Nucleoside

Nevertheless, it is known that biscarbamate can be removed under midly basic to neutral conditions and is hence suitable N-protecting group for nucleosides (Sikehi et al., 2006 and reference theirin). A solvent-free reaction utilizing a simple low-energy ball mill apparatus was reported to convert the amino groups of nucleosides S.36, adenosine, 2-deoxyadenosine, cytidine, 2-deoxycytidine, guanosine, and 2-deoxyguanosine as well as some of their ribosyl O-protected derivatives, to the corresponding bis-N-Boc carbamates S.37 (Sikehi et al., 2006). For guanosine compounds, the carbonyl group of the base moiety was also protected as its O-Boc enol carbonate (Figure X.X.X). Transient in situ O-silylation facilitated the preparation of bis-N-Boc nucleosides from unprotected sugars. This strategy allows the protection of nucleosides with a base-stable and acid-labile group suitable for the preparation of base-sensitive oligonucleotides as well as for further manipulation. However, the utility of this diBoc carbamate protection is yet to be explored in oligonucleotide…

the C8 position of guanosine is vulnerable to hydrolytic attack under either strongly acidic or strongly alkaline conditions. The 5,6 double bond of pyrimidine nucleosides also reacts with halogens and halohydrins to give the corresponding addition products (Shabarova and Bogdanov, 1994). Selected examples of the side reactions that occur during oligonucleotide synthesis are given below. Tri-O-acetyluridine (S.1) reacts with MSNT to produce the triazolo derivative S.2 (Figure 2.1.2; Reese and…

Discussion Overall, the method created for the determination of riboflavin via fluorescence has potential to provide useful information regarding the starting concentration of riboflavin as well as the consumption rate of the vitamin in media, when analyzed at different activation times. The decrease in riboflavin over time makes sense as the bacteria and archaea in the media use the vitamin as a cofactor in the digestion of cellulose as well as with other sugars and fats. (2) The The LOD and…

• Introduction Fluorouracil (or 5-FU) is an antineoplastic/cytotoxic (anti-cancer) chemotherapy drug used in the treatment of many type of cancers – The main one being bowel, or colorectal, cancer. As 5-FU has cured many people worldwide of bowel cancer, there are some side-effects that can affect the patient. This particular type of chemotherapy drug comes in several different forms to suit all stages of life who are affected with different types of cancer. (chemocare.com, 2015) • How Cancer…

depurination can occur via protonation of the purine nucleobase at both N1 and N7. The presence of the 2′-OH has a significant effect on the nucleoside’s susceptibility to depurination. For example, guanosine and adenosine are more resistant to depurination compared to deoxyadenosine and deoxyguanosine. Deoxyadenosine itself depurinates 1200 times faster than adenosine (York, 1981). Interestingly, N-acyl-protected purine nucleosides (particularly deoxyadenosine) are more prone to depurination…

g) Solubility: soluble in methanol, slightly soluble in water (13.4 mg/ml) and very slightly soluble in dichloromethane h) Route of administration: Oral i) Excretion: kidney j) Therapeutic category: Antiretroviral drug k) Metabolism: The cytochrome P450 enzyme system is not involved with the metabolism of Tenofovir disoproxil or Tenofovir. l) pKa value: 3.75 m) Trade Name: Viread 2.2.5 Drug profile of Efavirenz: Efavirenz is an antiretroviral drug and it belongs to the class of…

also periodically test the infants for presence of HSV in the cerebrospinal fluid. If the results show no progression of the disease into the cerebrospinal fluid, it provides evidence that Acyclovir can provide long-term suppression of HSV.2 Acyclovir is currently used to treat herpes simplex virus in both adults and infants. It is also used to treat genital herpes, herpes simplex encephalitis, and varicella-zoster. It can be administered intravenously or orally but this study only examined oral…

the elongation step of viral DNA replication. The study showed that Acyclovir is phosphorylated into monophosphate purine analog, and remained in the infected cells before being converted into the triphosphate active form by the viral thymidine kinase. Once in this form, DNA polymerase will substitute it for Guanine triphosphate into the viral DNA chain. Due to Acyclovir’s structure, the lack of a second hydroxyl group prevents another residue to be attached and terminates chain growth. This…

Under dephosphorylation, AMP, IMP, XMP and GMP molecules are dephosphorylated into their corresponding nucleotides which include Adenosine, Enosine, Xanthosine, Guanosine and the process is catalysed by the enzyme Nucleotidase. In step two, deamination, AMP (Nucleotide) and Adenosine (Nucleoside) is deaminated into IMP and Inosine respectively. This reaction is catalyzed by AMP deaminase and Adenosine deaminase. Guanine (nitrogenous base only) is deaminated into Xanthosine in the presence of…

male while 49% of the population is persons less than 15 years of age and 18.5% are under 5 years. (Mills, K2013) AIDS Over view- AIDS is defined as Acquired immunodeficiency syndrome and is caused by human immunodeficiency virus and it was first reported in United States in 1981. (Audrey, H 2008) HIV continuously destroys the body 's ability to fight with infections and certain tumors. As HIV advances, it attacks and destroys CD4 cells that the body can no longer fight with infections. When…