Anthocyanins Properties and Uses

Anthocyanins

• A spectrophotometric assay for total anthocyanins has been reported
• Delphinidin is an example of anthocyanin

Uses of Anthocyanin-rich Plant

• As a natural coloring agent
• Has beneficial cardiovascular effects (can lower blood pressure by 10-15% in patients with moderate essential hypertension)
• Antioxidant and hypocholesterolemic activities have been reported
• Traditionally, all parts of the plant have been employed as an astringent and cooling agent; it has a diuretic action

Cloves

• Botanical origin: Cloves are obtained from the unexpanded flower buds of Syzygium aromaticum, family Myrtaceae
• Synonyms: Caryophyllus aromaticus, Eugenia aromatica, Eugenia caryophyllata, Eugenia caryophyllus

Morphology of Cloves

• The flower buds are reddish brown in color
• The lower stalk-like portion is called hypanthium, while the upper is a crown or cap-shape

Characters of Cloves

• The easily broken, crimson to violet drug consists of the flower portions comprising a pitcher-shaped calyx
• The powder, examined microscopically, exhibits colored parenchymatous cells containing cluster crystals of calcium oxalate, mucilage-containing cells, vascular tissue, epidermal cells, anisocytic stomata, non-glandular trichomes (alembic and cottony), a few glandular trichomes and pollen grains with spiney exines

Constituents of Cloves

• A considerable quantity of free acids including citric, tartaric, and malic acids and the lactone of hydroxycitric acid
• Anthocyanins: such as the glycosides of delphinidin and cyanidin
• The Pharmacopoeia specifies an absorbance of not less than 0.35 for the whole drug and not less than 0.25 for the cut drug when measured at 520 nm in a prescribed aqueous extract

Microscopic Elements of Cloves

• Mucilaginous cells of the sepals and petals
• Small clusters of calcium oxalate crystals
• Oval to slightly triangular pollen grains, 30–40 um in diameter and having three germinal pores

Bioactive Principles of Cloves

• Flavonoid glycosides: quercetin glycosides (rutin, hyperoside), kaempferol glycosides (tiliroside, astragalin)
• Mucilage: present chiefly in the bracts and consists largely of galactomannans
• A small proportion of volatile oil (c. 0.02–0.1%) containing farnesol, farnesyl acetate, geraniol, and eugenol
• Phenolic acids: chlorogenic acid

Effects and Medicinal Uses of Cloves (Traditional)

• Used for the relief of symptoms of common cold and cough
• Used to relief of mild symptoms of mental stress
• Antispasmodic
• Diuretic (increase urine production)