RESUMEN
Bacterial quorum sensing (QS) and biofilm formation are promising targets for developing new therapies to treat chronic infections. Herein, we report the stereoselective synthesis of 18 new analogs of natural cadiolides. Among the new compounds, substances 8b, 8f, 8i, 9a, 9b and 9e completely inhibited the biofilm formation of Escherichia coli RP347 in vitro. In addition, compound 8b interfered acyl-homoserine lactone (AHL) mediated QS, while 9e interrupted the QS via autoinducer-2 (AI-2). Biological assays also revealed that synthetic intermediates alkynones are potent inhibitors of AI-2 and AHL-mediated QS. These results indicate that cadiolides and alkynones are good candidates for further structural modification for a new generation of more potent antimicrobial agents.
Asunto(s)
4-Butirolactona/farmacología , Antibacterianos/farmacología , Biopelículas/efectos de los fármacos , Percepción de Quorum/efectos de los fármacos , 4-Butirolactona/síntesis química , Antibacterianos/síntesis química , Escherichia coli/efectos de los fármacos , Escherichia coli/fisiología , Pruebas de Sensibilidad Microbiana , Pseudomonas aeruginosa/efectos de los fármacos , Pseudomonas aeruginosa/fisiología , EstereoisomerismoRESUMEN
In continuation of our quest for new redox-modulating catalytic antitumor molecules, selenium-containing quinone-based 1,2,3-triazoles were synthesized using rhodium-catalyzed C-H bond activation and click reactions. All compounds were evaluated against five types of cancer cell lines: HL-60 (human promyelocytic leukemia cells), HCT-116 (human colon carcinoma cells), SF295 (human glioblastoma cells), NCIH-460 (human lung cells) and PC3 (human prostate cancer cells). Some compounds showed good activity with IC50 values below 1 µM. The cytotoxic potential of the naphthoquinoidal derivatives was also evaluated in non-tumor cells, exemplified by L929 cells. Overall, these compounds represent promising new lead derivatives and stand for a new class of chalcogenium-containing derivatives with potential antitumor activity.
Asunto(s)
Antineoplásicos/síntesis química , Compuestos de Organoselenio/síntesis química , Quinonas/química , Rodio/química , Triazoles/síntesis química , Antineoplásicos/uso terapéutico , Catálisis , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Supervivencia Celular/efectos de los fármacos , Química Clic , Ensayos de Selección de Medicamentos Antitumorales , Humanos , Compuestos de Organoselenio/farmacología , Relación Estructura-Actividad , Triazoles/farmacologíaRESUMEN
A combined spectrophotometric-LC method is described for the determination of total lutein and zeaxanthin ester content in carotenoid ester concentrates, including their main geometrical isomers. The concept of composite-specific absorbance is introduced for this purpose. The method is applicable to carotenoid ester concentrates used as ingredients in oil suspensions and dosage forms. The sample is dissolved in a hexane-2-propanol mixture (95 + 5, v/v) for spectrophotometric measurement at a maximum absorption of ~445 nm. Subsequently, in parallel, a sample is saponified and chromatographed on a normal-phase HPLC column to determine the relative percentage profile of the main geometrical isomers of both carotenoid esters. This, in turn, is used to calculate the composite-specific absorbance of the sample for the final calculation of results. The method, which solely uses reference standards to validate chromatographic conditions, avoids the common error of applying the specific absorbance of only the trans isomer for the calculation of total carotenoid content when cis isomers are present.
Asunto(s)
Carotenoides/química , Suplementos Dietéticos/análisis , Ésteres/análisis , Ésteres/química , Luteína/análisis , Luteína/química , Zeaxantinas/análisis , Zeaxantinas/química , Cromatografía Líquida de Alta Presión , Estructura Molecular , Espectrofotometría Ultravioleta , EstereoisomerismoRESUMEN
Chalcogen-containing ß-lapachone derivatives were synthesized using a straightforward methodology and evaluated against several cancer cell lines (leukaemia, human colon carcinoma, prostate, human metastatic prostate, ovarian, central nervous system and breast), showing, in some cases, IC50 values below 1 µM. The cytotoxic potential of the lapachones evaluated was also assayed using non-tumor cells: human peripheral blood mononuclear cells, two murine fibroblast lines (L929 and V79 cells) and MDCK (canine kidney epithelial cells). These compounds could provide promising new lead derivatives for anticancer drug development. This manuscript reports important findings since few authors have described C-3 substituted ß-lapachone with potent antitumor activity. The methodology employed allowed the preparation of the compounds from lapachol within a few minutes in a green approach.
Asunto(s)
Antineoplásicos/síntesis química , Antineoplásicos/farmacología , Calcógenos/química , Naftoquinonas/farmacología , Animales , Antineoplásicos/química , Línea Celular , Proliferación Celular/efectos de los fármacos , Relación Dosis-Respuesta a Droga , Ensayos de Selección de Medicamentos Antitumorales , Humanos , Ratones , Modelos Moleculares , Estructura Molecular , Naftoquinonas/síntesis química , Naftoquinonas/química , Oxidación-Reducción , Relación Estructura-ActividadRESUMEN
1,2,3-Triazole-, arylamino- and thio-substituted naphthoquinones (24, 8, and 2 representatives, respectively) were synthesized in moderate yields and evaluated against several human cancer cell lines (blood, ovarian, breast, central nervous system, colon, and prostate cancers and melanoma), showing, for some of them, IC50 values below 2 µM. The cytotoxic potential of the tested naphthoquinones was also assayed on non-tumor cells such as human peripheral blood mononucluear cells (PBMC) and two murine fibroblast lines (L929 and V79 cells). α-Lapachone- and nor-α-lapachone-based 1,2,3-triazoles and arylamino-substituted naphthoquinones showed potent cytotoxicity against different cancer cell lines. The compounds may represent promising new lead derivatives for anticancer drug development. The electrochemical properties of selected compounds were evaluated in an attempt to correlate them with antitumor activity.
Asunto(s)
Naftoquinonas/química , Triazoles/química , Proliferación Celular , Química Clic , Humanos , Modelos Moleculares , Estructura Molecular , Relación Estructura-ActividadRESUMEN
In our continued search for novel trypanocidal compounds, twenty-six derivatives of para- and ortho-naphthoquinones coupled to 1,2,3-triazoles were synthesized. These compounds were evaluated against the infective bloodstream form of Trypanosoma cruzi, the etiological agent of Chagas disease. Compounds 17-24, 28-30 and 36-38 are described herein for the first time. Three of these novel compounds (28-30) were found to be more potent than the standard drug benznidazole, with IC50/24h values between 6.8 and 80.8µM. Analysis of the toxicity to heart muscle cells led to LC50/24h of <125, 63.1 and 281.6µM for 28, 29 and 30, respectively. Displaying a selectivity index of 34.3, compound 30 will be further evaluated in vivo. The electrochemical properties of selected compounds were evaluated in an attempt to find correlations with trypanocidal activity, and it was observed that more electrophilic quinones were generally more potent.
Asunto(s)
Naftoquinonas/química , Triazoles/química , Tripanocidas/síntesis química , Animales , Supervivencia Celular/efectos de los fármacos , Células Cultivadas , Cristalografía por Rayos X , Técnicas Electroquímicas , Electrodos , Ratones , Conformación Molecular , Miocitos Cardíacos/citología , Relación Estructura-Actividad , Triazoles/síntesis química , Triazoles/toxicidad , Tripanocidas/química , Tripanocidas/toxicidad , Trypanosoma cruzi/efectos de los fármacosRESUMEN
Continuing our screening program for novel anti-parasite compounds, we synthesized seven 1,4-naphthoquinones coupled to 1,2,3-triazoles, five nor-ß-lapachone-based 1,2,3-triazoles and ten α-lapachone-based 1,2,3-triazoles. These and other naphthoquinonoid compounds were evaluated for their activity against promastigote forms of antimony-sensitive and -resistant strains of Leishmania infantum (syn. Leishmania chagasi) and Leishmania amazonensis. The toxicity of these compounds to mammalian cells was also examined. The substances were more potent than an antimonial drug, with IC50 values ranging from 1.0 to 50.7 µM. Nor-α-lapachone derivatives showed the highest antileishmanial activity, with selectivity indices in the range of 10-15. These compounds emerged as important leads for further investigation as antileishmanial agents. Additionally, one of these compounds exhibited cross-resistance in Sb-resistant Leishmania and could provide a molecular tool for investigating the multidrug resistance mechanisms in Leishmania parasites.
Asunto(s)
Antiprotozoarios/síntesis química , Reacción de Cicloadición/métodos , Naftoquinonas/síntesis química , Triazoles/síntesis química , Alquinos/química , Animales , Antimonio/farmacología , Antiprotozoarios/química , Antiprotozoarios/farmacología , Azidas/química , Catálisis , Supervivencia Celular/efectos de los fármacos , Células Cultivadas , Cobre/química , Resistencia a Medicamentos/efectos de los fármacos , Leishmania/efectos de los fármacos , Leishmania infantum/efectos de los fármacos , Macrófagos Peritoneales/citología , Macrófagos Peritoneales/efectos de los fármacos , Ratones , Naftoquinonas/química , Naftoquinonas/farmacología , Pruebas de Sensibilidad Parasitaria , Especificidad de la Especie , Triazoles/química , Triazoles/farmacologíaRESUMEN
Five 2-hydroxy-3-substituted-aminomethyl naphthoquinones, nine 1,2,3-triazolic para-naphthoquinones, five nor-ß-lapachone-based 1,2,3-triazoles, and several other naphthoquinonoid compounds were synthesized and evaluated against the infective bloodstream form of Trypanosoma cruzi, the etiological agent of Chagas disease, continuing our screening program for new trypanocidal compounds. Among all the substances, 16-18, 23, 25-29 and 30-33 were herein described for the first time and fifteen substances were identified as more potent than the standard drug benznidazole, with IC(50)/24h values in the range of 10.9-101.5 µM. Compounds 14 and 19 with Selectivity Index of 18.9 and 6.1 are important structures for further studies.
Asunto(s)
Técnicas de Química Sintética , Química Clic , Descubrimiento de Drogas , Naftoquinonas/síntesis química , Naftoquinonas/farmacología , Triazoles/química , Trypanosoma cruzi/efectos de los fármacos , Animales , Ratones , Naftoquinonas/química , Naftoquinonas/toxicidad , Tripanocidas/síntesis química , Tripanocidas/química , Tripanocidas/farmacología , Tripanocidas/toxicidadRESUMEN
From January 1989 to April 1995, 465 specimens of Triatoma vitticeps were collected in the locality of Triunfo, 2nd District of Santa Maria Madalena municipal district, State of Rio de Janeiro. The bugs were found indoors by local residents with predominance of adults. The flight activity was high in hot months when the incidence in the domicile also increased. Two hundred and two bugs (111 alive and 91 dead) were examined for Trypanosoma cruzi infection. This was detected in 31 of the dead bugs (34 per cent) and 88 (79 per cent) of the live bugs examined. With a view to investigate the possible vertebrate hosts of the T. cruzi isolates, the blood of 122 mammnals was examined through Giemsa-stained smear, hemocultures and xenodiagnosis. T. cruzi was detected in three specimens of Didelphis marsupialis and T. (M.) theileri was detected in one specimen of Bos taurus. The parasites were isolated from triatomine feces, xenoculture and hemoculture. No evidence of human infection was detected in 58 inhabitants examined, as evaluated by indirect imunofluorescence technique using T. cruzi epimastigotes as antigens. These results show that T. vitticeps is still a sylvatic species although nymphs have found inside the domicile. Thus, an epidemiological vigilance is necessary to know the behaviour of this species following the continous modifications promoted by the presence of man.