Method for synthesis of 3'-iodofolic acid and 3'-bromofolic acid labelled with radioactive isotopes of iodine and bromine
SUBSTANCE: source of radioactive iodine or radioactive bromine is added to an aqueous solution of an alkaline salt of folic acid so that pH of this solution is approximately 7 in order to obtain a solution which contains folic acid or an iodide or bromide ion. PH of this solution is then lowered to 3.5-4.9 by adding an oxidising agent selected from N-chlorosulfamides of acids in a buffer solution to the said solution. The oxidising agent is mainly chloramines T or chloramines B.
EFFECT: possibility of adding isotopic tags to folic acid through radicals.
2 cl, 2 ex
The invention relates to the field of biochemistry and radiochemistry.
Folic acid belongs to the class of vitamins of group of Century
Folic acid and its derivatives, such as aminopterin and methotrexate, effectively absorbed by certain types of cancer. This makes possible the use of folic acid and its derivatives, labeled with radioactive isotopes for medical diagnostics and radiotherapy. Because folic acid in the body is contained in very small quantities (concentration in blood plasma is a fraction of micromole per liter), cooked preparations must possess high specific radioactivity, and the method of synthesis must be acceptable to work with short-lived isotopes such as iodine-121 or bromine-75 with a half-life of about 2 hours. These isotopes recently found increasingly wide application in positron emission tomography, as are positron emitters.
The literature describes methods of obtaining labeled with iodine different derivatives on the basis of solutions of the connection, which should be marked with radioactive iodine in the form of iodide ions and chloramine.
There is a method of tagging biological compounds, described in is: F..Greenwood & W.M.Hunter, Biochem. J. (1963) 89, 114. The reaction is carried out at a pH of 7.5
However, this too is in the case of applications for tagging iodine folic acid gives a very small outputs radioactivity (less than 1%).
To work around its impotency of folic acid in this reaction, was patented ways in which a glutamine residue folic acid joined easily audiruemaya tyrosine or histidine.
A method of obtaining derivatives of folic acid, labeled with iodine, as described in : US Patent No. 3989812,;  US Patent No. 4276280). When this happened compounds corresponding to the formula (1), iodine label held the position of R.
The method described in US Patente No. 3989812 is the following. To a solution consisting of 100 μl of 0.1 M sodium hydroxide and containing 1 MCI NaI125, 20 μl of 0.5 M NaH2PO4and 10 μl of 0.5 M sodium phosphate pH 7.4, add 10 μg of pteroyl-γ-glutamyl-tyrosine in phosphate buffer (0.05 M, pH 7.4) and 20 µl of freshly prepared solution of chloramine T in 0.05 M phosphate buffer pH 7.4 (5 mg/ml). After 15 seconds added 20 μl of a solution of sodium metabisulfite in 0.05 M phosphate buffer pH 7.4. The reaction mixture was separated on a column of BioGel-P2, and then DEAE ion-exchange column.
The disadvantage is that it is not formed folic acid labeled with iodine, and a derivative of folic acid, labeled with iodine, which significantly differs from folic acid on the structure, charge distribution, the presence of additional hydrophobic groups. This may change the conditions of his transport the cell compared to natural folic acid.
It is known, for example, what if instead of histidine or tyrosine is another residue glutamic acid, is a derivative of folic acid in the cell does not penetrate despite the fact that the molecule of glutamic acid takes up less space than a molecule of histidine or tyrosine.
In this connection, it seems to be a promising method to mark the isotopes of iodine and bromine itself folic acid, and not the products of its accession to other easily odirueyr molecules, i.e. method
to obtain compounds corresponding to the formula (2), where bromine or iodine occupies the position of R.
Moreover, this method should be suitable to work with quantities of iodine or bromine, lower micrograms.
The literature describes a method of labelling isotope I131compounds similar in structure to folic acid, aminopterin : D.G.Johus et al, J. Nuclear Med., v.9, No. 10, 1968, 530-536). In this way we obtain a 3'-etaminophen, i.e. iodine label is attached to the compound (formula (3)), and not to the structure, facilitating iodination.
To a solution of 10 MCi NaI131in 0.4 ml of sodium sulfate were added when mixing the following reagents in the order listed: powder aminopterin (20 mg); iodic acid 4.5 mg; iodine - 7.5 mg; dimethylformamide - 0.5 ml; and tetrachloride angle of the ar - 0.1 ml Vessel was closed and stirred for 18 hours. Then the reaction mixture was separated on a column with DEAE-cellulose.
However, the method gives a low output (4÷10%), low specific activity (in the above publication in several experiments was obtained a dispersion of 50-300 microcure to micromoles), the formation of large amounts of contaminants, including radioactive waste, and the duration of the procedure of synthesis (18 hours).
This method is close to the claimed the fact that mark directly the connection that close structural formula, and not its derivative.
Declare the object relates to a method for labeling isotopes of iodine or bromine directly folic acid.
In the patent and scientific literature, we found no way of tagging folic acid, so the prototype is missing.
We the inventive method for the preparation of 3'-itpolicy and 3'-bromelias acids labeled with radioactive isotopes of iodine and bromine, which consists in the fact that prepared the original solution containing folic acid, radioactive iodine or radioactive bromine in the form of iodide ion or bromide ion at pH 7, is added to the original solution was acidified solution of the oxidizing agent from the group of chlorinated amides of the acid and bring the pH of the solution to 3.5÷4.9, optimally up to 4.7, converting folic acid in the gel. The selection of the target product is carried out using reverse-phase chromatography. As the oxidant used chloramine-T or chloramine-Century
Our research has shown that the cause of failure when you try tagging the folic acid in the methods of  is the slowness of the reaction of folic acid with ignominity acid HIO, which means  is an active agent and is formed by the reaction of iodide ion with bleach. Because of the slowness of the reaction HIO with folic acid, the predominant system reactions become disproportionation HIO and its oxidation by excess chloramine, lead to a radical reduction of the yield of the target product and the growth of output products.
Conducting the reaction under conditions conducive to the formation of cations of the I+and Br+that has allowed us to develop efficient synthesis of itpolicy and bromelias acids labeled with isotopes of iodine and bromine.
The essence of our proposed method consists in the reaction of the salt with the use of oxidants type of bleach that all patents is carried out at a pH higher than 7, go to conduct the reaction at a pH much lower. However, if you perform the reaction under conditions in which synthesis is relatively large amounts of the unlabeled itpolicy acid, described in patents  - US Patent 2570391 (1951);  US Patent 2570392 (1951), where folic acid is in a solution of 5M HCl at low pH, as shown by our experiments, the majority (oxidant) chloramine expended on the formation of 3'-chlorpryifos and 3',5'-dichlorophenol acids. The latter cannot be separated from the desired product by reversed-phase chromatography, which is used to separate in our proposed method. We have found the pH value in the range of 3.5 and 4.9, in which both conditions are satisfied small reaction time (which is important for working with short-lived isotopes), large output and negligible output 3',5'-dichlorophenoxy acid. The difficulty lies in the fact that under such pH folic acid very slightly. Therefore, in the present method preparation (initial) solutions have a pH of about 7, and simultaneously with the beginning of the reaction the pH is reduced to 4.7. While folic acid turns into gel when all reagents have been added. In the gel persist for some time the reactivity of folic acid, sufficient for the passage of the target reaction to the end.
If the pH is below 3, 5, dramatically increases the proportion of 3',5'-dichlorophenoxy acid, which contaminates the target product and virtually inseparable by the method of reversed-phase chromatography; if the pH is higher 4,9, significantly reduces the yield of the target product.
A solution of 0.1 M sodium salt of folic acid is prepared by restorani is 480 mg of folic acid, pre-purified by recrystallization in 8 ml of a 0.28 M solution of sodium hydroxide. Then the pH of the solution was adjusted to 7 by adding about 1.2 ml of 0.1 M sulfuric acid solution in portions with vigorous stirring so that the formed in place of the addition of acid, the gel was immediately dissolved. Then the volume was adjusted to 10 ml of water and this solution is used for preparing a solution of the desired concentration.
Poured into a test tube and 30 μl of 5×10-2M sodium salt of folic acid, 10 μl of 5×10-4M KI and 50 μl of a solution of NaI containing 2 mCi of iodine-125 without media in 10-3M NaOH (solution A)is the initial solution.
After that, separately prepare a solution B. To do this consistently add 0.3 ml of water and 10 μl of 0.1 M solution of chloramine T (pre-cleaned from impurities dichloramine by extraction with carbon tetrachloride) +0.4 ml of acetate buffer (0.8 M acetic acid and 0.4 M sodium acetate). 30 μl of solution B is added to the solution And quickly mix. Within seconds, a gel is formed. Stand the mixture for 30 seconds, add 100 μl solution of 1 M potassium phosphate and 7×10-3M sodium sulfite dissolving gel and remove excess oxidant, mix. Next, add 1 ml of water. The resulting solution was injected into HPLC column 150×8 mm with a sorbent To-18 with a grain size of 5 microns, prefix is Ino balanced buffer solution: 0.05 M NaH 2PO4and 0.05 M Na2HPO4. After making the solution in the column it was washed with 15 ml of equilibrating buffer, then served eluent consisting of the same buffer, to which was added 4.5% (by volume) of acetonitrile. The flow rate of eluent 2.4 ml/min to Measure the optical density of the solution passed through the column at a wavelength of 260 nm. The output time of the peak 3'-itpolicy acid pre-determined using unlabeled 3'-itpolicy acid. In the experiment it was 25 minutes. Target product, released this peak, collected in a volume of 5 ml, then evaporated to a volume of 3 ml, with all of the acetonitrile is evaporated. The resulting solution contained 70% of all introduced into the reaction radioactivity. The specific activity of the preparation was 300 miles/μm. In the control experiment, instead of KI solution and a solution of NaI125added water. Received on the chromatograph peak 3',5'-dichlorophenoxy acid area was two hundred times less than the peak from 3'-itpolicy acid obtained in example 1.
Poured into a test tube and 30 ál of 0.05 M solution of sodium salt of folic acid (prepared as in example 1) and 60 μl of 0.0012 M solution of potassium bromide containing 0.04 MCI Br-82 (solution AI- source solution). After that, separately preparing a solution of BI. Why consistently add 0.3 ml of water and 30 μl of 0.1 M is astora chloramine T (pre-cleaned from impurities dichloramine by extraction with carbon tetrachloride) + 0.4 ml of acetate buffer (0.8 M acetic acid and 0.4 M sodium acetate). Then add 30 ál of solution BIto a solution of AI. Subsequent processing solutions and the selection of the target product produced as in example 1. Time vyhozhdeniya 3'-bromelias acid pre-determined by the unlabeled drug. The peak labeled 3'-bromelias acid contained 50% of the initial activity. The specific activity of the preparation was 350 Micros/ám.
The proposed method can be applied to isotope dilution, and without it. In the latter case, in the reaction mixture instead of the solution of non-radioactive isotope of iodine or bromine should be added the same volume of water. If you want to add more non-radioactive isotope than is indicated in the examples, it should be increased accordingly and the concentration of bleach and sodium sulfite. However, the concentration of chloramine cannot be increased more than twice compared to solution BIas will begin the precipitation. If you still need more bleach, you should take a larger volume of solution BIusing progressively more diluted buffer.
The inventive method can find application in diagnostics and therapy of oncological diseases in biological research.
1. Method for the preparation of 3'-itpolicy and 3'-bromelias acids labeled with radioactive isotopes of iodine or bromine, the bookmark is different in that, what to aqueous solution of alkali salt of folic acid added source of radioactive iodine or radioactive bromine so that the pH of this solution was about 7, to obtain a solution containing folic acid and iodide ion or bromide ion, and then lower the pH of the solution to 3.5 and 4.9, adding to the above solution of the oxidizing agent from the group of N-chlorosulfonic acid in the buffer solution.
2. The method according to claim 1, characterized in that as the oxidant used chloramine-T or chloramine-Century
FIELD: vitamins, chemical technology, food industry, pharmacy.
SUBSTANCE: invention relates to crystalline alkaline-earth salts of 5-methyl-(6R,S)-, -(6S)- and -(6R)-tetrahydrofolic acid with the content of at least one equivalent of crystallizing water per equivalent of 5-methyltetrahydrofolic acid, in particular, 5-methyl-(6R)-tetrahydrofolic acid crystalline calcium salt or to different types of 5-methyl(6S)-tetrahydrofolic acid crystalline calcium salts. These salts can be used in preparing medicinal agents or as a nutrition supplement for treatment or prophylaxis of folic acid-mediated diseases. Also, invention relates to a method for preparing crystalline salts of 5-methyl-(6R,S)-, -(6S)- and -(6R)-tetrahydrofolic acid by crystallization of the corresponding salt of 5-methyl-(6R,S)-, -(6S)- or -(6R)-tetrahydrofolic acid from a polar medium by using heat treatment at temperature above 60°C followed, if necessary, by drying the prepared product. Also, invention relates to a composition for pharmaceutical agents or nutrition supplements.
EFFECT: improved preparing method, valuable properties of salts and composition.
13 cl, 5 dwg, 4 tbl, 11 ex
FIELD: organic chemistry, medicine, pharmacy.
SUBSTANCE: invention relates to new azaheterocycles comprising fragment of piperidin-2-yl- of the general formula (1):
as separate enantiomers or mixture of enantiomers, or their pharmaceutically acceptable salts, oxides or hydrates. In compounds of the formula (1) R1 represents hydrogen atom, inert substitute or NH-protecting substitute; W represents optionally substituted azaheterocycle, such as: pyridin-3-yl, pyrazolo[1,5-a]pyridin-6-yl, 3,4-dihydro-2H-pyrido[1,2-a]pyrimidin-7-yl, 3,4-dihydro-2H-pyrido[1,2-a]pyrimidin-9-yl, imidazo[1,2-a]pyrimidin-6-yl, imidazo[1,2-a]pyrimidin-8-yl or [1,8]naphthyridin-3-yl. Compounds elicit activity with respect to nicotine receptors and can be used in pharmaceutical industry. Also, invention relates to the focused library for search of physiologically active compound-leaders, and to pharmaceutical compositions based on new compounds of the formula (1).
EFFECT: valuable medicinal and pharmacological properties of compounds.
9 cl, 1 tbl, 15 sch, 22 ex
SUBSTANCE: invention relates to 5-(1,1-dimethylheptyl)-2-[5-hydroxy-2-(3-hydroxypropyl)cyclohexyl]phenol of formula I:
which is uniformly labelled with tritium. This compound is an analogue of 5-(1,1-dimethylheptyl)-2-[5-hydroxy-2-(3-hydroxypropyl)cyclohexyl]phenol.
EFFECT: obtaining a compound which is a selective cannabinoid receptor agonist.
1 dwg, 1 ex
FIELD: chemistry; biochemistry.
SUBSTANCE: present invention relates to genetically modified yeast which independently produces cholesterol from a simple carbon source. The said yeast expresses 7-dehydrocholesterol reductase and 3β-hydroxysterine Δ24-reductase enzymes, while the sterol 24-C-methyltransferase enzyme is inactive. Cholesterol production of the said yeast is equal to or greater than 20% of all produced sterines. The invention also discloses a method of producing cholesterol and using the disclosed yeast strain to produce labelled and non-labelled cholesterol.
EFFECT: invention enables to obtain large amounts of cholesterol which is safe in terms of sanitation in.
12 cl, 13 dwg, 18 ex
SUBSTANCE: invention relates to novel compounds of formula (I) which can be used in diagnosis of tumorous diseases. In formula (I) , A is OH, C1-C5 alkoxy, N(C1-C5 alkyl)2, NH2; G is OH, O-C1-C5 alkyl; R1 and R2 independently denote H, 18F, 18F-C1-C5 alkoxy, 18F-C1-C5 alkyl, provided that if one of the substitutes R1 and R2 contain an 18F isotope, the other does not. The invention also relates to compounds of formulae and which are used in synthesis of formula (I) compounds, as well as to use of compounds of formula (IV) in synthesis of compounds of formula (I) or (II).
EFFECT: obtaining novel compounds which can be used in diagnosis of tumorous diseases.
29 cl, 4 ex, 8 tbl, 4 dwg
SUBSTANCE: invention relates to a method for synthesis of 13C-urea by reacting ammonia with carbon monoxide 13CO in the presence of oxygen, taken in molar ratio ranging from 8.9:2.8:1 to 4:2:1 at 15-25°C and pressure of 25-35 atm. The catalyst used is selenium powder taken in molar ratio Se:13CO ranging from 1:790 to 1:158. The solvent used is tetrahydrofuran or a mixture of tetrahydrofuran and methanol.
EFFECT: invention enables to obtain urea containing the stable 13C isotope with isotopic purity of not less than 99% in a single step.
1 cl, 6 ex
SUBSTANCE: invention relates to a method for synthesis of 1-13C-caprylic acid which is used as a diagnostic preparation when diagnosing motor-evacuation functions of the stomach. The method involves hydrocarboxylation reaction of 1-heptene with carbon monoxide 13CO and water at temperature 100-170°C and pressure not above 5 MPa, in the presence of a solvent and a catalyst system which contains a complex compound of palladium and triphenylphosphine in ratio ranging from 1:2 to 1:100, where the solvent used is dioxane and/or aromatic hydrodrocarbon.
EFFECT: obtaining 1-13C caprylic acid with high isotope purity, increased cost-effectiveness of the process owing to increased degree of utilisation of isotope material.
5 cl, 9 ex
SUBSTANCE: new pure syn-aminoacids of formulas I and II have ability of specific binding in biological system and may be used to produce image of tumor. II and I. In formulae I and II Y and Z are independently selected from group made of CH2 and (CR4R5)n, n=1, 2; R1-R3 are independently selected from group made of H and alkyl C1-C4; R4, R5 = H and R7 = 18F. Invention is related to method of synthesis of syn-aminoacids with formula II, which includes stages of ketone transformation into trans-spirit of formula I and transformation of produced trans-spirit into syn-aminoacid of formula II, and also to pharmaceutical composition for production of tumor image and method for production of tumor image.
EFFECT: improved efficiency of compounds and method of treatment.
12 cl, 1 tbl, 3 dwg, 3 ex
SUBSTANCE: invention refers to the conjugates of formula (V)
or (VI) : wherein X is -CO-NH- or -O-; their use as radiopharmaceuticals, processes for their preparation, and synthetic intermediates used in such processes.
EFFECT: use as radiopharmaceuticals.
25 cl, 15 ex
FIELD: chemistry; medicine.
SUBSTANCE: inventions relate to novel marked with tritium analogue of physiologically active compound- uniformly marked with tritium tylosin of formula: . Said compound is drastic antibiotic.
EFFECT: extension of assortment of marked analogues of physically active compound, which are applied in organic chemistry, in biology and in medicine.
1 cl, 1 dwg, 1 ex
SUBSTANCE: invention refers to synthesis of [18F]fluororganic compounds ensured by reaction of [18F]fluoride and relevant halogenide or sulphonate with alcoholic vehicle of formula 1 where R1, R2 and R3 represent hydrogen atom or C1-C18 alkyl.
EFFECT: possibility for mild process with low reaction time and high yield.
21 cl, 2 tbl, 27 ex
SUBSTANCE: present invention relates to biotechnology, more specifically to obtaining nucleoside-5'-triphosphates, labelled with phosphorous-32 (phosphorous-33) in the alpha-position, and can be used for analysis in molecular biology, genetics and medical biochemistry. The method is realised through treatment of labelled nucleosidephosphate in a buffer solution with a mixture of deoxyribonucleoside monophosphate kinase of bacteriophage T5 and pyruvate kinase with subsequent chromatographic purification of the target product.
EFFECT: simple method of obtaining nucleoside-5'-triphosphates and stable output of the target product.
FIELD: organic chemistry, labeled compounds.
SUBSTANCE: invention relates to a new highly labeled compound that represent an analog of the known physiologically active compound that is the strongest toxin and inhibitor of some viable important processes, for example, sodium ions transporting. [3H]-Saxitoxin dihydrochloride highly labeled with tritium corresponds to the formula: .
EFFECT: valuable properties of compound.
FIELD: organic chemistry, labeled compounds.
SUBSTANCE: invention relates to a novel compound - 2-amino-4-(β-hydroxyethylamino)anisole uniformly labeled with tritium The compound can be used in analytical chemistry and biological investigations. Early non-labeled 2-amino-4-(β-hydroxyethylamino)anisole is used as a dye.
EFFECT: valuable properties of compound.
FIELD: organic chemistry, labeled compounds, pharmacy.
SUBSTANCE: invention relates to a novel [3H]-fluvastatin of the formula: highly labeled with tritium with molar radioactivity 40-45 Ci/mmole. This compound can be used in analytical chemistry, biochemistry and applied medicine.
EFFECT: valuable properties of compound.
FIELD: labeled natural substances.
SUBSTANCE: invention provides a method for labeling humic and humic-like substances with tritium-containing agent, said agent being atomic tritium obtained via thermal catalytic dissociation of tritium on tungsten wire at pressure 0.3-0.6 Pa. Humic and humic-like substances are preliminarily deposited on reaction vessel walls utilizing lyophilization for aqueous solutions thereof. Thermal dissociation is effected by 5-10-sec pulses at tungsten wire temperature 1900-2000 K.
EFFECT: enabled uniform introduction of tritium and achieved radiation activity of preparation 69 to 254 GBc/g.
1 dwg, 2 tbl, 15 ex