sinapinic.gifJMOL view

Compound Name: 3,5-dimethoxy-4-hydroxycinnamic acid
Common Names: sinapinic acid, sinapic acid
IUPAC Name: (2E)-3-(4-hydroxy-3,5-dimethoxyphenyl)acrylic acid

CAS RN: 530-59-6
SMILES: COc1cc(cc(OC)c1O)/C=C/C(O)=O

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Molecular Formula: C11H12O5
Molecular Weight (average): 224.20998
Molecular Weight (monisotopic): 224.0685 Da
Melting point: 203-205°C (dec)
LogP (ACD v5.0 logD calculated): 1.29 +/- 0.37
pKa (ACD v5.0 pKa calculated): 3.98 +/- 0.50 (-COOH), 10.24 +/- 0.36 (-OH)
pKa (literature) [3]: 4.47
Proton affinity [1]: 209.2 +/- 0.38 kcal/mol (875.3 +/- 1.6 kJ/mol)
Sodium affinity [2]: 159 +/- 2 kJ/mol
Vapor pressure (ACD calculated): 3.12E-07 mmHg at 25°C
Radical Scavenging Ability [4]: 33.2 ((+/-0.58)

Spectral Information
IR Spectrum ATR 1 cm-1 resolution
UV Spectrum 1 nm resolution in methanol
UV spectrum 1 nm resolution in acetonitrile
SS-UV Spectrum 1 nm resolution solid state diffuse reflectance measurement
355nm MALDI spectrum 355nm Positive ion spectrum acquired on a Bruker Ultraflex TOF-TOF
355nm MALDI spectrum 355nm Negative ion spectrum acquired on a Bruker Ultraflex TOF-TOF

Sample Info:
Aldrich 98%, PN: D13480-0 (lot #: 01015AU)


[1] Mirza, S.P.; Raju, N.P.; Vairamani, M., Estimation of the Proton Affinity Values of Fifteen MALDI Matrices under Electrospray Ionization Conditions using the Kinetic Method, J. Amer. Soc. Mass Spectrom., 2004, 15, 431-5, DOI:
[2] Zhang, J., Knochenmuss, R., Stevenson, E., Zenobi, R., The gas-phase sodium basicities of common matrix-assisted laser desorption/ionization matrices, International Journal of Mass Spectrometry, 2002, 213, 237–250, DOI:
[3] B. Smyk and R. Drabent, Spectroscopic investigation of the equilibria of the ionic forms of sinapic acid, Analyst, 114, 1989, 723-726, DOI:
[4] S.S. Pekkarinen, H. Sto¨ckmann, K. Schwarz, I.M. Heinonen, A.I. Hopia Antioxidant Activity and Partitioning of Phenolic Acids in Bulk and Emulsified Methyl Linoleate, J. Agric. Food Chem. 1999, 47, 3036-3043 DOI: