https://dspace.library.iitb.ac.in/jspui/handle/100/13681 2026-03-16T02:31:30Z 2026-03-16T02:31:30Z BAJPAI S. CHELAKKOT R. PRABHAKAR R. INAMDAR M.M. https://dspace.library.iitb.ac.in/jspui/handle/100/42161 2023-03-17T06:09:44Z 2022-01-01T00:00:00Z

Role of Delta-Notch signalling molecules on cell-cell adhesion in determining heterogeneous chemical and cell morphological patterning BAJPAI S.; CHELAKKOT R.; PRABHAKAR R.; INAMDAR M.M. Cell mechanics and motility are responsible for collective motion of cells that result in overall deformation of epithelial tissues. On the other hand, contact-dependent cell-cell signalling is responsible for generating a large variety of intricate, self-organized, spatial patterns of the signalling molecules. Moreover, it is becoming increasingly clear that the combined mechanochemical patterns of cell shape/size and signalling molecules in the tissues, for example, in cancerous and sensory epithelium, are governed by mechanochemical coupling between chemical signalling and cell mechanics. However, a clear quantitative picture of how these two aspects of tissue dynamics, i.e., Signalling and mechanics, lead to pattern and form is still emerging. Although, a number of recent experiments demonstrate that cell mechanics, cell motility, and cell-cell signalling are tightly coupled in many morphogenetic processes, relatively few modeling efforts have focused on an integrated approach. We extend the vertex model of an epithelial monolayer to account for contact-dependent signalling between adjacent cells and between non-adjacent neighbors through long protrusional contacts with a feedback mechanism wherein the adhesive strength between adjacent cells is controlled by the expression of the signalling molecules in those cells. Local changes in cell-cell adhesion lead to changes in cell shape and size, which in turn drives changes in the levels of signalling molecules. Our simulations show that even this elementary two-way coupling of chemical signalling and cell mechanics is capable of giving rise to a rich variety of mechanochemical patterns in epithelial tissues. In particular, under certain parametric conditions, bimodal distributions in cell size and shape are obtained, which resemble experimental observations in cancerous and sensory tissues. © 2022 the royal society of chemistry

2022-01-01T00:00:00Z SASMAL S. PRAKASH G. DUTTA U. LASKAR R. LAHIRI G.K. MAITI D. https://dspace.library.iitb.ac.in/jspui/handle/100/42160 2023-03-17T06:09:44Z 2022-01-01T00:00:00Z

Directing group assisted rhodium catalyzed meta-C-H alkynylation of arenes SASMAL S.; PRAKASH G.; DUTTA U.; LASKAR R.; LAHIRI G.K.; MAITI D. Site-selective c-h alkynylation of arenes to produce aryl alkynes is a highly desirable transformation due to the prevalence of aryl alkynes in various natural products, drug molecules and in materials. To ensure site-selective c-h functionalization, directing group (dg) assisted c-h activation has been evolved as a useful synthetic tool. In contrast to dg-assisted ortho-c-h activation, distal meta-c-h activation is highly challenging and has attracted significant attention in recent years. However, developments are majorly focused on pd-based catalytic systems. In order to diversify the scope of distal meta-c-h functionalization, herein we disclosed the first rh(i) catalyzed meta-c-h alkynylation protocol through the inverse sonogashira coupling reaction. The protocol is compatible with various substrate classes which include phenylacetic acids, hydrocinnamic acids, 2-phenyl benzoic acids, 2-phenyl phenols, benzyl sulfonates and ether-based scaffolds. The post-synthetic modification of meta-alkynylated arenes is also demonstrated through dg-removal as well as functional group interconversion. © 2022 the royal society of chemistry

2022-01-01T00:00:00Z VEERAMANI K. NAYAK N. CAMERON N.R. KUMAR A. https://dspace.library.iitb.ac.in/jspui/handle/100/42159 2023-03-17T06:09:44Z 2022-01-01T00:00:00Z

Process intensification of dendritic fibrous nanospheres of silica (DFNS) via continuous flow: a scalable and sustainable alternative to the conventional batch synthesis VEERAMANI K.; NAYAK N.; CAMERON N.R.; KUMAR A. In this manuscript, we report the scalable continuous flow synthesis of dendritic fibrous nanospheres of silica (dfns) which have been speedily making a significant mark in the world of heterogeneous nanocatalysis for over a decade by virtue of their unique morphology. Further, this work also demonstrates the telescoping of the complete process intensification of this material through combination of scalable reactors like the spinning disk reactor and the dynamically agitated tubular reactor. This intensified synthetic protocol performed through continuous flow chemistry is a scalable, efficient, feasible, quicker, and sustainable route of synthesis. Interestingly, this protocol is generic and may be easily extrapolated to the process intensification of a wide range of similar hydrothermal biphasic nanoparticle systems, thus widening the horizons of controlled, intensified, and sustainable production of nanomaterials. © 2023 the royal society of chemistry.

2022-01-01T00:00:00Z KUMAR P. SEN A. RAJARAMAN G. SHANMUGAM M. https://dspace.library.iitb.ac.in/jspui/handle/100/42156 2023-03-17T06:09:43Z 2022-01-01T00:00:00Z

An unusual mixed-valence cobalt dimer as a catalyst for the anti-Markovnikov hydrophosphination of alkynes KUMAR P.; SEN A.; RAJARAMAN G.; SHANMUGAM M. The reaction of [co(pme3)4] (1) with a redox-active nnn pincer ligand (l1) led us to isolate a unique binuclear cobalt complex ([(pme3)2coii(l13−)coi(pme3)3] (2)) anchored by a three-electron reduced l1 in its unusual coordination mode. Such an unprecedented binuclear pincer/allyl cobalt complex consisting of the mixed-valence oxidation state of cobalt ions (+1 and +2) is confirmed by various analytical techniques (xps, epr, and uv-vis), and the experimentally determined electronic structure is well corroborated by detailed theoretical studies based on dft calculations. Complex 2 efficiently catalyzes the hydrophosphination of alkynes regioselectively, and affords the anti-markovnikov product in good to excellent yields without any additional strong bases or organolithium reagents. Both internal and terminal alkynes including propargylic alcohols were amenabled to accessing vinyl trivalent phosphines with exclusive e-selectivity. The isotopic labeling experiments confirmed the 1,2-anti-markovnikov addition of p-h from hpph2 across the alkyne stem. The preliminary 1h and 31p nmr investigations revealed that the coi nucleus in 2 is likely responsible for the catalytic outcome of the hydrophosphination of alkynes. Overall, the study discloses the importance of the exemplary structural platform offered by the redox-active pincer ligands in isolating unusual multi-nuclear complexes and the need to explore the multi-nuclear complexes as a catalyst besides the traditional mononuclear catalyst. © 2022 the royal society of chemistry

2022-01-01T00:00:00Z