Photophysical properties of Sulphur heterocyclic compound.pptx

## Project Description: Photophysical Properties of Biologically Active Sulfur-Containing Heterocyclic Compounds

This project investigates the photophysical properties of a class of organic molecules with significant potential in medicinal chemistry: biologically active sulfur-containing heterocyclic compounds.

Heterocyclic compounds are molecules with ring structures containing at least one atom other than carbon. When sulfur is incorporated into these rings, it creates unique properties that can be exploited in drug development. These sulfur-containing heterocyclic compounds often exhibit a wide range of biological activities, including anticancer, antidiabetic, and antimicrobial properties.

This project focuses on the **photophysical properties** of these molecules. Photophysical properties describe how these molecules interact with light. Understanding these properties is crucial for several reasons:

* **Drug Design:** Certain photophysical properties can influence a drug's ability to be absorbed by the body and reach its target site.
* **Activation:** Light can sometimes be used to activate these drugs, making them more effective or reducing side effects.
* **Diagnostics:** Some photophysical properties can be utilized in developing imaging techniques to diagnose diseases.

By studying the photophysical properties of these biologically active sulfur-containing heterocyclic compounds, this project aims to:

* Gain a deeper understanding of the relationship between molecular structure and photophysical behavior in this class of compounds.
* Identify promising candidates for further drug development based on their photophysical characteristics.
* Explore potential applications of these compounds in photoactivated therapies or diagnostic tools.

This project's findings can contribute significantly to the development of new and improved therapeutic agents with enhanced efficacy and targeted action.

1. A PROJECT REPORT ON Photophysical properties of Biologically active Sulphur containing heterocyclic compounds Submitted partial fulfilment of Master of Science in Chemistry Session : 2023-24 UNDER THE SUPERVISION OF Dr. Santosh Kumar Srivastav (Associate Professor ) SUBMITTED BY Himanshu Singh (M.Sc. IV Sem) M2275074 DE P AR T M E N T OF C HE M I S T R Y C . M . P . D eg r e e Co l l e g e M . G. M a r g , P r a y ag r a j -2 1 1 02

2. ABSTRACT Sulfur-containing heterocyclic compounds have garnered significant attention in the field of medicinal chemistry due to their diverse pharmacological activities and structural versatility. This review provides a comprehensive overview of the role of sulfur-containing heterocycles in medicinal applications, focusing on their synthesis, structural diversity, and therapeutic potential across various disease areas. We discuss the synthetic strategies employed for the preparation of sulfur-containing heterocyclic compounds, including classical methods such as Hantzsch thiazole synthesis, Gewald reaction, and modern approaches involving transition metal- catalyzed reactions and multicomponent reactions. Emphasis is placed on the structural features of sulfur-containing heterocycles, including aromaticity, ring strain, and functional group compatibility, and their influence on pharmacological properties.

3. Contd. Furthermore, we highlight the diverse biological activities exhibited by sulfur-containing heterocyclic compounds, including antimicrobial, antiviral, anti-inflammatory, antioxidant, and anticancer effects. We also discuss their mechanisms of action and potential applications as lead compounds or pharmacophores in drug discovery and development.

4. INTRODUCTION Heterocyclic compounds are organic compounds containing atoms of at least two different elements within a ring structure. When sulfur atoms are incorporated into these ring structures, they form sulphur -containing heterocyclic compounds. Sulphur -containing heterocyclic compounds play a significant role in medicinal chemistry due to their diverse pharmacological properties and structural versatility. These compounds contain one or more sulfur atoms within a ring structure, which can impart unique chemical and biological properties. Examples include thiazoles, thiophenes, thiazolidines, and thiazolidinones , which have shown promising activities as antimicrobials, antivirals, anti-inflammatory agents, and anticancer drugs.

5. Contd. Overall, sulphur -containing heterocyclic compounds represent an important class of Molecules in medicinal chemistry, offering diverse chemical structures and promising pharmacological activities for the discovery and development of new therapeutic agents .

6. Sulphur Containing Heterocyclic Componds Thiazoles and its derivatives Thiazole is a sulphur and nitrogen containing five membered heterocyclic compound with molecular formula C 3 H 3 NS. It is also known as 1,3-thiazole due to the presence of sulphur and nitrogen at 1st and 3rd position. Thiazole , at nitrogen undergoes alkylation to form thiazolium cation , which are precursors for the synthesis of many organic compounds. They undergo rearrangement through cleavage of CeS bond to form 1,4-thiazine derivatives. Thiazole is a versatile nucleus found in many bioactive molecules including natural compounds and possesses diverse pharmacological activities like anti-cancer, anti-microbial, anti-inflammatory , anti- convulsant , anti-viral, anti-tubercular etc .

7. Contd. Thiazole represent an important class among S heterocycles which provide a large number of marketed drugs. Thiazole has ability to adsorb metal ion due to its involvement in coordination chemistry and thus they are utilized with graphene , fluorine, SnO 2 nanoparticles to develop nanocomposites , which were helpful in detection of heavy metal ions. Chemically thiazole is a weak base having pKa value of 2.52 and exhibits aromatic behaviour .

8. Thiophene and its derivatives Thiophene is a five-membered aromatic ring molecule containing sulphur , found in nature and used in drugs , materials for electronics like LEDs, and polymers. It resembles benzene in its chemical behaviour due to its electron structure, but is generally more reactive. Chlorine substitution in thiophene further enhances its reactivity compared to benzene . Thiophene is a colourless liquid with a boiling point similar to benzene. Both also form mixtures with ethanol that cannot be easily separated. Thiophene and its derivatives, like benzothiophene and dibenzothiophene , can form bonds with metals through their sulphur atom, especially when modified with electron-donating groups. These molecules exhibit a wide range of medicinal properties, including anti-microbial, anti-cancer, and anti-inflammatory effects.

9. Thiopyran-based medicinal agents reported for different molecular targets

10. Thiopyran and its derivatives Thiopyran is a class of six membered heterocyclic compounds containing sulphur as heteroatom. On the basis of position of double bond, thiopyran exits in two isomeric forms i.e. 2H-thiopyran and 4H-thiopyran. Due to varied substitutions on the thiopyran nucleus, this class of S heterocycles possess a vast number of pharmacological activities such as anti-bacterial, anti-cancer, anti-hyperplasia , anti-inflammatory , anti-viral, anti-bacterial and anti-glaucoma . Further, it has been noted that oxide forms of thiopyran (S-oxides and S,S-dioxides) lead to enhancement in the biological activity of the core thiopyran .

11. Contd. Thiopyrans have been utilized in both synthetic and medicinal chemistry, and also found in many natural products such as thromoboxanes , serricornin , tetrahydrodicranenone and cyclopentanoids . Thus, thiopyran based molecules provide flexible intermediates in the organic synthesis for the development of manybioactive molecule for diverse targets. Thiopyrans are both proton and hydride donors and in oxidative conditions like (Cl 2 , I 2 , PCl 5 , Ph 3 Cþ, ClO 4 ), they produce thiopyrilium salts. Molecular mechanic computations and vibrational spectrum studies confirmed that 5,6-dihydro-2H-thiopyran molecule exhibits half-chair conformation .

12. Thiazolidine-based medicinal agents reported for different molecular targets

13. Thiazolidine and its derivatives Thiazolidine , a sulphur analogue of oxazolidine , consists of five membered ring containing S and N at 1 and 3 positions, respectively. Thiazolidine-2,4-diones, considered as important therapeutically-active molecules among this class and hold large number of biological activities such as anti-tubercular, antimicrobial , anti-diabetic, anti-inflammatory, anti-oxidant, anticonvulsant, antifungal and anticancer etc. A molecule containing thiazolidine moiety was reported to behave as good ligand for palladium and thus palladium- thiazolidine based compound was identified as catalyst and showed noteworthy activity in Heck and Suzukie Miyaura reactions at conc. of 0.1 mol %. Thiazolidine ligands, derived from the D- Penicillamine and L-cysteine, provide a fascinating approach for the synthesis of chiral secondary alcohols with R and S configuration.

14. CONCLUSION Heterocyclic compounds have numerous applications in pharmaceutical chemistry and play a key role in biochemical functions. A lot of heterocycles are employed in medicine as medications to treat a variety of ailments and injuries. These medications that contain heterocyclic core skeletons like as antifungal, anti-inflammatory, antibacterial, antiviral, anti-oxidants, anticonvulsants, anthelmintic, antipyretics, anti-allergic, anti-histamine, herbicidal, anticancer, antihypertensive and anti-leprosy agents . The behavior or properties of these compounds, discuss their potential applications or significance in various fields such as pharmaceuticals or materials science, and suggest directions for future research.

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