RESUMEN
This paper describes a sensitive and selective method for the simultaneous determination of bispinacolato diboron (B2Pin2) and tetrahydroxy diboron (B2(OH)4) in a small molecule Active Pharmaceutical Ingredient (API) by gas chromatography - mass spectrometry (GC-MS). These reagents are commonly used in the Suzuki-Miyaura coupling reaction and analytical methods are typically required to monitor these reagents at the Threshold of Toxicological Concern (TTC) level since they are Class II impurities based on ICH M7 guideline. In this study, hexylene glycol was added to derivatize B2(OH)4 before direct injection to the GC-MS, and B2Pin2 is analyzed in the same analysis without derivatization. Under the optimal conditions, the limit of detection (LOD) and the limit of quantitation (LOQ) were 65 ng/mL and 130 ng/mL respectively. Average recoveries of the analytes spiked in the drug substance at the 13 ppm (LOQ) and 104 ppm (TTC) levels were in the range of 77.9 %-85.3 % with relative standard deviations (RSDs) of 2.8 %-6.8 %. The linearity for both analytes was established in the range of 0.130-2.080 µg/mL with a correlation coefficient (r) of 0.9998 and the derivatization reaction is very rapid and complete within 15 minutes.
Asunto(s)
Preparaciones Farmacéuticas , Cromatografía de Gases y Espectrometría de Masas , Indicadores y Reactivos , Límite de DetecciónRESUMEN
A series of chlorinated bisindole pyrroles, lynamicins A-E (1-5), was discovered from a novel marine actinomycete, NPS12745, which was isolated from a marine sediment collected off the coast of San Diego, California. Close to full length 16S rRNA sequence analysis indicated that NPS12745 is a novel strain of a recently described marine actinomycete with the proposed genus name Marinispora. The antimicrobial spectrum of these compounds was evaluated against a panel of 11 pathogens, which demonstrated that these substances possess broad-spectrum activity against both Gram-positive and Gram-negative organisms. Significantly, compounds 1-5 were active against drug-resistant pathogens such as methicillin-resistant Staphylococcus aureus and vancomycin-resistant Enterococcus faecium.
Asunto(s)
Actinobacteria/química , Antibacterianos/aislamiento & purificación , Antibacterianos/farmacología , Bacterias Gramnegativas/efectos de los fármacos , Bacterias Grampositivas/efectos de los fármacos , Hidrocarburos Clorados/aislamiento & purificación , Hidrocarburos Clorados/farmacología , Indoles/aislamiento & purificación , Indoles/farmacología , Pirroles/aislamiento & purificación , Pirroles/farmacología , Actinobacteria/genética , Antibacterianos/química , California , Farmacorresistencia Bacteriana/efectos de los fármacos , Enterococcus faecium/efectos de los fármacos , Hidrocarburos Clorados/química , Indoles/química , Biología Marina , Resistencia a la Meticilina/efectos de los fármacos , Pruebas de Sensibilidad Microbiana , Estructura Molecular , Pirroles/química , Staphylococcus aureus/efectos de los fármacos , Resistencia a la Vancomicina/efectos de los fármacosRESUMEN
We examined the effects of halogens on the production of salinosporamide A (NPI-0052) by the obligate marine actinomycete Salinispora tropica NPS465, specifically the production of analogs containing halogens other than chlorine. Adding NaF, NaBr and NaI directly to the production medium prepared in seawater containing -3% NaCl did not induce the production of the corresponding analogs. Replacing seawater with 2-3% NaI in the production medium enhanced the production of NPI-0052 by 2.1 fold. Replacing seawater with 2-3% NaBr in the production medium suppressed the production of NPI-0052 but induced the production of a brominated analog at very low yield. Using a stepwise enrichment of bromide in the seed cultures in order to reduce the chloride ion carried over to the production medium, the production of the brominated analog was enhanced by 4 fold. We also demonstrated that the growth of this obligate marine actinomycete is dependent upon sodium concentration, not chloride concentration.
Asunto(s)
Actinomycetales/metabolismo , Bromuros/farmacología , Lactonas/química , Lactonas/metabolismo , Pirroles/química , Pirroles/metabolismo , Compuestos de Sodio/farmacología , Fluoruro de Sodio/farmacología , Yoduro de Sodio/farmacología , Actinomycetales/efectos de los fármacos , Actinomycetales/crecimiento & desarrollo , Cromatografía Líquida de Alta Presión , Medios de Cultivo/química , Lactonas/aislamiento & purificación , Estructura Molecular , Pirroles/aislamiento & purificaciónRESUMEN
Salinosporamide A (NPI-0052; 3), a highly potent inhibitor of the 20S proteasome, is currently in phase I clinical trials for the treatment of cancer. During the course of purifying multigram quantities of 3 from Salinispora tropica fermentation extracts, several new salinosporamides were isolated and characterized, most of which represent modifications to the chloroethyl substituent at C-2. Specifically, 3 was isolated along with the known compound salinosporamide B (4), the previously undescribed methyl congener salinosporamide D (7), and C-2 epimers of 3 and 7 (salinosporamides F (9) and G (10), respectively). Salinosporamide I (13), in which the methyl group at the ring junction is replaced with an ethyl group, and the C-5 deshydroxyl analogue salinosporamide J (14), were also identified. Replacement of synthetic sea salt with sodium bromide in the fermentation media produced bromosalinosporamide (12), 4, and its C-2 epimer (11, salinosporamide H). In addition to these eight new salinosporamides, several thioester derivatives were generated semisynthetically. IC50 values for cytotoxicity against human multiple myeloma cell line RPMI 8226 and inhibition of the chymotrypsin-like (CT-L) activity of purified rabbit 20S proteasomes were determined for all compounds. The results indicate that thioesters may directly inhibit the proteasome, albeit with reduced potency compared to their beta-lactone counterparts.
Asunto(s)
Actinobacteria/química , Lactonas , Inhibidores de Proteasoma , Pirroles , Actinobacteria/crecimiento & desarrollo , Bahamas , Cristalografía por Rayos X , Concentración 50 Inhibidora , Lactonas/química , Lactonas/aislamiento & purificación , Lactonas/farmacología , Biología Marina , Conformación Molecular , Estructura Molecular , Pirroles/química , Pirroles/aislamiento & purificación , Pirroles/farmacologíaRESUMEN
Salinosporamide A (1, NPI-0052) is a potent proteasome inhibitor in development for treating cancer. In this study, a series of analogues was assayed for cytotoxicity, proteasome inhibition, and inhibition of NF-kappaB activation. Marked reductions in potency in cell-based assays accompanied replacement of the chloroethyl group with unhalogenated substituents. Halogen exchange and cyclohexene ring epoxidation were well tolerated, while some stereochemical modifications significantly attenuated activity. These findings provide insights into structure-activity relationships within this novel series.
Asunto(s)
Actinobacteria , Antineoplásicos/síntesis química , Lactonas/síntesis química , Inhibidores de Proteasoma , Pirroles/síntesis química , Animales , Antineoplásicos/química , Antineoplásicos/farmacología , Línea Celular , Línea Celular Tumoral , Humanos , Lactonas/química , Lactonas/farmacología , Biología Marina , FN-kappa B/antagonistas & inhibidores , Pirroles/química , Pirroles/farmacología , Conejos , Estereoisomerismo , Relación Estructura-ActividadRESUMEN
During the course of our screening program designed to discover novel anticancer and anti-infective agents from marine microorganisms, a strain of Streptomyces aureoverticillatus (NPS001583) isolated from a marine sediment was found to produce a novel macrocyclic lactam with cytotoxicity against various tumor cell lines. Using extensive MS, UV, and NMR spectral analyses, the structure has been established as compound 1, aureoverticillactam, a 22-atom macrocyclic lactam incorporating both triene and tetraene conjugated olefins.
Asunto(s)
Actinobacteria/química , Antineoplásicos/aislamiento & purificación , Lactamas/aislamiento & purificación , Macrólidos/aislamiento & purificación , Streptomyces/química , Alquenos/química , Aminoglicósidos/química , Animales , Antineoplásicos/química , Antineoplásicos/farmacología , Ensayos de Selección de Medicamentos Antitumorales , Células HT29 , Humanos , Lactamas/química , Lactamas/farmacología , Macrólidos/química , Macrólidos/farmacología , Estructura Molecular , Resonancia Magnética Nuclear Biomolecular , Polienos/química , Células Tumorales CultivadasRESUMEN
Leporin B (1), a novel demethylated analogue of leporin A (2), was isolated from a taxonomically unidentified fungal strain as part of an effort to discover compounds with the ability to increase expression levels of the enzyme hexokinase II. The structure was determined by spectral methods, including 1D and 2D NMR, and HRMS. The relative stereochemistry was assigned by NOESY experiments and coupling constants.