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Macrocyclic Receptors for Biomolecules and Biochemical Sensing
Published in Satish Kumar, Priya Ranjan Sahoo, Violet Rajeshwari Macwan, Jaspreet Kaur, Mukesh, Rachana Sahney, Macrocyclic Receptors for Environmental and Biosensing Applications, 2022
Satish Kumar, Priya Ranjan Sahoo, Violet Rajeshwari Macwan, Jaspreet Kaur, Mukesh, Rachana Sahney
Synthetic nucleosides analogues are pharmaceutically important molecules that resemble naturally occurring nucleosides. These are largely used as anti-viral agents (Acyclovir), a drug for cancer and rheumatologic diseases (azathioprine, allopurinol) and even bacterial infections (trimethoprim). The chemical modification of three-component of a nucleoside, i.e., purine or pyrimidine bases, five-membered sugar (ribose/deoxyribose) and hydroxymethyl group as a polar group are the key steps for the synthesis of these pharmaceutically active compounds. The interaction of nucleoside analogs with different viral polymerases (DNA polymerases/reverse transcriptase/RNA polymerases) follows different inhibition pathways for viral replication. Acyclovir is an antiviral agent that has been used against herpes simplex and varicella-zoster virus infections.
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Published in Valerio Voliani, Nanomaterials and Neoplasms, 2021
Tianmeng Sun, Yu Shrike Zhang, Pang Bo, Dong Choon Hyun, Miaoxin Yang, Younan Xia
Hydrophilic drugs, including biomacromolecules (e.g., proteins, peptides, and nucleic acids) [56] and many small molecules [57], also play an important role in treating various types of cancers. For example, trastuzumab, a monoclonal antibody that interferes with the human epidermal growth factor receptor 2 (HER2), is now routinely used to treat early-stage and metastatic breast cancer for many years; and gemcitabine, a nucleoside analogue, has been used to treat bladder, pancreas, ovarian, breast, and non-small-cell lung cancers. Nevertheless, successful utilization of hydrophilic drugs has been hindered by a number of obstacles, such as poor uptake by cells because of their inability to cross the lipid-rich, hydrophobic cell membranes, low bioavailability arising from their poor stability against proteolytic and hydrolytic degradation, and short half-life in the circulatory system [56, 58].
Chitosan-Based Nanocarriers
Published in Bhupinder Singh, Om Prakash Katare, Eliana B. Souto, NanoAgroceuticals & NanoPhytoChemicals, 2018
Sumit Sharma, V.R. Sinha, Amita Sarwal, Rahul Shukla
Advancement in nanotechnology has explored delivery of nanoparticles at tumor sites, with the aim of increased retention time specifically for the antineoplastic drugs with a narrow therapeutic window and serious systemic side effects. For instance, gemcitabine, a nucleoside analogue, which acts by inhibiting DNA synthesis and causing apoptosis, is reported to exhibit antitumor activity in various clinical studies. Despite its antitumor efficacy, the drug is associated with systemic side effects, a short biological half-life of approximately 17 minutes, and poor cellular uptake. Parsian et al. (2016) has developed chitosan-coated iron oxide nanoparticles (CsMNPs), which gained attention with their biocompatibility, biodegradability, low toxicity, and target ability into tumor tissue under a magnetic field. Gemcitabine in chitosan magnetic nanoparticles increases the anticancer efficacy of the drug. Magnetic nanoparticles were synthesized by in situ precipitation of ferrous and ferric salts, and drug was loaded into the nanoparticles. Magnetic nanoparticles were coated with chitosan, which prevents their agglomeration. Moreover, it has been evidently shown that low molecular weight chitosan produces comparatively smaller nanoparticles with a porous and loose internal structure, allowing greater drug loading. The release of gemcitabine from CsMNPs was found to be higher at pH 4.2, which ensures maximum drug availability inside the tumor cells. This is attributed to pH-dependent decomposition of chitosan at acidic pH in tumor tissue.
Cloning, expression, and characterization of an arabitol dehydrogenase and coupled with NADH oxidase for effective production of L-xylulose
Published in Preparative Biochemistry & Biotechnology, 2022
Chen-Yuan Zhu, Yi-Hao Zhu, Hua-Ping Zhou, Yuan-Yuan Xu, Jian Gao, Ye-Wang Zhang
Rare sugars, especially monosaccharides, have been widely used as nucleoside analogues, drug precursors, calorie-free sweeteners, and bulk agents in the yields of food, medicine, and nutrition industry.[1–3] L-xylulose (empirical formula C5H10O5), as one of the important rare sugars, plays critical roles in various organisms as a metabolic intermediate.[4,5] It is usually used as a prerequisite to produce some pharmaceuticals that can be made into antiviral drugs, such as β-xylose and α-ribose.[6,7] According to the previous reports, it also shows the prospect of being an anticancer and cardioprotective agent.[8–11] Moreover, its nucleoside analogues are commonly used as a medicine for the therapy of Hepatitis B and Acquired Immuno Deficiency Syndrame (AIDS).