RESUMEN

Seventeen simple isoquinolines, 15 1-benzylisoquinolines, and 19 protoberberines were tested for their inhibitory activities against Epstein-Barr virus early antigen (EBV-EA) activation induced by 12-O-tetradecanoylphorbol-13-acetate (TPA) in Raji cells. Among the tested alkaloids, the inhibitory activity of all 1-benzylisoquinolines and 11 protoberberines was higher than that of beta-carotene. The 1-benzylisoquinolines 19, 21, 22, 29, and 34 and protoberberines 41, 47-49, 51, 52, and 55 showed potent inhibitory effects on EBV-EA induction (96-100% inhibition at 1 x 10(3) mol ratio/TPA). These alkaloids were more active than the naturally occurring alkaloids, 23, 25, 33, 53, and 54. In addition, fifteen simple isoquinolines, eighteen 1-benzylisoquinolines and eight protoberberines were evaluated with respect to their ability to scavenge 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radicals. Nine simple isoquinolines, ten 1-benzylisoquinolines, and four protoberberines were more potent than alpha-tocopherol, and four 1-benzylisoquinolines, 20 and 28-30, exhibited potent activities (SC50 4.5-5.8 microM). Their activities were higher than the naturally occurring alkaloids, 23, 25, and 33. Therefore, some of the isoquinoline alkaloids indicating the high activity on both assays may be potentially valuable cancer chemopreventive agents. Structure-activity relationships are discussed for both tests.

Asunto(s)

Anticarcinógenos/farmacología , Alcaloides de Berberina/farmacología , Isoquinolinas/farmacología , Anticarcinógenos/síntesis química , Anticarcinógenos/química , Antígenos Virales/efectos de los fármacos , Antígenos Virales/metabolismo , Alcaloides de Berberina/síntesis química , Alcaloides de Berberina/química , Carcinógenos/antagonistas & inhibidores , Carcinógenos/toxicidad , Línea Celular , Supervivencia Celular/efectos de los fármacos , Quimioprevención , Relación Dosis-Respuesta a Droga , Ensayos de Selección de Medicamentos Antitumorales , Depuradores de Radicales Libres/síntesis química , Depuradores de Radicales Libres/química , Depuradores de Radicales Libres/farmacología , Radicales Libres/química , Herpesvirus Humano 4/efectos de los fármacos , Herpesvirus Humano 4/metabolismo , Humanos , Isoquinolinas/síntesis química , Isoquinolinas/química , Estructura Molecular , Estereoisomerismo , Relación Estructura-Actividad , Acetato de Tetradecanoilforbol/antagonistas & inhibidores , Acetato de Tetradecanoilforbol/toxicidad

RESUMEN

The photodegradation products of the anticancer drug, dacarbazine, cause adverse reactions including local venous pain when injected intravenously. In this study, we attempted to identify which of these products is responsible. We synthesized or purchased five photodegradation products of dacarbazine (dimethylamine, 5-diazoimidazole-4-carboxamide (Diazo-IC), 4-carbamoylimidazolium-5-olate, 5-carbamoyl-2-(4-carbamoylimidazol-5-ylazo)imidazolium-5-olate and 2-azahypoxanthine) and examined the pain reaction induced by their intraperitoneal administration in mice using an abdominal stretching or constriction assay. Only Diazo-IC clearly induced pain reaction in mice in a dose-dependent manner, the other products caused no pain reaction. The threshold concentration for pain reaction in mice was estimated to be about 0.1 mg mL-1. While diclofenac sodium significantly reduced acetic-acid-induced pain reaction in mice, it did not influence those induced by Diazo-IC. This result suggests that the mechanism of Diazo-IC-induced pain is different from that of acetic-acid-induced inflammatory pain. Dacarbazine itself produced marked relaxation of rat thoracic aorta strips in a concentration-dependent manner, but there was no difference between the activity of dacarbazine and its photo-exposed solution, so constriction or relaxation of blood vessels is unlikely to be a factor in the pain reaction. In conclusion, Diazo-IC generated by photodegradation of dacarbazine solution causes the side-effect of venous pain. Dacarbazine solution that has turned pink should not be used, because Diazo-IC is an intermediate in the formation of the reddish product, 5-carbamoyl-2-(4-carbamoylimidazol-5-ylazo)imidazolium-5-olate. Drip infusion preparations of dacarbazine should be shielded from light.

Asunto(s)

Antineoplásicos Alquilantes/efectos adversos , Dacarbazina/efectos adversos , Dolor/inducido químicamente , Enfermedades Vasculares/inducido químicamente , Abdomen , Animales , Dacarbazina/análogos & derivados , Inflamación , Infusiones Parenterales , Luz , Masculino , Ratones , Dimensión del Dolor , Fotólisis , Ratas , Ratas Wistar

RESUMEN

[reaction: see text] 1-Phenylsulfonylallenes possessing a hexynyl appendage in refluxing toluene in the presence of catalytic amount of rhodium(I) catalyst under a carbon monoxide atmosphere underwent regioselective formal [2 + 2 + 1]-cycloaddition to produce the corresponding bicyclo[5.3.0]dec-1,7-dien-9-one derivatives in acceptable yields.

RESUMEN

Treatment of (5S,6S)-5,6-bis(tert-butyldimethylsiloxy)-8-(substituted)oct-1-en-7-yne derivatives, prepared from diethyl L-tartrate, with Co(2)(CO)(8) afforded the corresponding cobalt-complexed enynes, which were subsequently exposed to the typical Pauson-Khand conditions to furnish highly stereoselectively or exclusively (2S,3S,6S)-2,3-bis(tert-butyldimethylsiloxy)-9-(substituted)bicyclo[4.3.0]non-1(9)-en-8-ones. On the other hand, (3S,4S)-1-(substituted)oct-7-en-1-yne-3,4-diol congeners produced, on exposure to the Pauson-Khand conditions, (2S,3S,6R)-2,3-dihydroxy-9-(substituted)bicyclo[4.3.0]-non-1(9)-en-8-one derivatives in a highly stereoselective manner. The newly developed procedure has been shown to be useful for construction of the 2,3-bis(oxygenated)-7-(substituted)bicyclo[4.3.0]non-6-en-8-one framework in a stereocomplementary as well as stereoselective fashion.

RESUMEN

A new stereoselective total synthesis of (+/-)-swainsonine is described. Successive treatment of cis-3,4-epoxy-7-(p-toluenesulfonamido)-1-heptyne with dicobalt octacarbonyl, Lewis acid, and cerium(IV) ammonium nitrate effected stereoselective formation of the trans-2-ethynyl-3-hydroxypiperidine skeleton with retention of configuration at the propynyl center. The piperidine derivative thus prepared was converted into the title compound efficiently.

RESUMEN

First total syntheses of (+)-secosyrins 1 and 2 and total syntheses of (+)-syributins 1 and 2 are described. The two chiral centers of diisopropyl tartrate were incorporated into target natural products. Stereoselective construction of the spiro skeleton of secosyrins could be realized by taking advantage of an alkyne-cobalt complex. The synthesis of these compounds established their relative and absolute stereochemistry unambiguously.