Ø In the organic chemistry the classwhich contains a hydroxyl group that is directly bound to an aromatic hydrocarbongroup.Ø Phenolic compound is a substancewhich contain benzoic molecules with one or many hydroxylgroup.Ø Polyphenols contain one or many hydroxyl groupØ In plants they are produce assecondary natural metabolites as biogenetically phenylpropanoids that’s way inplants physiological role fulfill by them. Plant phenolic compoundsØ In plants phenolic compounds areabundantly present.
Ø In oaks and mangroves they are particularly present abundantly.Ø Thousands of phenolic compounds are knownnow.Ø 40% is the total of organic carbonpresent in the biosphere.
Ø In vascular plants they are presentin cell wall plant defense and flower colour etc.OccurrenceØ Phenolic compounds are widely presentas secondary metabolites.Ø In vascular plantsØ In bryophytes Ø In fungi bacteria and algae Vitamin –EØ Nuts fish oil and vegetables containvitamin –E which is a fat soluble vitamin.Ø They have not a single molecule but afamily if a molecule has four called as tocopherols and rest of these four iscalled tocoterienols. Vitamin-CØ Vitamin-c molecule consists of onelactone ring with two hydroxyl group on it and have two chiral carbon.
Ø Due to presence of several hydroxylgroup present in the exteracellular areas of the body so it is called watersoluble antioxidant.Ø Due to its polar nature and watersolubility it can be converted from the body more readily .to neutralize theaqueous free radical and reactive oxygen so it reacts with them. TanninsØ Tannin word is drived from the Frenchits meaning is tanning substance using for range of natural polyphenols.Ø In 1962 swain and bate-smithformulated the acceptable definition for vegetable tannins.Ø Phenolic compounds have unique group(plant tannin) of high molecular weight they have a power to complex strongly with carbohydrates andprotein. Antioxidant properties of phenolic compoundØ Phenolic compounds have antioxidantaction it is due to their high tendency to chelate metal with heavy metals likecopper and iron.Ø Free radicals are main components inplant system as well as in human body it can be easily damage cell due topresence of free electrons.
Ø Cell damage cause by free radicalscan be repair by compounds which are released by proteins and green vegetables. Plant microorganismcommunication Ø For stimulants to spore germinationflavonoid compound play role as signal molecule phytoalexins detoxifying agent.Ø Flavonoid may also play protectingrole depends on the role of microorganism in plant.Ø anthocyanin’s are pigments whichrelated to the color of leaves fruits and flowers.
Ø It is used for flavoring as chemical .the flavor may be act asrepellent to pest and pollinators. Phenolic compounds in plants defenseØ RipplingØ InhibitorØ Natural animal toxicantsØ E.g.
simple phenolic, complextannins and resins in the plant surfaceand deter bird.Plant whispers (communication)A best example is the lima bean .whencaterpillar feeds on the leaf surface many things happen. A cloud of fragrancesis released due to physical damage. Chemicals are produced by all leaves fordefense because fragrance warned whole plant of the impending danger. Thefragrance mixture acts as express highway of information.
Message is understandby neighbouring plants and they also start defensive measures.