Ebenaceae extractives. Part IV. Diosindigo A, a blue pigment from several Diospyros species

Techinantitla building complex, in the Amanalco neighborhood of the ancient city of Teotihuacan, is famous for the iconography and quality of the mural paintings found in this site. A significant part of this heritage has been lost due to looting. In recent years, an interdisciplinary research project was developed to study the limited patrimony that was left. As part of this study, we first employed geophysical techniques to reconstruct the architectural pattern of the compound’s remaining walls, where other paintings may still be found. Then, we applied a non-invasive methodology to characterize a large set of fragments recovered in the 1980s and to gain information on their pigments and manufacturing techniques. This methodology included False Color Infrared Imaging, X-ray Fluorescence and Fiber-Optics Reflectance Spectroscopy, and led to the identification of hematite, calcite, malachite, azurite and an unidentified blue pigment. The results were compared with a previous study performed on a set of Techinantitla mural paintings looted in the 1960s. A broader comparison with contemporary mural paintings from other Teotihuacan complexes shows good agreement in the materials used. These results may suggest a standardization in the making of Teotihuacan mural painting during the Xolapan period (350 to 550 AD).

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C. elegans discriminates colors to guide foraging

Science ◽

10.1126/science.abd3010 ◽

2021 ◽

Vol 371 (6533) ◽

pp. 1059-1063 ◽

Cited By ~ 1

Author(s):

D. Dipon Ghosh ◽

Dongyeop Lee ◽

Xin Jin ◽

H. Robert Horvitz ◽

Michael N. Nitabach

Keyword(s):

Stress Response ◽

Cellular Stress ◽

Color Discrimination ◽

Cellular Stress Response ◽

Blue Pigment ◽

Natural Environments ◽

C Elegans ◽

Evolutionarily Conserved ◽

Foraging Decisions ◽

Light Guides

Color detection is used by animals of diverse phyla to navigate colorful natural environments and is thought to require evolutionarily conserved opsin photoreceptor genes. We report that Caenorhabditis elegans roundworms can discriminate between colors despite the fact that they lack eyes and opsins. Specifically, we found that white light guides C. elegans foraging decisions away from a blue-pigment toxin secreted by harmful bacteria. These foraging decisions are guided by specific blue-to-amber ratios of light. The color specificity of color-dependent foraging varies notably among wild C. elegans strains, which indicates that color discrimination is ecologically important. We identified two evolutionarily conserved cellular stress response genes required for opsin-independent, color-dependent foraging by C. elegans, and we speculate that cellular stress response pathways can mediate spectral discrimination by photosensitive cells and organisms—even by those lacking opsins.

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FLIm and Raman Spectroscopy for Investigating Biochemical Changes of Bovine Pericardium upon Genipin Cross-Linking

Molecules ◽

10.3390/molecules25173857 ◽

2020 ◽

Vol 25 (17) ◽

pp. 3857

Author(s):

Tanveer Ahmed Shaik ◽

Alba Alfonso-Garcia ◽

Martin Richter ◽

Florian Korinth ◽

Christoph Krafft ◽

...

Keyword(s):

Raman Spectroscopy ◽

Fluorescence Lifetime ◽

Density Functional ◽

Bovine Pericardium ◽

Biochemical Changes ◽

Blue Pigment ◽

Cross Linking ◽

Fluorescence Lifetime Imaging ◽

Fluorescence Intensity Ratio ◽

Cross Linker

Biomaterials used in tissue engineering and regenerative medicine applications benefit from longitudinal monitoring in a non-destructive manner. Label-free imaging based on fluorescence lifetime imaging (FLIm) and Raman spectroscopy were used to monitor the degree of genipin (GE) cross-linking of antigen-removed bovine pericardium (ARBP) at three incubation time points (0.5, 1.0, and 2.5 h). Fluorescence lifetime decreased and the emission spectrum redshifted compared to that of uncross-linked ARBP. The Raman signature of GE-ARBP was resonance-enhanced due to the GE cross-linker that generated new Raman bands at 1165, 1326, 1350, 1380, 1402, 1470, 1506, 1535, 1574, 1630, 1728, and 1741 cm−1. These were validated through density functional theory calculations as cross-linker-specific bands. A multivariate multiple regression model was developed to enhance the biochemical specificity of FLIm parameters fluorescence intensity ratio (R2 = 0.92) and lifetime (R2 = 0.94)) with Raman spectral results. FLIm and Raman spectroscopy detected biochemical changes occurring in the collagenous tissue during the cross-linking process that were characterized by the formation of a blue pigment which affected the tissue fluorescence and scattering properties. In conclusion, FLIm parameters and Raman spectroscopy were used to monitor the degree of cross-linking non-destructively.

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Optimization of Fermentation Conditions for Blue Pigment Production by Bacterial Strain T2013

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.1073-1076.286 ◽

2014 ◽

Vol 1073-1076 ◽

pp. 286-291

Author(s):

Yong Zuo ◽

Peng Jiang ◽

Xiao Long Wang ◽

Bin Fu ◽

Xiao Long Yang ◽

...

Keyword(s):

Bacterial Strain ◽

Orthogonal Test ◽

Blue Pigment ◽

Liquid Volume ◽

Initial Value ◽

Fermentation Time ◽

Fermentation Conditions ◽

Inoculum Volume ◽

Optimization Of Fermentation ◽

Single Factor Experiment

The fermentation conditions of Bacterial Strain T2013 were studied. The fermentation conditions of T2013 were investigated with single-factor experiment. In addition to, the fermentation conditions were optimized through the orthogonal test. The results showed the highest production of blue pigment was obtained on condition that fermentation time was 2d, the liquid volume was 50ml in the 250ml shake-flask, the inoculum volume was 2%, the initial value of pH was 7.6, fermentation temperature was 37°C and the speed was 150r/min.The fermentation conditions of Bacterial Strain T2013 were preliminarily determined,whichprovides a theoretical basis for the industrial production of blue pigment.

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