ANTINEOPLASTIC AGENTS (Part-II) By Mrs. Rashmi Kumari Assistant Professor PG Department of Chemistry Magadh University Bodh-Gaya Stream: M.Sc. Organic Chemistry (Sem.-IV) Classes of Antineoplastic Agents • Alkylating Agents • Antimetabolites • Natural Products • Hormonal Agents • Anti Tumor Antibiotics • Miscellaneous Agents • Works by affecting DNA synthesis and function. Alkylating Agents • Alkylating agents • Nitrogen Mustard: • Uracil Mustard, • Melphalan • Ethylamine Derivatives • Nitrosourea • Alkyl Sulphonates • Platinum Complexes Mode of Action of Alkylating Agents Nitrogen Mustards • They substitute alkyl group for H forming DNA adduct. • Functional group can form inter/intra stand crosslink in DNA Mode of Action: Nitrogen Mustards Structure Activity Relationship • R can be either aliphatic or aromatic. • Case-1. R=Aliphatic Substituent • R an aliphatic substituent will push electrons to the amine. This electronic enrichment enhances the nucleophilic character of the lone pair of electrons and increases the speed of SN2. Structure Activity Relationship • Case-2. R=Aromatic Substituent • An aromatic substituent will stabilize the lone pair of electrons through resonance.This resonance slows the rate of intermolecular nucleophilic attack azridinium ion formation and DNA alkylation. The highest stability of aromatic mustard not only permits oral administration but also attenuate the severity of side effects. Uracil Mustard • Uracil Mustard (Uramustine) • Used in Lymphatic Malignancies • Selectively inhibits the synthesis of DNA promotes cell death of cancer cells. Structure of Uracil Mustard Synthetic route: SOCl2 I II Melphalan Melphalan I II III V VI IV Antimetabolites • Antimetabolites are structurally related to normal compounds that exist within the cell.t • Antimetabolites generally interfere with the availability of normal purine pyrimidine nucleotide precursors either by inhibiting their synthesis or by competing with them in DNA or RNA synthesis. • They are cell-cycle specific. • Their maximal cytotoxic effects are in S-phase. Antimetabolites Purine Antagonist : 6-Mercaptopurine • 6-Mercaptopurine is the thiol analog of Hypoxanthin. • 6-Mercaptopurine and 6-Thioguanine were the first purine analogs to prove beneficial for treating neoplastic disease. • 6-Mercaptopurine is specifically used for: • Acute lymphocytic leukemia (ALL) • Chronic myeloid leukemia (CML) • Crohn’s disease and • Ulcerative colitis. 6-Mercaptopurine Mode of Action of 6-Mercaptopurine Synthetic Route : 6-Mercaptopurine II I II III IV V VI 2 VII VIII Email: [email protected].