{
  "dataset": "Purely Peptides Research Library",
  "file": "relationships",
  "description": "Structural and origin relationships between compound records (records), and shared-origin groups (sharedOrigins). Each is anchored to an exact quotation from a record field.",
  "version": "2026-10-21",
  "license": "CC-BY-4.0",
  "licenseUrl": "https://creativecommons.org/licenses/by/4.0/",
  "attribution": "Purely Peptides Research Library, https://purelypeptides.org/research/, licensed CC BY 4.0",
  "notice": "Research reference data about peptide identity, structure and the published literature. It is not product information, makes no claim about any product, and is not medical advice.",
  "count": 35,
  "records": [
    {
      "id": "r01",
      "kind": "contained-in",
      "from": "ac-sdkp",
      "to": "thymosin-beta-4",
      "quotation": {
        "compoundId": "ac-sdkp",
        "field": "identityOverview",
        "quote": "Ac-SDKP is the acetylated N-terminal tetrapeptide of thymosin beta-4"
      }
    },
    {
      "id": "r02",
      "kind": "contained-in",
      "from": "alpha-msh",
      "to": "cosyntropin",
      "quotation": {
        "compoundId": "cosyntropin",
        "field": "sequence.sequenceNotes",
        "quote": "Note the first thirteen residues are shared with alpha-MSH — the terminal processing is what differs."
      }
    },
    {
      "id": "r03",
      "kind": "contained-in",
      "from": "kpv",
      "to": "alpha-msh",
      "quotation": {
        "compoundId": "kpv",
        "field": "nomenclatureNotes",
        "quote": "KPV is the C-terminal tripeptide of alpha-melanocyte-stimulating hormone, residues 11 to 13"
      }
    },
    {
      "id": "r04",
      "kind": "analogue-of",
      "from": "melanotan-i",
      "to": "alpha-msh",
      "quotation": {
        "compoundId": "melanotan-i",
        "field": "identityOverview",
        "quote": "Afamelanotide, widely supplied as Melanotan I, is a linear thirteen-residue analog of alpha-melanocyte-stimulating hormone carrying norleucine and D-phenylalanine substitutions."
      }
    },
    {
      "id": "r05",
      "kind": "analogue-of",
      "from": "melanotan-ii",
      "to": "alpha-msh",
      "quotation": {
        "compoundId": "melanotan-ii",
        "field": "identityOverview",
        "quote": "Melanotan II is a synthetic cyclic heptapeptide analog of alpha-melanocyte-stimulating hormone"
      }
    },
    {
      "id": "r06",
      "kind": "same-chain-other-form",
      "from": "pt-141",
      "to": "melanotan-ii",
      "quotation": {
        "compoundId": "pt-141",
        "field": "nomenclatureNotes",
        "quote": "The compound is structurally the C-terminal free acid of the Melanotan II scaffold"
      }
    },
    {
      "id": "r07",
      "kind": "analogue-of",
      "from": "shu9119",
      "to": "melanotan-ii",
      "quotation": {
        "compoundId": "shu9119",
        "field": "nomenclatureNotes",
        "quote": "SHU9119 shares the Melanotan II ring architecture and differs by a single substitution, D-Phe to D-2-Nal"
      }
    },
    {
      "id": "r08",
      "kind": "analogue-of",
      "from": "cagrilintide",
      "to": "amylin",
      "quotation": {
        "compoundId": "cagrilintide",
        "field": "identityOverview",
        "quote": "Cagrilintide is a long-acting synthetic amylin analog"
      }
    },
    {
      "id": "r09",
      "kind": "analogue-of",
      "from": "pramlintide",
      "to": "amylin",
      "quotation": {
        "compoundId": "pramlintide",
        "field": "identityOverview",
        "quote": "Pramlintide is an engineered analog of human amylin carrying three proline substitutions"
      }
    },
    {
      "id": "r10",
      "kind": "analogue-of",
      "from": "cjc-1295",
      "to": "sermorelin",
      "quotation": {
        "compoundId": "sermorelin",
        "field": "nomenclatureNotes",
        "quote": "CJC-1295 is a tetrasubstituted analog of this fragment"
      }
    },
    {
      "id": "r11",
      "kind": "analogue-of",
      "from": "examorelin",
      "to": "ghrp-6",
      "quotation": {
        "compoundId": "examorelin",
        "field": "nomenclatureNotes",
        "quote": "Its relationship to GHRP-6 is a single methyl group"
      }
    },
    {
      "id": "r12",
      "kind": "same-chain-other-form",
      "from": "ghk-cu",
      "to": "ghk",
      "quotation": {
        "compoundId": "ghk-cu",
        "field": "nomenclatureNotes",
        "quote": "GHK-Cu is a trade and literature name for the Cu(II) complex of the tripeptide glycyl-L-histidyl-L-lysine."
      }
    },
    {
      "id": "r13",
      "kind": "same-chain-other-form",
      "from": "pal-ghk",
      "to": "ghk",
      "quotation": {
        "compoundId": "pal-ghk",
        "field": "identityOverview",
        "quote": "Pal-GHK is the N-palmitoylated derivative of the GHK tripeptide"
      }
    },
    {
      "id": "r14",
      "kind": "analogue-of",
      "from": "retatrutide",
      "to": "gip-1-42",
      "quotation": {
        "compoundId": "retatrutide",
        "field": "structuralNotes",
        "quote": "retatrutide is built on a GIP scaffold rather than a GLP-1 scaffold"
      }
    },
    {
      "id": "r15",
      "kind": "analogue-of",
      "from": "tirzepatide",
      "to": "gip-1-42",
      "quotation": {
        "compoundId": "tirzepatide",
        "field": "structuralNotes",
        "quote": "The scaffold is GIP, not GLP-1."
      }
    },
    {
      "id": "r16",
      "kind": "contained-in",
      "from": "glp-1-7-36-amide",
      "to": "glp-1-7-37",
      "quotation": {
        "compoundId": "glp-1-7-36-amide",
        "field": "nomenclatureNotes",
        "quote": "GLP-1(7-37) is a separate molecule with an additional terminal glycine and a free carboxyl"
      }
    },
    {
      "id": "r17",
      "kind": "analogue-of",
      "from": "liraglutide",
      "to": "glp-1-7-37",
      "quotation": {
        "compoundId": "liraglutide",
        "field": "structuralNotes",
        "quote": "Built on the GLP-1(7-37) scaffold by a different strategy from semaglutide."
      }
    },
    {
      "id": "r18",
      "kind": "analogue-of",
      "from": "semaglutide",
      "to": "glp-1-7-37",
      "quotation": {
        "compoundId": "semaglutide",
        "field": "structuralNotes",
        "quote": "Built on the GLP-1(7-37) scaffold, retaining its C-terminal glycine."
      }
    },
    {
      "id": "r19",
      "kind": "contained-in",
      "from": "glucagon",
      "to": "oxyntomodulin",
      "quotation": {
        "compoundId": "oxyntomodulin",
        "field": "sequence.sequenceNotes",
        "quote": "The first twenty-nine are the complete glucagon sequence; the C-terminal extension is KRNRNNIA."
      }
    },
    {
      "id": "r20",
      "kind": "analogue-of",
      "from": "survodutide",
      "to": "glucagon",
      "quotation": {
        "compoundId": "survodutide",
        "field": "structuralNotes",
        "quote": "The 29-residue main chain is glucagon-derived."
      }
    },
    {
      "id": "r21",
      "kind": "analogue-of",
      "from": "mazdutide",
      "to": "oxyntomodulin",
      "quotation": {
        "compoundId": "mazdutide",
        "field": "structuralNotes",
        "quote": "Described in its literature as an oxyntomodulin analog."
      }
    },
    {
      "id": "r22",
      "kind": "analogue-of",
      "from": "hng",
      "to": "humanin",
      "quotation": {
        "compoundId": "hng",
        "field": "identityOverview",
        "quote": "HNG is a synthetic single-substitution analog of humanin carrying glycine in place of serine at position 14."
      }
    },
    {
      "id": "r23",
      "kind": "analogue-of",
      "from": "hngf6a",
      "to": "humanin",
      "quotation": {
        "compoundId": "hngf6a",
        "field": "identityOverview",
        "quote": "HNGF6A is a synthetic humanin analog with F6A and S14G substitutions"
      }
    },
    {
      "id": "r24",
      "kind": "analogue-of",
      "from": "hngf6a",
      "to": "hng",
      "quotation": {
        "compoundId": "hng",
        "field": "nomenclatureNotes",
        "quote": "HNGF6A additionally replaces Phe6 with alanine."
      }
    },
    {
      "id": "r25",
      "kind": "contained-in",
      "from": "kisspeptin-10",
      "to": "kisspeptin-14",
      "quotation": {
        "compoundId": "kisspeptin-14",
        "field": "nomenclatureNotes",
        "quote": "KP-14 contains the kisspeptin-10 sequence at its C terminus."
      }
    },
    {
      "id": "r26",
      "kind": "same-chain-other-form",
      "from": "matrixyl",
      "to": "kttks",
      "quotation": {
        "compoundId": "matrixyl",
        "field": "identityOverview",
        "quote": "Palmitoyl pentapeptide-4 is the pentapeptide KTTKS with an N-terminal palmitoyl group"
      }
    },
    {
      "id": "r27",
      "kind": "same-chain-other-form",
      "from": "n-acetyl-selank-amidate",
      "to": "selank",
      "quotation": {
        "compoundId": "n-acetyl-selank-amidate",
        "field": "identityOverview",
        "quote": "N-Acetyl Selank Amidate is the Selank heptapeptide with an acetyl group on the N-terminal threonine residue and an amide at the C-terminal proline."
      }
    },
    {
      "id": "r28",
      "kind": "same-chain-other-form",
      "from": "n-acetyl-semax-amidate",
      "to": "semax",
      "quotation": {
        "compoundId": "n-acetyl-semax-amidate",
        "field": "identityOverview",
        "quote": "N-Acetyl Semax Amidate is the Semax heptapeptide with an acetyl group on the N-terminal methionine residue and an amide at the C-terminal proline."
      }
    },
    {
      "id": "r29",
      "kind": "contained-in",
      "from": "pe-22-28",
      "to": "spadin",
      "quotation": {
        "compoundId": "pe-22-28",
        "field": "nomenclatureNotes",
        "quote": "the same seven residues form the C-terminal end of the longer sortilin-propeptide-derived peptide spadin"
      }
    },
    {
      "id": "r30",
      "kind": "contained-in",
      "from": "sermorelin",
      "to": "tesamorelin",
      "quotation": {
        "compoundId": "tesamorelin",
        "field": "sequence.sequenceNotes",
        "quote": "Sermorelin, also in this library, is the first 29 residues of this same sequence"
      }
    },
    {
      "id": "r31",
      "kind": "contained-in",
      "from": "tb-500",
      "to": "thymosin-beta-4",
      "quotation": {
        "compoundId": "tb-500",
        "field": "sequence.sequenceNotes",
        "quote": "The residue sequence LKKTETQ corresponds to positions 17-23 of mature human thymosin beta-4"
      }
    },
    {
      "id": "r32",
      "kind": "analogue-of",
      "from": "setmelanotide",
      "to": "alpha-msh",
      "quotation": {
        "compoundId": "setmelanotide",
        "field": "identityOverview",
        "quote": "A review by Swan et al. (PMID 38834138) describes setmelanotide as an analogue of alpha-melanocyte-stimulating hormone; that is a review-level parent attribution, not a residue-by-residue design account."
      }
    },
    {
      "id": "r33",
      "kind": "analogue-of",
      "from": "shu9119",
      "to": "alpha-msh",
      "quotation": {
        "compoundId": "shu9119",
        "field": "identityOverview",
        "quote": "Gimenez et al. (PMID 35404053) describe SHU9119 as a cyclic heptapeptide analogue of alpha-melanocyte-stimulating hormone."
      }
    },
    {
      "id": "r34",
      "kind": "analogue-of",
      "from": "pralmorelin",
      "to": "ghrp-6",
      "quotation": {
        "compoundId": "pralmorelin",
        "field": "nomenclatureNotes",
        "quote": "Arvat et al. (PMID 9285939) describe GHRP-2 as a synthetic super-analog of GHRP-6, although the chain printed in their abstract omits Ala3; the six-residue chain recorded here matches PubChem CID 6918245."
      }
    },
    {
      "id": "r35",
      "kind": "contained-in",
      "from": "kpv",
      "to": "melanotan-i",
      "quotation": {
        "compoundId": "kpv",
        "field": "sequence.sequenceNotes",
        "quote": "The same three residues occupy positions 11 to 13 of Melanotan I, where Lys11 follows Gly10 and Val13 carries the C-terminal amide; that containment does not fix the termini of isolated KPV."
      }
    }
  ],
  "sharedOrigins": [
    {
      "id": "proglucagon",
      "kind": "precursor",
      "label": "Proglucagon",
      "members": [
        {
          "compoundId": "glucagon",
          "quotation": {
            "compoundId": "glucagon",
            "field": "nomenclatureNotes",
            "quote": "Glucagon, GLP-1 and oxyntomodulin are related through processing of a shared precursor"
          }
        },
        {
          "compoundId": "oxyntomodulin",
          "quotation": {
            "compoundId": "oxyntomodulin",
            "field": "identityOverview",
            "quote": "Oxyntomodulin is an endogenous proglucagon-derived peptide"
          }
        },
        {
          "compoundId": "glp-1-7-36-amide",
          "quotation": {
            "compoundId": "glp-1-7-36-amide",
            "field": "identityOverview",
            "quote": "Deacon et al. (PMID 7556682) isolated this form from human colon and conclude that it is a product of proglucagon processing."
          }
        },
        {
          "compoundId": "glp-1-7-37",
          "quotation": {
            "compoundId": "glp-1-7-37",
            "field": "identityOverview",
            "quote": "Mojsov et al. (PMID 3543057) describe the glucagon-like peptides as liberated from proglucagon in both the pancreas and the intestine."
          }
        },
        {
          "compoundId": "glp-2",
          "quotation": {
            "compoundId": "glp-2",
            "field": "identityOverview",
            "quote": "Orskov et al. (PMID 2714431) characterize human and pig intestinal GLP-2 as a proglucagon processing product."
          }
        }
      ]
    },
    {
      "id": "sortilin-propeptide",
      "kind": "precursor",
      "label": "Sortilin propeptide",
      "members": [
        {
          "compoundId": "pe-22-28",
          "quotation": {
            "compoundId": "pe-22-28",
            "field": "identityOverview",
            "quote": "PE 22-28 is a synthetic heptapeptide corresponding to residues 22 to 28 of the sortilin propeptide."
          }
        },
        {
          "compoundId": "spadin",
          "quotation": {
            "compoundId": "spadin",
            "field": "nomenclatureNotes",
            "quote": "Spadin derives from the propeptide released during sortilin maturation."
          }
        }
      ]
    },
    {
      "id": "type-i-procollagen",
      "kind": "precursor",
      "label": "Type I procollagen",
      "members": [
        {
          "compoundId": "kttks",
          "quotation": {
            "compoundId": "kttks",
            "field": "identityOverview",
            "quote": "KTTKS is the unmodified pentapeptide from type I procollagen"
          }
        },
        {
          "compoundId": "matrixyl",
          "quotation": {
            "compoundId": "matrixyl",
            "field": "identityOverview",
            "quote": "corresponding to a fragment sequence of type I procollagen"
          }
        }
      ]
    },
    {
      "id": "kiss1",
      "kind": "precursor",
      "label": "KISS1-derived peptides",
      "members": [
        {
          "compoundId": "kisspeptin-10",
          "quotation": {
            "compoundId": "kisspeptin-10",
            "field": "identityOverview",
            "quote": "the human KISS1-derived kisspeptin sequence"
          }
        },
        {
          "compoundId": "kisspeptin-14",
          "quotation": {
            "compoundId": "kisspeptin-14",
            "field": "identityOverview",
            "quote": "Kisspeptin-14 is a KISS1-derived peptide"
          }
        }
      ]
    },
    {
      "id": "mt-rnr2",
      "kind": "gene-region",
      "label": "Mitochondrial 16S rRNA gene region",
      "members": [
        {
          "compoundId": "humanin",
          "quotation": {
            "compoundId": "humanin",
            "field": "identityOverview",
            "quote": "Humanin is a 24-residue peptide encoded within the mitochondrial 16S ribosomal RNA gene"
          }
        },
        {
          "compoundId": "shlp2",
          "quotation": {
            "compoundId": "shlp2",
            "field": "identityOverview",
            "quote": "SHLP2 is a 26-residue peptide assigned to a small open reading frame within the mitochondrial 16S rRNA region."
          }
        },
        {
          "compoundId": "shlp3",
          "quotation": {
            "compoundId": "shlp3",
            "field": "identityOverview",
            "quote": "SHLP3 is a 38-residue peptide from the same mitochondrial region as humanin"
          }
        },
        {
          "compoundId": "shlp6",
          "quotation": {
            "compoundId": "shlp6",
            "field": "identityOverview",
            "quote": "SHLP6 is a 20-residue peptide assigned to the mitochondrial 16S rRNA region"
          }
        }
      ]
    },
    {
      "id": "spexin-galanin-kisspeptin",
      "kind": "gene-family",
      "label": "Spexin, galanin and kisspeptin genes",
      "members": [
        {
          "compoundId": "spexin",
          "quotation": {
            "compoundId": "spexin",
            "field": "structuralNotes",
            "quote": "Evolutionary analysis supports local duplication of spexin, galanin and kisspeptin genes before two rounds of vertebrate whole-genome duplication."
          }
        },
        {
          "compoundId": "galanin",
          "quotation": {
            "compoundId": "spexin",
            "field": "structuralNotes",
            "quote": "Evolutionary analysis supports local duplication of spexin, galanin and kisspeptin genes before two rounds of vertebrate whole-genome duplication."
          }
        },
        {
          "compoundId": "kisspeptin-10",
          "quotation": {
            "compoundId": "spexin",
            "field": "structuralNotes",
            "quote": "Evolutionary analysis supports local duplication of spexin, galanin and kisspeptin genes before two rounds of vertebrate whole-genome duplication."
          }
        },
        {
          "compoundId": "kisspeptin-14",
          "quotation": {
            "compoundId": "spexin",
            "field": "structuralNotes",
            "quote": "Evolutionary analysis supports local duplication of spexin, galanin and kisspeptin genes before two rounds of vertebrate whole-genome duplication."
          }
        }
      ]
    },
    {
      "id": "glucagon-family",
      "kind": "peptide-family",
      "label": "Glucagon family",
      "members": [
        {
          "compoundId": "gip-1-42",
          "quotation": {
            "compoundId": "gip-1-42",
            "field": "identityOverview",
            "quote": "Horváth et al. (PMID 37528104) place GIP among the gastrointestinal peptides of the glucagon family."
          }
        },
        {
          "compoundId": "glucagon",
          "quotation": {
            "compoundId": "glucagon",
            "field": "identityOverview",
            "quote": "Horváth et al. (PMID 37528104) place glucagon among the gastrointestinal peptides of the glucagon family."
          }
        },
        {
          "compoundId": "glp-1-7-36-amide",
          "quotation": {
            "compoundId": "glp-1-7-36-amide",
            "field": "identityOverview",
            "quote": "Horváth et al. (PMID 37528104) place GLP-1 among the gastrointestinal peptides of the glucagon family."
          }
        },
        {
          "compoundId": "glp-1-7-37",
          "quotation": {
            "compoundId": "glp-1-7-37",
            "field": "identityOverview",
            "quote": "Horváth et al. (PMID 37528104) place GLP-1 among the gastrointestinal peptides of the glucagon family."
          }
        },
        {
          "compoundId": "glp-2",
          "quotation": {
            "compoundId": "glp-2",
            "field": "identityOverview",
            "quote": "Horváth et al. (PMID 37528104) place GLP-2 among the gastrointestinal peptides of the glucagon family."
          }
        },
        {
          "compoundId": "exenatide",
          "quotation": {
            "compoundId": "exenatide",
            "field": "identityOverview",
            "quote": "Horváth et al. (PMID 37528104) place the exendins among the gastrointestinal peptides of the glucagon family."
          }
        },
        {
          "compoundId": "oxyntomodulin",
          "quotation": {
            "compoundId": "oxyntomodulin",
            "field": "identityOverview",
            "quote": "A review by Bataille and Dalle (PMID 25115338) describes oxyntomodulin as a member of the glucagon family; that is a review-level family attribution."
          }
        }
      ]
    }
  ]
}