well-established drug target. All clinically approved androgen receptor antagonists possess similar chemical structures and exhibit the same mode of action on the androgen receptor. Although initially effective, resistance to these androgen receptor antagonists usually develops and the cancer quickly progresses to castration-resistant and metastatic states. Yet even in these late-stage patients, the androgen receptor is critical for the progression of the disease. Thus, there is a continuing need for novel chemical classes of androgen receptor antagonists that could help overcome the problem of resistance. In this study, we implemented and used the synergetic combination of virtual and experimental screening to discover a number of new 10-benzylidene-10H-anthracen-9-ones that not only effectively inhibit androgen receptor transcriptional activity, but also induce almost complete degradation of the androgen receptor. Of these 10-benzylidene-10H-anthracen-9-one analogues, a lead compound (VPC-3033) was identified that showed strong androgen displacement potency, effectively inhibited androgen receptor transcriptional activity, and possesses a profound ability to cause degradation of androgen receptor. Notably, VPC-3033 exhibited significant activity against prostate cancer cells that have already developed resistance to the second-generation antiandrogen enzalutamide (formerly known as MDV3100). VPC-3033 also showed strong antiandrogen receptor activity in the LNCaP in vivo xenograft model. These results provide a foundation for the development of a new class of androgen receptor antagonists that can help address the problem of antiandrogen resistance in prostate cancer. Mol Cancer Ther; 12(11); 2425–35. ©2013 AACR.

A series of 10-substituted 4,5-dichloro-10 H -anthracen-9-ones were synthesized in the search for novel agents against keratinocyte hyperproliferation. The antiproliferative activity of these novel anthrones was evaluated using the human keratinocyte line HaCaT as the primary test system. Structure–activity relationships with respect to the nature and position of the substituents at the benzyl moiety were studied, with a 3-hydroxy-4-methoxy-substitution pattern being the most potent (IC 50 = 0.7 μM) and comparable to the potency of the antipsoriatic anthralin. In contrast to anthralin, inhibition of keratinocyte hyperproliferation was not mediated by damage to the keratinocyte membrane, as the activity of lactate dehydrogenase released from the cytoplasm was in the control range. These findings may be rationalized as a benefit of the ineffectiveness of the novel anthrones to interact with the free radical 2,2-diphenyl-1-picrylhydrazyl.

A series of 10-substituted hydroxy-10 H -acridin-9-ones were synthesized and studied as potential antipsoriatic agents. The antiproliferative activity of the novel derivatives, which can be considered as aza-analogues of the antipsoriatic drug anthralin, was determined using the human keratinocyte cell line HaCaT. Structure–activity relationships with respect to the nature of the N-substituent at the acridone scaffold were delineated. Release of lactate dehydrogenase (LDH) was used to exclude non-specific cytotoxic effects. As compared to anthralin, N-substitution of the acridone scaffold in the target compounds provided agents devoid of radical producing properties, which was documented by their ineffectiveness to interact with the free radical 2,2-diphenyl-1-picrylhydrazyl. This was in excellent agreement with the data obtained from the LDH assay in which the novel compounds did not induce membrane damage. Benzyl substitution at the 10-position yielded keratinocyte growth inhibitory activity in the low micromolar range. The most potent inhibitor of keratinocyte hyperproliferation was compound 8a having an N-methyl group and a 1,3-dihydroxy arrangement at the acridone scaffold, with an IC 50 value comparable to that of anthralin.

A novel series of 1,5- and 1,8-disubstituted 10-benzylidene-10H-anthracen-9-ones and 10-(2-oxo-2-phenylethylidene)-10H-anthracen-9-ones was synthesized to assess the substituent effects on biological activity. The 3-hydroxy-2,4-dimethoxy-benzylidene analogue 16 h displayed strong antiproliferative activity against several tumor cell lines, including multi-drug resistant phenotypes. Flow cytometric studies showed that KB/HeLa cells treated by elected compounds were arrested in the G2/M phases of the cell cycle. Among the compounds tested for inhibition of tubulin polymerization, 14 compounds proved to be exceptionally active with IC(50) values1 microM. In the 1,5-dichloro-derived series of benzylideneanthracenones, E/Z isomers were separated and biological effects were monitored. We found that the olefinic geometry had no significant effect on biological activity. Furthermore, the E isomeric 1,5-dichloro-substituted phenacylidenes entirely proved to be more potent inhibitors of tubulin polymerization than the recently described 10-(2-oxo-2-phenylethylidene)-10H-anthracen-9-ones. In conclusion, the present study improves understanding of the action of anthracenone-based tubulin polymerization inhibitors and contributes to the design of further potent anti-tubulin drugs.

A series of N-unsubstituted hydroxy-10H-acridin-9-ones were synthesized and evaluated for inhibitory action against HaCaT keratinocyte growth, in order to explore their potential as antipsoriatic agents. For structure-activity relationship studies, the number and position of the hydroxyl groups were modified, the oxygen functions substituted or replaced, or additional functional groups were introduced into the acridone scaffold. 1,8-Dihydroxy-10H-acridin-9-one (4), which is an aza-analogue of the antipsoriatic anthralin, was only marginally active. However, 1,3-dihydroxy-substituted 5ee was the most potent acridone within this series and inhibited keratinocyte growth with an IC(50) value comparable to that of anthralin. In contrast to anthralin, nearly all members of the acridone series were devoid of radical generating properties, which were determined by their capability to interact with the free radical 2,2-diphenyl-1-picrylhydrazyl. Structures with a phenolic hydroxyl or an aromatic amine arranged ortho or para to the acridone NH group were exceptions. Also in contrast to anthralin, membrane-damaging effects as documented by the release of lactate dehydrogenase into the culture medium were not observed for acridones.

Tubulin-binding 9-benzylidene-naphtho[2,3-b]thiophen-4-ones 1a and 1b and benzylidene-9(10H)-anthracenone 2 were evaluated for their ability to induce cell death. We examined the effect of the molecules on cell cycle progression, organization of microtubule networks, and apoptosis induction. As determined by flow cytometry, cancer cells were predominantly arrested in metaphase with 4N DNA before cell death occurred. By using indirect immunofluorescence techniques we visualized microtubule depolymerization recognizable by short microtubule fragments scattered around the nucleus. The incubation with 1a and 2 resulted in chromatin condensation, nuclear fragmentation, and cell shrinkage, which are, among others, typical features of apoptotic cell death. Furthermore, time- and dose-dependent induction of apoptosis in SH-SY5Y cells was detected via cleavage of Ac-DEVD-AMC, a fluorigenic substrate for caspase-3. We observed a lower apoptotic activity in neuroblastoma cells overexpressing Bcl-xL, suggesting activation of the mitochondrial apoptosis pathway. Western blot analysis demonstrated that caspase-3, an apoptosis mediator, was activated in a time-dependent manner after exposure of SH-SY5Y cells to drugs 1a and 2. Taken together, the agents investigated in the present study display strong apoptosis-inducing activity and therefore show promise for the development of novel chemotherapeutics.

Benzenesulfonate derivatives of naphtho[2,3-b]thiophen-4(9H)-one and 9(10H)-anthracenone were prepared and found to inhibit microtubule formation by an in vitro tubulin polymerization assay. Several analogues showed potent cytotoxic activity in an assay based on K562 leukemia cells with IC50 values of

A number of phenothiazine-, phenoxazine- and related tricyclics-derived chloroacetamides were synthesized and evaluated in vitro for antiprotozoal activities against Leishmania major (L. major) promastigotes. Several analogs were remarkably potent inhibitors, with antileishmanial activities being comparable or superior to those of the reference antiprotozoal drugs. Furthermore, we explored the structure-activity relationships of N-10 haloacetamides that influence the potency of such analogs toward inhibition of L. major promastigote growth in vitro. With respect to the mechanism of action, selected compounds were evaluated for time-dependent inactivation of Trypanosoma brucei trypanothione reductase. Our results are indicative of a covalent interaction which could account for potent antiprotozoal activities.

A novel series of 9-benzylidene-naphtho[2,3-b]thiophen-4-ones and structurally related compounds were synthesized and evaluated for their ability to inhibit tubulin polymerization. The 4-hydroxy-3,5-dimethoxy-benzylidene analogue 15d was identified as a potent cytotoxic agent in an assay based on K562 leukemia cells. Antiproliferative activity of 15d and the 2,4-dimethoxy-3-hydroxy-benzylidene analogue 15e was additionally evaluated against a panel of 12 tumor cell lines, including multidrug resistant phenotypes. All resistant cell lines were sensitive to these compounds. Concentration-dependent flow cytometric studies showed that K562 cells as well as KB/HeLa cells treated by 15d were arrested in the G2/M phases of the cell cycle. Moreover, four compounds strongly inhibited tubulin polymerization with activities higher or comparable to those of the reference compounds. In competition experiments, the most active compounds strongly displaced radiolabeled colchicine from its binding site in the tubulin, showing IC50 values virtually 3- to 4-fold lower than that of colchicine.

Background: The efficacy of acupuncture treatment for chronic low-back pain has not been reliably proven because of a lack of good quality studies, leading to the necessity of developing the German Acupuncture Trial for Chronic Low-Back Pain (GERAC-cLBP) study. Objective: The aim is to assess the effectiveness of traditional Chinese acupuncture for chronic low-back pain compared to sham acupuncture and with a conventional standard therapy. Methods: This trial is a nationwide, multicenter, randomized, prospective, partially blinded study. The primary endpoint is the success rate after 6 months. Success is defined as an improvement of 33% or more of three pain-related items on the Van-Korff Pain Score or an improvement of 12% or more in the disability measured by the Hanover Functional Ability Questionnaire. Assessment of the effectiveness of the blinding of patients to the form of acupuncture they received will be conducted. All clinical endpoints are assessed centrally by blinded independent observers. Th...

The basic structure of linearly anellated lapacho quinones, naphtho[2,3-b]furan-4,9-dione (7), was modified in the search for novel agents against keratinocyte hyperproliferation. The synthesis and structure-activity relationships of several heterocycle-fused naphthoquinones as well as a full range of 2- and 7-substituted derivatives of one of these, 8-hydroxynaphtho[2,3-b]thiophene-4,9-dione (8a), are described. Out of a total of 71 analogues, particularly 2-thenoyl-substituted 26l, 2-nicotinoyl-substituted 26m, and 2-oxadiazole-substituted 35a compared favorably with the antipsoriatic agent anthralin. Their potency for suppression of keratinocyte hyperproliferation, which was evaluated using HaCaT cells as a model, was combined with comparably low membrane-damaging effects toward keratinocytes, as established by the release of lactate dehydrogenase activity from the cytoplasm of the cells. With respect to the mechanism of action, redox activation of lapacho quinones by one- and two-electron reduction in isolated enzymatic assays was studied, and their potential to generate superoxide was confirmed in the keratinocyte-based hyperproliferation assay.

A series of 2-arylmethyl-substituted anthracenones were synthesized and tested as inhibitors of three types of 12-lipoxygenase isoforms in epidermal homogenate of mice, bovine platelets and porcine leucocytes. Their inhibitory activities were compared with those to inhibit the 5-lipoxygenase enzyme in bovine leucocytes. Structure–activity relationships are described with particular emphasis on modifications of the terminal aryl nucleus. The ability of the compounds to selectively inhibit the 12-lipoxygenase enzymes was dependent on a high overall lipophilicity of the inhibitor, whereas compounds with decreased lipophilicity were also inhibitors of the 5-LO enzyme. Among the more lipophilic inhibitors, the unsubstituted 2-phenylmethyl analogue 6a as well as the carboxylic acid ester 6q appeared to be selective inhibitors of platelet-type 12-LO isoform.

Recently, the in vitro bleeding time test (IVBT) was proved to be a very sensitive screening method for the detection of vWD, showing rather good correlation between the closure time and the level of vWF. The vWF levels have been found to be significantly lower in healthy humans who are group O than in those who belong to the other ABO blood groups (non-group O). The aim of this study was to detect whether these differences in vWF levels in normal persons correspond to differences in nonvascular primary hemostasis when investigated by the IVBT.Healthy blood donors (n = 162) without evidence of hemostatic disorders, without ingestion of drugs for at least 2 weeks, and with normal in vivo bleeding time endpoints, normal factor VIII clotting activity levels, normal structure of vWF multimers, and normal ristocetin-induced platelet aggregation were examined by IVBT. IVBT was performed with two automated systems (Thrombostat 4000, VDG [TST]; and a platelet function analyzer (PFA-100, Dade Behring [PFA]). CaCl2 and ADP were used as aggregants for the two TST tests (TST-CaCl2 and TST-ADP), and ADP- or epinephrine (Epi)-coated membranes were used with the two PFA tests (PFA-ADP and PFA-Epi).Closure time in the IVBT significantly correlated with the blood groups, but in reverse order (as did blood volume; data not shown): TST-ADP (mean +/- SD): group O, 89 +/- 14.6 seconds versus non-group O, 82 +/- 13 seconds (p0.01); TST-CaCl(2): group O, 154 +/- 28.9 seconds versus non-group O, 140 +/- 31.3 seconds (p0.01); PFA-ADP: group O, 91 +/- 13.4 seconds versus non-group O, 86 +/- 11.9 seconds (p0.05); PFA-Epi: group O, 112 +/- 15.4 seconds versus non-group O, 104 +/- 16.7 seconds (p0.05). Donors with vWFor =77.5 % had longer closure time than those with vWF77.5 % (p0.05).Significant ABO-group-specific differences in nonvascular primary hemostasis could be found by IVBT. The differences are small, however, and lie within the normal range. Whether these differences have any biologic relevance can only be speculated.

The synthesis and biological properties of 10-benzoyl-1,8-dihydroxy-9(10H)-anthracenones are described. The compounds were evaluated for their ability to inhibit the growth of the human keratinocyte cell line HaCaT and the 5-lipoxygenase enzyme in bovine polymorphonuclear leukocytes. In addition, generation of hydroxyl radicals was determined as measured by deoxyribose degradation. The results obtained with the new compounds show that substitution with a 4-hydroxy (4f) or a 4-benzyloxy group (4i) at the phenyl ring of the C-10 substituent resulted in potent antiproliferative agents. No correlation was found between hydroxyl-radical formation and the 5-LO inhibitory or antiproliferative action of the compounds.

Summary A novel series of 10-aminomethylene substituted 1,8-dihydroxy-9(10H)-anthracenones was synthesized and evaluated both in the bovine polymorphonuclear leukocyte 5-lipoxygenase (5-LO) and in the HaCaT keratinocyte proliferation assay for their enzyme inhibitory and antiproliferative activity, respectively. The synthesis required readily available formanilides as starting materials and a modified Vilsmeier type reaction with the parent anthracenone. The most potent inhibitor of 5-LO was a 4-hydroxyphenyl analog, whereas a 4-nitrophenyl substituent was essential for potent antiproliferative activity. The results of this study indicate that an activated double bond at C-10 of phenylalkylidene-substituted anthracenones is required for potency.

A novel series of carboxylic and hydroxamic acids based on 1,8-dihydroxy-9(10H)-anthracenone were synthesized from 8-hydroxy-1-methoxy-9,10-anthracenedione as the key intermediate and evaluated both in the bovine polymorphonuclear leukocyte 5-lipoxygenase (5-LO) assay and in the HaCaT keratinocyte proliferation assay for their enzyme inhibitory and antiproliferative activity, respectively. The most potent inhibitors in both assays were the N-methylated hydroxamic acids 5d-8d with straight chain alkyl spacers. Incorporation of these structural features on the anthracenone pharmacophore resulted in increased inhibitory activity against 5-LO while the antiproliferative activity was retained. In addition, prooxidant properties as measured by deoxyribose degradation and cytotoxicity as assessed by LDH release were largely reduced as compared with the antipsoriatic anthralin. Contrary to anthralin, antioxidant properties were observed as documented by the reactivity of the novel compounds against free radicals and inhibition of lipid peroxidation in model membranes.

Various natural products with the chromane and chromene scaffold exhibit high antiprotozoal activity. The natural product encecalin (7) served as key intermediate for the synthesis of different ethers 9, amides 11, and amines 12. The chromane analogues 14 and the phenols 15 were obtained by reductive amination of ketones 13 and 6, respectively. Angelate 3, ethers 9, and amides 11 did not show considerable antiprotozoal activity. However, the chromene and chromane derived amines 12, 14, and 15 revealed promising antiprotozoal activity and represent novel lead compounds. Whereas benzylamine 12a and α-methylbenzylamine 12g were active against P. falciparum with IC50 values in the range of chloroquine, the analogous phenols 15a and 15b were unexpectedly 10- to 25-fold more potent than chloroquine with selectivity indexes of 6760 and 1818, respectively. The phenylbutylamine 14d based on the chromane scaffold has promising activity against T. brucei rhodesiense and L. donovani.

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.

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. Furthermore, the reduction of 1,8-diacetoxyanthracenedione with SnCl(2) in HCl and acetic acid leads to 1,8-dihydroxy-9(10H)-anthracenone (anthralin) rather than 4,5-dihydroxy-9(10H)-anthracenone (isoanthralin), which was prepared by ether cleavage of 4,5-dimethoxy-9(10H)-anthracenone. In light of these findings some biological studies on antipsoriatic anthracenones have to be reconsidered.

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. However, the formation of anthracenones depends on the nature of the peri substituents. No products were obtained from the 1,8-dimethyl-substituted anthracenedione and the parent compound with no substituents.

A series of linearly anellated lapacho quinone analogues substituted at the 2-position of the tricyclic naphtho[2,3-b]furan-4,9-dione system were synthesized and evaluated for their ability to suppress keratinocyte hyperproliferation using HaCaT cells as the primary test system. While very good in vitro potency with IC(50) values in the submicromolar range was attained with electron-withdrawing substituents, some compounds were found to induce plasma membrane damage, as evidenced by the release of LDH activity from cytoplasm of the keratinocytes. The most potent analogue against keratinocyte hyperproliferation was the 1,2,4-oxadiazole 18, the potency of which was combined with comparably low cytotoxic membrane damaging effects. Structure-activity relationship studies with either metabolically stable or labile analogues revealed that the quinone moiety was required for activity. Selected compounds were studied in detail for their capability to generate superoxide radicals both in isolated enzymatic one- and two-electron reduction assays as well as in a HaCaT cell-based assay.

A total of 53 N-benzoylated phenoxazines and phenothiazines, including their S-oxidized analogues, were synthesized and evaluated for antiproliferative activity, interaction with tubulin, and cell cycle effects. Potent inhibitors of multiple cancer cell lines emerged with the 10-(4-methoxybenzoyl)-10H-phenoxazine-3-carbonitrile (33b, IC(50) values in the range of 2-15 nM) and the isovanillic analogue 33c. Seventeen compounds strongly inhibited tubulin polymerization with activities higher than or comparable to those of the reference compounds such as colchicine. Concentration-dependent flow cytometric studies revealed that inhibition of K562 cell growth was associated with an arrest in the G2/M phases of the cell cycle, indicative of mitotic blockade. Structure-activity relationship studies showed that best potencies were obtained with agents bearing a methoxy group placed para at the terminal phenyl ring and a 3-cyano group in the phenoxazine. A series of analogues highlight not only the phenoxazine but also the phenothiazine structural scaffold as valuable pharmacophores for potent tubulin polymerization inhibitors, worthy of further investigation.

The first synthesis of 2,6-aceanthrylenedione (6), a cyclic vinylog of anthraquinone and a useful starting material for the synthesis of 1-phenylaceanthrylene-2,6-diones such as 7, 8, and 9, is described. (10-Oxo-10H-anthracen-9-ylidene) acetyl chloride (5) cyclizes intramolecularly at room temperature in the presence of AlCl(3) to give 6. We found that 6 is a cytotoxic compound that inhibits tubulin polymerization.

A series of anthracenone-based oxime ethers and -esters were synthesized in order to evaluate their antiproliferative activity. Several investigated compounds displayed strong antiproliferative activity against K562 leukemia cells and proved to be strong inhibitors of tubulin polymerization. In this context, anthracenone-based oxime ethers and -esters are considered to contribute to the development of novel antiproliferative drugs, based on tubulin interaction.

A series of 10-(2-oxo-2-phenylethylidene)-10H-anthracen-9-ones were synthesized and evaluated for interactions with tubulin and for antiproliferative activity against a panel of human and rodent tumor cell lines. The 4-methoxy analogue 17b was most potent, displaying IC(50) values ranging from 40 to 80 nM, including multidrug resistant phenotypes, and had excellent activity as an inhibitor of tubulin polymerization (IC(50) = 0.52 microM). Concentration-dependent flow cytometric studies showed that KB/HeLa cells treated with 17b were arrested in the G2/M phases of the cell cycle (EC(50) = 90 nM). In competition experiments, 17b strongly displaced [(3)H]-colchicine from its binding site in the tubulin. The results obtained demonstrate that the antiproliferative activity is related to the inhibition of tubulin polymerization.

A prospective study was designed to evaluate a possible role of an endured infection with Chlamydia pneumoniae or Chlamydia trachomatis as a cause for sudden sensorineural hearing loss. For this in 60 patients with a first episode of a sensorineural hearing loss and-60 sex-matched and aged-matched controls, following a complete otoneurological diagnosis blood tests for IgA, IgM and IgG with regard to Chlamydia pneumoniae and trachomatis were evaluated. We found a statistically significant higher prevalence of IgA positivity of Chlamydia pneumoniae in patients with sudden sensorineural hearing loss (chi2-test, p0.017). For this, Chlamydia pneumoniae may be a possible cause for sudden sensorineural hearing loss. A targeted antibiotic therapy, as it has been discussed for myocardial infarction, might possibly open an additional treatment option for sudden sensorineural hearing loss.

In a group of elderly patients over 65 years of age with at least two cardiovascular diagnoses requiring chronic medication (n=424), drug therapy at hospital discharge and at home thereafter was followed for a 1-year period. Two home visits took place at 3 months and 12 months after initial discharge. A median of six prescriptions had already been given at the time of discharge; this number increased slightly during ambulatory follow-up. After 1 year, about 30% of the patients had to take more than ten dosing units per day. After discharge, about 50% of all prescriptions were subject to changes in the choice of the preparation (brand-generic) or the agent used [within a class of similar agents, e.g. angiotensin converting enzyme inhibitors (ACIs)]. The prescription of some problematic agents (benzodiazepines, non-steroidal anti-inflammatory agents) increased during the ambulatory follow-up, but pivotal medications for cardiovascular indications (e.g., ACI) given at discharge were maintained. Over-the-counter (OTC) drugs—which were not part of the discharge medication—contributed to 12% of all drugs taken at V4. The majority of the prescriptions (95% of about 2,000 prescriptions surveyed at each visit) was in agreement with the drug’s approval status and was appropriate in terms of absence of contraindications. At home visits, therapy with ACI or beta-blocking agents was in agreement with clinical guidelines, although under-dosing was obvious. Blood pressure control (

Because Parkinsonism is underdiagnosed in the community, we have validated screening modalities in the field setting and developed a screening procedure to enhance recognition of undiagnosed patients. In a first survey, we identified suspect cases among patients consulting 9 general practitioners (GPs) over a 3-week period using in parallel: (1) a published questionnaire; (2) a standardized examination by the GPs; (3) clinical impression of the GPs; or (4) pre-established diagnoses. Parkinsonism was ascertained by two neurologists with a 1-year follow-up and FP-CIT-SPECT. In total, 1,411 patients consulted the GPs, 1,030 participated in the study, 87 possible cases were identified by at least one of four screening modalities, 12 suffered from Parkinsonism, and 4 of these 12 were de novo cases. Statistical analysis demonstrated that with appropriate evaluation, the questionnaire is highly sensitive and excludes most nonaffected persons, and that the GPs' clinical impression is more specific. We therefore tested in a second survey the efficacy of a serial screening, starting with the questionnaire, followed by a standardized GP evaluation, and then by neurological examination. Of 1,353 participants seen by 9 GPs during a 3-week period, 5 de novo cases were identified. This simple screening protocol significantly enhances recognition of incipient Parkinsonism.

The efficacy of acupuncture treatment for chronic low-back pain has not been reliably proven because of a lack of good quality studies, leading to the necessity of developing the German Acupuncture Trial for Chronic Low-Back Pain (GERAC-cLBP) study.The aim is to assess the effectiveness of traditional Chinese acupuncture for chronic low-back pain compared to sham acupuncture and with a conventional standard therapy.This trial is a nationwide, multicenter, randomized, prospective, partially blinded study. The primary endpoint is the success rate after 6 months. Success is defined as an improvement of 33% or more of three pain-related items on the Van-Korff Pain Score or an improvement of 12% or more in the disability measured by the Hanover Functional Ability Questionnaire. Assessment of the effectiveness of the blinding of patients to the form of acupuncture they received will be conducted. All clinical endpoints are assessed centrally by blinded independent observers. The sample size, with a total of 1062 patients to be enrolled, is based on power calculations. Independent central randomization, data collection, data processing, and statistical analysis are provided. Success rates will be tested for differences using two-sided Fisher exact tests. In the primary analysis, all tests will be carried out on the basis of the intention-to-treat principle. Secondary analyses will be conducted according to protocol approaches.The pilot phase of the trial started in February 2002, the estimated duration of the study is 2.5 years. Enrollment is anticipated to be completed in the winter of 2003.The GERAC-cLBP study is currently the world's largest controlled trial of the effectiveness of acupuncture treatment for low-back pain. It will contribute to the evaluation of efficacy by means of evidence based medicine.