Betalain
Betalains are a class of red and yellow indole-derived pigments found in plants of the Caryophyllales, where they replace anthocyanin pigments. Betalains also occur in some higher order fungi. They are most often noticeable in the petals of flowers, but may color the fruits, leaves, stems, and roots of plants that contain them. They include pigments such as those found in beets.
Description
The name "betalain" comes from the Latin name of the common beet (Beta vulgaris), from which betalains were first extracted. The deep red color of beets, bougainvillea, amaranth, and many cactuses results from the presence of betalain pigments. The particular shades of red to purple are distinctive and unlike that of anthocyanin pigments found in most plants.
There are two categories of betalains: * Betacyanins include the reddish to violet betalain pigments. Among the betacyanins present in plants include betanin, isobetanin, probetanin, and neobetanin. * Betaxanthins are those betalain pigments which appear yellow to orange. Among the betaxanthins present in plants include vulgaxanthin, miraxanthin, portulaxanthin, and indicaxanthin.
Plant physiologists are uncertain of the function that betalains serve in those plants which possess them, but there is some preliminary evidence that they may have fungicidal properties. Furthermore, betalains have been found in fluorescent flowers.
Chemistry

Chemical structure of betanin.
It was once thought that betalains were related to anthocyanins, the reddish pigments found in most plants. Both betalains and anthocyanins are water soluble pigments found in the vacuoles of plant cells. However, betalains are structurally and chemically unlike anthocyanins and the two have never been found in the same plant together. For example, betalains contain nitrogen whereas anthocyanins do not.
It is now known that betalains are aromatic indole derivatives synthesized from tyrosine. They are not related chemically to the anthocyanins and are not even flavonoids. Each betalain is a glycoside, and consists of a sugar and a colored portion. Their synthesis is promoted by light.
The most heavily studied betalain is betanin, also called beetroot red after the fact that it may be extracted from red beet roots. Betanin is a glucoside, and hydrolyzes into the sugar glucose and betanidin. It is used as a food coloring agent, and the color is sensitive to pH. Other betalains known to occur in beets are isobetanin, probetanin, and neobetanin. The color and antioxidant capacity of betanin and indicaxanthin (betaxanthin derived of L-proline) are affected by dielectric microwave heating. Addition of TFE (2,2,2-trifluoroethanol) is reported to improve the hydrolytic stability of some betalains in aqueous solution. Furthermore, a betanin-europium(III) complex has been used to detect calcium dipicolinate in bacterial spores, including Bacillus anthracis and B. cereus.
Other important betacyanins are amaranthine and isoamaranthine, isolated from species of Amaranthus.
Taxonomic significance
Betalain pigments occur only in the Caryophyllales and some Basidiomycota (mushrooms). Where they occur in plants, they sometimes coexist with anthoxanthins (yellow to orange flavonoids), but never occur in plant species with anthocyanins.
Among the flowering plant order Caryophyllales, most members produce betalains and lack anthocyanins. Of all the families in the Caryophyllales, only the Caryophyllaceae (carnation family) and Molluginaceae produce anthocyanins instead of betalains. The limited distribution of betalains among plants is a synapomorphy for the Caryophyllales, though their production has been lost in two families.
Economic uses
Betanin is commercially used as a natural food dye. It can cause beeturia (red urine) and red feces in some people who are unable to break it down. The interest of the food industry in betalains has grown since they were identified by in vitro methods as antioxidants. which may protect against oxidation of low-density lipoproteins.
The 'Hopi Red Dye' amaranth is rich in betacyanins and produces red flowers which the Hopi Amerindians used as the source of a deep red dye.

Semisynthetic derivatives
Betanin extracted from the red beet was used as starting material for the semisynthesis of an artificial betalainic coumarin, which was applied as a fluorescent probe for the live-cell imaging of Plasmodium-infected erythrocytes.

gen info
Native to South America, The first species recorded in the Philippines was Bougainvillea spectabilis. The other species, B. glabra and B. peruviana were introduced much later. The cultivated hybrids have produced a considerable variety in size, color, form and numbers of showy bracts. The genus is derives its name from Antoiine de Bougainville, first Frenchman to cross the Pacific.
Botany
Bogambilya is a woody climber that can grow to a height of more than 10 meters, with large thorny stems and long drooping branches. The leaves are dark green, petioled, alternate, ovate, with entire margins, 6 to 10 centimeters long, broadest near the base. Thorns are the axils assist the plant in climbing. Flowers are in groups of threes, forming clusters at the terminal portion of the branches, each group subtended by three, broad, purplish, oblong-ovate and acuminate bracts, about 3 to 5 centimeters long. Flowers are small, each inserted on a bract, tubular, inflated midway through its length, of varying colors. Numerous cultivars are cultivated in the Philippines, with single or multiple bracts, in varied colors of red, purple, pink, yellow or white.
Distribution
- Native to South America.
- One of the most popular ornamental plants in the Philippines.
- Cultivars with variegated leaves were recently introduced.
Constituents
- Reported constituents on B. glabra are pinitol, betacyanine, flavonoids, tannins and alkaloids.
- Study showed the presence of plastid-bound oxalic acid oxidase in the leaves.
- Studies have isolated flavonoids, phenolic compounds, ribosome inactivating proteins, amylase inhibitors, oxidase and pinitol.
- Hydoalcoholic and petroleum ether extracts yielded alkaloids, glycosides, carbohydrates, anthraquinone, flavanoids, terpenoids, saponins, steroids, proteins, fixed oils, fats, and tannins. (28)
Properties
- Leaves considered to have antiinflammatory activity.
- Considered anti-diabetic, antibacterial.
- Pinitol considered antidiabetic.
Parts utilized
Leaves, stems, flowers
Uses
Folkloric
- Not known in the Philippines for any medicinal use.
- Traditional practitioners in Mandsaur use the leaves for a variety of disorders, for diarrhea, and to reduce stomach acidity.
- Used for cough and sore throat.
- For blood vessels and leucorrhea: a decoction of dried flowers, 10 g in 4 glasses of water.
- For hepatitis, a decoction of dried stems, 10 g in 4 glasses of water.
- In Panama, an infusion of the flowers of B. glabra used as treatment for low blood pressure.
- Nupe people of Niger use a crude extract of leaves for diabetes.