Pyrimidine

ultraviolet (UV) radiation, and various chemicals agents. DNA damage types used for this work are produced by ionizing radiation (IR) and ultraviolet radiation (UV). Ultraviolet (UV) light from sunlight, can make up to 105 DNA lesions (pyrimidine dimers) in cell per day. Pyrimidine…

formed from a sugar-phosphate backbone and containing the 4 bases, adenine, thymine, guanine and cytosine, complementarily paired with hydrogen bonding. A and G are purines and have a double ring whereas T and C are pyrimidines and have only a single ring. Within the helix a pyrimidine is always paired with a purine such that G is always paired with C and T with A. The difference between A, B and Z DNA arises when you look at the conformation of the helix. A-DNA, like B-DNA, is a right handed…

we reported the synthesis of fused and isolated triazoles based on thieno[2,3-d]pyrimidines. The synthesized 1,2,4-triazolo compounds were screened for their anticancer activity at a concentration of 10 μΜ against a panel of 60 cell lines derived from nine different types of cancers, and also screened for their PDE 5 inhibitory activity. The possibility of combining 1,2,4-triazolo moiety to thieno[2,3-d]pyrimidines should open new opportunities for the rational design of medicinal agents.…

1) Centrioles are a paired feature of animal mitotic spindles that protrude away from the centrisome of cells and are primarily tasked with the creation of microtubules. The microtubules give way to mitotic spindles, which play a vital role in both mitosis and cytokinesis as they give cilia and flagellum the ability to generate motion and they ensure both newly formed cells contain paired centrioles during the later stages of cell division. Kinetochores are protein structures that produce…

components into surrounding tissue (121). Key players that help mediate necrosis include ROS, Calcium ions, poly-ADP-ribose-polymerase (PARP), and lysosomal proteases (888). PARP is an enzyme that is responsible for repairing DNA damage, such as strand breaks. Cells that have undergone a traumatic cellular insult typically have damaged DNA. PARP will deplete cellular ATP in an attempt to repair the massive damage to DNA. Several proteases are activated by increased cellular calcium ion…

When Francis Crick and James Watson(top photo) discovered the secret of life found in DNA, many believed that the genetic revolution was upon them. As the understanding of genetic code grew, people began to hope for healthier lives and an end of inherited diseases. Although the fear of scientists playing god grew as well. This simple molecule was now basic unit of creation, and another pair of scientists were looking to find how its structure worked. Rosalind Franklin and Maurice…

There is no doubt that benzene is aromatic. Now we must ask: how can we insert a heteroatom into the ring and retain aromaticity? What kind of atom is needed? If we want to replace one of the carbon atoms of benzene with a heteroatom, we need an atom that can be trigonal to keep the flat hexagonal ring and that has a p orbital to keep the six delocalized electrons. Nitrogen is ideal so we can imagine replacing a CH group in benzene with a nitrogen atom. The orbitals in the ring have not changed…

in patients with cancer is to reduce the presence of malignant cells. This may be achieved by causing a lethal cytotoxic event in the cancer cell that will arrest tumour progression. Targets for cytotoxic attack include inhibition of purine and pyrimidine synthesis, inhibition of DNA and RNA synthesis and chemical attack on the integrity of the structure of cellular DNA. Since these treatments reduce the mechanisms of cell proliferation in general, they are toxic to both tumour cells and…

In 2003, li Also as much coworkers70 synthesized 3-arylimidazo[1,2-a]pyrimidines from imidazo[1,2-a]pyrimidine a unsubstituted heterocycle In those 3-position Toward performing regulate arylation response with aryl bromides. Those creator utilized Pd(OAc)2 (2 mol %) Concerning illustration An catalyst, PPh3 (4 mol %) Likewise An ligand, Also Cs2CO3 (2 equiv) Concerning illustration An base, those response advanced proficiently in 1,4-dioxane during 100 °C. Those yield might have been attained in…

and most of the UV-C radiation is absorbed by stratospheric ozone. The UV-B destroys part of the DNA and this causes death and other mutations to happen. As you can see in figure 1, the UV-B photon comes in and destroys parts of the DNA creating pyrimidine dimers, which are areas of damage on a molecular level. The effects of UV-B on amphibians changes between…