@article {46717, title = {Analysis and artificial neural network prediction of melting properties and ideal mole fraction solubility of cocrystals}, journal = {Crystal Growth \& Design}, volume = {20}, year = {2020}, month = {SEP }, pages = {5745-5759}, type = {Article}, abstract = {

Different artificial neural network (ANN) models have been developed and examined for prediction of cocrystal properties based on pure component physical properties only. From the molecular weight, melting temperature, melting enthalpy, and melting entropy of the pure compounds, the corresponding melting properties of the cocrystals and the cocrystal ideal solubility have been successfully predicted. Notably, no information whatsoever about the cocrystals is needed, besides the identification of the two compounds from which the cocrystal is formed. In total, 30 cocrystal systems of 8 different model components, namely, theophylline, piracetam, gabapentin-lactam, tegafur, nicotinamide, salicylic acid, syringic acid, and 4,4{\textquoteright}-bipyridine, with distinct coformers have been chosen as the model systems for the construction of ANN models. In all the cases, 70\% of the data points have been used to train the model, and the rest were used to test the capability of the model (as a validation set) as selected through a random selection process. The training process was stopped with overall r(2) values above 0.986. In particular, the models capture how the coformer structure influences the targeted physical properties of cocrystals.

}, issn = {1528-7483}, doi = {10.1021/acs.cgd.0c00182}, author = {Gamidi, Rama Krishna and Rasmuson, Ake C.} } @article {47691, title = {Separation of a diastereomeric diol pair using the mechanical properties of crystals}, journal = {Crystengcomm}, volume = {23}, year = {2021}, month = {OCT}, pages = {7056-7060}, type = {Article}, abstract = {We report the separation of a (2S,3R/S)-3-ethyl-1-phenylhex-5-ene-2,3-diol (ephd) diastereomeric pair with visually indistinguishable acicular morphologies based on their mechanical responses, which is found to be more efficient than conventional separation methods. Furthermore, the molecular crystals of (2S,3R)-ephd show elastic deformation, while (2S,3S)-ephd fractures in a brittle manner under similar conditions.}, doi = {10.1039/d1ce01055g}, author = {Gamidi, Rama Krishna and Dandawate, Monica and Choudhury, Rahul and Tothadi, Srinu and Nangia, Ashwini and Reddy, D. Srinivasa} } @article {47896, title = {Transition metal- and oxidant-free regioselective synthesis of 3,4,5-trisubstituted pyrazoles by means of [3+2] cycloaddition reactions}, journal = {ChemistrySelect}, volume = {7}, year = {2022}, month = {MAR}, pages = {e202200605}, type = {Article}, abstract = {

A highly efficient regioselective synthesis of 3,4,5-trisubstituted pyrazoles via transition metal- and oxidant-free, three component [3+2] cycloaddition with thiazolidinedione chalcones, benzaldehydes and N-tosylhydrazine is described. The reaction proceeds through C-C and C-N bond formations under mild reaction conditions to produce structurally diverse polysubstituted pyrazoles in moderate to good yields.

}, keywords = {3, 4, 5-trisubstituted pyrazoles, Cycloaddition, Multicomponent reaction, Oxidant free, Regioselectivity, Transition metal free}, issn = {2365-6549}, doi = {10.1002/slct.202200605}, author = {Allaka, Bhargava Sai and Basavoju, Srinivas and Gamidi, Rama Krishna} } @article {48923, title = {2-Amino-5-methylene-pyrimidine-4,6-dione-based Janus G-C nucleobase as a versatile building block for self-assembly}, journal = {Organic and biomolecular chemistry }, year = {2023}, month = { AUG }, type = {Article; Early Access}, abstract = {

This communication reports a nature-inspired Janus G-C nucleobase featuring two recognition sites: DDA (G mimic) and DAA (C mimic), which is capable of forming a linear tape-like supramolecular polymer structure. As demonstrated herein, the amino group of this self-assembling system can be further modified to yield a highly stable quadruple H-bonding system as well as a masked self-assembling system cleavable upon exposure to light.

}, keywords = {DNA Triplex, Peptide nucleic acid, Polymers}, issn = {1477-0520}, doi = {10.1039/d3ob01174g}, author = {Wagh, Mahendra A. and Shinde, Dinesh R. and Gamidi, Rama Krishna and Sanjayan, Gangadhar J.} } @article {48467, title = {Ultrasound assisted green protocol for the synthesis of quinoxaline based bisspirooxindoles: crystal structure analysis, enone umpolung, DFT calculations, anti-cancer activity, and molecular docking studies}, journal = {Synthetic Communications}, volume = {53}, year = {2023}, month = {JUN}, pages = {835-854}, type = {Article}, abstract = {

A series of novel quinoxaline based bisspirooxindolo-pyrrolizidines were synthesized through 1,3-dipolar cycloaddition under ultrasonication with shorter reaction time and good yields. The compounds were well characterized by various spectroscopic methods and finally single crystal X-ray diffraction method (4c, 4d). DFT energy calculations confirm the regioselectivity due to enone umpolung effect. The in vitro anti-cancer activity of the synthesized compounds (4a-s) shows that the compounds 4g and 4q exhibited good anti-cancer activity with IC50 values14.51 +/- 1.1 and 11.36 +/- 0.23 mu M against DU-145 prostate cancer cell line; and 16.78 +/- 0.95 and 14.28 +/- 0.64 mu M against Hela cervical cancer cell lines when compared to the standard anti-cancer drug doxorubicin (1.75 +/- 0.06 and 1.35 +/- 0.09 mu M). In silico molecular docking studies indicated that the synthesized compounds may serve as a potential lead for the further development of novel anti-cancer agents.

}, keywords = {Anti-cancer activity, bisspirooxindoles, DFT calculations, Hirshfeld surface, ultrasonication}, issn = {0039-7911}, doi = {10.1080/00397911.2023.2199360}, author = {Baddepuri, Sravanthi and Allaka, Bhargava Sai and Gamidi, Rama Krishna and Faizan, Mohmmad and Pawar, Ravinder and Basavoju, Srinivas} } @article {49018, title = {Synthesis, crystal growth, physicochemical study of 1,3-dihexyl-2-me-thyl-1H-benzo[d]imidazol-3-ium bromide and in silico nonlinear optical property determination}, journal = {Journal of Molecular Structure}, volume = {1307}, year = {2024}, month = {JUL }, type = {Article}, abstract = {

This study encompasses the synthesis and characterization of 1,3-dihexyl-2-methyl-1H-benzo[d]imidazol-3-ium bromide (DHBIB) using techniques such as NMR, IR, and HRMS. The study also explores the influence of different solvents, specifically water and acetonitrile, on the growth of single crystals. An intriguing observation is the transformation of crystal packing from orthorhombic to monoclinic when solvent conditions change, illustrating the pivotal role of the cation in controlling the crystal structure of DHBIB salts. The analysis of its electronic properties reveal a deep -lying LUMO (-3.73 eV), suggesting DHBIB{\textquoteright}s electron -accepting characteristics. Furthermore, the study records absorption maxima ( lambda max ) at 279 nm and 282 nm in various solvents, demonstrating that DHBIB lacks absorption in the visible range (400-800 nm), making it promising for non-linear optical (NLO) applications. Analysis of the natural bond orbital (NBO) stabilization energies 50.87, 42.12, and 45.33 kcal/mol along pi(C3-C4) -\> pi*(C6-C8), pi(C3-C4) -\> pi*(C10-C12), and pi (C10-C12) -\> pi*(C6-C8) reveal a preference for intramolecular charge transfer in DHBIB. Enhanced first and second -order hyperpolarizabilities ( beta ; 13.47x10 -30 esu, gamma ; 75.36x10 - 36 esu) compared to benzimidazole and benzimidazolium salicylate salt further supports its potential for NLO applications.

}, keywords = {DHBIB, Hyperpolarizability, Monoclinic, NBO, Orthorhombic}, issn = {0022-2860}, doi = {10.1016/j.molstruc.2024.137956}, author = {Siddiqui, Zahir Ali and Gamidi, Rama Krishna and Sekar, Nagaiyan and More, Sandeep} } @article {49090, title = {Ultrasound-assisted ionic liquid-mediated green method for synthesis of 1,3-diphenylpyrazole-based spirooxindolopyrrolizidines, their anti-tubercular activity, molecular docking study and ADME predictions}, journal = {New Journal of Chemistry}, volume = {48}, year = {2024}, month = {JUN }, pages = {9970-9980}, type = {Article}, abstract = {

The aim of the study is to develop the synthesis of a novel series of potent anti-tubercular (anti-TB) activity of 1,3-diphenylpyrazole-based spirooxindolopyrrolizidine derivatives via an efficient green approach achieved by using an ionic liquid ([Bmim]BF4) under ultrasonication. The title compounds 4a-4ad with a general molecular formula CaHbX(0-2)NcOd (X = F/Cl/Br) were produced with high yields in shorter reaction time and well characterized by using spectral techniques; and finally single crystal X-ray diffraction method (4b). The newly synthesized compounds were evaluated for their in vitro anti-TB activity against Mycobacterium tuberculosis H37Rv strain. Among all, six compounds 4e (C36H29N5O4), 4g (C34H28N4O3), 4q (C36H28F2N4O2), 4r (C36H28ClFN4O2), 4y (C36H29BrN4O2) and 4z (C36H28BrFN4O2) exhibited significant anti-TB activity with MIC value 6.25 mu g mL-1, when compared to the standard drug ethambutol (MIC:1.56 mu g mL-1). In silico molecular docking studies were performed against M. tuberculosis enoyl-acyl carrier protein reductase inhibitor. The compounds 4o, 4p, 4y and 4aa were exhibited least binding energies -12.58, -12.61, -12.58 and -12.57 kcal mol-1, respectively. These results reveal that the produced compounds might be used for the future generation of novel anti-TB drugs. The study aims to develop and synthesis of a novel series of 1,3-diphenylpyrazole-based spirooxindolopyrrolizidine derivatives as potent anti-TB agents via an efficient green approach by using an ionic liquid ([Bmim]BF4) under ultrasonication.

}, issn = {1144-0546}, doi = {10.1039/d4nj00563e}, author = {Baddepuri, Sravanthi and Gamidi, Rama Krishna and Kumari, Jyothi and Sriram, Dharmarajan and Basavoju, Srinivas} }