[ANALYSIS OF THE EFFECT OF TRIPHENYL TIN COMPOUNDS AFTER INTRAVENOUS INJECTION IN EXPERIMENTAL ANIMALS].
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The genetic toxicology of the major dyestuffs used in foods, drugs and cosmetics has been reviewed. Published data for azo, triphenylmethane and xanthene dyes from short-term assays for muta-carcinogenicity have been summarized and discussed according to usage, current and previous worldwide legislative status. Certain other synthetic food dyes, commercial mixtures, natural and polymeric colourants as well as a section on aminoazobenzene and its derivatives have been included. Genotoxicity has been discussed with reference to structural chemistry, levels of exposure, absorption and metabolism and to epidemiological information. The extent of agreement between data from different tests and correlations with animal cancer assays have been considered. Synthetic dyes from the 3 major structural classes exhibit genotoxicity, whilst only 2 natural colours have proved active. Activity may be due to the presence of certain functional groups, notably nitro- and amino-substituents which are metabolized to ultimate electrophiles that may be stabilized by electronic interaction with aryl rings. Metabolic processes such as azo-reduction may be activating or detoxifying. the low but significant correlation between animal carcinogenicity and short-term test data may be increased with further screening, especially involving chromosome assays. It is suggested that a human cancer hazard may exist where significant quantities of finished benzidine dye samples are handled. Such risks from exposures to other colours and the possibility of human germ-line mutation induction by dyestuffs cannot be meaningfully assessed.
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HIV-1 integrase is a critical enzyme for replication of HIV, and its inhibition is one of the most promising new drug strategies for anti-retroviral therapy, with potentially significant advantages over existing therapies. In this report, a series of HIV-1 inhibitors isolated from the organic extract of fermentations from terrestrial fungi is described. These fungal species, belonging to a variety of genera, were collected from throughout the world following the strict guidelines of Rio Convention on Biodiversity. The polyketide- and terpenoid-derived inhibitors are represented by two naphthoquinones, a biphenyl and two triphenyls, a benzophenone, four aromatics with or without catechol units, a linear aliphatic terpenoid, a diterpenoid, and a sesterterpenoid. These compounds inhibited the coupled and strand-transfer reaction of HIV-1 integrase with an IC(50) value of 0.5-120 micro M. The bioassay-directed isolation, structure elucidation, and HIV-1 inhibitory activity of these compounds are described.
Some novel terpenyl pyrimidine derivatives 2(a-d) and 6(a-b) have been synthesised from alpha/beta-ionone keteneacetals 1 and 5. The terpenyl pyrimidine 2e has been synthesised from beta-ionone 3 in two steps in quantitative yield. The pyrimidine derivatives were screened for in-vivo antilesihmanial activity. The compounds 2d, 2e, 6a and 6b showed promising in-vivo antileishmanial activity.
Poly (3'-O-carboxymethyl-2'-deoxyctidine) (VII) has been synthesised by the polymerisation of 3'-O-carboxymethyl-4-N-phenoxyacety-2'-deoxycytidine (V) and removal of the phenoxyacetyl groups under acidic conditions. V was obtained by the action of 2,4-dinitrophenyl phenylacetate on 3'-O-carboxymethyl-5'-O-triphenylmethyl-2'-deoxycytidine (III) followed by removal of the triphenylmethyl group under carefully controlled acidic conditions. The polymer, VII gave a hypochromic effect of about 20% at 250nm when mixed with poly (1) in 0.2Macetate, pH 5.0. It appeared, therefore, that a complex was formed. Upon heating a solution of this complex there was an initial decrease in optical density followed by a much larger increase to give a Tm of about 60 degrees. Attempts to form the 3'-O-carboxymethyl derivative of 4-N-phenoxyacetyl-5'-O-'triphenylmethyl-2'-deoxycytidine to give a shorter synthetic route to VII were not successful. 3'-O-Carboxymethyl-2'-deoxycytidine was obtained by removal of thetriphenylmethyl group from III. Attempts to polymerise this compound in concentrated aqueous solution with a water-soluble carbodiimide were not successful.
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We synthesized and tested three series of bisphosphonates for their activity in inhibiting the growth of three human tumor cell lines: MCF-7 (breast), NCI-H460 (lung), and SF-268 (CNS). The first series of compounds consisted of 49 nitrogen-containing bisphosphonates, the most active species being a tetrakispivaloyloxymethyl (POM) ester, having an (average) IC(50) of 6.8 microM. The second series of compounds consisted of nine terphenylbisphosphonates, the most active species also being a POM ester, having an IC(50) of 2.2 microM. The third series of compounds consisted of seven halogen or cyanophenylbisphosphonates, the most active species again being a POM ester, having an IC(50) of 500 nM. Taken together, these results are of interest because they show that bisphosphonate esters can have potent activity against a variety of tumor cell lines, with the most active terphenyl- and halophenyl-containing species having IC(50) values approximately 10-40x lower than the most potent commercially available bisphosphonates.
This work represents the first step to set up a toxicity testing procedure and to evaluate the sensitivity of the test microorganism to several classes of environmental pollutants. First, three different techniques were employed to standardise the microbial inoculum, then two different toxicity assessment protocols have been compared: Microtox and a dehydrogenase (DHase) activity inhibition test. The main goal was the optimisation of a microbial bioassay based on the dehydrogenase activity (DHase) inhibition in Pseudomonas fluorescens bacterial strain ATCC 13525. Triphenyl tetrazolium chloride (TTC) was used as electron acceptor and its reduction produces Triphenyl formazane (TPF). The P. fluorescens DHase inhibition bioassay was investigated for being a reliable and rapid method for assessing toxicity. The optimisation of the operating conditions resulted in a repeatable bioassay. Then, P. fluorescens and Vibrio fischeri sensitivity were firstly compared by testing Zn++, one of the reference compounds for Microtox test. In addition, other compounds (Ni++, Cd++, Cu++, phenol) were also tested with both bioassays. A high statistical significance of data was obtained with the logistic curve. The present work has demonstrated that P. fluorescens is as sensitive as Microtox culture (V. fischeri), for some of the metal ions. With reference to organic compounds, the lower sensitivity of P. fluorescens to phenol makes its use difficult in organic polluted samples.
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The fluorescence and laser properties of seven specially chosen aromatic compounds are studied at 293 degrees C. The quantum yield of fluorescence, gamma, decay times, tauf, of the deaerated and non-deaerated solutions are measured. The oscillator strength, fe, fluorescence rate constants, kf, natural lifetimes, tauT0, and intersystem crossing rate constants, kST, are calculated. Some laser parameters are calculated or measured experimentally. It is found that the position of the Tbeta level plays an important role in the fluorescence and laser properties of aromatic compounds. If the Tbeta level is situated below the Sp level, it decreases the quantum yield of fluorescence and the decay time and increases the threshold of laser action. If, due to some structural changes of a molecule, the Tbeta level is situated higher than the Sp level, then the quantum yield of fluorescence and the decay times are increasing and the threshold of laser action is decreasing. Such influence of the position of the Tbeta level upon fluorescence and laser properties of aromatic compound is explained by the fact that the Sp level mixes with the Tbeta level more readily than with other taupipi* levels.
The calcium antagonist felodipine, the lipid-peroxidation inhibitor H290/51, and the angiotensin II type 1 (AT1)-receptor antagonist candesartan all exert beneficial effects on myocardial ischemia/reperfusion injury. This study was undertaken to test the hypothesis that a combination of these drugs with different pharmacologic properties could exert additive cardioprotective effects. Anesthetized pigs were subjected to 45 min of left anterior descending coronary artery occlusion followed by 240 min of reperfusion. Five groups of pigs were randomly given either 0.65 microM (7 nmol/kg) felodipine, 1.0 microM (3.1 microg/kg) H 290/51, 4.2 microM (20 microg/kg) candesartan, a cocktail of these three drugs, or vehicle (n = 6 for each) for 30 min starting at 5 min before reperfusion by coronary venous retroinfusion, which delivers drugs specifically to the ischemic regions. Systolic segment shortening (%SS) was measured by sonomicrometer. The myocardial area at risk and the final infarct size were determined by Evans blue and 2,3,5-triphenyl tetrazolium chloride staining. The hemodynamics did not change significantly during the study. In the vehicle group, the recovery of coronary flow was not maintained during reperfusion, and it was significantly lower after 240 min of reperfusion than during the preischemic period (p < 0.05). The coronary flow in the drug-treated groups was approximately the same by the end of the reperfusion period as that before the induction of ischemia. In the ischemic myocardium, %SS slightly recovered during reperfusion in the four drug-treated groups, but not in the vehicle group. The infarct size, expressed as a percentage of the myocardial area at risk, was smaller in all four drug-treated groups compared with the vehicle group. The infarct size in the cocktail group was significantly smaller than that in the groups given felodipine, H290/51, or candesartan alone. These results demonstrate that a combination of a calcium antagonist, a lipid-peroxidation inhibitor, and an angiotensin AT1-receptor antagonist has an additive effect on infarct limitation, indicating that combined therapy with agents having different pharmacologic modes of action may provide better cardioprotection than any of the drugs alone. The findings also support the view that reperfusion injury is possibly mediated by a combination of mechanisms.
A new original drug IEM-967 (a sulfoderivative in aromatic series with riged molecular structure) exhibited both stimulating and inhibitory gonadotropic effects, depending on reactivity of the system hypothalamus-hypophysis-gonads as well as on periods of the drug administration, in chronic experiments on rats. At the same time, the drug did not possess any peripheral estrogenic action on uterus and vaginal epithelium. The drug both resembled and had a number of differences and advantages as compared with the earlier synthesized compound sigetin in its effect on the gonadotropics function of hypophysis. Synthesis and study of effective medicinal agents causing selective effects on the gonadotropic function of hypophysis are of importance for obstetric and gynecological practice.
The objectives of this study were to isolate the antioxidative components in the broth filtrate of Aspergillus candidus (CCRC 31543), to characterize their antioxidative properties, and to evaluate their safety. Three major compounds were isolated and identified as 3,3' '-dihydroxyterphenyllin, 3-hydroxyterphenyllin, and candidusin B. In the linoleic acid peroxidation system, the inhibition of peroxidation in these three compounds was greater than 95% and was significantly higher than that of alpha-tocopherol but equal to that of BHA at 12.5-200 microg/mL. As measured using the Rancimat method in lard, 3,3' '-di-OH-terphenyllin exhibited a protection factor value of 7.82, which was substantially higher than those of BHA (5.58) and alpha-tocopherol (4.29) at 200 microg/mL. 3,3' '-di-OH-terphenyllin and 3-OH-terphenyllin also exhibited marked scavenging effects on the alpha,alpha-diphenyl-beta-picrylhydrazyl radicals (94.7 and 96.0%, respectively), which were similar to those of BHA and alpha-tocopherol. Safety studies showed that these three compounds were neither cyto- nor geno-toxic toward human intestine 407 (INT 407) cells, nor mutagenic toward Salmonella typhimurium TA98 and TA100.
A new compound isolated from cultures of Aspergillus candidus Link is shown to be 3-hydroxyterphenyllin. The structure was assigned by comparing the 1H and 13C nmr spectra of the metabolite and its acetate derivative with those of terphenyllin and terphenyllin triacetate.
Late-stage malignant melanoma is a cancer that is refractory to current chemotherapeutic treatments. The average survival time for patients with such a diagnosis is 6 months. In general, the vast majority of anticancer drugs operate through induction of cell cycle arrest and cell death in either the DNA synthesis (S) or mitosis (M) phase of the cell cycle. Unfortunately, the same mechanisms that melanocytes possess to protect cells from DNA damage often confer resistance to drugs that derive their toxicity from S or M phase arrest. Described herein is the synthesis of a combinatorial library of potential proapoptotic agents and the subsequent identification of a class of small molecules (triphenylmethylamides, TPMAs) that arrest the growth of melanoma cells in the G1 phase of the cell cycle. Several of these TPMAs are quite potent inducers of apoptotic death in melanoma cell lines (IC(50) approximately 0.5 muM), and importantly, some TPMAs are comparatively nontoxic to normal cells isolated from the bone marrow of healthy donors. Furthermore, the TPMAs were found to dramatically reduce the level of active nuclear factor kappa-B (NFkappaB) in the cell; NFkappaB is known to be constitutively active in melanoma, and this activity is critical for the proliferation of melanoma cells and their evasion of apoptosis. Compounds that reduce the level of NFkappaB and arrest cells in the G1 phase of the cell cycle can provide insights into the biology of melanoma and may be effective antimelanoma agents.
A novel 2,2'-epoxy-terphenyllin, candidusin C, in addition to the well known secondary metabolites terphenyllin, 3-hydroxyterpenyllin and chlorflavonin, has been isolated from the chemically unexplored fungus Aspergillus campestris. The latter three are known secondary metabolites from Aspergillus candidus and therefore a large number of Aspergilli were screened for production of these compounds to see whether they could be regarded as chemotaxonomical indicators of section membership in the monotypic Aspergillus section Candidi. The results indicated that A. campestris and A. taichungensis should be placed in Candidi and this was further confirmed by morphological and physiological similarities. Three species outside the section Candidi produced candidusin related secondary metabolites: Aspergillus arenarius, A. ellipticus and Penicillium raistrickii. Chlorflavonin, however, was only found in section Candidi.