Protopine
Chemical compound
From Wikipedia, the free encyclopedia
Protopine is an alkaloid occurring in opium poppy,[2] Corydalis tubers[3] and other plants of the family papaveraceae, like Fumaria officinalis.[4]
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| Names | |
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| IUPAC name
7-Methyl-2′H,2′′H-7,13a-secobis([1,3]dioxolo)[4′,5′:2,3;4′′,5′′:9,10]berbin-13a-one | |
| Systematic IUPAC name
5-Methyl-4,6,7,14-tetrahydro-2H,10H-bis([1,3]benzodioxolo)[4,5-c:5′,6′-g]azecin-13(5H)-one | |
| Identifiers | |
3D model (JSmol) |
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| ChEBI | |
| ChEMBL | |
| ChemSpider | |
| ECHA InfoCard | 100.004.546 |
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| KEGG | |
PubChem CID |
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| UNII | |
CompTox Dashboard (EPA) |
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| Properties | |
| C20H19NO5 | |
| Molar mass | 353.369 g/mol |
| Appearance | white crystals |
| Density | 1.399 g/cm3 |
| Melting point | 208 °C (406 °F; 481 K) |
| practically insoluble | |
| Solubility in chloroform | 1:15 |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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It has been found to inhibit histamine H1 receptors and platelet aggregation, and acts as an analgesic.[5][6]
Biosynthesis
Protopine is derived in the plants such as the opium poppy, Papaver somniferum, from the benzylisoquinoline alkaloid (S)-reticuline through a progressive series of five enzymatic transformations: 1) berberine bridge enzyme to (S)-scoulerine; 2) (S)-cheilanthifoline synthase/CYP719A25 to (S)-cheilanthifoline; 3) (S)-stylopine synthase/CYP719A20 to (S)-stylopine; 4) (S)-tetrahydroprotoberberine N-methyltransferase to (S)-cis-N-methylstylopine.[7]
The final step is oxidation by the enzyme methyltetrahydroprotoberberine 14-monooxygenase:[8][9]
-cis-N-methylstylopine.svg)
Metabolism
The enzyme protopine 6-monooxygenase converts protopine into dihydrosanguinarine.[8][10] NADP+ and water are the by-products.
The enzyme uses reduced nicotinamide adenine dinucleotide phosphate (NADPH), and oxygen, with the initial product being 6-hydroxyprotopine, which spontaneously forms dihydrosanguinarine, found in plants such as Sanguinaria canadensis.[11]