Volatile Oil Constituents of Grapefruit Juice

Abstract

were determined in these two by means of the sensitive chromotropic acid test (2). The fresh and freshly canned juices contained 0.2 mg. of methanol per kg. of juice and the stored juice, 23 mg. per kg• Acids ac*dic material was found in the residue from the stripping column run of the stored juice and a small amount in the freshly canned juice, a sample of fresh juice was rechecked for the presence of volatile acids. The distillate from fresh grapefruit juice was neutral.The /)-phenylphenacyl esters obtained from the acids in the stripper residue of the stored juice were separated by chromatographic adsorption on silicic acid (74). The major portion of this was found to be the derivative of acetic acid, representing 23.3 mg. of acetic acid per kg. of juice. The melting point of the ester was 110-112°C. and a mixed melting point with /j-phenylphenacyl acetate

Grapefruit Juice Inhibits the Metabolic Activation of Clopidogrel

“…22 Bergamottin is found in grapefruit juice at a concentration of ~3-33 µmol/l and nootkatone at a concentration of ~2-3 µmol/l. 27,28 Considering the surprisingly strong interaction observed in the current study, it is plausible that grapefruit juice reduced clopidogrel bioactivation by inhibiting both CYP3A4 and CYP2C19. It should be noted that, in addition to the liver, CYP2C19 is also expressed in the small intestine 29 and could therefore participate in the activation of clopidogrel during the first pass in both the intestine and the liver.…”

“…Bergamottin and nootkatone inhibited the CYP2C19‐catalyzed 5‐hydroxylation of omeprazole with half‐maximal inhibitory concentrations (IC 50 ) of 0.3 µmol/l and 22.5 µmol/l (inhibition constant, K i : 0.5 µmol/l), respectively 22 . Bergamottin is found in grapefruit juice at a concentration of ~3–33 µmol/l and nootkatone at a concentration of ~2–3 µmol/l 27 , 28 . Considering the surprisingly strong interaction observed in the current study, it is plausible that grapefruit juice reduced clopidogrel bioactivation by inhibiting both CYP3A4 and CYP2C19.…”

THE IDENTIFICATION OF SOME VOLATILE CONSTITUENTS OF CONCORD GRAPE JUICE a

“…or more of fruit. The volatile oil is fractionated by distillation or by chemical or chromatographic procedures, and the fractions are identified (2, 3,4,5,7,8,15,16,20). I n the present article, a procedure is.…”

Analysis of Alcohols in Essential Oils of Grapefruit, Lemon, Lime, and Tangerine

“…Since all but four of these alzohols were isolated and identified in orange 3il (Hunter and Moshonas, 1965)) further verification of their identity is not repeated here. Linalool, one of the carveols, aterpineol, geraniol, and one of the linalool monoxides have been reported in grapefruit juice (Kirchner and Miller, 1953). The remaining alcohols, the other linalool oxide, lctanol, trans-Z-S-p-menthadiene-l-01, nonanol, cis-Z,S-p-menthadiene-l-01, decanol, citronellol, nerol, the other carveol, dodecanol, 1 ,S-p-menthadiene-9-01, nerolidol, elemol, S-pmenthene-1,2-diol, and o-phenol phenol are TOW shown to be constituents in grapefruit oil.…”

“…Little attention has been given to the alcoholic composition in citrus cold-pressed oils other than the orange. Kirchner and Miller ( 1953)) investigating the volatile constituents of grapefruit juice, identified 6 alcohols. Kovats (1963)) working on the composition of Brandis distilled lime oil, reported 11 alcohols, and Ikeda and Spitler (1964)) reporting on a method for estimating esters and alcohols in California lemon oil, identified 3 alcohols.…”