On the biosynthetic origin of carminic acid

Abstract

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 Planococcus (mealybugs) and Pseudaulacaspis genera shows that the ability to form these pigments is taxonomically more widely spread than previously documented. The shared core-FK-biosynthetic pathway and wider taxonomic distribution suggests a common evolutionary origin for the trait in all coccid dye producing insect species.

Heterologous production of the widely used natural food colorant carminic acid in Aspergillus nidulans

“… 14 have speculated that the reaction proceeds spontaneously driven by the formation of the energetically more favourable anthraquinone structure. We have previously observed rapid spontaneous oxidation of chemically synthesized flavokermesic acid anthrone 9 supporting this view. In contrast, we note that flavokermesic acid generated in S .…”

“…Targeted LC-HRMS analysis of this strain confirmed the formation of carminic acid 22 (Supplementary File, Fig. 13 ), along with dcII 9 , 23 and a dcII isomer (Supplementary File, Fig. 14 ), showing that UGT2 was functional in A .…”

“…2 ) and was in accordance with previously reported values 19 while flavokermesic acid was compared to an authentic reference isolated from D . coccus 9 (Supplementary File, Fig. 3 ).…”

“…Based on that, we have presented a five-step biosynthesis model for the natural process in D . coccus 9 (Fig. 1 ), which depends on one polyketide synthase (PKS), one or two monooxygenases and a C-glucosyltransferase.…”

Analysis of Biomolecules in Cochineal Dyed Archaeological Textiles by Surface-Enhanced Raman Spectroscopy.

“…Therefore, carmine is usually a very complex material integrated by a large list of different colorants and other biological molecules as well as fragments of the insect body, waxy exudates and residue from the environment, although carminic acid is the main component of this mixture. In fact, chromatographic methods have revealed the presence of other minor colorants in the cochineal extract, such as kermesic and avokermesic acids, as well as other unidenti ed compounds 3 . All these molecules can also form a complex with the metal used in the fabrication of the carmine lac.…”