PHYTOCHEMICAL ANALYSIS

-- Phytochemical Analysis is a bimonthly peer-reviewed scientific journal established in 1991 and published by John Wiley & Sons. It covers research on the utilization of analytical methodology in botany.

-- Phytochemicals are chemical compounds that occur naturally in plants (phyto means "plant" in Greek).

INDICATORS/REAGENTS FOR PHYTOCHEMICAL SCREENING

*Glycosides

Glycosides in general, are defined as the condensation products of sugars (including polysaccharides) with a host of different varieties of organic hydroxy (occasionally thiol) compounds (invariably monohydrate in character), in such a manner that the hemiacetal entity of the carbohydrate must essentially take part in the condensation. Glycosides are colorless, crystalline carbon, hydrogen and oxygen-containing (some contain nitrogen and sulfur) water-soluble phytoconstituents, found in the cell sap. 

*Alkaloids

These are the largest group of secondary chemical constituents made largely of ammonia compounds comprising basically of nitrogen bases synthesized from amino acid building blocks with various radicals replacing one or more of the hydrogen atoms in the peptide ring, most containing oxygen. The compounds have basic properties and are alkaline in reaction, turning red litmus paper blue. 

*Phenolics

Phenolics, phenols or polyphenolics (or polyphenol extracts) are chemical components thatoccur ubiquitously as natural colour pigments responsible for the colour of fruits of plants.

They are very important to plants and have multiple functions.

*Flavonoids 

Flavonoids are important group of polyphenols widely distributed among the plant flora.

The compounds are derived from parent compounds known

as flavans. Quercetin, kaempferol and quercitrin are common flavonoids

present in nearly 70% of plants.

*Saponins

Saponins therefore possess ‘soaplike’ behaviour in water, i.e. they produce foam. Saponins are soluble in water and insoluble in ether, and like glycosides on hydrolysis, they give

aglycones. Saponins are extremely poisonous, as they cause heamolysis of blood and are known to cause cattle poisoning. They possess a bitter and acrid taste, besides causing irritation to mucous membranes. 

*Tannins

These are widely distributed in plant flora. They are phenolic compounds of high molecular

weight. Tannins are soluble in water and alcohol and are found in the root, bark, stem and

outer layers of plant tissue. 

*Steroids

Plant steroids also referred to as ‘cardiac glycosides’ are one of the most naturally occurring plant phytoconstituents that have found therapeutic applications as arrow poisons or cardiac drugs. The cardiac glycosides are basically steroids with an inherent ability to afford a very specific and powerful action mainly on the cardiac muscle when administered through injection into man or animal.

*Essential Oils

Essential oils have a tendency evaporate on exposure to air even at ambient conditions and are therefore also referred to as volatile oils or ethereal oils. They mostly contribute to the odoriferous constituents or ‘essences’ of the aromatic plants that are used abundantly in enhancing the aroma of some spices. Essential oils have been associated with different plant parts including leaves, stems, flowers, roots or rhizomes.

*Anthraquinones

These are derivatives of phenolic and glycosidic compounds. They are solely derived from

anthracene giving variable oxidized derivatives such as anthrones and anthranols.

*Terpenes

They are flammable unsaturated hydrocarbons, existing in liquid form commonly

found in essential oils, resins or oleoresins. Terpenoids are classified according to the number of isoprene units involved in the formation of these compounds.

PLANT WITH PHYTOCHEMICALS

Lemon Balm

*Lemon balm is a perennial herb which grows up to 1 meter high. Lemon balm has an angular stem which branches. The leaves grow in opposite pairs and have a typical lemon flavour when bruised. The white to cream coloured small flowers bloom the whole summer and partly during autumn.

Parts used

-Mainly the lemon balm leaves, which are harvested just before blooming. 

Phytochemicals

These are typical phytochemicals found in lemon balm: citronellal, triterpenens, geranial, neral, rosmarinic acid, geraniol, flavonoids, polyphenols.

Benefits of Lemon Balm

The Greek Dioscorides used lemon balm as a medicinal herb and describes it as being useful to treat a disordered state of the nervous system. In the 1600s the Swis physisina Paracelsus called it Hearts Delight as it could revivify a man. Lemon balm is known for its calming and soothing properties. Lemon balm is used to treat sleeping problems, stimulation of the appetite and nervous stomach ailments. Tests with mice have shown that lemon balm has sedative properties. 

*The lemon balm flowers are visited by bees which collect honey. The name Melissa is coming from a Greek word meaning bee. Lemon balm is also used in the kitchen as a spice, because of its lemon flavour. The lemon balm leaves are often used to decorate meals, drinks and desserts.