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A simple and efficient method for the synthesis of highly functionalized furo[3,2- c ]coumarins was developed. The reaction occurred via initial formation of biscoumarins from the reaction of 4-hydroxycoumarins and aldehydes/aryl methyl ketones in the presence of molecular iodine in DMSO followed by lactone ring opening, cyclization and oxidative aromatization process. The reaction conditions were moderate, work-up procedure was simple and products were obtained in high yield. [ABSTRACT FROM AUTHOR]

Abstract: Some novel tetrazole fused pyrido[2,3-c]coumarin derivatives 5/7/9 were synthesized from a one-pot three-component reaction of 4-chloro-3-formylcoumarins 2, sodium azide 3, and alkyl/aryl acetonitriles 4/6/8. [Copyright &y& Elsevier]

Abstract: Pyrimido[4,5-d]pyrimidine derivatives 4 have been prepared in an efficient and regioselective manner in water via multi-component reaction of isothiocyanate 1, aromatic aldehyde 2, N,N-dimethyl-6-amino uracil 3 in the presence of p-toluenesulfonic acid (p-TSA) as a Lewis acid catalyst. [Copyright &y& Elsevier]

Abstract: Some novel spiro substituted pyrido[2,3-c]coumarin derivatives were synthesized from 4-hydroxycoumarin by exploring ‘tertiary amino effect’ reaction strategy. [Copyright &y& Elsevier]

This study reports the environmental fate and ecological hazard of the three heavy metals (HMs), viz. copper (Cu), manganese (Mn) and zinc (Zn) in soil influenced by municipal solid waste (MSW) dumping. The experimental site is situated in the vicinity of Deepor Beel, a Ramsar site located in Guwahati, India. This study assessed (i) the distribution pattern of Cu, Mn and Zn in six geochemical fractionations; (ii) the mobility, bioavailability and toxicity of Cu, Mn and Zn based on eight contamination and ecological indices, and (iii) the impact of Cu, Mn and Zn on soil quality. Altogether, 18 soil samples were collected and analysed from the study site using stratified random sampling. Pollution indices and multivariate statistics were applied on the data to identify the level and source of analysed HMs. Sequential extraction has revealed that the binding strength of Cu, Mn and Zn had a uniform trend. Mobility and potential bioavailability of studied HMs were in the order Mn > Cu > Zn. Analysed HMs were dominantly associated with non-bioavailable fractions. The observed low values of various contamination factors indicated the lesser contamination load posed by these metals. Conversely, their high enrichment factor and geo-accumulation index values indicated the sources of these metals were anthropogenic. Overall, the pollution and ecological indices registered lower contamination. Yet, it would be prudent to adopt efficient MSW management strategies for eliminating any future risk emanating out of this dumping site and posing threat to nearby Deepor Beel and its associated flora and fauna. Image 1 • Environmental risks associated with three heavy metals (Cu, Mn and Zn) in the soils were determined. • Municipal solid wastes (MSW) containing heavy metals (HM) pose ecological risk. • Major sources of these HMs were anthropogenic in nature. • Scientific waste management is needed to protect Deepor Beel, a Ramsar site. [ABSTRACT FROM AUTHOR]

Abstract: Some novel functionalized dihydropyrido[2,3-d]pyrimidine derivatives 4 were synthesized using a one-pot three-component reaction of 6-aminouracils 1, aryl aldehydes 2 and 3-cyanoacetyl indole 3 using InCl3 as catalyst. [Copyright &y& Elsevier]

Earthworms are known to bio-degrade various types of organic materials added or already present in soil. Two soils were collected from different land use patterns viz. an agricultural land (AL) and an undisturbed land (UL) of a mountain ecosystem of State of Himachal Pradesh in India for the present investigation. A laboratory microcosm study was carried out to elucidate effects of various agricultural-soil amendments, viz. wood ash (WA), rice husk (RH), cow dung (CW) and their mixture (MA) applied @25 t ha −1 , on selective biological and chemical properties of earthworm ( Eisenia fetida ) casts and growth in the collected soils. Subsequently, earthworms were reared in soils from both AL & UL, treated with the amendments; and the resultant earthworm cast (E w C) properties were found to be largely determined by the nature of amendments rather than land use types. Soils treated with MA produced casts displayed higher nutrient content, microbial biomass C with higher activities of dehydrogenase and urease. Earthworm growth and cast formation were greater in the soil from UL over soil from AL for all treatments except WA, implying better acclimatization and earthworm activity in the former. Further, casts produced under UL had higher nutrient mobilization and enzyme activity in comparison to AL. Results suggested that agricultural intervention in an undisturbed land might weaken its ability to support growth, development in conjunction with the activities of earthworms and associated enzymes. [ABSTRACT FROM AUTHOR]

A holistic appraisal of three non-edible biofuel plants, with in depth analysis of their environmental impact, socioeconomic potential, and contribution to rural and circular bio-economy is the main focus of this review. Bioenergy is designated as a smart option to mitigate energy-based demands of an escalating human population, the resultant environmental pollution, and challenges of climate change. To the best of our knowledge, this is the first concerted and comparative assessment of Jatropha curcas, Pongamia pinnata and Mesua ferrea as biofuel resources, with concurrent evaluation of the environmental and socioeconomic perspectives. Ease of availability, non-edibility, higher biomass, and resilience to climatic variations, render them potential biofuel capital for a cleaner and greener future. Their environmental perspectives are critically assessed in this review based on the roles in phytoremediation, bioadsorption, carbon sequestration, and soil conditioning. The detailed analysis of biogas, biopesticide, cosmetic products, and biofuel yield, reinforce the economic potential of the three plants under review. The socioeconomic implications, practical challenges, and limitations of crops for biofuel, especially in the predominantly rural, low income, agrarian milieu, are comprehensively discussed. Therefore, in the concluding section, the review offers new directions for policies and frameworks toward sustainable and circular bio-economy in biofuel sector. [Display omitted] • First comparative study of three biofuel plants J. curcas, P. pinnata and M. ferrea. • Environmental and socio-economic aspects of biofuel plants were discussed. • Multipurpose usage of these plants was explored. • Discussed challenges and limitations associated with the farming of these plants. • Deliberated on sustainable and circular bio-economy in biofuel sector. [ABSTRACT FROM AUTHOR]