Extraction, isolation and structure elucidation of flavonoids: Quercetin

Extraction, isolation and structure elucidation of- Flavonoids Quercetin
Introduction
FLAVONOIDS & THEIR EXAMPLES
Quercetin
general isolation method
Extraction and isolation
Extraction from neem leaves
Isolation of Quercetin Methanolic Extract of Azadirachta indica leaves
Structure elucidation of Quercetin
Health benefits
Side Effects of Quercetin

1. Extraction, isolation and structure elucidation of- Flavonoids : Quercetin Prepared By: MOHAMMAD KHALID (Assistant Professor ) Krishna Pharmacy College, Bijnor (UP)

2. contents Introduction FLAVONOIDS & THEIR EXAMPLES Quercetin general isolation method Extraction and isolation Extraction from neem leaves Isolation of Quercetin Methanolic Extract of Azadirachta indica leaves Structure elucidation of Quercetin Health benefits Side Effects of Quercetin 15 May 2020 Krishna Pharmacy college, Bijnor 2

3. introduction  Flavonoids are a group of polyphenolic compounds, diverse in chemical structure and characteristics, found ubiquitously in plants. Flavonoids (or bioflavonoids) (from the Latin word flavus meaning yellow, their color in nature) are a class of plant secondary metabolites . Flavonoids are phenolic compounds widely present in plant and Foods of plant origin. Flavonol Glycosides: The two well known glycosides belonging to this class are namely: Rutin and Quercetin , whereas the less important ones are— galangin , gossypin , hibiscitrin , kaempferin and avecularin . 15 May 2020 Krishna Pharmacy college, Bijnor 3

4. FLAVONOIDS & THEIR EXAMPLES Flavone :- Luteolin , Apigenin , Tangeritin Flavonol :- Flavanone :- Flavanonol - Taxifolin , Dihydrokaempferol Hesperetin , Naringenin , Eriodictyol , Homoeriodictyol Quercetin , Kaempferol , Myricetin , Fisetin , Isorhamnetin , Pachypodol , Rhamnazin 15 May 2020 Krishna Pharmacy college, Bijnor 4

5. Quercetin Quercetin is a bioflavonoid (or flavonoid), which is a type pigment found in almost all herbs, fruits, and vegetables. Quercetin is the aglycone form of other flavonoid glycosides, such as rutin and quercitrin , found in citrus fruit, buckwheat and onions. Quercetin forms the glycosides, quercitrin and rutin , together with rhamnose and rutinose , respectively. 15 May 2020 Krishna Pharmacy college, Bijnor 5

6. Continue…. Biological Sources: Quercetin occurs in the bark of Quercus tinctoria and some other species of Quercus . It is also obtained from Alsculus hippocastarum L., horse chest nut, belonging to family Hippocastanaceae . It is also found in Thuja occidentalis L., Morus alba L., Humulus lupulus L., Fraxinus excelsior L., Vitis vinifera and the other plants . Description: The crystals are yellow in colour when obtained from ethanol or methanol. It is practically insoluble in cold water and ether. Flavine yellow shade obtained from the quercitron bark by extraction under high pressure steam which is used exclusively in dyeing fabrics 15 May 2020 Krishna Pharmacy college, Bijnor 6

7. Continue…. The structure of Q uercetin : IUPAC name: 2-(3,4-dihydroxyphenyl)-3,5,7-trihydroxy-4H-chromen-4-one Quercitin on hydrolysis in an acidic medium gives rise to rhamnose and quercetin (i.e., 5, 7, 3’, 4’-tetrahyroxy flavonol ). 15 May 2020 Krishna Pharmacy college, Bijnor 7

8. Chemical Tests: It exhibits a brown fluorescence under the UV-light. It gives a distinct yellow precipitate initially with a solution of basic lead acetate, but it gets dissolved on further addition of the reagent in excess. It reduces Tollen’s reagent to give a silver mirror. It gives Shinoda test to form yellow or crimson red colour when it mix with magnesium ribbon and conc. hydrochloric acid . 15 May 2020 Krishna Pharmacy college, Bijnor 8

9. general isolation method 15 May 2020 Krishna Pharmacy college, Bijnor 9

10. Extraction and isolation Finely ground dried plant material Extract is conc. To dryness at 40 C temp Aqueous extract The combined organic layer of each portion is evaporated to dryness in vaccum at 40 C. Using rotatary evaporator The extracted flavonoid can be isolated by Column Chromatography Extract with methanol Removal of methanol Add Hexane, DCM, 1-Butanol 15 May 2020 Krishna Pharmacy college, Bijnor 10

11. Extraction from neem leaves Neem Leaves Air-dried Powder (40-60 mesh) (300 gm) Petroleum ether 60-80 C Benzene Acetone Methanol Hot Water 15 May 2020 Krishna Pharmacy college, Bijnor 11

12. Isolation of Quercetin Methanolic Extract of Azadirachta indica leaves Methanolic extract of Neem leaves was subjected to fractionation by Column Chromatography. The Column 72 cm in length and 5 cm in diameter was used. Slurry of silica gel (400gm; 60-120 mesh size) prepared in petroleum ether (600-800C) was added to the column. Methanolic extract (3 gm) was loaded on the column and the column was than eluted with various solvents i.e. Petroleum ether (600-800C), Benzene, CHCl3, CHCl3: Acetone (1:1), Acetone, Acetone: Ethanol (1:1), Ethanol, Methanol and distilled Water in the order of their increasing polarity. 15 May 2020 Krishna Pharmacy college, Bijnor 12

13. Continue…. The acetone fraction resulted in the precipitation of white crystalline compound. The methanolic fraction, kept in refrigerator resulted in the precipitation of yellow powder which was further purified. Qualitative analysis of the isolated compound was done. The isolated compound was subjected to TLC to ascertain its nature and its m.p . was determined. The isolated compound was subjected to U.V. (U.V.-Visible Spectrophotometer, Elico -make), I.R, Mass, 1H and13C NMR Spectroscopy (C.D.R.I., Lucknow ) and the structure of isolated compound was determined . 15 May 2020 Krishna Pharmacy college, Bijnor 13

14. Azadirachta indica Leaves Methanolic Extract (3gm) Column Chramatography Eluted with Petroleum ether (60-80 C), (1:1), Acetone, Acetone: Ethanol (1:1), Benzene, CHCl 3 , CHCl 3 : Acetone Ethanol, Methanol, Water Methanolic Yellow powder (Flavonoid in nature; m.p. 316 C) Acetone White Crystalline Compound (Phenolic in nature; m.p. 61-64 C) 15 May 2020 Krishna Pharmacy college, Bijnor 14

15. Structure elucidation of Quercetin Molecular formula: C 15 H 10 O 7 Molecular weight: 302.236 g/ mol Molecular structure: It contain 5 hydroxyl group. 15 May 2020 Krishna Pharmacy college, Bijnor 15

16. Continue…. Hydrolysis of Quercetin , gives Phloroglucinol + protocatechuic acid. Hydrolysis 15 May 2020 Krishna Pharmacy college, Bijnor 16

17. Continue…. The structure was further supported by the fact that on boiling with alcoholic potash pentamethyl quercetin gives 6-OH, ω,2,4-trimethyl acetophenone and veratric acid. Veratric acid 15 May 2020 Krishna Pharmacy college, Bijnor 17

18. Continue…. The structure was further supported by its synthesis from Kostaneck‘s Synthesis using ,2,4 dimethoxy,6-hydroxy acetophenone and 3,4-dimethoxy benzaldehyde as starting materials. Q uercetin 15 May 2020 Krishna Pharmacy college, Bijnor 18

19. Health benefits Cancer Diarrhea Allergies, Asthma, Hay Fever Heart Disease Hypertension Interstitial Cystitis Prostatitis Diabetes Rheumatoid Arthritis (RA) Athletic Endurance 15 May 2020 Krishna Pharmacy college, Bijnor 19

20. Side Effects of Quercetin Quercetin Cause Cancer On the other hand, a handful of studies from reputable sources claim high doses of quercetin cause cancer. Researchers found that the high concentrations of the element would actually bind with and damage chromosomes and DNA structures resulting in a cancerous mutation. High concentrations of the flavonoid also disrupted the activity of enzymes and particularly interfered with estrogen and thyroid hormones. These studies claim that there is a documented risk to young children consuming high doses of it and getting sick with a rare form of leukemia . Birth Defects Scientists theorize that birth defects could occur in the unborn children of women who consumed high doses of quercetin at the time of conception and throughout pregnancy. 15 May 2020 Krishna Pharmacy college, Bijnor 20

21. references Organic Chemistry of Natural Products Vol I and II by O.P Agarwal . Kokate.C.K Purohit A.P. And Gokhale.S.B , Pharmacognosy , 40th edition. Trease G.E and Evans,W.C . Pharmacognosy , 15th edition . http:// www.authorstream.com/Presentation/anshiilm-783766-isolation-identification-of-quercetin https ://www.slideshare.net/roshniannbaby/flavanoids https://en.wikipedia.org/wiki/Quercetin 15 May 2020 Krishna Pharmacy college, Bijnor 21

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