ABSTRACT
UNLABELLED: The knowledge and understanding of Bacillus coagulans inactivation during a thermal treatment in tomato pulp, as well as the influence of temperature variation during thermal processes are essential for design, calculation, and optimization of the process. The aims of this work were to predict B. coagulans spores inactivation in tomato pulp under varying time-temperature profiles with Gompertz-inspired inactivation model and to validate the model's predictions by comparing the predicted values with experimental data. B. coagulans spores in pH 4.3 tomato pulp at 4 °Brix were sealed in capillary glass tubes and heated in thermostatically controlled circulating oil baths. Seven different nonisothermal profiles in the range from 95 to 105 °C were studied. Predicted inactivation kinetics showed similar behavior to experimentally observed inactivation curves when the samples were exposed to temperatures in the upper range of this study (99 to 105 °C). Profiles that resulted in less accurate predictions were those where the range of temperatures analyzed were comparatively lower (inactivation profiles starting at 95 °C). The link between fail prediction and both lower starting temperature and magnitude of the temperature shift suggests some chemical or biological mechanism at work. Statistical analysis showed that overall model predictions were acceptable, with bias factors from 0.781 to 1.012, and accuracy factors from 1.049 to 1.351, and confirm that the models used were adequate to estimate B. coagulans spores inactivation under fluctuating temperature conditions in the range from 95 to 105 °C. PRACTICAL APPLICATION: How can we estimate Bacillus coagulans inactivation during sudden temperature shifts in heat processing? This article provides a validated model that can be used to predict B. coagulans under changing temperature conditions. B. coagulans is a spore-forming bacillus that spoils acidified food products. The mathematical model developed here can be used to predict the spoilage risk following thermal process deviations for tomato products.
Subject(s)
Bacillus , Food Microbiology , Fruit/microbiology , Hot Temperature , Models, Biological , Solanum lycopersicum/microbiology , Spores, Bacterial/growth & development , Food Handling , Humans , Kinetics , TemperatureABSTRACT
Glucagon-like peptide 1 (GLP-1) is a 30 or 31 amino acid peptide hormone that contributes to the physiological regulation of glucose homeostasis and food intake. Herein, we report the discovery of a novel class of 11 amino acid GLP-1 receptor agonists. These peptides consist of a structurally optimized 9-mer, which is closely related to the N-terminal 9 amino acids of GLP-1, linked to a substituted C-terminal biphenylalanine (BIP) dipeptide. SAR studies resulted in 11-mer GLP-1R agonists with similar in vitro potency to the native 30-mer. Peptides 21 and 22 acutely reduced plasma glucose excursions and increased plasma insulin concentrations in a mouse model of diabetes. These peptides also showed sustained exposures over several hours in mouse and dog models. The described 11-mer GLP-1 receptor agonists represent a new tool in further understanding GLP-1 receptor pharmacology that may lead to novel antidiabetic agents.
Subject(s)
Hypoglycemic Agents/chemistry , Hypoglycemic Agents/pharmacology , Oligopeptides/chemistry , Oligopeptides/pharmacology , Receptors, Glucagon/agonists , Amino Acid Sequence , Animals , CHO Cells , Cricetinae , Cricetulus , Dogs , Dose-Response Relationship, Drug , Glucagon-Like Peptide-1 Receptor , Humans , Hypoglycemic Agents/chemical synthesis , Hypoglycemic Agents/pharmacokinetics , Male , Mice , Models, Molecular , Molecular Sequence Data , Oligopeptides/chemical synthesis , Oligopeptides/pharmacokinetics , Protein ConformationABSTRACT
The discovery and optimization of a novel series of prolinol-derived GHSR agonists is described. This series emerged from a 11,520-member solid-phase library targeting the GPCR protein superfamily, and the rapid optimization of low micromolar hits into single-digit nanomolar leads can be attributed to the solid-phase synthesis of matrix libraries, which revealed multiple non-additive structure-activity relationships. In addition, the separation of potent diastereomers highlighted the influence of the alpha-methyl stereochemistry of the phenoxyacetamide sidechain on GHSR activity.
Subject(s)
Pyrrolidines/chemical synthesis , Pyrrolidines/pharmacology , Receptors, G-Protein-Coupled/drug effects , Receptors, Ghrelin/agonists , Combinatorial Chemistry Techniques , Molecular Structure , Pyrrolidines/chemistry , Stereoisomerism , Structure-Activity RelationshipABSTRACT
1H-tetrazole-1-alkanenitrile SR-9g exhibits a >10-fold in vivo potency enhancement over the lead nitrile 1 and has acceptable oral bioavailability in rats and dogs. An enantiospecific synthesis of 1H-tetrazole-1-alkanenitrile nitriles 9 has been developed.
Subject(s)
Growth Hormone/metabolism , Nitriles/pharmacology , Tetrazoles/pharmacology , Administration, Oral , Animals , Biological Availability , Cytochrome P-450 Enzyme System/metabolism , Dogs , Magnetic Resonance Spectroscopy , Molecular Structure , Nitriles/chemical synthesis , Nitriles/pharmacokinetics , Pituitary Gland , Rats , Structure-Activity Relationship , Tetrazoles/chemical synthesis , Tetrazoles/pharmacokineticsABSTRACT
A novel class of Growth Hormone Secretagogues (GHS), based on a tetrazole template, has been discovered. In vitro SAR and in vivo potency within this new class of GHS are described. The tetrazole 9q exhibits good oral bioavailability in rats and dogs as well as efficacy following an oral 10 mg/kg dose in dogs. Solution and solid phase protocols for the synthesis of tetrazole based GHS have been developed.
