No abstract

For the present study Quercetin has been extracted and applied onto the gamma irradiated cotton. Fabrics and powder have been exposed to different absorbed doses and dyeing has been performed at various parameters. It is observed that 20 kGy is the optimum absorbed dose for surface modification of cotton. It has been also found that good colour strength has been obtained at 60 • C by dyeing optimal fabric for 40 min using dye bath of pH6 keeping liquor concentration of 1:30 and electrolyte concentration of 1 g. 7% of tannic acid as pre-mordant and 5% of Copper sulphate as post mordant was optimum conditions to get good fastness properties according to ISO standard methods. Quercetin from acacia bark under ionizing radiation can safely be used as possible substitute to reddish-brown synthetic dyes.

Completely hydrophobic AEE-active conjugated polymers self-assemble into nanospheres, hollow nanostructures and free-standing sheets in solvents of weakened quality. These morphologies correlate well with the AEE features.

Flavonoids are natural polyphenolic compounds, which are responsible for the taste and colors of medicinal plants, herbs, fruits, vegetables. Fruits (e.g., Berries, cherries, plums, apples, lemons, oranges, and grapes etc) and vegetables (e.g., broad beans, olives, onions, spinach, shallot etc) are the main sources of flavonoids. They also exist abundantly in cocoa products, black and green tea, red wine, red pepper, chamomile, celery, parsley, ginkgo, and mint. Flavonoids derivatives can also be synthesized through esterification, halogenation, alkoxylation, alkylation, aromatic hydroxylation, acylation and conjugation with various organic compounds. Flavonoids can be supplemented in a staple of food as nutraceutical agents and have an important role in human diet. They possess diverse biological activities including anti-inflammation, anti-oxidation, anti-cancer, anti-diabetes, anti-obesity, antimutagenic, neuroprotective and also have beneficial effects on oxidative stress, inflammation, insulin resistance, lipid metabolism and neurodegenerative diseases (e.g., amyotrophic lateral sclerosis, Huntington’s disease, Parkinson’s disease and Alzheimer’s disease). Flavonoids contain a 15-carbon skeleton; the basic structure consists of a flavan nucleus, a combination of two benzene and one pyran rings. Flavonoids are divided into eight important groups i.e., flavones, flavanols, isoflavones, flavan-3-ols, flavanonols, anthocyanidins, chalcones, and flavanones. A structure-activity relationship exists between flavonoids and their antioxidant activities. Flavonoids are effective in chelating metal ions and scavenging free radicals. The antioxidant properties of flavonoids are governed by their –OH groups, differences in hydrophobicity and molecular planarity.

Flavonoids are the pigments present in plants which mostly found in terrestrial plants. Flavonoids are indeed a naturally present group of polyphenolic compounds present in plants. They were driven by the term "flavus," which means "yellow." It is a 15-carbon skeleton compound. They have fused aromatic ring and benzopyran heterocyclic ring having oxygen atom in it along with phenyl substituent. They are synthesized from Phenylalanine. In cereals and Herbs, they are mainly found. Flavonoids are compounds that are biologically active. They provide color and protection from ultraviolet rays. They have many classes based upon oxidative status, number, and types of substituents present. Flavonoids exist naturally in the form of polymers, most commonly in dimers form. They occur primarily in β-glycosides form except for Catechins. They can help in the inhibition of enzymes and stimulate some hormones along with some neurotransmitters. They also show the properties of scavenging free radicals. They can inhibit or kill many bacterial strains, viral enzymes, and pathogenic protozoans. There are various techniques and methods for the synthesis of natural products artificially. In the present study, we have attempted to cover different synthetic methods for flavonoid synthesis to find its best way to synthesize. It was concluded that Baker & Venkatraman synthesis and Claisen-Schmidt condensation are well-known methods used to synthesize flavonoids.