Sravani Sana
@zibolab.web.unc.edu
Radiochemist/ Research Associate
Biomedical Research Imaging Center, University of North Carolina, Chapel Hill
RESEARCH, TEACHING, or OTHER INTERESTS
Chemistry, Organic Chemistry, Process Chemistry and Technology, Radiology, Nuclear Medicine and imaging
Scopus Publications
Scholar Citations
Scholar h-index
Scholar i10-index
Scopus Publications
Mohammad Nuruzzaman, Brandon M. Colella, Chiamaka P. Uzoewulu, Alissa E. Meo, Elizabeth J. Gross, Seiya Ishizawa, Sravani Sana, He Zhang, Meredith E. Hoff, Bryce T. W. Medlock,et al.
American Chemical Society (ACS)
The past decade has seen a remarkable growth in the number of bioconjugation techniques in chemistry, biology, material science, and biomedical fields. A core design element in bioconjugation technology is a chemical reaction that can form a covalent bond between the protein of interest and the labeling reagent. Achieving chemoselective protein bioconjugation in aqueous media is challenging, especially for generally less reactive amino acid residues, such as tryptophan. We present here the development of tryptophan-selective bioconjugation methods through ultrafast Lewis acid-catalyzed reactions in hexafluoroisopropanol (HFIP). Structure-reactivity relationship studies have revealed a combination of thiophene and ethanol moieties to give a suitable labeling reagent for this bioconjugation process, which enables modification of peptides and proteins in an extremely rapid reaction unencumbered by noticeable side reactions. The capability of the labeling method also facilitated radiofluorination application as well as antibody functionalization. Enhancement of an α-helix by HFIP leads to its compatibility with a certain protein, and this report also demonstrates a further stabilization strategy achieved by the addition of an ionic liquid to the HFIP medium. The nonaqueous bioconjugation approaches allow access to numerous chemical reactions that are unavailable in traditional aqueous processes and will further advance the chemistry of proteins.
Sravani Sana, Srinivas Reddy Dannarm, Ramya Tokala, Sowmya Dastari, Manda Sathish, Rahul Kumar, Rajesh Sonti, and Nagula Shankaraiah
Royal Society of Chemistry (RSC)
A sustainable visible light-mediated protocol for the synthesis of 6-aryl-derived naphtho/anthraimidazo [1,2-a]pyridine-based molecules has been achieved via Ru(ii) catalyzed C–H activation/annulation between heteroarenes and sulfoxonium ylides.
Sravani Sana, Sowmya Dastari, Dannarm Srinivas Reddy, Ramya Tokala, Manda Sathish, Rajesh Sonti, and Nagula Shankaraiah
Royal Society of Chemistry (RSC)
A sustainable photoredox-mediated protocol for the construction of unsymmetrical diarylamines using a Cu/Ru catalytic system has been successfully devised with a wide substrate scope and good yields.
Darshana Bora, Srinivas Reddy Dannarm, Stephy Elza John, Sravani Sana, Rajesh Sonti, and Nagula Shankaraiah
Wiley
AbstractA regioselective ruthenium‐catalysed strategy for synthesising mono‐, ortho‐sulfonamidated β‐carboline derivatives using sulfonyl azide was accomplished by relying on the intrinsic directing property of β‐carbolines. This protocol is apt for all types of substitutions with compelling yields. We have investigated the reaction mechanism using ESI‐MS by arresting the intermediates associated with this selective transformation. The achieved molecules were also surfaced with potential percentage inhibition against cancer cell lines. In addition, practical and computational analysis on these new scaffolds demonstrated photophysical properties.
Dilep Kumar Sigalapalli, Gaddam Kiranmai, G. Parimala Devi, Ramya Tokala, Sravani Sana, Chaturvedula Tripura, Govinda Shivaji Jadhav, Manasa Kadagathur, Nagula Shankaraiah, Narayana Nagesh,et al.
Elsevier BV
Sravani Sana, Velma Ganga Reddy, T. Srinivasa Reddy, Ramya Tokala, Rahul Kumar, Suresh K. Bhargava, and Nagula Shankaraiah
Elsevier BV
Jayachandra Rayadurgam, Sravani Sana, M. Sasikumar, and Qiong Gu
Royal Society of Chemistry (RSC)
Some of the most prominent and promising catalysts in organic synthesis for the requisite construction of C–C and C–N bonds are palladium (Pd) catalysts, which play a pivotal role in pharmaceutical and medicinal chemistry.
Vidyasrilekha Yele, Sai Kiran S.S. Pindiprolu, Sravani Sana, D.S.V.N.M. Ramamurty, Jayanthi R.K. Madasi, and Swapna Vadlamani
Bentham Science Publishers Ltd.
Background: Microtubules are considered to be an important therapeutic target for most of the anticancer drugs. These are highly dynamic structures comprising of α-tubulin and β-tubulin which are usually heterodimers and found to be involved in cell movement, intracellular trafficking, and mitosis inhibition of which might kill the tumour cells or inhibit the abnormal proliferation of cells. Most of the tubulin polymerization inhibitors, such as Vinca alkaloids, consist of Indole as the main scaffold. The literature also suggests using triazole moiety in the chemical entities, potentiating the inhibitory activity against cell proliferation. So, in our study, we used indole triazole scaffolds to synthesize the derivatives against tubulin polymerization. Objective: The main objective of this study to synthesize indole triazole conjugates by using environmentally friendly solvents (green chemistry) and click chemistry. To carry out the MTT assay and tubulin polymerization assay for the synthesized indole triazole conjugates. Methods: All the synthesized molecules were subjected to molecular docking studies using Schrodinger suite and the structural confirmation was performed by Mass, proton-NMR and carbon-NMR, documented in DMSO and CDCL3. Biological studies were performed using DU145 (prostate cancer), A-549 (lung cancer) and, MCF-7 (breast cancer), cell lines obtained from ATCC were maintained as a continuous culture. MTT assay was performed for the analogues using standard protocol. Cell cycle analysis was carried out using flow cytometry. Results: The Indole triazole scaffolds were synthesized using the principles of Green chemistry. The triazole formation is mainly achieved by using the Click chemistry approach. Structural elucidation of synthesized compounds was performed using Mass spectroscopy (HR-MS), Proton-Nuclear Magnetic Spectroscopy (1H-NMR) and Carbon-Nuclear Magnetic Spectroscopy (13C-NMR). The XP-docked poses and free energy binding calculations revealed that 2c and 2g molecules exhibited the highest docking affinity against the tubulin-colchicine domain (PDB:1SA0). In vitro cytotoxic assessment revealed that 2c and 2g displayed promising cytotoxicity in MTT assay (with CTC50 values 3.52μM and 2.37μM) which are in good agreement with the computational results. 2c and 2g also arrested 63 and 66% of cells in the G2/M phase, respectively, in comparison to control cells (10%) and tubulin polymerization inhibition assay revealed that 2c and 2g exhibited significant inhibition of tubulin polymerization with IC50 values of 2.31μM, and 2.62μM, respectively in comparison to Nocodazole, a positive control, resulted in an IC50 value of 2.51μM. Conclusion: Indole triazole hybrids were synthesized using click chemistry, and docking studies were carried out using Schrodinger for the designed molecules. Process Optimization has been done for both the schemes. Twelve compounds (2a-2l) have been successfully synthesized and analytical evaluation was performed using NMR and HR-MS. In vitro evaluation was for the synthesized molecules to check tubulin polymerization inhibition for antiproliferative action. Among the synthesized compounds, 2c and 2g have potent anticancer activities by inhibiting tubulin polymerization.
Ramya Tokala, Surbhi Mahajan, Gaddam Kiranmai, Dilep Kumar Sigalapalli, Sravani Sana, Stephy Elza John, Narayana Nagesh, and Nagula Shankaraiah
Elsevier BV
Ramya Tokala, Sravani Sana, Uppu Jaya Lakshmi, Prasanthi Sankarana, Dilep Kumar Sigalapalli, Nikhil Gadewal, Jyoti Kode, and Nagula Shankaraiah
Elsevier BV
Sravani Sana, Velma Ganga Reddy, Sonal Bhandari, T. Srinivasa Reddy, Ramya Tokala, Akash P. Sakla, Suresh K. Bhargava, and Nagula Shankaraiah
Elsevier BV
Sonal Bhandari, Sravani Sana, Vandana Lahoti, Ramya Tokala, and Nagula Shankaraiah
Royal Society of Chemistry (RSC)
Herein, we report a facile tandem approach for the synthesis of both spiro-oxindole-fused pyrroloindolines and benzofurano-pyrrolidines via a Lewis acid-catalyzed domino ring-opening annulation using activated spiro-aziridines and heteroarenes.
Sravani Sana, Ramya Tokala, Deepti Madanlal Bajaj, Narayana Nagesh, Kiran Kumar Bokara, Gaddam Kiranmai, Uppu Jaya Lakshmi, Swapna Vadlamani, Venu Talla, and Nagula Shankaraiah
Elsevier BV
Ramya Tokala, Darshana Bora, Sravani Sana, Fabiane M. Nachtigall, Leonardo S. Santos, and Nagula Shankaraiah
American Chemical Society (ACS)
A Ru(II)-catalyzed regioselective C-H activation toward hydroxymethylation of β-carbolines and isoquinolines as effective directing groups has been developed, and the mechanism was probed by using online electrospray ionization-tandem mass spectrometry. The introduction of the hydroxymethyl group in the biologically relevant molecules routed via C-H functionalization remains an important task. Gratifyingly, this protocol draws attention to the regioselective formation of monohydroxymethylated β-carboline/isoquinoline products exclusively.
Sonal Bhandari, Sravani Sana, Balasubramanyam Sridhar, and Nagula Shankaraiah
Wiley
AbstractAn efficient microwave‐assisted one‐pot method has been developed for the construction of pyrrolidine fused bis‐spirooxindoles through insitu generated azomethine ylide from decarboxylative condensation of isatins and primary α‐amino acids with concomitant [3+2] cycloaddition of 3‐alkenyl oxindoles. These reactions were effectively accelerated by microwave irradiation in ethanol solvent without any additives or catalyst and enable broad substrate scope, atom‐economy, eco‐friendly, and good yields. The structure and stereochemistry of pyrrolidine fused bis‐spirooxindole ring was unambiguously established by single‐crystal X‐ray analysis.
Ramya Tokala, Sowjanya Thatikonda, Usha Sree Vanteddu, Sravani Sana, Chandraiah Godugu, and Nagula Shankaraiah
Wiley
AbstractA new series of (E)‐3‐[(1‐aryl‐9H‐pyrido[3,4‐b]indol‐3‐yl)methylene]indolin‐2‐one hybrids were synthesized and evaluated for their in vitro cytotoxic activity against a panel of selected human cancer cell lines, namely, HCT‐15, HCT‐116, A549, NCI‐H460, and MCF‐7, including HFL. Among the tested compounds, (E)‐1‐benzyl‐5‐bromo‐3‐{[1‐(2,5‐dimethoxyphenyl)‐9H‐pyrido[3,4‐b]indol‐3‐yl]methylene}indolin‐2‐one (10 s) showed potent cytotoxicity against HCT‐15 cancer cells with an IC50 value of 1.43±0.26 μm and a GI50 value of 0.89±0.06 μm. Notably, induction of apoptosis by 10 s on the HCT‐15 cell line was characterized by using different staining techniques, such as acridine orange/ethidium bromide (AO/EB) and DAPI. Further, to understand the mechanism of anticancer effects, various assays such as annexin V‐FITC/PI, DCFDA, and JC‐1were performed. The flow cytometric analysis revealed that compound 10 s arrests the HCT‐15 cancer cells at the G0/G1 phase of the cell cycle. Additionally, western blot analysis indicated that treatment of 10 s on HCT‐15 cancer cells led to decreased expression of anti‐apoptotic Bcl‐2 and increased protein expression of both pro‐apoptotic Bax and caspase‐3, ‐8, and ‐9, and cleaved PARP with reference to actin. Next, a clonogenic assay revealed the inhibition of colony formation in HCT‐15 cancer cells by 10 s in a dose‐dependent manner. Moreover, upon testing on normal human lung cells (HFL), the compounds were observed to be safer with a low toxicity profile. In addition, viscosity and molecular‐docking studies showed that compound 10 s has typical intercalation with DNA.
Ramya Tokala, Sowjanya Thatikonda, Sravani Sana, Phanindranath Regur, Chandraiah Godugu, and Nagula Shankaraiah
Royal Society of Chemistry (RSC)
A series of β-carboline-linked 2,4-thiazolidinedione hybrids was synthesized and studied for their DNA affinities and cytotoxicities. The most potent compound was 19e with IC50 of 0.97 ± 0.13 μM.
Chander Singh Digwal, Upasana Yadav, P. V. Sri Ramya, Sravani Sana, Baijayantimala Swain, and Ahmed Kamal
American Chemical Society (ACS)
A novel vanadium-catalyzed one-pot domino reaction of 1,2-diketones with amidines has been identified that enables their transformation into imides and amides. The reaction proceeds by dual acylation of amidines via oxidative C(CO)-C(CO) bond cleavage of 1,2-diketones to afford N,N'-diaroyl-N-arylbenzamidine intermediates. In the reaction, these intermediates are easily hydrolyzed into imides and amides through vanadium catalysis. This method provides a practical, simple, and mild synthetic approach to access a variety of imides as well as amides in high yields. Moreover, one-step construction of imide and amide bonds with a long-chain alkyl group is an attractive feature of this protocol.