Identification of unknown colorants in pre-Columbian textiles dyed with American cochineal (Dactylopius coccus Costa) using high-performance liquid chromatography and tandem mass spectrometry (original) (raw)

On the biosynthetic origin of carminic acid

Insect biochemistry and molecular biology, 2018

The chemical composition of the scale insect Dactylopius coccus was analyzed with the aim to discover new possible intermediates in the biosynthesis of carminic acid. UPLC-DAD/HRMS analyses of fresh and dried insects resulted in the identification of three novel carminic acid analogues and the verification of several previously described intermediates. Structural elucidation revealed that the three novel compounds were desoxyerythrolaccin-O-glucosyl (DE-O-Glcp), 5,6-didehydroxyerythrolaccin 3-O-β-D-glucopyranoside (DDE-3-O-Glcp), and flavokermesic acid anthrone (FKA). The finding of FKA in D. coccus provides solid evidence of a polyketide, rather than a shikimate, origin of coccid pigments. Based on the newly identified compounds, we present a detailed biosynthetic scheme that accounts for the formation of carminic acid (CA) in D. coccus and all described coccid pigments which share a flavokermesic acid (FK) core. Detection of coccid pigment intermediates in members of the Planococc...

Absolute Quantification of Carminic Acid in Cochineal Extract by Quantitative NMR

Food Hygiene and Safety Science (Shokuhin Eiseigaku Zasshi), 2010

A quantitative NMR (qNMR) method was applied for the determination of carminic acid. Carminic acid is the main component in cochineal dye that is widely used as a natural food colorant. Since several manufacturers only provide reagent-grade carminic acid, there is no reference material of established purity. To improve the reliability of analytical data, we are developing quantitative nuclear magnetic resonance (qNMR), based on the fact that the intensity of a given NMR resonance is directly proportional to the molar amount of that nucleus in the sample. The purities and contents of carminic acid were calculated from the ratio of the signal intensities of an aromatic proton on carminic acid to nine protons of three methyl groups on DSS-d 6 used as the internal standard. The concentration of DSS-d 6 itself was corrected using potassium hydrogen phthalate, which is a certified reference material (CRM). The purities of the reagents and the contents of carminic acid in cochineal dye products were determined with SI-traceability as 25.3ῌ92.9 and 4.6ῌ30.5 based on the crystalline formula, carminic acid potassium salt trihydrate, which has been confirmed by X-ray analysis. The qNMR method does not require a reference compound, and is rapid and simple, with an overall analysis time of only 10 min. Our approach thus represents an absolute quantitation method with SI-traceability that should be readily applicable to analysis and quality control of any natural product.

Natural product chemistry, part 100: The structure of carissone, C15H24O2

Monatshefte f�r Chemie Chemical Monthly, 1990

Cl5H2402, M = 236.2, monoclinic, P 2l, a = 7.229 (7), b = 14.925 (9), c = 6.235 (9) ~, 13 = 92.40 (9) °, V= 672.1A 3, T= -133 °C, Z = 2 , Dx= 1.17g cm -3. The X-ray diffraction analysis of this sesquiterpenoid from Carissa opaca confirmed the previously proposed constitution of the isolate and, furthermore, allowed precise NMR assignment.

The structure of the colourant/pigment, carmine derived from carminic acid

The colourant/pigment carmine synthesised from carminic acid and calcium and aluminium acetates has been examined chemically and spectroscopically to determine its structure. As with alizarin, it appears probable that the material is a tetramer but composed of four carminic acid units with aluminium involved with the 5,6-dioxy groups in five-membered rings and calcium chelated with the 10-carbonyl group ofthe anthraquinone system.

Carboxylic Acid Organic Chemistry MSc Chemistry

Hasnain Ali , 2024

Material Related Carboxylic Acid Physical and Chemical Characteristics Preparation of Carboxylic Acid Reaction of Carboxylic Acid Application of Carboxylic Acid Organic Chemistry MSc Class