# US 10,865,183 B2 · Compounds, reagents, and uses thereof > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,865,183 B2 - Document ID: US10865183B2 - Status: Granted - Kind: B2 - Application number: 16/321,135 - Filed: 2017-07-27 - Published: 2019-05-23 - Granted: 2020-12-15 - Earliest claimed: 2016-07-28 - Assignees: Metabolon, Inc. - Applicants: Metabolon, Inc. - Inventors: Qibo Zhang; Anne M. Evans - Web page: https://patentgrep.com/patent/US10865183B2 ## CPC - C07D 207/16: Carbon atoms having three bonds to hetero atoms with at the most one bond to halogen, e.g. ester or nitrile radicals - A61P 3/10: for hyperglycaemia, e.g. antidiabetics - A61P 9/12: Antihypertensives - A61P 13/12: of the kidneys - C07B 59/002: {Heterocyclic compounds} - C07K 5/06026: {the side chain containing 0 or 1 carbon atom, i.e. Gly or Ala} - G01N 33/5308: {for analytes not provided for elsewhere, e.g. nucleic acids, uric acid, worms, mites} - A61K 38/00: Medicinal preparations containing peptides (peptides containing beta-lactam rings A61K31/00; cyclic dipeptides not having in their molecule any other peptide link than those which form their ring, e.g. piperazine-2,5-diones, A61K31/00; ergot alkaloids of the cyclic peptide type A61K31/48; containing macromolecular compounds having statistically distributed amino acid units A61K31/74; medicinal preparations containing antigens or antibodies A61K39/00; medicinal preparations characterised by the non-active ingredients, e.g. peptides as drug carriers, A61K47/00) - C07B 2200/05: Isotopically modified compounds, e.g. labelled - G01N 2800/347: Renal failures; Glomerular diseases; Tubulointerstitial diseases, e.g. nephritic syndrome, glomerulonephritis; Renovascular diseases, e.g. renal artery occlusion, nephropathy - G01N 2800/52: Predicting or monitoring the response to treatment, e.g. for selection of therapy based on assay results in personalised medicine; Prognosis - C07D: HETEROCYCLIC COMPOUNDS (macromolecular compounds C08) - A61P: SPECIFIC THERAPEUTIC ACTIVITY OF CHEMICAL COMPOUNDS OR MEDICINAL PREPARATIONS - C07B: GENERAL METHODS OF ORGANIC CHEMISTRY; APPARATUS THEREFOR (preparation of carboxylic acid esters by telomerisation C07C67/47; telomerisation C08F) - C07K: PEPTIDES (peptides in foodstuffs A23; obtaining protein compositions for foodstuffs, working-up proteins for foodstuffs A23J; preparations for medicinal purposes A61K; peptides containing beta-lactam rings C07D; cyclic dipeptides not having in their molecule any other peptide link than those which form their ring, e.g. piperazine-2,5-diones, C07D; ergot alkaloids of the cyclic peptide type C07D519/02; macromolecular compounds having statistically distributed amino acid units in their molecules, i.e. when the preparation does not provide for a specific; but for a random sequence of the amino acid units, homopolyamides and block copolyamides derived from amino acids C08G69/00; macromolecular products derived from proteins C08H1/00; preparation of glue or gelatine C09H; single cell proteins, enzymes C12N; genetic engineering processes for obtaining peptides C12N15/00; compositions for measuring or testing processes involving enzymes C12Q; investigation or analysis of biological material G01N33/00) - G01N: INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES (measuring or testing apparatus or processes other than immunoassay, involving enzymes or microorganisms C12M, C12Q) - A61K: PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES (devices or methods specially adapted for bringing pharmaceutical products into particular physical or administering forms A61J3/00; chemical aspects of, or use of materials for deodorisation of air, for disinfection or sterilisation, or for bandages, dressings, absorbent pads or surgical articles A61L; soap compositions C11D) ## Abstract The present invention provides a compound of formula (I) or a salt thereof and their use as a biomarker in assessing or monitoring kidney function in a subject, determining predisposition to developing reduced kidney function, classifying a subject according to level of kidney function, diagnosing or monitoring chronic kidney disease. Compositions and method of making of the compound of formula (I) are also described. ## Claims ### Claim 1 A compound represented by the following formula: or a salt thereof, wherein the compound is at least 60%, 70%, 80%, 90%, 95%, 99%, 99.5% or 99.9% pure. ### Claim 2 (depends on 1) The compound of claim 1, wherein the compound is represented by the following formula: or a salt thereof. ### Claim 3 (depends on 1) The compound of claim 1, wherein the compound is isotopically labeled. ### Claim 4 A method of determining the level of a compound represented by the following formula: or a salt thereof, in a subject comprising: (1) preparing an analytical sample from a biological sample obtained from the subject; (2) determining the level of the compound using chromatography, mass spectrometry, enzyme-linked immunosorbent assay (ELISA), antibody linkage, immunoblotting, immunohistochemistry (IHC), other immunochemical methods, or a combination thereof. ### Claim 5 (depends on 4) The method of claim 4, further comprising comparing the level of the compound in the biological sample obtained from the subject to the level of the compound in a reference sample. ### Claim 6 (depends on 4) The method of claim 4, wherein the method further comprises using the determined level of the compound in a mathematical model to assess kidney function. ### Claim 7 (depends on 4) The method of claim 4, wherein the method further comprises analyzing the biological sample to determine the level of one or more additional biomarkers relevant for the assessment of kidney function. ### Claim 8 (depends on 7) The method of claim 7, wherein the additional biomarkers are selected from the group consisting of pseudouridine, N-acetylthreonine, 2-C-mannopyranosyl tryptophan, N-acetylserine, N-acetylalanine, N6-carbamoylthreonyl adenosine, 4-acetamidobutanoate, erythritol, myo-inositol, erythronate, urea, arabitol, N2,N2-dimethylguanosine, N1-methyladenosine, 3-methylglutarylcarnitine, S-adenosylhomocysteine, N-acetylmethionine, N6-acetyllysine, Kynurenine, arabonate, succinylcarnitine, ribose, xylonate, N-formylmethionine, O-methylcatechol sulfate, 2-methylbutyrylcarnitine, phenylacetylglutamine, N2,N5-diacetylornithine, tryptophan, creatinine, urate, 3-indoxylsulfate and p-cresol sulfate. ### Claim 9 (depends on 4) A The method of claim 4 further comprising calculating the estimated glomerular filtration rate (eGFR) of the subject using an algorithm that utilizes the determined level of the compound. ### Claim 10 (depends on 9) The method of claim 9, wherein the calculated estimated glomerular filtration rate (eGFR) is used for assessing kidney function in the subject. ### Claim 11 (depends on 4) The method of claim 4, wherein the compound is represented by the following formula: or a salt thereof. ### Claim 12 A kit comprising a compound represented by the following formula: or a salt thereof, and instructions for measuring the level of the compound in a biological sample. ### Claim 13 (depends on 12) The kit of claim 12 further comprising one or more instructions selected from the group consisting of assessing or monitoring kidney function in a subject, determining predisposition to developing reduced kidney function in a subject, classifying a subject according to level of kidney function, diagnosing or monitoring chronic kidney disease (CKD) in a subject, diagnosing or monitoring acute kidney injury (AKI) in a subject, and calculating estimated glomerular filtration rate (eGFR) in a subject based on the level of the compound detected in a biological sample obtained from the subject. ### Claim 14 (depends on 12) The kit of claim 12, wherein the compound is represented by the following formula: or a salt thereof. ### Claim 15 (depends on 12) The kit of claim 12, wherein the compound is isotopically labeled. ### Claim 16 (depends on 15) The kit of claim 15, wherein the compound is N,N,N-Trimethyl-13C3-L-Alanyl-L-Proline. ### Claim 17 (depends on 12) The kit of claim 12, wherein the kit further comprises one or more additional biomarkers selected from the group consisting of pseudouridine, N-acetylthreonine, 2-C-mannopyranosyl tryptophan, N-acetylserine, N-acetylalanine, N6-carbamoylthreonyl adenosine, 4-acetamidobutanoate, erythritol, myo-inositol, erythronate, urea, arabitol, N2,N2-dimethylguanosine, N1-methyladenosine, 3-methylglutarylcarnitine, S-adenosylhomocysteine, N-acetylmethionine, N6-acetyllysine, kynurenine, arabonate, succinylcarnitine, ribose, xylonate, N-formylmethionine, O-methylcatechol sulfate, 2-methylbutyrylcarnitine, phenylacetylglutamine, N2,N5-diacetylornithine, tryptophan, creatinine, urate, 3-indoxylsulfate and p-cresol sulfate. ### Claim 18 A method for preparing a compound represented by the following formula: or a salt thereof, comprising reacting a compound represented by the following formula: or a salt thereof, with a methylation reagent CH3X or (CH3)2SO4, wherein X is Cl, Br, I or OSO2CF3. ### Claim 19 (depends on 18) The method of claim 18, wherein the compound is represented by the following formula: or a salt thereof, and the method comprises reacting L-alanyl-L-proline with CH3X or (CH3)2SO4.