Flavonoids Part 1

A six-membered heterocyclic ring system found in many natural products, especially flavonoids.

A group of plant pigments that are responsible for many of the colors we see in flowers, fruits, and leaves. They are structurally similar to the pyran ring system.

A type of flavonoid that has a specific arrangement of rings and substituents. They are known for their bright yellow and orange colors.

A type of flavonoid composed of a phenyl ring (B ring) attached to a pyran ring (C ring) and a benzene ring (A ring). The phenyl ring (B ring) is attached at the 2-position of the pyran ring (C ring).

Flavonoids without any sugar molecules attached.

Flavonoids with sugar molecules (glycones) attached to them.

The sugar portion of flavonoid glycosides that provides structural diversity.

The non-sugar portion of flavonoid glycosides, generally a flavonoid aglycone.

A chemical process in plants that produces flavonoids. It involves two key pathways: the shikimate pathway and the acetate-malonate pathway.

The process of adding a sugar molecule to a flavonoid molecule.

The initial steps of flavonoid biosynthesis involve the condensation of one molecule of p-coumaroyl CoA (a cinnamate derivative) with three molecules of malonyl-CoA. This process generates a chalcone molecule.

The enzyme chalcone synthase (CHS) catalyzes the reaction between p-coumaroyl CoA and malonyl-CoA to produce chalcone. This step is crucial for the formation of the basic flavonoid structure.

Chalcone is subsequently converted into flavanone by the enzyme chalcone flavanone isomerase (CHI). This isomerization is a key step in the flavonoid pathway, leading to the formation of different subclasses of flavonoids.

Flavanone serves as a central intermediate in the flavonoid pathway. This branch point allows for the biosynthesis of various flavonoid subclasses, including anthocyanins, flavonols, and isoflavones.

Following the formation of flavanone, the flavonoid pathway diverges into several branches, each leading to the production of a specific class of flavonoids. This diversification allows for the biosynthesis of a wide array of flavonoids with varying structures and functions.

A type of flavanone characterized by a 2,3-dihydro-2-phenylchromen-4-one structure.

A group of naturally occurring pigments that are responsible for the red, purple, and blue colors in plants.

The sugar-free form of anthocyanins.

Anthocyanins are found in various fruits and vegetables, such as berries, currants, grapes, and leafy vegetables.

Anthocyanins are particularly abundant in berries, currants, grapes, and some tropical fruits.

Anthocyanins are also found in red to purplish blue-colored leafy vegetables, grains, roots, and tubers.

Anthocyanins contribute to the colors of fruits and vegetables.

A type of flavonoid with a 2-phenylbenzopyrone structure. They are typically colorless or yellow and accumulate in the outer parts of plants like leaves and skin.

A type of flavonoid with a 3-hydroxy-2-phenylbenzopyrone structure. They are known for their diverse color range and play crucial roles in plant growth and defense.

A precursor to anthocyanidins, a type of flavonoid responsible for red, blue, and purple colors in plants.

A large group of flavonoids typically found in leguminous plants like soybeans. They are known for their estrogenic properties and potential health benefits.

A subcategory of flavonoids with a 3-phenylchroman backbone structure.

Compounds that have estrogenic effects in the body but originate from plants.

Flavonoids are a diverse group of plant pigments known for their antioxidant and anti-inflammatory properties. They are responsible for the vibrant colours of flowers, fruits, and leaves.

Flavonoids are a group of polyphenolic compounds that share a common basic structure. This structure consists of a phenyl ring (B ring) attached to a pyran ring (C ring) and a benzene ring (A ring). The phenyl ring (B ring) is attached at the 2-position of the pyran ring (C ring).

The stability of anthocyanins, meaning their ability to retain color, is determined by various factors including light, temperature, pH, metal ions, and presence of antioxidants. These factors can affect the pigment's structure and ultimately alter its color.

The B-ring in the structure of anthocyanidins contributes to their stability. A higher concentration of hydroxyl (OH) groups in this ring increases the stability of the pigment, leading to more intense colors, often leaning towards blue tones.

The addition of hydroxyl (OH) groups to the anthocyanin structure leads to a shift in color towards blue hues. More hydroxyl groups mean a more pronounced blue shade.

The presence of methoxyl (OCH3) groups in anthocyanidins can hinder their stability, potentially leading to a reduction in color intensity. This effect is due to changes in the molecular structure and interactions within the anthocyanin molecule.

Pelargonidin is a type of anthocyanidin that typically produces orange or red colors. It is often found in strawberries and other fruits and flowers.

Cyanidin is a type of anthocyanidin commonly found in red berries like raspberries and cranberries. It produces red to magenta hues and is known for its antioxidant properties.

Delphinidin is a type of anthocyanidin that produces magenta to purple colors. It is often found in blueberries, blackberries, and eggplants, contributing to their deep hues.

Copigmentation is a phenomenon that enhances the color of anthocyanins. This occurs when anthocyanins interact with other molecules in the plant, such as flavonols or tannins, resulting in a deeper and more intense color.

A class of flavonoids consisting of two flavonoid units linked together through a covalent bond, such as C-C or C-O-C.

A type of flavan-3,4-diol derivative. It's named for the anthocyanidins produced during acid hydrolysis, which give a red color.

A group of flavonoids that undergo hydrolysis to produce anthocyanidin.

A polyhydroxy flavan-3-ol structure. It's known for its two chiral centers, carbon 2 and 3, and its isomers, catechin and epicatechin.

An isomer of catechin, it differs by its configuration. Catechin has a trans positioning, while epicatechin has a cis configuration.

An enzyme involved in the synthesis of anthocyanidins. It catalyzes the conversion of leucoanthocyanidins to anthocyanidins.

The final step in the biosynthesis of anthocyanidins. Leucoanthocyanidins are converted to anthocyanidins with a red color.

They are dimers of flavonoids, meaning they are formed by the covalent linkage of two monoflavonoids. This bond connects through C-C or C-O-C.