First report of isolation of maleamic acid from natural source Polygonatum cirrhifolium—A potential chemical marker for identification

Polygonatum cirrhifolium (Meda) plant is being used in number of rejuvenating Ayurvedic formulations. Ever rising demands, lack of natural sources, and insufficient quantity, to meet the requirements of market, the raw material has led toward the use of official substitutes recommended by the Department of AYUSH that has further encouraged manufacturers for adulteration of formulations by other substandard/spurious raw drugs. Literature reveals that more than 60% Ayurvedic parameters as well as pharmacological actions of Ashtawarga plants do not match with their substitutes leading to reduced efficacy of the drugs along with loss of faith for use of herbal drugs. Consumers are forced to pay for the material which has never been used for high-cost claimed formulation. The situation is being exploited by manufacturers because regulatory authorities lack the tools (marker compound) needed for identification of authentic plant. Methanolic extract of rhizomes of plant was subjected to column chromatography. Isolated compound has been characterized as (Z)-4-amino-4-oxobut-2-enoic acid (maleamic acid/maleamate/maleic monoamide/maleic acid monoamide) by chemical test, melting point, IR/NMR/mass/UV spectral analysis. It is the first report in Polygonatum genus and can be used as a marker for identification of the plant in market formulations.     

1,8‐Naphthalimide: A Potent DNA Intercalator and Target for Cancer Therapy

The poor pharmacokinetics, side effects and particularly the rapid emergence of drug resistance compromise the efficiency of clinically used anticancer drugs. Therefore, the discovery of novel and effective drugs is still an extremely primary mission. Naphthalimide family is one of the highly active anticancer drug based upon effective intercalator with DNA. In this article, we review the discovery and development of 1,8‐naphthalimide moiety, and, especially, pay much attention to the structural modifications and structure activity relationships. The review demonstrates how modulation of the moiety affecting naphthalimide compound for DNA binding that is achieved to afford a profile of antitumor activity. The DNA binding of imide and ring substitution at naphthalimide, bisnaphthalimide, naphthalimide‐metal complexes is achieved by molecular recognition through intercalation mode. Thus, this synthetic/natural small molecule can act as a drug when activation or inhibition of DNA function, is required to cure or control the cancer disease. The present study is a review of the advances in 1,8‐naphthalimide‐related research, with a focus on how such derivatives are intercalated into DNA for their anticancer activities.     

Genetic diversity in the human major histocompatibility complex: lessons for vaccination approaches to HIV infection

The major histocompatibility complex (MHC) harbours genes that have a primary function of regulating immune responsiveness. Our data on the distribution patterns of molecular subtypes of HLA class I and II extended haplotypes in India suggest that: (1) Asian Indians have extreme diversity in the MHC region, with several novel and unique alleles and disease-associated MHC haplotypes (e.g. the autoimmune-favouring A26-B8-DR3 haplotype); (2) there have been selective environmental and microbial pressures in India that directed either the generation of novel alleles through founder effect or the expansion of other alleles due to geophysical or socio-economic barriers, and (3) Asian Indians have a unique repertoire of peptide-presenting molecules to deal with pathogen-derived autoreactive antigens. This level of polymorphism concentrated within the MHC presents a formidable obstacle to the development of peptide-based vaccines, e.g. for AIDS. Further, studies conducted by us and others have provided a genetic basis for the possible predisposition and fast progression of HIV infections in the Indian population. Since there is selective predominance of different HLA alleles and haplotypes in different populations, a dedicated global screening effort is required to develop MHC-based vaccines against infectious diseases.     

Fluorogenic ratiometric dipodal optode containing imine-amide linkages: Exploiting subtle thorium (IV) ion sensing

The (13E,19E)-N1′,N3′-bis[4-(diethylamino)-2-hydroxybenzylidene]malonohydrazide (L) has been developed for the detection of Th⁴⁺ ions using dual channel signalling system. The UV–vis absorbance and fluorescence spectroscopic data revealed the formation of L–Th⁴⁺ complex in 1:1 equilibrium. The density functional theory (DFT) also confirms the optimum binding cavity for the recognition of metal ion. The binding constant computed from different mathematical models for an assembly of L–Th⁴⁺. The detection limit of L for Th⁴⁺ recognition is to a concentration down to 0.1 μM (0.023 μg g⁻¹). The present sensing system is also successfully applied for the detection of Th⁴⁺ ion present in soil near nuclear atomic plants.     

Expedient Protocols for the Installation of 1,5‐Benzoazepino‐Based Privileged Templates on the 2‐Position of 1,4‐Benzodiazepine Through a Phenoxyl Spacer

An efficient novel strategy for the hetero‐annulation of 2‐chloro‐1,4‐benzodiazepine ring, substituted on its 5‐position with a carboxamido group ( 5 ), has been developed to allow the incorporation of 1,5‐benzodiazepine, 1,5‐benzothiazepine, and 1,5‐benzoxazepine ( 8 , 9 , 10 , 11 , 12 , 13 ) rings through their dimethylaminomethylene ketone intermediate ( 7 ).     

Microwave-Assisted Synthesis of Five-Membered O,N,N-Heterocycles

The development of new strategies for synthesis of five-membered O,N,N-heterocycles has remained a highly attractive but challenging proposition. An overview of the application of microwave irradiation in oxygen and two nitrogen atoms containing five-membered heterocyclic compounds synthesis is presented, focusing on the developments in the past 5–10 years. This contribution covers the literature concerning the total synthesis of five-membered O,N,N-heterocycles.     

Microwave-Assisted Synthesis of Six-Membered O-Heterocycles

The development of new strategies for synthesis of six-membered O-heterocycles has remained a highly attractive but challenging proposition. An overview of the application of microwave irradiation in oxygen-containing six-membered heterocyclic compounds synthesis is presented, focusing on the developments in the past 5–10 years. This contribution covers the literature concerning the total synthesis of six membered O-heterocycles.     

Nitrogen-Containing Six-Membered Heterocycles: Solid-Phase Synthesis

Solid-phase organic synthesis is a rapidly expanding area of synthetic chemistry that is being widely exploited in the search for new medicinally important compounds using combinatorial techniques. In recent decades, a large number of reports related to solid-phase synthesis of heterocycles have appeared because of the wide variety of their biological activity. In this review, we report the important role of solid-phase synthesis in the synthesis of nitrogen containing six-membered ring heterocycles.