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Antimetabolites
Published in David E. Thurston, Ilona Pysz, Chemistry and Pharmacology of Anticancer Drugs, 2021
Capecitabine (XelodaTM) is a prodrug of doxifluridine, a fluorinated pyrimidine nucleoside with a cytostatic activity, which is no longer used clinically (Figure 3.11). The pyrimidine ring has a fluorine atom at the 6-position (rather than the 5-position as in 5-FU), a 4-amino group as found in cytarabine, gemcitabine, and gemcitabine but protected as a pentyloxycarbamate. The N1-sugar is modified with a 5′-methyl substituent and a 2′-hydroxy group with an inverted configuration compared to that found in cytarabine. Thus, it is a multiple prodrug of 5-FU designed to be given orally and to be metabolized by a three-enzyme cascade specifically in cancer cells.
Alternative Medicine in Vitiligo Including Home Remedies
Published in Vineet Relhan, Vijay Kumar Garg, Sneha Ghunawat, Khushbu Mahajan, Comprehensive Textbook on Vitiligo, 2020
P. corylifolia has a specifically local action on the arterioles of the subcapillary plexuses, which become dilated, increasing plasma in the area. The skin turns erythematous and the melanocytes become stimulated. In vitiligo, melanocytes function improperly, and their stimulation by the medication leads them to synthesize and exudate pigments that diffuse slowly into the vitiligo patches [5,12]. Covalent binding of the drug to pyrimidine bases, which is phytochemically induced, is also responsible for its therapeutic efficacy. Thymine dimer adducts on the opposite strands of DNA are involved in the photoconjunction. Psoralen intercalates into the DNA, forming mono- and di-adducts in the presence of UV light [13].
Introduction to the disorders of purine and pyrimidine metabolism
Published in William L. Nyhan, Georg F. Hoffmann, Aida I. Al-Aqeel, Bruce A. Barshop, Atlas of Inherited Metabolic Diseases, 2020
William L. Nyhan, Georg F. Hoffmann, Aida I. Al-Aqeel, Bruce A. Barshop
Dihydropyrimidine dehydrogenase is involved in the catabolism of 5 fluorouracil, and so patients receiving cancer chemotherapy are at risk for severe toxicity. We recommend screening for uracil-thyminuria in candidates for chemotherapy. A list of pyrimidine and other medications that might interfere with pyrimidine degradation is shown in Table 64.1.
Synthesis, DFT calculations, and anti-proliferative evaluation of pyrimidine and selenadiazolopyrimidine derivatives as dual Topoisomerase II and HSP90 inhibitors
Published in Journal of Enzyme Inhibition and Medicinal Chemistry, 2023
Samar El-Kalyoubi, Samiha A. El-Sebaey, A. M. Rashad, Hanan A. AL-Ghulikah, Mostafa M. Ghorab, Sherin M. Elfeky
Since cancer cells possess an inherent ability for drug resistance, there is a continuous need for novel potent anti-proliferative agents that target multiple signalling pathways to ensure the effectiveness of cancer therapeutic agents1,2. Pyrimidie-dione (uracil) is a common naturally occurring pyrimidine derivative. Its 5-fluoro derivative was first introduced in the fifties of the last century and is still widely used as an antitumor, especially in colon and breast carcinoma3 5-Flourouracil exhibits its anti-proliferative activity by inhibiting DNA repair and replication4. 5-Fluorouracil has been shown to inhibit thymidylate synthase5, and it can misincorporateinto DNA in place of uracil, resulting in cytotoxic activity6. Different fused uracil derivatives (I) showed potent anti-proliferative activity through catalytic inhibition of the Topoisomerase II enzyme and stabilisation of covalent DNA-Topoisomerase II cleavage complexes7.
Small molecule Son of Sevenless 1 (SOS1) inhibitors: a review of the patent literature
Published in Expert Opinion on Therapeutic Patents, 2021
Severin K. Thompson, Andreas Buckl, Alexander G. Dossetter, Ed Griffen, Adrian Gill
Extensive structural diversity on the benzylamine moiety is also explored, with a matched pair comparison of potent (IC50 < 1 µM) compounds 23a–23n suggesting a generally broad tolerance for functional diversity. While the trifluoroaniline group shown in 23a is the most frequently occurring arene ring in the patent application, other substituents at the R3 position are occasionally seen. For those compounds unsubstituted at the R3 position, greater potency is achieved with hydrogen, alkyl, and halogen R1 substituents in combination with several potential fluorinated alkanes and ethers in the R2 position. Although potent bicyclic analogs were shown (e.g. compounds 23m and 23n), heteroarenes appeared to be poorly tolerated. Diverse substituents at position 2 of the pyrimidine ring were explored, as shown by the presence of 17 matched pairs represented by structure 24. A general tolerance for small substituents is observed, with compounds 24a–24f all showing IC50 values <1 µM in both the TR-FRET disruption assay and pERK assay.
Surface modified nanoliposome formulations provide sustained release for 5-FU and increase cytotoxicity on A431 cell line
Published in Pharmaceutical Development and Technology, 2020
Ümran Yaman, Minela Aslan, Sukru Ozturk, Kezban Ulubayram, İpek Eroğlu
5-FU (5-Fluoro-2,4-dihydroxy pyridine) is a cytotoxic drug commonly used in the treatment of many types of cancer (Miura et al. 2010). It is an antimetabolite of fluoropyrimidine and is used in the treatment protocols of many types of cancer including skin cancer. It is classified as a pyrimidine analog because it interferes with DNA and RNA synthesis by mimicking the building blocks necessary for synthesis (Kim et al. 2018). 5-FU is generally administered to patients every day as i.v. bolus for 5 consecutive days followed by re-administration after 28days in 3 cycles. In case surgery is not convenient, 5-FU can be applied as intravenous injection or topical form for skin cancer treatment (Thomas et al. 2011). Therefore, the aim of this study was to prepare 5-FU loaded nanoliposomes and polymer coated 5-FU loaded nanoliposomes for intra-tumoral injection. Poly-L-lysine (PLL) and Polyethyleneimine (PEI) at different polymer:liposome concentrations were used for the coating of the nanoliposomes. Nanoliposome formulations were fully characterized and cytotoxicity studies on the A431 epidermoid carcinoma cell line were carried out. Results from this study suggests that, this novel approach could provide an effective and reliable treatment option for skin cancer as compared to currently existing treatment strategies.