PPT-Phenols and Tannins Pharmacognosy I

Mosul University College of Pharmacy LA Dilbreen Barzanji Phenols and phenolic glycosides Phenols probably constitute the largest group of plant secondary metabolites Widespread in nature and to be found in most classes of natural compounds having aromatic moieties they range from simple structures with one aromatic ring to highly complex polymeric substances such as tannins and . Faculty of Pharmacy GRDPGIMT Rajpur Road Dehradun Uttarakhand India Email kupraveensifycom 2 Faculty of Pharmacy Kumaun University Bhimtal Nainital Uttarakhand India Tannins are obtained upon the decomposition of vegetation They will generally be and how to identify them. 2. Classification. Primary. : carbon with –OH is bonded to one other carbon. Secondary. : carbon with –OH is bonded to two other carbons. Tertiary. : carbon with –OH is bonded to three other carbons. Alcohol . – alkyl chain attached to an –OH. . R-OH. Phenol . - aromatic attached to an –OH. Nomenclature. 1. Name the longest chain of carbons which includes the carbon with the hydroxyl group.. Different Atomic Charge Schemes . for Predicting . p. Ka. . Variations . in . Substituted Anilines and . Phenols. KEVIN C. GROSS,1 PAUL G. . SEYBOLD,1 CHRISTOPHERM. . . HADAD2. 1Department . of Chemistry, Wright State University, Dayton, Ohio . Thiols. , . and ethers. Nomencalture. of alcohols. Use the end . ol. Examples. . Hydrogen bonding in alcohols and phenols. Alcohols and phenols form hydrogen bonds, and hence they have relatively high boiling points. This also makes the lower alcohols miscible with water. As the R group becomes larger, the solubility of alcohols in water decreases dramatically.. Stephanie Diamond, Emilee Landers, Andrea Sierra-. Cadavid. What are tannins?. Large molecular weight phenolic compounds. Condensed and . Hydrolyzable. c. hemistry.about.com. Chemistry of Tannins. Hydrolyzable. PHENOLS. Alcohols and Phenols. Alcohols contain an OH group connected to a . a. saturated C (sp. 3. ). They are important solvents and synthesis intermediates. Phenols contain an OH group connected to a carbon in a benzene ring. . Complex organic, non-nitrogenous plant products.. Derivatives of polyhydroxy benzoic acid (polyphenols).. Ability to precipitate proteins. Having high molecular weight (500 to > 20000).. Historically, tannin containing drugs are related to their tanning property i.e. their ability to transform fresh hides into imputrescible leather.. 45. -Alcohols . have the general formula R. -. OH and are characterized by the presence of a . hydroxyl group, . -. OH. . -Phenols . have a hydroxyl group attached directly to an aromatic ring. . -Thiols . Afroz. . Lecturer. Daffodil International University. Pharmacognosy. is the study of medicinal drugs derived from plants or other natural sources. . . Or . Role of . Pharmacognosy. in . allopathy. and traditional systems of medicine namely, . Ayurveda. , . Unani. , . Siddha. , Homeopathy and Chinese systems of medicine.. COMPILED BY . DR NISHA SHARMA. Alcohols contain an OH group connected to a . a. saturated C (sp. 3. ). They are important solvents and synthesis intermediates. Phenols contain an OH group connected to a carbon in a benzene ring. Methanol, CH. Lecturer . Luma. . Amer. Department of . Pharmaceutical Chemistry. /Collage of pharmacy . 2 . ed. . stage.. Identification of Phenols. phenols are stronger acids than water and. will dissolve in 5% . Dr. Geeta Singh. Assistant Professor. Department of Chemistry. D.D.U. Gorakhpur University, Gorakhpur. 1. Fungicides. . Fungicides . are those compounds which are used to protect plants effected from fungi. .