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Crystal structures of the Schiff base derivatives (E)-N′-[(1H-indol-3-yl)methylidene]isonicotinohydrazide ethanol monosolvate and (E)-N-methyl-2-[1-(2-oxo-2H-chromen-3-yl)ethylidene]hydrazinecarbothioamide
(International Union of Crystallography, 2017-03-24) Saranya, Sivaraj; Haribabu, Jebiti; Bhuvanesh, Nattamai S.P.; Karvembu, Ramasamy; Gayathri, Dasararaju
The crystal structures of two title Schiff base derivatives, C15H12N4O·C2H6O (1·EtOH) and C13H13N3O2S (2), were determined at 110 and 100K, respectively. In the crystal of compound 1·EtOH, the (E)-N′-[(1H-indol-3-yl)methylidene]isonicotinohydrazide and ethanol molecules are linked by O-H⋯O, N-H⋯O and N-H⋯N hydrogen bonds, forming a tape structure running along the b-axis direction. The tapes are weakly linked via a C-H⋯N interaction. In the crystal of compound 2, (E)-N-methyl-2-[1-(2-oxo-2H-chromen-3-yl)ethylidene]hydrazinecarbothioamide molecules are linked via N-H⋯O and C-H⋯O hydrogen bonds, forming a helical chain along the b-axis direction. The chains are further linked into a layer expanding parallel to (102) through C-H⋯S interactions.
Heterostructure of two different 2D materials based on MoS2 nanoflowers@rGO: an electrode material for sodium-ion capacitors
(Royal Society of Chemistry, 2018-09-05) Ramakrishnan, Kiruthiga; Nithya, Chandrasekaran; Karvembu, Ramasamy
Sodium ion capacitors are under extensive investigation as companionable pre-existing lithium ion batteries and sodium ion batteries. Finding a suitable host for sodium ion storage is still a major challenge. In this context, here we report a MoS2 nanoflowers@rGO composite produced via a hydrothermal method followed by an ultra sonication process as a sodium ion symmetric hybrid supercapacitor. The structural and electrochemical performances of the electrode material were investigated to establish its applicability in sodium ion capacitors. The electrochemical performance was evaluated using metallic sodium in a half cell configuration which delivered a maximum specific capacitance of 226 F g−1 at 0.03 A g−1. When examined as a symmetric hybrid electrode (full cell) it delivered a maximum capacitance of 55 F g−1 at 0.03 A g−1. This combination may be a new gateway for upcoming research work which deals with sodium ion storage applications. The results confirmed that the as-synthesized MoS2 nanoflowers@rGO heterostructure electrode exhibited notable electrochemical behaviour.
Spectroscopic, anticancer and antioxidant studies of fluxional trans-[PdCl2(S-acylthiourea)2] complexes
(Elsevier B.V., 2021-07-19) Dorairaj. Dorothy Priyanka; Haribabu. Jebiti; Chithravel. Vadivalagan; Vennila. Kailasam N; Bhuvanesh. Nattamai; Echeverria. Cesar; Hsu. Sodio C.N.; Karvembu, Ramasamy
A library of palladium(II) acylthiourea complexes (1–6) of the type [PdCl2{C8H13N2OS(R)}2] [where R = C6H4CH3(o) (1), C6H5 (2), C6H4OCH3(p) (3), C6H4OC2H5(p) (4), C10H7 (5) or C6H5Cl(p) (6)] was synthesized and characterized by UV–Visible, FT-IR, 1H NMR, 13C NMR and ESI-Mass spectroscopy, and elemental analysis. Single crystal X-ray structure of complex 4 revealed the monodentate coordination of acylthiourea ligand through sulphur atom to the palladium ion in a trans fashion. In addition, variable-temperature (VT) NMR studies were performed to analyze the fluxional nature of complexes. The interaction of complexes with calf thymus (CT) DNA and BSA (bovine serum albumin) was analyzed by spectroscopic and molecular docking studies. The results inferred intercalation binding mode of the complexes with DNA. All the complexes exhibited good binding with BSA as well. Further, the complexes were found to act as good scavengers of DPPH as deduced from the antioxidant assay. In vitro cytotoxicity of the compounds against A549 (lung) cancer and HEK293 (human embryonic kidney) normal cell lines was investigated by MTT assay. Among the six complexes, complex 5 bearing a napthyl substitution in acylthiourea exhibited a remarkable activity against A549 cell line with an IC50 value of 14.8 µM and was more active than cisplatin (IC50 = 17.8 µM). On the other hand, it showed less toxicity on HEK293 cell line. The cell death mechanism was analyzed by AO/EB and DAPI staining, flow cytometry and Western blot investigations, which revealed that complex 5 could initiate cell death through apoptosis.
Tris-(2-pyridyl)-pyrazolyl Borate Zinc(II) Complexes: Synthesis, DNA/Protein Binding and In Vitro Cytotoxicity Studies
(MDPI, 2021-12-03) Narwane, Manmath; Dorairaj, Dorothy Priyanka; Chang, Yu-Lun; Karvembu, Ramasamy; Huang, Yu-Han; Chang, Hsueh-Wei; Hsu, Sodio C. N.
Abstract
Zn(II) complexes bearing tris[3-(2-pyridyl)-pyrazolyl] borate (Tppy) ligand (1–3) was synthesized and examined by spectroscopic and analytical tools. Mononuclear [TppyZnCl] (1) has a Zn(II) centre with one arm (pyrazolyl-pyridyl) dangling outside the coordination sphere which is a novel finding in TppyZn(II) chemistry. In complex [TppyZn(H2O)][BF4] (2) hydrogen bonding interaction of aqua moiety stabilizes the dangling arm. In addition, solution state behaviour of complex 1 confirms the tridentate binding mode and reactivity studies show the exogenous axial substituents used to form the [TppyZnN3] (3). The complexes (1–3) were tested for their ability to bind with Calf thymus (CT) DNA and Bovine serum albumin (BSA) wherein they revealed to exhibit good binding constant values with both the biomolecules in the order of 104–105 M−1. The intercalative binding mode with CT DNA was confirmed from the UV-Visible absorption, viscosity, and ethidium bromide (EB) DNA displacement studies. Further, the complexes were tested for in vitro cytotoxic ability on four triple-negative breast cancer (TNBC) cell lines (MDA-MB-231, MDA-MB-468, HCC1937, and Hs 578T). All three complexes (1–3) exhibited good IC50 values (6.81 to 16.87 μM for 24 h as seen from the MTS assay) results which indicated that these complexes were found to be potential anticancer agents against the TNBC cells.
Synthesis of sulfanyl derivatives of 1,2,4-triazoles via an acid catalyzed intramolecular cyclization of isothiosemicarbazones: structural characterization, E/Z isomerism, mechanistic insights and in vitro cytotoxicity
(Royal Society of Chemistry, 2026-03-10) Snisha, Kallivalappil; Karthikeyan, Mano Chitra; Bhuvanesh, Nattamai; Arockiam, Antony Joseph Velanganni; Karvembu, Ramasamy
Sulfanyl derivatives of 1,2,4-triazoles (CL1–CL3) were synthesized via a Lewis or Brønsted acid catalyzed intramolecular cyclization of corresponding isothiosemicarbazones (TL1–TL3). All the synthesized isothiosemicarbazones and their cyclized sulfanyl 1,2,4-triazole derivatives were well characterized by spectroscopic techniques and single crystal XRD analyses. The E/Z isomerism of the isothiosemicarbazones was elucidated using NMR spectroscopy and single crystal XRD analysis. Mechanistic investigations, supported by controlled experiments and spectroscopic evidence, revealed that the cyclization proceeded via an ionic pathway with the evolution of hydrogen. The cytotoxic effect of the cyclized sulfanyl 1,2,4-triazole derivatives (CL1–CL3) was evaluated by MTT assay against MDA-MB-231 (breast), MCF-7 (breast), and HeLa (cervical) cancer cell lines, as well as HEK-293 (kidney) normal cell line, taking 5-fluorouracil (5-FU) as a reference drug. All the substituted sulfanyl-1,2,4-triazoles showed higher cytotoxicity toward MDA-MB-231 and HeLa cells than 5-FU, while exhibiting low toxicity toward HEK-293 cells, indicating good selectivity toward cancer cells. Substituted compounds [CL2 (p-OCH3) and CL3 (p-NO2)] displayed enhanced activity compared to the unsubstituted one (CL1), indicating the influence of the substituents on cytotoxicity. Fluorescence staining assays (AO/EB, Hoechst 33342, Rhodamine 123 and DCFH-DA) further supported the observed cytotoxic effects, and suggested that the compounds promoted apoptotic cell death via intracellular reactive oxygen species (ROS) generation, depletion of mitochondrial membrane potential (MMP) and damage to nuclear material.
Machine learning–based prioritization of sub-watersheds for soil erosion management: A case study of the Bardha watershed
(Elsevier B.V., 2026-03-26) Shekar, Padala Raja; Mathew, Aneesh; Arun, P. S.; Surya Prasanth, M; Alshehri, Fahad; Zhran, Mohamed
Soil erosion is a major environmental concern that affects land productivity and water quality. Although soil erosion is a serious global environmental challenge, understanding its potential influence in the Bardha Watershed is important due to its topographical characteristics and the dependence of local communities on land resources for agriculture. Morphometric analysis helps assess a watershed's physical characteristics to understand its erosion potential. In this study, sub-watersheds were delineated using the shuttle radar topography mission (SRTM) digital elevation model (DEM) to accurately derive drainage and terrain characteristics. To enhance the precision of sub-watershed prioritization, morphometric analysis is combined with multi-criteria decision-making (MCDM) techniques. This research ranks sub-watersheds in the Bardha watershed in Chhattisgarh using morphometric parameters in combination with four MCDM approaches: additive ratio assessment (ARAS), multi-objective optimization by ratio analysis (MOORA), visekriterijumsko kompromisno rangiranje (VIKOR) and simple additive weighting (SAW). The criteria weights for these MCDM methods are determined using the criteria importance through intercriteria correlation (CRITIC) method. Furthermore, the novelty of this study lies in the integration of machine learning (ML) techniques, specifically support vector machine (SVM) and random forest (RF). By combining the outputs of all six methods, the study developed a unified priority map, which was subsequently classified into high, medium, and low priority zones. The study found that sub-watershed 3 (SW3) and SW4 fall into the common high-priority category; SW2, SW6, and SW7 into the medium category; and SW1 and SW5 into the low-priority group. This integrated method makes decision-making stronger by letting planners focus on high-priority sub-watersheds for strategic development, conservation, and optimal land management. This study aligns with SDG 15 by addressing land degradation through the identification and management of soil erosion-prone areas.
Morphometric analysis for prioritizing sub‑watersheds of Murredu River basin, Telangana State, India, using a geographical information system
(Springer, 2022-05-16) Shekar, Padala Raja; Mathew, Aneesh
The Murredu watershed in Telangana State was chosen for the morphometric and land use/land cover (LULC) analysis in this current study. Geographical information system (GIS) and remote sensing (RS) techniques can estimate the morphometric features and LULC analysis of a catchment. A total of fourteen sub-watersheds (SWs) were created from the watershed (SW 1 to SW 14), and sub-watersheds were prioritized based on morphometric and LULC features. Evaluation of various morphometric characteristics such as linear aspects, relief aspects, and aerial aspects has been carried out for every sub-watershed to prefer ranking. Four parameters were utilized for the LULC analysis to rank and prioritize sub-watersheds. The sub-watersheds were categorized into three groups as low, medium, and high, for soil and water conservation priority based on morphometric and LULC analysis. Using morphometric analysis, higher priorities have been assigned to SW 12 and SW 1, while using LULC analysis, higher priorities have been assigned to SW 9 and SW 11. SW 10 and SW 13 are the most common sub-watersheds that fall within the same priority while using morphometric and LULC analysis. The coefficient of regression results reveals that stream length and stream order, and also stream number and stream order, have a strong association. The deployment of soil and water conservation measures may be conducted in the high-priority sub-watersheds.
Detection of land use/land cover changes in a watershed: A case study of the Murredu watershed in Telangana state, India
(KeAi Communications, 2022-12-20) Shekar, Padala Raja; Mathew, Aneesh
Land-use change refers to a change in how a particular area of land is utilised or managed by humans. Land-cover change refers to a change in some continuous features of the land, such as vegetation type, soil conditions, and so on. For the purpose of identifying change-vulnerable areas and creating sustainable ecosystem services, mapping and quantifying the state of land use/land cover (LULC) changes and change-causing factors are crucial. The present research utilizes a geographic information system (GIS) and remote sensing (RS) techniques to categorise and identify changes in a Murredu watershed in Telangana state, India, between 1996 and 2019. Five major LULC categories (agricultural land, forest, barren land, built-up area, and waterbodies) from satellite images of 1996 to 2019 were mapped. The maximum likelihood approach was used to supervise the classification process, and high-resolution Google Earth Pro was used to evaluate the accuracy of the classified map. The accuracy of the mapping was evaluated using the error matrix and Kappa statistics. Overall classification accuracy for the classified image of 2019 was found to be 90 % with overall kappa statistics of 85.98%. From these findings, change detection analysis shows that the area used for agricultural land, barren land, forest, built-up areas, and waterbodies has increased by 5.17%, 3.39%, 0.84%, and 0.26%, respectively, between 1996 and 2019. The forest area has decreased by 9.67% at the same time. Therefore, this research anticipates that the findings might provide information to planners, land managers, and decision-makers for the sustainable management and development of the natural resource.
Investigating the contrast diurnal relationship of land surface temperatures with various surface parameters represent vegetation, soil, water, and urbanization over Ahmedabad city in India
(Elsevier Ltd, 2022-01-30) Mathew, Aneesh; Sarwesh, P; Khandelwal, Sumit
Many climatic problems have arisen due to congested and inefficient planning, reduced vegetation cover, and increased pollution from factories and vehicles. One such primary concern is increased land surface temperature (LST) contributes to the urban heat island (UHI) occurrence. This research aims to understand better the UHI effect in the region neighbouring the Indian city of Ahmedabad. MODIS sensor data (onboard Aqua and Terra platforms) and Landsat data were used for the study. The research was done for the summer, monsoon, and winter seasons in the research region, using data from thirteen years between 2003 and 2015. The current study looked at LSTs' spatial and temporal differences to assess the SUHI effect over Ahmedabad city. The association between diurnal LST and various surface variables such as vegetation, built-up, soil, water, and so on has also been examined. A variety of land surfaces influences the diurnal variations of LSTs. The diurnal associations of LST with vegetation, urbanization, soil, and water factors have been studied. The overall study of LST' relationship with all of the various parameters reveals a very significant dynamic relationship.
Prioritising sub-watersheds using morphometric analysis, principal component analysis, and land use/land cover analysis in the Kinnerasani River basin, India
(IWA Publishing, 2022-08-30) Shekar, Padala Raja; Mathew, Aneesh
Due to the depletion of natural resources including land and water as a result of rapid population increase, industrialisation, and urbanisation, effective resource management is essential for long-term development. The Kinnerasani Watershed in Telangana State was chosen for the research based on morphological analysis, principal component analysis (PCA), and land use/land cover (LULC) analysis in this study. A catchment’s morphometric characteristics, PCA, and LULC analysis can be estimated using geographic information system (GIS) and remote sensing (RS) approaches. The watershed generated 24 sub-watersheds (SWs) in all (SW1–SW24). SWs were ranked using morphometric features, PCA, and LULC features. To determine the final priority of SWs, several morphometric characteristics, including linear, shape, and relief aspects, have been estimated for each SW and given ranks based on compound parameter values. To prioritise SWs, the PCA was used to extract five parameters from morphometric characteristics. The LULC analysis used four characteristics to prioritise the SWs. SW3, SW9, and SW12 have been prioritised for morphometric analysis; SW2 and SW3 have been prioritised for PCA; and SW17, SW19, SW23, and SW24 have been prioritised for LULC analysis. The common SWs within each priority according to three different methodologies are SW4, SW6, SW10, SW13, SW15, and SW21. The results show that the high-priority locations have greater runoff and soil erosion issues, so it is essential to design and implement watershed management techniques such as check dams, construction of farm ponds, and construction of earthen embankments in these areas. The decision-making authorities might use the findings to plan and implement watershed management initiatives to minimise soil erosion in high-priority locations. © 2023 International Journal of Mining and Geo-Engineering. All rights reserved.