SREERAMA RAJASEKHAR
@svcop.in
Associate Professor, Department of Pharmaceutical Cheistry
Sri Venkateswara College of Pharmacy
RESEARCH INTERESTS
Organic Chemistry, Computational Chemistry, Peptide Synthesis, Green Chemistry
Scopus Publications
Scholar Citations
Scholar h-index
Scholar i10-index
Scopus Publications
Sreerama Rajasekhar, Soumyadip Das, Ramanathan Karuppasamy, Balamurali Musuvathi Motilal, and Kaushik Chanda
Wiley
In this study, we assess the effective inhibition of a series of thiazolidine derivatives (1a–1q) were adopting structure‐based drug design. Thiazolidine is a five‐membered ring structure with thioether and amino groups at positions 1 and 3. Although, thiazolidine may bind to a wide range of protein targets, it is a major heterocyclic core in medicinal chemistry. Different scoring utilities including AutoDock Vina, Glide, and MM/GBSA analysis were performed to commensurate the improvement of screening progress. The evaluated binding affinities were validated by molecular dynamics simulations over a period of 20 ns for the interactions between the Mycobacterium tuberculosis protein PrpR with three novel scaffolds (1b, 1j, and 1k). All the scaffolds exhibited distinct stable interactions with the significant residues like Arg169, Arg197, Tyr248, Arg308, and Gly311 respectively. Further, the inhibitory activities of scaffolds were predicted and evaluated by machine learning based algorithm to rank the above proposed compounds. This study reveals the potential of 1k and 1j as effective inhibitor candidates for the treatment of tuberculosis.
Upala Dasmahapatra, Sreerama Rajasekhar, Grandhe Neelima, Barnali Maiti, Ramanathan Karuppasamy, Poornima Murali, Balamurali MM, and Kaushik Chanda
Wiley
Sreerama Rajasekhar, Soumyadip Das, M. M. Balamurali, and Kaushik Chanda
Wiley
Sreerama Rajasekhar, Ramanathan Karuppasamy, and Kaushik Chanda
Wiley
Drug resistance in tuberculosis is major threat to human population. In the present investigation, we aimed to identify novel and potent benzimidazole molecules to overcome the resistance management. A series of 20 benzimidazole derivatives were examined for its activity as selective antitubercular agents. Initially, AutodockVina algorithm was performed to assess the efficacy of the molecules. The results are further enriched by redocking by means of Glide algorithm. The binding free energies of the compounds were then calculated by MM‐generalized‐born surface area method. Molecular docking studies elucidated that benzimidazole derivatives has revealed formation of hydrogen bond and strong binding affinity in the active site of Mycobacterium tuberculosis protein. Note that ARG308, GLY189, VAL312, LEU403, and LEU190 amino acid residues of Mycobacterium tuberculosis protein PrpR are involved in binding with ligands of benzimidazoles. Interestingly, the ligands exhibited same binding potential to the active site of protein complex PrpR in both the docking programs. In essence, the result portrays that benzimidazole derivatives such as 1p, 1q, and 1 t could be potent and selective antitubercular agents than the standard drug isoniazid. These compounds were then subjected to molecular dynamics simulation to validate the dynamics activity of the compounds against PrpR. Finally, the inhibitory behavior of compounds was predicted using a machine learning algorithm trained on a data collection of 15,000 compounds utilizing graph‐based signatures. Overall, the study concludes that designed benzimidazoles can be employed as antitubercular agents. Indeed, the results are helpful for the experimental biologists to develop safe and non‐toxic drugs against tuberculosis.
Anusha G, Sujatha V, Shalini R, Bhaskar Reddy K, and Rajasekhar S
GP Innovations Pvt. Ltd.
This is due in part to vitamin D deficiency (vitamin D is a primary modulator of intestinal calcium and phosphate absorption), which is caused by a lack of sunlight combined with low vitamin D dietary intake and cutaneous synthesis. Secondary hyperparathyroidism is caused by low calcium intake and vitamin D deficiency, which is characterised as a serum 25-hydroxyvitamin D (25 (OH) D concentration below 12 ng/ml and is related to increased bone turnover and, indirectly, an increased risk of fracture. Furthermore, recent findings indicate that vitamin D deficiency is more widespread than previously thought, owing to a revision of the traditional 25 (OH) D threshold level below which parathyroid hormone secretion (PTH) begins to increase. Pre-prepared application forms were distributed among the study population to fill the required details, encouraged to fill the form by own. Those who are uneducated or unable to fill the form are helped by project staff. The value of z is 2.44949, the value of p is 0.01428 and the result is significant at p < 0.05 are obtained for the calcium levels of pre and post-test results of all study groups when compared against BMI. The value of z is 1.36471, the value of p is 0.00321 and the result is significant at p < 0.05 are obtained for the T-values of pre and post-test results of all study groups when compared against BMI. After observing the findings, it is clear that after eating prescribed nutritional food for three months, the ionised Calcium levels, overall Calcium levels, and bone density have increased significantly as compared to before taking nutritional food. As a result, the nutrient food given is a good source of calcium and helps postmenopausal women strengthen their bones. Furthermore, it is recommended that all age groups consume the recommended food kit to minimise the risk of osteoporosis and bone fracture.
Kaushik Chanda, Sreerama Rajasekhar, and Barnali Maiti
Georg Thieme Verlag KG
In 2014, more than 80% of the marketed drugs in the US contained heterocyclic compounds, which play a major role in the drug-discovery process, as one of the primary components. Benzoxazole, consisting of an oxazole ring fused with a benzene ring, has shown profound impact in drug discovery research owing to its important bioactivity. This moiety has also shown important properties in material science. The synthesis of this privileged scaffold from readily available chemicals remains a primary focus for the synthetic chemistry community. In this review, efforts have been made to focus on the latest information available on the different synthetic strategies such as solution phase, multicomponent, green and solid phase chemistry and applications of different benzoxazole derivatives. Furthermore, the updated synthetic information incorporated in this review article will help to improve future synthesis of this scaffold. 1 Introduction 2 Solution-Phase Synthetic Approach to Substituted Benzoxazoles 2.1 Condensation of o-Aminophenol with Carboxylic Acids 2.2 Condensation of o-Aminophenol with Aldehydes 2.3 Condensation of o-Aminophenol with Orthoesters, ortho-Haloamides, or 1,1-Dihaloalkenes 2.4 Synthesis of Benzoxazoles from Schiff Bases 2.5 Miscellaneous 3 Multicomponent Synthetic Approach to Substituted Benzoxazoles 4 Solid-Phase Synthetic Approach to Substituted Benzoxazoles 5 Green Synthetic Approach to Substituted Benzoxazoles 5.1 Condensation of o-Aminophenol with Aldehydes 5.2 Condensation of o-Aminophenol with ortho-Substituted Benzamides 5.3 Condensation of o-Aminophenol with Carboxylic Acid and its Derivatives 5.4 Condensation of o-Aminophenol with Alcohols or Amines 5.5 Miscellaneous 6 Bioactive Derivatives of Benzoxazoles 7 Conclusion and Outlook
Sreerama Rajasekhar, Barnali Maiti, M. M. Balamurali, and Kaushik Chanda
Bentham Science Publishers Ltd.