ABSTRACT
The determination of vitamins in various food matrices is necessary for monitoring the quality and safety indicators of food, including the control of the use of vitamins as food additives - food colorings and antioxidants. As well it is necessary to evaluate the level of consumption of vitamins by different age and sex categories of the population. The analysis of the regulatory and methodical basis in the field of determining the content of vitamins in food, including food supplements, has been held. It is shown that the sample preparation process plays an important role in the procedure of determination of vitamins. The modern problems of sample preparation of foods depending on their matrix are considered. The tasks to improve the methodological base, including the harmonization of interstate and national standards of the Russian Federation with international regulatory documents, are marked. It is emphasized that the most promising methods of vitamins' determination for further development are mass-spectrometry and capillary electrophoresis. The selected methods are characterized by high authenticity of the results. Mass-spectrometric detection is characterized by identification reliability. Capillary electrophoresis is characterized of simplicity of analysis.
Subject(s)
Antioxidants/analysis , Dietary Supplements/analysis , Food Analysis/methods , Food Analysis/standards , Vitamins/analysis , Humans , RussiaSubject(s)
Analgesics, Opioid/metabolism , Opioid Peptides/metabolism , Peptide Fragments/metabolism , Receptors, Opioid/metabolism , Tritium/metabolism , Amino Acid Sequence , Analgesics, Opioid/chemistry , Animals , Brain/metabolism , Opioid Peptides/chemistry , Opioid Peptides/genetics , Peptide Fragments/chemistry , Peptide Fragments/genetics , Rats , Tritium/chemistryABSTRACT
Analgesic activities of dermorphin (DM), [DPro6]-DM, and their C-terminal tripeptides were comparatively studied. Analgesic activity was evaluated in tail flick, hot plate, tail pinch, formalin, and acetic acid writhing tests describing different levels of organization of pain sensitivity. Intraperitoneal administration of the peptides decreased the pain threshold in all these tests. The C-terminal tripeptides DM(5-7) and [DPro6]-DM(5-7) demonstrated analgesics activity comparable or sometimes higher than that of the full-length molecules. The effect of DM, [DPro6]-DM, and C-terminals fragments DM(5-7) and [DPro6]-DM(5-7) decreased after co-administration with naloxone, which points to the opioid nature of analgesic activity of the peptides.
Subject(s)
Analgesics, Opioid/pharmacology , Oligopeptides/pharmacology , Opioid Peptides/pharmacology , Pain/drug therapy , Analgesics, Opioid/antagonists & inhibitors , Animals , Drug Antagonism , Male , Mice , Naloxone/antagonists & inhibitors , Naloxone/pharmacology , Narcotic Antagonists/pharmacology , Oligopeptides/antagonists & inhibitors , Opioid Peptides/antagonists & inhibitors , Pain/physiopathology , RatsABSTRACT
A tritium-labeled C-terminal fragment of dermorphin (H-Tyr-13,4-3HJPro-Ser-NH2) and its isomer (H-Tyr-D-[3,4-3H]Pro-Ser-NH2) with molar radioactivity of 35 Ci/mmol were synthesized, and their pharmacokinetics and metabolism in rat organs were studied after their intramuscular injections. The tripeptides were detected in the blood only for 5 min after the injection, and maximum contents of both compounds (approximately 5% of the total amount of the injected label) were registered in the kidneys after 20 min. Both stereomers were shown to penetrate into the brain. We failed to detect any radioactive metabolite, except proline, due to rapid proteolytic degradation of these peptides.
