Koushik Sarkar
@sxccal.edu
Assistant Professor, Department of Chemistry
St. Xavier's College (Autonomous), Kolkata
RESEARCH, TEACHING, or OTHER INTERESTS
Chemistry, Organic Chemistry, Inorganic Chemistry, Biochemistry
Scopus Publications
Scholar Citations
Scholar h-index
Scholar i10-index
Scopus Publications
Tuhina Mondal, Poulami Hota, Koushik Sarkar, Anup Debnath, Bikash Kumar Shaw, and Shyamal K Saha
Royal Society of Chemistry (RSC)
Transition-metal-based metal–organic frameworks (MOFs) have received great interest for the development of low cost, platinum-free, non-precious water splitting electrocatalysts for hydrogen generation to resolve the energy crisis.
Soumitra Dinda, Koushik Sarkar, Bikash Kumar Panda, Kausikisankar Pramanik, and Sanjib Ganguly
Springer Science and Business Media LLC
Koushik Sarkar, Hemanta Kumar Datta, Sabir Ahmed, and Parthasarathi Dastidar
Wiley
AbstractA new series of organic‐inorganic‐hybrid‐systems (OIHS) was synthesized with the aim of developing metallogels that might display ‘drug‐like’ function. Reaction of two dicarboxylate ligands namely 3‐carboxycinnamic acid (3‐cca) and 4‐carboxycinnamic acid (4‐cca) with various bivalent metal ions (Cu(II), Zn(II), Co(II), Cd(II), Mn(II)) produced a new series of OIHS which were crystallographically characterized; five of which were coordination polymers (CP1‐CP5) and one metal‐organic polyhedra (MOP‐1). Reaction of 3‐cca with various metal ions in presence of DMSO/water produced five metallogels (MG1‐MG5) of which the Zn(II)‐metallogel namely MG1 was evaluated for both anti‐cancer and anti‐bacterial properties against murine tumor cell line B16‐F10 (human skin cancer model) and gram positive bacterium S. aureus. While MTT and cell migration assays established the anti‐cancer activity of MG1 against B16‐F10, flow cytometry and laser scanning confocal microscopy (LSCM) images under various staining conditions supported apoptotic pathway of cancer cell death. Anti‐bacterial ability of MG1 was also established against S. aureus by zone inhibition, and flow cytometry and LSCM studies under various staining conditions. MG1 was also demonstrated to be effective in killing the intracellular bacterial cells when B16‐F10 cells were infected with S. aureus thereby suggesting its potential in treating post‐operative cancer surgery model system.
Sahidul Mondal, Koushik Sarkar, and Pradyut Ghosh
American Chemical Society (ACS)
A series of seven new bis-heteroleptic Ru(II) probes (1[PF6]2-7[PF6]2) along with two previously reported probes (8[PF6]2 and 9[PF6]2) containing a similar anion binding triazole unit (hydrogen bond donor) functionalized with various substituents are employed in a detailed comparative investigation for the development of superior selective probes for H2PO4-. Various solution- and solid-state studies, such as 1H-DOSY NMR, dynamic light scattering (DLS), single-crystal X-ray crystallography, and transmission electron microscopy (TEM), have established that the selective sensing of H2PO4- by this series of probes is primarily due to supramolecular aggregation driven enhancement of 3MLCT emission. Intestingly, 1[PF6]2 and 7[PF6]2, having an electron-deficient (π-acidic) aromatic pentafluorophenyl substituent are found to be superior probes for H2PO4- in comparison to the other aryl- and polyaromatic-substituted analogues (2[PF6]2-6[PF6]2, 8[PF6]2, and 9[PF6]2), in terms of a higher enhancement of the 3MLCT emission band, a greater binding constant, and a lower detection limit. The superiority of 1[PF6]2 and 7[PF6]2 could be due to better supramolecular aggregation properties in the cases of pentafluorophenyl analogues via both hydrogen bonding and anion-fluorine/anion-π noncovalent interactions.
Protap Biswas, Koushik Sarkar, and Parthasarathi Dastidar
Wiley
AbstractCrystallographically characterized M2L4 type cationic Cu(II)‐metallacryptands [MC(X)] derived from a series of bis‐pyridyl‐bis‐urea ligands (LX; X = O, S, C) are self‐assembled to single‐layered vesicular aggregates in DMSO, DMSO/water, and DMSO/DMEM (biological media). One such vesicle is MC(O)‐vesicle that is demonstrated to be able to load and release (pH responsive) an anticancer drug, namely doxorubicin hydrochloride (DOX). DOX‐loaded MC(O)‐vesicle is also successfully transported within MDA‐MB‐231 cells—a highly aggressive human breast cancer cell line. Such self‐assembling behavior to form vesicular aggregates by metallacryptands (MCs) is hitherto unknown.
Sourabh Bera, Abhinanda Chowdhury, Koushik Sarkar, and Parthasarathi Dastidar
Wiley
AbstractA series of coordination polymers synthesized from a bis‐pyridyl linker, namely 4,4′‐azopyridine (L), selected non‐steroidal‐anti‐inflammatory drugs (NSAIDs), namely diclofenac (Dic), ibuprofen (Ibu), flurbiprofen (Flu), mefenamic acid (Mefe), and naproxen (Nap), and Zn(NO3)2 were characterized by single crystal X‐ray diffraction. One of the coordination polymers, namely CP3 derived from Flu, was able to form metallovesicles in DMSO, DMSO/H2O and DMSO/DMEM (biological media) as revealed by TEM, AFM and DLS. Metallovesicle formation by CP3 was further supported by loading a fluorescent dye, namely calcein, as well as an anti‐cancer drug, doxorubicin hydrochloride (DOX), as revealed by UV‐vis and emission spectra, and fluorescence microscopy. DOX‐loaded metallovesicles of CP3 (DOX@CP3‐vesicle) could be delivered in vitro to a highly aggressive human breast cancer cell line, namely MDA‐MB‐231, as revealed by MTT and cell migration assays, and also cell imaging performed under laser scanning confocal microscope (LSCM). Thus, a proof of concept for developing a multi‐drug delivery system derived from a metallovesicle for delivering an anti‐cancer drug to cancer cells is demonstrated for the first time.
Koushik Sarkar, Sabir Ahmed, and Parthasarathi Dastidar
Wiley
AbstractDeveloping hierarchical supramolecular structures is important for better understanding of various biological functions and possibly generating new materials for biomedical applications. Herein, we report the first examples of functional vesicles derived from cationic spherical organic molecules (C1‐C3) which were readily synthesized by reacting a C3‐symmetric tris‐benzimmidazole derivative (possessing a 1,3,5‐ethyl substituted aromatic core) with 1,3,5‐substituted tris‐bromomethyl benzene derivatives. Vesicle formation by C1‐C3 was probed by high‐resolution microscopy (TEM and AFM), dynamic light scattering (DLS) and fluorescence microscopic imaging of calcein‐loaded vesicles. One of the vesicles [Vesicle(C3)] displayed the ability to load the anticancer drug doxorubicin (DOX). The drug was subsequently released from DOX@Vesicle(C3) in a stimuli‐responsive manner in presence of the well‐known vesicle destroyer Triton X‐100, as revealed by in vitro cell migration assay carried out on a highly aggressive human breast cancer cell line (MDA‐MB‐231).
Koushik Sarkar and Parthasarathi Dastidar
Wiley
AbstractA structural rationale was adopted to design a series of metallogels from a newly synthesized urea‐functionalized dicarboxylate ligand, namely, 5‐[3‐(pyridin‐3‐yl)ureido]isophthalic acid (PUIA), that produces metallogels upon reaction with various metal salts (CuII, ZnII, CoII, CdII, and NiII salts) at room temperature. The gels were characterized by dynamic rheology and transmission electron microscopy (TEM). The existence of a coordination bond in the gel state was probed by FTIR and 1H NMR spectroscopy in a ZnII metallogel (i.e., MG2). Single crystals isolated from the reaction mixture of PUIA and CoII or CdII salts characterized by X‐ray diffraction revealed lattice inclusion of solvent molecules, which was in agreement with the hypothesis based on which the metallogels were designed. MG2 displayed anti‐inflammatory response (prostaglandin E2 assay) in the macrophage cell line (RAW 264.7) and anticancer properties (cell migration assay) on a highly aggressive human breast cancer cell line (MDA‐MB‐231). The MG2 metallogel matrix could also be used to load and release (pH responsive) the anticancer drug doxorubicin. Fluorescence imaging of MDA‐MB‐231 cells treated with MG2 revealed that it was successfully internalized.
Parthasarathi Dastidar, Rajdip Roy, Rumana Parveen, and Koushik Sarkar
Wiley
AbstractLow‐molecular‐weight gelators (LMWGs) are an important class of soft materials that offer various potential applications including drug delivery. Structural diversities of the reported LMWGs and lack of molecular‐level understanding of the self‐assembly process of gelation make it difficult to design a gelator a priori. Most often gelators are discovered in a serendipitous manner and second‐generation gelators are designed by modifying known gelling scaffolds. Since gel network within which the solvent molecules are immobilized is often found to be crystalline, a supramolecular synthon approach in the context of crystal engineering is demonstrated to be quite effective in designing LMWGs for various applications including therapeutics. Self‐drug‐delivery systems, wherein the need for a delivery vehicle does not exist, are becoming an effective alternative to conventional drug delivery systems. In the form of a simple gel (for non‐invasive topical application) or injectable gel (for invasive subcutaneous applications), LMWGs derived from drugs provide an effective way to develop self‐drug‐delivery systems. This review article encompasses the early development of LMWG research, describes gradual transition from discovering just a gelator to a gelator having potential material applications including drug delivery, and highlights the merit of supramolecular synthon approach in designing LMWGs for self‐drug‐delivery applications.
Sayantan Ganguly, Paramita Kar, Maharudra Chakraborty, Koushik Sarkar, and Ashutosh Ghosh
Royal Society of Chemistry (RSC)
Three new one-dimensional CoII/CoIII chains have been synthesized using N-salicylidene-l-alanine/N-salicylidene-l-phenylalanine and 2,2′-bipyridine/1,10-phenanthroline. All three complexes exhibit phenoxazinone synthase-like activity.
Koushik Sarkar, Shaik Khasimbi, Souvik Mandal, and Parthasarathi Dastidar
American Chemical Society (ACS)
Metal-ligand coordination involving hydrogen-bond-functionalized ligands was employed rationally to get an easy access to a series of metallogelators derived from 3-pyridyl derivatives of nonsteroidal anti-inflammatory drugs [e.g., ibuprofen, sulindac, and flurbiprofen designated as 3-pyIBU, 3-pySUL, and 3-pyFLR, respectively] and biogenic metal centers [Zn(II), Cu(II), Mn(II), and Ag(I)]. A total of 13 metallogels (MG1-MG13) were obtained by allowing the ligands and the metal salts to react in dimethyl sulfoxide (DMSO)/water at room temperature. A slightly different solvent system (DMSO/water/MeOH) afforded four crystalline coordination complexes of 3-pyIBU, namely, [{Cu(3-pyIBU)4(DMSO)2}(NO3)2] (CC1), [{Ag(3-pyIBU)2}(BF4)] (CC2), [{Ag(3-pyIBU)2}(ClO4)] (CC3), and [{Cu(3-pyIBU)4(CH3OH)2}(OTf)] (CC4), which were fully characterized by single-crystal X-ray diffraction. However, none of these coordination complexes produced metallogels-the results corroborated well with the rationale, based on which the metallogelators were obtained. Two selected metallogels (MG3 and MG9) could be leached out from the corresponding metallogels to the bulk solvent to the extent of 51 and 59%, respectively after 24 h of incubation at 37 °C, indicating their plausible use in topical application. Moreover, one of the selected metallogelators, i.e., MG9, displayed anti-inflammatory response and was able to inhibit the migration of highly aggressive human breast cancer cells MDA-MB-231, suggesting its plausible use as anticancer agent.
Koushik Sarkar and Parthasarathi Dastidar
Wiley
AbstractA 2D coordination polymer derived from 5‐azidoisophthalic acid (AIA) and Cu(NO3)2 was designed with the aim of modulating the activity of a digestive enzyme α‐chymotrypsin (ChT). The coordination polymer namely {[Cu0.5(μ‐AIA)0.5(H2O)]⋅2 H2O}α (CP1) was successfully synthesized and fully characterized by single‐crystal X‐ray diffraction (SXRD). An exfoliated nanosheet (ENS) of CP1 was readily produced by overnight stirring of hand‐ground CP1 crystals dispersed in DMSO. ENS(CP1) was demonstrated to be acting as an inhibitor of ChT; as much as ≈97 % inhibition of ChT was achieved with 100 μm of ENS(CP1) using N‐succinyl‐l‐phenylalanine‐p‐nitroanilide (SPNA) as substrate. Enzyme kinetics data revealed that the inhibition of ChT followed a competitive pathway. An enzyme assay under varying ionic strength and varying concentration of free histidine revealed that the active site His‐57 participated in coordination with the CuII metal center of ENS(CP1) thereby preventing the substrate (SPNA) from binding with the enzyme resulting in efficient inhibition.
Koushik Sarkar and Parthasarathi Dastidar
American Chemical Society (ACS)
Koushik Sarkar and Parthasarathi Dastidar
American Chemical Society (ACS)
A C3-symmetric triazine based triboronic acid (HG1) was designed and synthesized. HG1 was found to give hydrogel in DMSO-water (1:9). The hydrogel was rheo-reversible and thermoreversible over a few cycles. Single-crystal X-ray diffraction (SXRD) studies on the crystals of HG1 established the presence of honeycomb network in which solvent molecules (DMSO and water) were occluded. SXRD data corroborated well with the hypothesis based on which HG1 was designed. Stimuli responsive release (in vitro) of insulin and doxorubicin from the hydrogel was also achieved.
P. Dastidar, S. Ganguly, and K. Sarkar
Elsevier
Mithun Paul, Koushik Sarkar, Jolly Deb, and Parthasarathi Dastidar
Wiley
AbstractIncreased levels of intracellular prostaglandin E2 (PGE2) have been linked with the unregulated cancer cell migration that often leads to metastasis. Non‐steroidal anti‐inflammatory drugs (NSAIDs) are known inhibitors of cyclooxygenase (COX) enzymes, which are responsible for the increased PGE2 concentration in inflamed as well as cancer cells. Here, we demonstrate that NSAID‐derived ZnII‐based coordination polymers are able to inhibit cell migration of human breast cancer cells. Various NSAIDs were anchored to a series of 1D ZnII coordination polymers through carboxylate–Zn coordination, and these structures were fully characterized by single‐crystal X‐ray diffraction. Hand grinding in a pestle and mortar resulted in the first reported example of nanoscale coordination polymers that were suitable for biological studies. Two such hand‐ground nanoscale coordination polymers NCP1 a and NCP2 a, which contained naproxen (a well‐studied NSAID), were successfully internalized by the human breast cancer cells MDA‐MB‐231, as was evident from cellular imaging by using a fluorescence microscope. They were able to kill the cancer cells (MTT assay) more efficiently than the corresponding mother drug naproxen, and most importantly, they significantly inhibited cancer cell migration thereby displaying anticancer activity.
Koushik Sarkar and Parthasarathi Dastidar
Wiley
AbstractA mixed ligand approach was exploited to synthesize a new series of MnII‐based coordination polymers (CPs), namely, CP1 {[Mn(μ‐dpa)(μ‐4,4′‐bp)]⋅MeOH}∞, CP2 {[Mn3(μ‐dpa)3(2,2′‐bp)2]}∞, CP3 {[Mn3(μ‐dpa)3(1,10‐phen)2]⋅2 H2O}∞, CP4 {[Mn(μ‐dpa)(μ‐4,4′‐bpe)1.5]⋅H2O}∞, CP5 {[Mn2(μ‐dpa)2(μ‐4,4′‐bpe)2]⋅ DEF}∞, and CP6 {[Mn(μ‐dpa)(μ‐4,4′‐bpe)1.5]⋅ DMA}∞ (dpa=3,5‐dicarboxyphenyl azide, 2,2′‐bp=2,2′‐bipyridine, 1,10‐phen=1,10‐phenanthroline, 4,4′‐bpe=1,2‐bis(4‐pyridyl)ethylene, 4,4′‐bp=4,4′‐bipyridine, DEF=N,N‐diethylformamide, DMA=N,N‐dimethylacetamide), to develop multifunctional CPs. Various techniques, such as single‐crystal X‐ray diffraction (SXRD), FTIR spectroscopy, elemental analysis, and thermogravimetric analysis, were employed to fully characterize these CPs. The majority of the CPs displayed a four‐connected sql topology, whereas CP4 and CP6 exhibited a two‐dimensional SnS network architecture, which was further entangled in a polycatenation mode. Compound CP1 displayed an open framework structure. The CPs were scaled down to the nanoregime in a ball mill for cell imaging studies. Whereas CP2 and CP4 were employed for cell imaging with RAW264.7 cells, CP1 was exploited for both cell imaging and heterogeneous catalysis in a cyanosilylation reaction.
Parthasarathi Dastidar, Sumi Ganguly, and Koushik Sarkar
Wiley
AbstractA supramolecular gel results from the immobilization of solvent molecules on a 3D network of gelator molecules stabilized by various supramolecular interactions that include hydrogen bonding, π–π stacking, van der Waals interactions, and halogen bonding. In a metallogel, a metal is a part of the gel network as a coordinated metal ion (in a discrete coordination complex), as a cross‐linking metal node with a multitopic ligand (in coordination polymer), and as metal nanoparticles adhered to the gel network. Although the field is relatively new, research into metallogels has experienced a considerable upsurge owing to its fundamental importance in supramolecular chemistry and various potential applications. This focus review aims to provide an insight into the development of designing metallogelators. Because of the limited scope, discussions are confined to examples pertaining to metallogelators derived from discrete coordination complexes, organometallic gelators, and coordination polymers. This review is expected to enlighten readers on the current development of designing metallogelators of the abovementioned class of molecules.
Koushik Sarkar, Mithun Paul, and Parthasarathi Dastidar
Royal Society of Chemistry (RSC)
Multifunctional vesicles derived from Cu(ii) metal–organic polyhedra (MOP) displayed the ability to encapsulate and release anti-cancer drug doxorubicin for the first time.
Mithun Paul, Koushik Sarkar, and Parthasarathi Dastidar
Wiley
AbstractBy applying a recently developed crystal engineering rationale, four C3 symmetric tris(pyridylamide) ligands namely 1,3,5‐tris(nicotinamidomethyl)‐2,4,6‐triethylbenzene, 1,3,5‐tris(isonicotinamidomethyl)‐2,4,6‐triethylbenzene, 1,3,5‐tris(nicotinamidomethyl)‐2,4,6‐trimethylbenzene, and 1,3,5‐tris(isonicotinamidomethyl)‐2,4,6‐trimethylbenzene, which contain potential hydrogen‐bonding sites, were designed and synthesized for generating AgI coordination polymers and coordination‐polymer‐based gels. The coordination polymers thus obtained were characterized by single‐crystal X‐ray diffraction. The silver metallogels were characterized by transmission electron microscopy (TEM) and dynamic rheology. Upon exposure to visible light, these silver metallogels produced silver nanoparticles (AgNPs), which were characterized by TEM, powder X‐ray diffraction, energy dispersive X‐ray and X‐ray photoelectron spectroscopy. These NPs were found to be effectively catalyzed the reduction of 4‐nitrophenolate to 4‐aminophenolate without the use of any exogenous reducing agent.