Anthocyanin (Etymology: greek. anthos = Flower, kyáneos = purple) is a water soluble pigment that reflects the red to blue range of the visible spectrum. It is often observed in the plant kingdom, where it serves to color anything from fruits to the autumn leaves. The pigment acts as a powerful antioxidant helping to protect the plant from UV damage. It can be used as a pH indicator because it changes from red in acids to blue in bases. Anthocyanins belong to a class of compounds called flavonoids. The anthocyanins themselves are subdivided into the sugar-free anthocyanidine aglycons and the anthocyanin glycosides. They are considered secondary metabolites and allowed as a food additive with E-number 163. Approximatly 250 different anthocyanins are known.

Flavonoids are a group of chemical compounds, low molecular weight phenylbenzopyrones, found in all vascular plants. In the diet, flavonoids are found in many fruits, vegetables, teas, wines, nuts, seeds, and roots. Many of the medicinal actions of foods, juices, herbs, and bee pollen are directly related to their flavonoid content. Although not considered vitamins, flavonoids have a number of nutritional functions have been described as biological response modifiers; most act as antioxidants, and some have anti-inflammatory properties. Flavonoids have been shown to prevent or slow the development of some cancers.

Over 4000 flavonoid compounds have been characterized and classified according to chemical structure. They are usually subdivided into 5 subgroups: 1. Flavonols, 2. Flavones, 3. Flavanones, 4. Flavan-3-ols, 5. Anthocyanidins

Polyphenols are a group of vegetable chemical substances, characterized by the presence of more than one phenolic group. Their phenolic reactions produce gelatines, alkaloids and other proteins. The polyphenols are responsible for the coloring of some plants. Polyphenols have been shown to be strong antioxidants with potential health benefits.

Phytochemicals are sometimes referred to as phytonutrients and these terms are often used interchangeably. Most broadly defined, they could be said to be any chemical or nutrient derived from a plant source.
Many years of world-leading, high-quality research, documenting a majority of the health related flavonoids (about 4000 known as of yet), had established the anthocyanin family of 539 members as a superior potentially biologically active family.

Anthocyanins possess a vast number of potential biological and medical effects. A very few members of this great family of molecules carry a chemical structure called Orthodihydroxy bindings (B-ring), which makes them extremely potent as remedies in pharmaceutical applications. These few molecules have been the subjects of active clinical medical research since the formation of the Biolink Group in late 1998.

The two most interesting molecules from a medical point of view are Cyanidin 3G and Delphinidin 3G. These molecules have been synthesized by the Biolink Group for medical applications under the names BSC 3G and BSD 3G.