Biological Applications & Environmental aspects of Organometallic Compounds

It is the descriptive approach on Applicational aspects of Organometallic Compounds with a higly Interactive e-Content with appropriate links, references....

1. Biological Applications & Environmental Aspects of Organometallic Compounds Rudresh M.Sc . Department of Studies & Research in Chemistry Tumkur University, Tumakuru. 1

2. Introduction Organometallic Chemistry an interdisciplinary science , has grown at a phenomenal pace during the last three decades. In earlier , Organometallic chemistry & Biology are consider as a incompatible disciplines . Continued efforts of researchers have led to realisation that this two disciplines are made compatible has resulted in a new field called Bioorganometallic Chemistry . 2

3. 3 Continued..... The pronounced biological effects of Organometallic compounds led to their wide applications viz. Organometallic Compounds As Drugs As Pesticides As Anti -knock agents As Catalytic Agents As Environmental Concern

4. 4 Organometallic Compounds in Medicine Systematic investigation on the chemotherapeutic applications of Organometallic began with the classical work of Paul Ehrlich . Paul Ehrlich (1854—1915) a Nobel prize winning German Physician and Scientist who in the fields of Haematology and Immunology and Antimicrobial chemotherapy. Among his foremost achievements were finding a cure for Syphilis in 1909 and inventing the precursor technique to Gram staining bacteria. In 1908 he honoured with Nobel prize in Physiology or Medicine.

5. 5 Organomercurials (i.e. Organo-Mercury compounds)are the first Organometallic to be used in chemotherapy of Syphilis has been superseded by modern antibiotics, many of these are widely used as antiseptics and diuretics. Organo-Mercuric Compounds in Medicine Thiomersal   Merbromin dibromohydroxymercurifluorescein Phenylmercuric acetate  

6. 6 Organo-Silicon compounds in Medicine The Applications of organo silicon derivatives have been increasing at fast rate. From the point of their medicinal applications of organosilicon derivatives can be devided into three major groups Organosilicon compounds having no carbon analogues or having biologically inert analogues eg :-- Silatranes Silatranes are have extensive interest due to their Biological activities as well as medicinal uses like healing of wounds , Stimulate hair growth (pilotropic activity),pharmacological properties viz, antitumor, anticancer , anti-bacterial , anti-inflammatory , fungicidal activity, stimulating effects in animal production and seed germination effects in plants.

7. 7 Continued..... (ii) Silylated derivatives of Bioactive organic compounds :--the presence of SiMe3 group , for example Testosterone renders in non polar solvents , the hydrolysability of O-Si bonds which makes it behave as an effective prodrug. (iii) Sila-pharmaca :--the replacement of carbon atom(s) in organic drugs by silicon has a aroused considerable interest OSiMe3

8. 8 Organo-Arsenic comounds in Medicine The Significant investigations of Paul Ehrlich were expounded the Chemotherapeutic  aspects of Organo-Arsenic compounds. Majority of Arsenic(v) compounds are anti parasitic agents . Are used in the treatment of Trypanosomiasis were derivatives of Atoxyl Atoxyl (Mono-sodium p-aminophenylarsonate)

9. 9 In 1907 Ehrlich was prepared a new organo arsenic derivative with different substituents on the aromatic ring as well as on arsenic atom and was named as “ Salvarsan ” Continued... Salvarsan was widely used as pharmaceutical tratment of infections for the treatment of infections by Spirochetes or trypanosomes, especially Syphilis . Salvarsan

10. 10 Organometallic compounds as Anti-Tumour Drugs E.Krause had been noticed the activity of organo-Lead compounds such as Pr 3 PbF , (C 6 H 11 ) 6 Pb 2 , and Ph 4 Pb are shows Anti-tumour activity towards mouse cancers. The Discovery of Significant anti-cancer activity of Cisplatin led to an extensive investigation on the biological properties of compounds . Cis- dichlorodiammineplatinum(II) Similar compounds of Cisplatin

11. 11 Organometallic Compounds in Agriculture and Horticulture A wide variety of Organometallic compounds are finding increasing uses as pesticides. Triphenyltin hydroxide and acetate both are preferably used in numerous formulations for the control of a variety of fungal growths especially Potato blight . Tricyclohexyltin hydroxide is very effective Acaricide for controlling fruit tree red spider mite on apples pears.

12. 12 Continued...... Organo tin compounds are also used as Anti-fouling agents, i.e. Protecting various surface like that of wood from the growth of mould . Ethephon(2-chloroethylphosphonic acid) used as a plant growth regulators and as fruit ripening agents ClCH 2 CH 2 CH 3 PO 3 H 2 + H 2 O C 2 H 4 + HCl + H 3 PO 4 2-chloroethyl Ethene phosphonic acid Organometallic Compounds in Agriculture and Horticulture

13. 13 Organometallic Compounds in Agriculture and Horticulture A Boron analogue ClCH 2 CH 2 B(OR) 2 has also been proposed as a plant growth regulator. Silicone oils have been applied to the surface of the plant leaves to the control the rate of transpiration thus aiding Agriculture in arid zones. Some of the Organometallics are also having applications of Herbicidal control activity. For eg., Phosphorous derivatives like N-Phosphomethylglycine

14. 14 Organometallic Compounds in Agriculture and Horticulture Methyl arsenic compounds like Monosodium salt of Methyl arsenic acid is widely used as Herbicide (under the name of Doconate) Tri-n butyltin flouride was show to be selective in controlling weeds without damage to the Corn (or) Rice

15. 15 Non-Available Inorganic Substances Available Inorganic Substances Inorganic Coordination compounds, Organometallic compounds, Organometallodical compounds Inorganic Compound-Biota Association Environmental Aspects of Organometallic Compounds Cycle of Inorganic and Organometallic Materials in the Environment Mobilization Chemical reactions Incorporation Removal

16. 16 For being able to perform their life function, such as Maintenance , self Growth & reproduction . biota appear to depend essentially on certain elements and preferably avoid some other elements in the view of their toxicity. They are 27 essential and 11 toxic elements With 4 Common members between the two groups form a large variety of compounds. Majority of the elements in the periodic table are metallic in character. These are bounded up in the nature in the form a Insoluble Inorganic compounds in Rocks and Sediments . These have to be mobilized by weathering Process involving abiotic chemical reactions and biologically mediated interactions.

17. 17 This type of Interaction, Generally Converts insoluble substances into soluble ones, which are then converted into coordination , Organometallic and organometalloidal compounds. These undergo interactions with biota either on the Surface of cells (or) through the membranes i.e in to the Cellular portion The ensuing biochemical reactions produce new chemical Species which may be released into the environment and thus become available to other biota. Alternatively these Organometallic moieties associated with cellular material may be deposited upon the death of the organism in Sediments and thus rejoin the pool of non-available Substances awaiting mobilization. Continued….

18. 18 References ‘ Organometallic Chemistry—A Unified Approach ’—R C Mehrotra, A Singh; second edition, New Age International Publishers ,2015. ‘ Environmental Aspects of Organometallic Chemistry ‘ by Peter Craig, Wiley Publications. An Article Entitled ‘ Concerning Organometallic compounds in Environment : Occurane, Fate and Impact ’ by Kovacs Melinda Haydee and Kovacs Emoke Dalma; Chemistry and Chemical Engineering Faculty, Babes-Bolyai University, Cluj-Napoca, Romania.