Publications by authors named "Chand Raina"

Article Synopsis
  • Researchers discovered two new types of TDP1 inhibitors that can effectively inhibit the TDP1 enzyme, crucial for DNA repair, at low concentrations, with the strongest compound showing an IC value of 0.65 μM.
  • The inhibitors were synthesized from monoterpene compounds and they demonstrated a synergistic effect when tested with the cancer drug topotecan in HEK293FT cells with functional TDP1.
  • This synergy suggests that using non-toxic inhibitors alongside existing cancer therapies can improve treatment effectiveness while minimizing harmful side effects.
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Tyrosyl-DNA phosphodiesterase 1 (Tdp1) is an important DNA repair enzyme in humans, and a current and promising inhibition target for the development of new chemosensitizing agents due to its ability to remove DNA damage caused by topoisomerase 1 (Top1) poisons such as topotecan and irinotecan. Herein, we report our work on the synthesis and characterization of new Tdp1 inhibitors that combine the arylcoumarin (neoflavonoid) and monoterpenoid moieties. Our results showed that they are potent Tdp1 inhibitors with IC values in the submicromolar range.

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The molecular chaperone heat shock protein 90 (Hsp90) is a current inhibition target for the treatment of diseases, including cancer. In humans, there are two major cytosolic isoforms of Hsp90 (Hsp90α and Hsp90β). Hsp90α is inducible and Hsp90β is constitutively expressed.

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Tyrosyl-DNA phosphodiesterase 1 (Tdp1) is a promising therapeutic target in cancer therapy. Combination chemotherapy using Tdp1 inhibitors as a component can potentially improve therapeutic response to many chemotherapeutic regimes. A new set of usnic acid derivatives with hydrazonothiazole pharmacophore moieties were synthesized and evaluated as Tdp1 inhibitors.

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Exploration of microbial dynamics of Streptomyces lavendulae ACR-DA1, a psychrotrophic isolate from the North-Western Himalayan cold desert, was carried out using matrix-assisted laser desorbtion ionisation-time of flight mass spectrometer. Valinomycin was found as a major produce and cyclic depsipeptide montanastatin as a minor produce. The yield of the valinomycin was found to be 0.

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Background And Objective: The DNA repair enzyme tyrosyl-DNA-phosphodiesterase 1 (TDP1) is a current inhibition target to improve the efficacy of cancer chemotherapy. Previous studies showed that compounds combining adamantane and monoterpenoid fragments are active against TDP1 enzyme. This investigation is focused on the synthesis of monoterpenoid derived esters of 1-adamantane carboxylic acid as TDP1 inhibitors.

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Article Synopsis
  • The search for new inhibitors of DNA repair enzymes, particularly Tyrosyl-DNA phosphodiesterase 1 (Tdp1), is crucial for improving treatments for cancer and neurodegenerative diseases.
  • A new class of semisynthetic small molecule inhibitors derived from bile acids was identified through virtual screening, showing promise to enhance the effectiveness of existing anticancer drugs by reducing Tdp1 activity.
  • In vitro studies revealed that these derivatives can inhibit Tdp1 with a potency of up to 0.29 µM, and further docking studies indicate a strong fit of these ligands within Tdp1's active site.
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Present study relates to the effect of valproic acid, an epigenetic modifier on the metabolic profile of Aspergillus fumigatus (GA-L7), an endophytic fungus isolated from Grewia asiatica L. Seven secondary metabolites were isolated from A. fumigatus (GA-L7) which were identified as: pseurotin A, pseurotin D, pseurotin F2, fumagillin, tryprostatin C, gliotoxin and bis(methylthio)gliotoxin.

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