Identification and occurrence of the novel alkaloid pentahydroxypentyl-tetrahydro-beta-carboline-3-carboxylic acid as a tryptophan glycoconjugate in fruit juices and jams.
The novel carbohydrate-derived beta-carboline, 1-pentahydroxypentyl-1,2,3,4-tetrahydro-beta-carboline-3-carboxylic acid, was identified in fruit- and vegetable-derived products such as juices, jams, and tomato sauces. This compound occurred as two diastereoisomers, a cis isomer (the major compound) and a trans isomer, ranging from undetectable amounts to 6.5 microg/g. Grape, tomato, pineapple, and tropical juices exhibited the highest amount of this alkaloid (up to 3.8 mg/L), whereas apple, banana, and peach juices showed very low or nondetectable levels. This tetrahydro-beta-carboline was also found in jams (up to 0.45 microg/g), and a relative high amount was present in tomato concentrate (6.5 microg/g) and sauce (up to 1.8 microg/g). This beta-carboline occurred in fruit-derived products as a glycoconjugate from a chemical condensation of D-glucose and L-tryptophan that is highly favored at low pH values and high temperature. Production, processing treatments, and storage of fruit juices and jams can then release this beta-carboline. Fruit-derived products and other foods containing this compound might be an exogenous dietary source of this glucose-derived tetrahydro-beta-carboline.
Herraiz
Tomas
T
Instituto de Fermentaciones Industriales, CSIC, Juan de la Cierva, 3, 28006, Madrid, Spain. therraiz@ifi.csic.es
Galisteo
Juan
J
D001628:Beverages / Q000032:analysis*; D002243:Carbolines / Q000032:analysis*; D002851:Chromatography, High Pressure Liquid; D005638:Fruit / Q000737:chemistry*; D006001:Glycoconjugates / Q000032:analysis*; D013058:Mass Spectrometry; D013237:Stereoisomerism; D014364:Tryptophan; D014675:Vegetables / Q000737:chemistry*
C464844:1-pentahydroxypentyl-1,2,3,4-tetrahydro-carboline-3-carboxylic acid; D002243:Carbolines; D006001:Glycoconjugates; D014364:Tryptophan