Aurones Could Be Used as Golden Fabric Dyes

  • Author: ChemistryViews.org
  • Published: 26 July 2019
  • Copyright: Wiley-VCH Verlag GmbH & Co. KGaA
  • Source / Publisher: Beilstein Journal of Organic Chemistry/Beilstein Institute
thumbnail image: Aurones Could Be Used as Golden Fabric Dyes

Aurones (pictured) are a subtype of the flavonoids, a family of natural products. They are named for their golden yellow color (aurum = Latin for gold). The compounds consist of a benzofuranone and a benzylidene group. While the properties of many other flavonoids are well studied, the aurones have garnered much less research interest. Most studies have focused on their fluorescence properties and on the influence of substituents on the benzylidene part. The use of aurones as dyes or pigments had not been reported so far.


Joza Schmitt and Scott T. Handy, Middle Tennessee State University, Murfreesboro, USA, have studied the influence of substituents at the benzofuranone ring on the optical properties of aurones, evaluated their toxicity, and tested the compounds' potential as fabric dyes. The team synthesized a range of aurones from substituted benzofuranones and p-tolualdehyde via a Knoevenagel condensation.


The researchers recorded the UV–Vis spectra of the products to evaluate the influence of the different substituents. They found that the position of the substituent was generally more important than its type. Different substituents at the 4- or 5-positions of the benzofuranones caused a redshift of the absorption maximum by ca. 10 nm compared to the unsubstituted compound, while hydroxylation at the 6-position caused a significant blueshift of about 40 nm.


The team also evaluated the toxicity of the compound and found that, depending on the substitution, it was similar to slightly higher than the toxicity of the commonly used yellow dye tartrazine. Halogen substituents in the 6- or 7-positions of the benzofuranone led to lower toxicity. The researchers tested some of the synthesized aurones as fabric dyes and found that the compounds adhered to different natural fabrics such as silk and wool. Unexpectedly, they also gave vibrant colors on polypropylene, which can usually only be dyed efficiently when it is melted.


 

Article Views: 590

Sign in Area

Please sign in below

Additional Sign In options

Please note that to comment on an article you must be registered and logged in.
Registration is for free, you may already be registered to receive, e.g., the newsletter. When you register on this website, please ensure you view our terms and conditions. All comments are subject to moderation.

Article Comments - To add a comment please sign in

Bookmark and Share

If you would like to reuse any content, in print or online, from ChemistryViews.org, please contact us first for permission. more


CONNECT:

ChemistryViews.org on Facebook

ChemistryViews.org on Twitter ChemistryViews.org on YouTube ChemistryViews.org on LinkedIn Sign up for our free newsletter


A product of ChemPubSoc Europe (16 European Chemical Societies)and Wiley-VCH