THE MERCK INDEX on CD-ROM / Version 12:3 / 1999
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Monograph number:  7625.

Title: Piperine .

CAS Registry number: [94-62-2]
CAS name(s): (E,E)- 1-[5-(1,3-Benzodioxol-5-yl)-1-oxo-2,4-pentadienyl]piperidine;
             (E,E) -1-piperoylpiperidine.
Molecular formula: C17H19NO3;
Molecular weight: 285.34.
Percent Composition: C 71.56%, H 6.71%, N 4.91%, O 16.82%.

Literature references: Isolated from black pepper ( Piper nigrum L.); also in P. longum L.
   ,P. retrofractum Vahl. ( P. offici narum C.D.C.), and P. clusii C.D.C.; in root bark
   of Piper genicula tum Sw., Piperaceae. Extraction procedure: Caze neuve, Caillot,
   Bull. Soc. Chim. [2] 27, 291 (1877). Synthesis: Rugheimer, Ber. 15, 1390 (1882);
   Newman, Chem. Products 16, 379 (1953); Normant, Feugeas, Compt. Rend. 258, 2846 (1964).
   Spectroscopic structural elucidation and preparative separation of piperine and its
   stereoisomers isopiperine, isochavicine and chavicine, q.v.: R. De Cleyn, M. Verzele,
   Bull. Soc. Chim. Belg. 84, 435 (1975). Synthesis of isomers: R. Grewe et al., Ber. 103, 
   3752 (1970); of piperine and isochavicine: S. Tsuboi et al., Tetrahedron Letters 1979,
   1043. Stereoselective synthesis of piperine: R. A. Olsen, G. O. Spessard, J. Agr. Food
   Chem. 29, 942 (1981). More toxic to houseflies than pyrethrum: Harvill et al., Contrib.
   Boyce Thompson Inst. 13, 87 (1943).

Properties:  Monoclinic prisms from alcohol, mp 130° . Tasteless at first, but burning
   aftertaste. Neutral to litmus. pK (18°): 12.22. Almost insol in water (40 mg/liter at
   18°), in petr ether. One gram dissolves in 15 ml alcohol, 1.7 ml chloroform,
   36 ml ether. Sol in benzene, acetic acid.

Melting Point: 130°

Derivative:  (E,Z)- Form,
Additional name(s): isochavicine.
Properties: Crystals from chloroform + hexane, mp 89° (Grewe), 103° (De Cleyn) .
   uv max (methanol): 333 nm (epsi 16300) .
Melting Point: 89° (Grewe), 103° (De Cleyn)
UV Maxima: 333

Derivative:  (Z,E)- Form,
Additional name(s): isopiperine.
Properties: Crystals from chloroform + hexane, mp 110° (Grewe), 86° (De Cleyn) .
   uv max (methanol): 332 nm (epsi 21800) .
Melting Point: 110° (Grewe), 86° (De Cleyn)