Synthesis and anti-inflammatory activity of the major metabolites of imrecoxib

We have developed a novel and moderately selective COX-2 inhibitor, imrecoxib, as a new anti-inflammatory drug. We describe herein the preparation of the major metabolites M2 and M4 of imrecoxib, as well as the in vitro and in vivo activities of the two compounds. The results showed that both M2 and M4 are potential COXs inhibitors with a moderate COX-1/COX-2 selectivity, and their anti-inflammatory activity in vivo was equal to or slightly higher than the clinical celecoxib.     

Synthesis of one of the major mouse metabolites of lovastatin and simvastatin

An unequivocal synthesis of the mouse liver metabolites of lovastatin and simbastatin resulting from β-oxidation of the lactone portion is described.     

Synthesis and structural assignment of two major metabolites of the LTA4H inhibitor DG-051

The same two major CYP mediated metabolites of DG-051 were produced in the presence of rat, dog, monkey and human liver microsomes. Their respective structures were hypothesized based on mass spectrometry data correlated with the parent structure and confirmed by comparison with authentic synthetic samples. The number of regioisomers synthesized as candidates for metabolite M1 was narrowed down using a metabolic study of a selectively deuterated DG-051 analogue.     

Synthesis and antiviral activities of the major metabolites of the HIV protease inhibitor ABT-378 (Lopinavir)

The HIV protease inhibitor ABT-378 (Lopinavir) is metabolized rapidly and extensively by CYP-3A4 catalyzed oxidation. Three of the major metabolites identified were synthesized and their antiviral (HIV) activities determined.     

Concurrent quantification of tryptophan and its major metabolites

An imbalance in tryptophan (TRP) metabolites is associated with several neurological and inflammatory disorders. Therefore, analytical methods allowing for simultaneous quantification of TRP and its major metabolites would be highly desirable, and may be valuable as potential biomarkers. We have developed a HPLC method for concurrent quantitative determination of tryptophan, serotonin, 5-hydroxyindoleacetic acid, kynurenine, and kynurenic acid in tissue and fluids. The method utilizes the intrinsic spectroscopic properties of TRP and its metabolites that enable UV absorbance and fluorescence detection by HPLC, without additional labeling. The origin of the peaks related to analytes of interest was confirmed by UV–Vis spectral patterns using a PDA detector and mass spectrometry. The developed methods were validated in rabbit fetal brain and amniotic fluid at gestational day 29. Results are in excellent agreement with those reported in the literature for the same regions. This method allows for rapid quantification of tryptophan and four of its major metabolites concurrently. A change in the relative ratios of these metabolites can provide important insights in predicting the presence and progression of neuroinflammation in disorders such as cerebral palsy, autism, multiple sclerosis, Alzheimer disease, and schizophrenia.     

Modelling the emergent dynamics and major metabolites of the human colonic microbiota

We present here a first attempt at modelling microbial dynamics in the human colon incorporating both uncertainty and adaptation. This is based on the development of a Monod‐equation based, differential equation model, which produces computer simulations of the population dynamics and major metabolites of microbial communities from the human colon. To reduce the complexity of the system, we divide the bacterial community into 10 bacterial functional groups (BFGs) each distinguished by its substrate preferences, metabolic pathways and its preferred pH range. The model simulates the growth of a large number of bacterial strains and incorporates variation in microbiota composition between people, while also allowing succession and enabling adaptation to environmental changes. The model is shown to reproduce many of the observed changes in major phylogenetic groups and key metabolites such as butyrate, acetate and propionate in response to a one unit pH shift in experimental continuous flow fermentors inoculated with human faecal microbiota. Nevertheless, it should be regarded as a learning tool to be updated as our knowledge of bacterial groups and their interactions expands. Given the difficulty of accessing the colon, modelling can play an extremely important role in interpreting experimental data and predicting the consequences of dietary modulation.     

Synthesis and analysis of selenomethionine metabolites

This paper describes the enzymatic synthesis of selenomethionine metabolites of the transmethylation and polyamine synthesis pathways: adenosylselenomethionine, adenosylselenohomocysteine, decarboxylated adenosylselenomethionine, and methylselenoadenosine. These compounds and the corresponding methionine metabolites were simultaneously separated by a single HPLC run. The sensitivity of the HPLC method is about 20 pmol per compound. The method may be used for direct analysis of the metabolite levels in tissues or cells treated with selenomethionine and it provides an assay method for the pulse-chase type of analysis of relative flows for both selenium- and sulfur-containing compounds in transmethylation and polyamine pathways.     

Synthesis and antirheumatic activity of the metabolites of esonarimod

We have developed esonarimod, (+/-)-2-acetylthiomethyl-4-(4-methylphenyl)-4-oxobutanoic acid, as a new antirheumatic drug. Now we describe herein the preparation of the enantiomers of (+/-)-deacetylesonarimod, the pharmaceutically active metabolites of esonarimod, and comparison of their antirheumatic activities. No significant difference has been observed between the two enantiomers. In a pre-clinical study of esonarimod, other metabolites were detected in rat blood or urine. We also synthesized these compounds as authentic samples to analyze the human metabolites in clinical studies of esonarimod.     

Synthesis and biological evaluation of phenstatin metabolites

Previous investigations on the incubation of phenstatin with rat and human microsomal fractions revealed the formation of nine main metabolites. The structures of eight of these metabolites have been now confirmed by synthesis and their biological properties have been reported. Eaton's reagent was utilized as a convenient condensing agent, allowing, among others, a simple multigram scale preparation of phenstatin. Synthesized metabolites and related compounds were evaluated for their antiproliferative activity in the NCI-60 cancer cell line panel, and for their effect on microtubule assembly. Metabolite 23 (2'-methoxyphenstatin) exhibited the most potent in vitro cytotoxic activity: inhibition of the growth of K-562, NCI-H322M, NCI-H522, KM12, M14, MDA-MB-435, NCI/ADR-RES, and HS 578T cell lines with GI(50) values <10nM. It also showed more significant tubulin polymerization inhibitory activity than parent phenstatin (3) (IC(50)=3.2 μM vs 15.0 μM) and induced G2/M arrest in murine leukemia DA1-3b cells. The identification of this active metabolite led to the design and synthesis of analogs with potent in vitro cytotoxicity and inhibition of microtubule assembly.     

Two major metabolites of 8-prenylnaringenin are estrogenic in vitro

8-prenylnaringenin (8-PN) and preparations containing 8-prenylnaringenin have been suggested for use in medicinal and cosmetic applications like hormone replacement or bust enhancement. However, the safety of application is still under considerable debate. Recently it has been shown that human liver microsomes are converting 8-prenylnaringenin to 12 metabolites, with (E)-8-(4'-hydroxyisopentenyl)naringenin (8-PN-OH) and (E)-8-(4'-oxoisopentenyl)naringenin (8-PN=O) being among the most abundant. Applying two independent in vitro test systems we demonstrate that these two metabolites of 8-prenylnaringenin are estrogenic in vitro. These results represent an important piece of information towards the discussion of safety of use of preparations containing 8-prenylnaringenin.     

Identification of the major metabolites of resveratrol in rat urine by HPLC-MS/MS

To identify the major metabolites of resveratrol in rat, rat urine samples were pretreated by using solid-phase extraction technique (SPE) with polyamide cartridges. And a LC-MS/MS method with electrospray ionisation (ESI), negative ion mode and collision induced dissociation (CID), was used to elucidate the structures of the major metabolites of resveratrol. According to the results of our experiment, we found that the main metabolites of resveratrol were resveratrol monoglucuronide (M1), dihydroresveratrol monosulfate (M2), resveratrol monosulfate (M3) and dihydroresveratrol (M4).     

Determination of Quinidine and its major metabolites by high-performance liquid chromatography

A specific and precise assay, capable of quantitating in human plasma simultaneously but separately quinidine, dihydroquinidine and the quinidine metabolites 2′-quinidinone, 3-OH-quinidine and a third metabolite found — tentatively identified as the product formed by rearrangement of quinidine-N-oxide — is reported. The assay uses a normal phase high-performance liquid chromatographic (HPLC) system with a variable-wavelength UV detector at 235 nm and has a limit of sensitivity at approximately 20 ng/ml. The mobile phase consists of hexanes—ethanol—ethanolamine (91.5:8.47:0.03). A 2-ml plasma sample is worked up by adding primaquine base as an internal standard and extracting with ether—dichloromethane—isopropanol (6:4:1). The organic extract is evaporated and the residue reconstituted in 100—600 μl of mobile phase and an aliquot injected onto the column.Comparison of this procedure with the Edgar and Sokolow (dichloroethane) extraction—fluorescence procedure and with the Cramer and Isaksson (benzene) double extraction—fluorescence assay indicates that both fluorescence procedures give quinidine concentrations up to 2.3 times those determined by HPLC. These discrepancies were shown to be due to carry-over of metabolites and some extraneous background fluorescence.     

Paired-ion chromatographic analysis of tamoxifen and two major metabolites in plasma

Diclofenac was converted into either its methyl or ethyl ester in methanol or ethanol containing 0.1% or 0.5% sulfuric acid, respectively. The ester was extracted and subjected to gas—liquid chromatography with electron-capture detection. The esterification resulted in an increased sensitivity of the gas chromatographic detection, three times better than that previously reported for the formation of indolone ring in trifluoroethanol containing 0.5% sulfuric acid.     

Changes in major components of tea fungus metabolites during prolonged fermentation

Changes in major components and microbes in tea fungus broth (or kombucha; teakwass) prepared from nine different sources during a prolonged fermentation of up to 60 days were investigated. Cell concentrations of both yeasts and acetic acid bacteria in broth were generally higher than those in the cellulosic pellicles. The residual sucrose concentration decreased linearly with time, although the rate fell after the first month. Metabolic fates of glucose and fructose produced as a result of the hydrolysis of sucrose were different. Glucose was not produced in parallel with fructose (0.085 g 100 ml(-1) d(-1)) but was produced with a lower initial rate (0.041 g 100 ml(-1) d(-1)). Both titratable acidity and gluconic acid increased steadily with time for all samples, although gluconic acid was not generated for 6 days until the fermentation had begun. Acetic acid increased slowly to a maximum value of 1.1 g 100 ml(-1) after 30 days; thereafter, it decreased gradually. Gluconic acid contributed to the titratable acidity and thus, the taste of tea fungus broth, during the final stage of fermentation. It is concluded that the desired quality or composition of kombucha can be obtained through the proper control of fermentation time.     

Synthesis of the major oligosaccharide components of murine haemangioendothelioma cells

Murine haemangioendothelioma cells in culture synthesize lactosaminoglycan-type glycoproteins which are found both associated with cells and secreted into the culture medium. Pronase-derived glycopeptides, prepared from the [3H]glucosamine-labeled glycoproteins that were secreted into the culture medium were found to contain about 10% of the labeled products as large size (Mr greater than 5000) 3H-labeled glycopeptides. In contrast, 40% of the cellular 3H-glycopeptides were found to be of this large size class of glycopeptides. These large size glycopeptides did not bind to Con A-Sepharose but did bind to Datura stramonium-agarose, from which they were eluted with chitobiose. The glycopeptides which did not bind to Datura-lectin were sulfated complex-type oligosaccharides which were not degraded by endo-beta-galactosidase. The glycopeptides which bound to Datura-lectin were degraded by endo-beta-galactosidase (or keratanase) to yield Gal----GlcNAc----Gal and glycopeptides, which were resistant to further endo-beta-galactosidase digestion and which no longer bound to Datura lectin-agarose. A major [3H]glucosamine-labelled glycoprotein (Mr approx. 75000) was found to be susceptible to endo-beta-galactosidase degradation and is probably the major cellular constituent having lactosaminoglycan-type side chains in these cells. An in vitro assay to measure leucocyte-haemangioendothelioma interactions indicated that treatment of haemangioendothelioma cells with endo-beta-galactosidase reduced leucocyte binding to these cells by 80%.     

Synthesis of sesquiterpene metabolites in a Trichothecium roseum culture

During the cultivation Trichothecium roseum forms biologically active sesquiterpenes in particular trichothecin and trichothecolon. The quantitative ratio of these compounds in cultural liquid changes depending on the cultivation conditions. The compounds taking part in terpenoids shant specifically increase the synthesis of sesquiterpenes in fungus culture. A possibility of intertransformation of different trichothecenes provides the stability of the fungus-producent to its toxical metabolites. A fermental system carrying out the transformation of trichothecin into trichotecolon has been revealed.     

Synthesis of intracellular and extracellular metabolites by Rhodotorula glutinis

A close relationship has been established between the production of extracellular and intracellular lipids and polysaccharides by Rhodotorula glutinis. Their synthesis depended on the pH of the medium. The composition and dynamics of polyol content in the cells, and the presence of acids typical of exolipids in the composition of intracellular lipids under certain conditions, suggest that the components of extracellular lipids are synthesized within the yeast cell.