The main purpose of this study was to determine if a method developed in the laboratory by HPLC‐ESI‐QToF was able to identify the characteristic compounds of the Mexican cochineal (Dactylopius coccus) in freshly dyed wool fiber and following an artificially accelerated aging process. Wool fibers were dyed with various formulations of popular interest (red‐orange, Mexican red, cochineal red, and purple). These formulations are currently used by indigenous communities in the south of Mexico. Some dyed wools were aged in an UV chamber, in order to simulate the deterioration that a fiber dyed in a previous time could have. Notable results were the identification of the main component, carminic acid, and the respective biomarkers of the Mexican cochineal (dcII, dcIV, and dcVII) with a small amount of sample and in a short time, in three of the four formulations before and after aging, thus providing a method that can probably be used for conservation purposes of cultural heritage. It was concluded that when alum is used as a mordant and as a carbonate pH fixer, the fixation of cochineal on the wool is not very strong. This is one of the few works where Mexican cochineal has been studied, simulating the deterioration due to the passage of time in wool samples of different colors with the same natural dye. As a way of describing the color more objectively, the color was measured with the CIE L*A*B* scale in the four formulations of interest, in recently dyed and artificially aged wool.

This study aims to optimise the dyeing process of cotton fabrics using Mexican cochineal ( Dactylopius coccus Costa). The objective is to obtain purple hues through the design of experiments and by using multivariate analysis. Plackett–Burman experimental designs and the response surface method were used to systematically optimise the dyeing parameters. The meta‐mordanting process was the most critical factor affecting the achievement of purple hues, followed by cochineal concentration, toner concentration and dyeing time. The multivariate analysis of principal component analysis with discriminant analysis was applied to determine the significance of washing methods and toner types. Various traditional Mexican toners, including tequesquite , cardon and ash, were evaluated. The washing method was not significant, while the toner type showed a tendency towards clustering, indicating a significant effect on the dyeing process. The most recommended method was the one using tequesquite , with 20% on weight of fabric (owf) cochineal, 5% owf toner and a dyeing time of 66 minutes. Cardon was recommended as a viable toner alternative. This research provides a reproducible method for achieving desired purple shades, preserving traditional dyeing techniques from Mexican indigenous cultures.

The bacterial Quorum Sensing system refers to the recognition of signaling molecules called autoinducers produced by bacteria when a certain cell density is reached in the environment. Those cell-density-dependent autoinducers regulate and coordinate diverse functional processes, such as bioluminescence, biofilm production, sporulation, and even the expression of some virulence factors, among others. There is a wide variety of autoinducers, and for Gram-negative bacteria, the canonical autoinducers are the N-acyl-homoserine lactones (AI-1). Presently, the production of autoinducers in Leptospira has not been described; therefore, the objective of this study was to detect and identify autoinducers in this bacterial genus. We report here the expression of AI-1 in cultures ≥2.4 × 10⁸ of Leptospira meyeri. Ethyl acetate extracts of Leptospira culture supernatants were capable of activating the β-galactosidase system in the biosensor Agrobacterium tumefaciens strain NTL4. Partial identification of the leptospiral supernatant extracts was done by thin-layer chromatography (TLC), showing a similar retention factor to the synthetic standard N-Octanoyl-DL-homoserine lactone (C8-AHL) in the Leptospira supernatant extracts. In addition, infrared spectroscopy (IR) analysis showed peaks corresponding to the lactone and amide groups in both the C8-AHL standard and the Leptospira meyeri culture extracts. Moreover, High-Performance Liquid Chromatography–Mass Spectrometry (HPLC-MS/MS) confirmed the same retention time (10.7 ± 0.1 min) in both the Leptospira meyeri supernatant extracts and the C8-AHL standard. These results show that Leptospira meyeri synthesizes N-acyl homoserine lactone family autoinducers, particularly the N-Octanoyl-DL-homoserine lactone, and lay the groundwork for future research on Quorum Sensing systems in Leptospira.