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Objective: Costus pictus D. Don is a traditionally used plant in Naojan area of Golaghat district of Assam, India specifically for treating diabetes. Six compounds were isolated from standardized methanolic extract of the aerial parts (MECP). The prime objective was to select most potent antidiabetic compounds among the isolated compounds viz. F67, F12, F16, F3032, F37 & F48 by using in vitro and in vivo methods. Methods: Isolated compounds were subjected to initial screening by in vitro α-amylase inhibition activity assay using iodine-starch and DNSA (3,5-dinitrosalicylic acid) methods. Compounds depicting promising in vitro activity were selected for in vivo Streptozotocin (STZ) induced antidiabetic screening activity. Then based on the in vivo results, most potent compounds were selected for instrumental characterization by Q-TOF ESI-MS, 1HNMR, 13CNMR & FTIR. Results: Amongst the six compounds isolated from MECP, three compounds viz. F12, F16 & F48 showed potent in vitro activity. They were subsequently subjected to evaluation of the antidiabetic activity in vivo by oral administration, at dose of 10, 20 & 50 mg/kg body weight respectively, using Wister rat (120-150 g) and Glibenclamide (10mg/k body weight) as standard. Two compounds, F12 and F48 at dose of 50 mg/kg body weight, reversed STZ induced diabetic parameters (increased blood glucose level, altered plasma profile and histoarchitecture of the pancreatic and hepatic cells) with statistical significance (P<0.05), that was comparable with the standard. Hence, instrumental characterization by Q-TOF ESI-MS, 1HNMR, 13CNMR & FTIR of compounds F12 and F48 isolated from MECP was carried out which established their identity as (3,5,7-Trihydroxy-3'-hydroxy 4'-methoxy) flavanone or [3,5,7-Trihydroxy- 2-(3'-hydroxy-4'-methoxy phenyl)-2,3-dihydrochromen-4-one] and 3,5,8 trihydroxy-7-methoxy-2-phenyl-2,3-dihydrochromen-4-one or [7-methoxy-3, 5, 8 trihydroxy flavanone] respectively. Conclusion: The study culminated in elucidation of two flavanones as most potent compounds in exhibiting antidiabetic activities. The findings were thus successful in validating the traditional practices in Golaghat district of Assam, India, associated with the use of Costus pictus D. Don in the treatment of diabetes. [ABSTRACT FROM AUTHOR]

Among synthesized 1,2,4-trioxane derivatives, six compounds were found to be considerably potent, with better activity against resistant strain of P. falciparum than the sensitive strain. The IC50 values of the best compound with 4-hydroxyphenyl substitution were found to be 0.391 and 0.837 µg/mL against sensitive and resistant strain of P. falciparum, respectively. Results of the tested compounds were comparable with that of the standard drug, chloroquine (IC50 = 0.044 and 0.205 µg/mL against sensitive and resistant strain of P. falciparum, respectively). Docking simulation, in silico drug-likeness and ADMET studies further validated the results of in vitro antimalarial activity. Trioxane derivatives exhibited good binding affinity for the P. falciparum cysteine protease falcipain 2 receptor (PDB id: 3BPF) with well defined drug-like and pharmacokinetic properties based on Lipinski’s rule of five with additional physicochemical and ADMET parameters. In view of having antimalarial potential, newly reported 1,2,4-trioxane derivative(s) may be useful as novel antimalarial lead(s) in the discovery and development of future antimalarial drug candidates as P. falciparum falcipain 2 inhibitors against resistant malaria. [ABSTRACT FROM AUTHOR]

The first decarbonylative insertion of an alkyne through C−H/C−C activation of six-membered compounds is reported. The Ru-catalyzed reaction of 3-hydroxy-2-phenyl-chromones with alkynes works most efficiently in the presence of the ligand PPh3 to provide spiro-indenebenzofuranones. Unlike previously reported metal-catalyzed decarbonylative annulation reactions, in the present decarbonylative annulation reaction, the annulation occurs before extrusion of carbon monoxide. [ABSTRACT FROM AUTHOR]

In this article, a comprehensive review on bioactive flavonoids that are abundant in medicinal and functional food (dietary) plants has been made, with special reference to antimalarial flavonoid molecules. Flavonoids have been found to exist in plants/plant medicines comprising numerous polyphenolic compounds with a wide structural diversity having pharmacological potential in diverse range of therapeutic areas. Flavonoids derived from certain dietary plants described herein have been investigated for their antimalarial effectiveness against malaria parasites, particularly Plasmodium falciparum. The biological target specificity of their antimalarial action is so interesting that they act at protein targets at molecular level other than the conventional antimalarial targets. This approach may be a basis of establishing plant flavonoids as future antimalarial leads for the development of new and potent antimalarial drug molecules. [ABSTRACT FROM AUTHOR]