Antioxidant and Antivenom Potential of an Essential Oil, 4-(2-Oxo-propyl)-cyclopentane-1,3-dione, and Allantoin Derived from the Polyherbal Combination of Aristolochia indica L. and Piper nigrum L.

The goal of this study was to identify new compounds from a methanol extract of a polyherbal combination of Aristolochia indica L. and Piper nigrum L. (MECAIPN), two traditional medicinal plants used to cure envenomation, as well as to assess their antioxidant and antivenom properties. MECAIPN yielded EA1 (an essential oil), AA2 (4-(2-oxo-propyl)-cyclopentane-1,3-dione), and W3 ((2,5-dioxo-imidazolidin-4-yl)-urea) (Allantoin). Although EA1 had stronger radical scavenging activity, AA2 had higher DPPH and ferric ion radical scavenging activity, and W3 had higher molybdenum ion radical scavenging activity due to being a single molecule, the binding investigation revealed that EA1 has a greater Stern-Volmer quenching constant (Ksv) than AA2 and W3. Synchronous measurements indicated that EA1, AA2, and W3 bind to tryptophan and tyrosine residues in venom, causing denaturation of the secondary structure of the residue. Finally, the current study concludes that EA1 has more therapeutic antivenom potential, which could be related to the synergism of chemicals found in it. When it came to single compounds, AA2 had stronger antioxidant and antivenom capabilities than W3. To understand the mechanism of action and manufacture the green antivenom medication, more testing of the EA1 and compounds remains required.

Enhancement in anti-tubercular activity of indole based thiosemicarbazones on complexation with copper(I) and silver(I) halides: Structure elucidation, evaluation and molecular modelling.

A series of monomeric tetrahedral complexes of stoichiometry, [MX(HL)(Ph3P)2] (In case of M = Cu, H1L, X = I, 1; Br, 2; Cl, 3; H3L, X = I, 4; Br, 5; Cl, 6; H4L, X = I, 7; Br, 8; Cl, 9 and in case of M = Ag, H1L, X = Cl, 13; Br, 14; H2L, X = Cl, 15, Br 16; H3L, X = Cl, 17, Br, 18) were synthesized by the reaction of copper (I) or silver (I) halides with indole-3-thiosemicarbazone (H1L) or 5-methoxy indole-3-thiosemicarbazone (H2L) or 5-methoxy indole-N1-methyl-3-thiosemicarbazone (H3L), whereas dimers of stoichiometry, [Cu2(µ-X)2(η1-S-H2L)2(Ph3P)2] (X = I, 10; Br, 11; Cl, 12) were obtained by the reaction of copper (I) halides with indole-N1-methyl-3-thiosemicarbazone (HIntsc-N1-Me, H2L). The synthesized complexes were characterized using NMR (1H and 13C) and single crystal X-ray diffraction (H2L, 3, 7, 8, 10, 11 and 13) as well as elemental analysis. Anti- M. tuberculosis activity of ligands (H1L-H4L) and their metal complexes (1-18) were evaluated against M. tuberculosis H37RV strain ATCC 27294. It has been observed that there is unusual enhancement in anti TB activity of these ligands on complexation with copper (I) and silver (I). Molecular modelling studies in the active binding site are also giving complementary theoretical support for the experimental biological data acquired.

Synthesis, structure, and catalytic properties of V(IV), Mn(III), Mo(VI), and U(VI) complexes containing bidentate (N, O) oxazine and oxazoline ligands.

Synthesis of seven complexes containing oxazoline ([(L(1))(2)V=O] (4), [(L(1))(2)MoO(2)] (5), [(L(1))(2)UO(2)] (6); HL(1) (1) [HL(1) = 2-(4',4'-dimethyl-3'-4'-dihydroxazol-2'-yl)phenol]), chiral oxazoline ([(L(2))(2)UO(2)] (7); HL(2) (2) [HL(2) = (4'R)-2-(4'-ethyl-3'4'-dihyroxazol-2'-yl)phenol]), and oxazine ([(L(3))(2)V=O] (8), [(L(3))(2)Mn(CH(3)COO(-))] (9), [(L(3))(2)Co] (10); HL(3) (3) [HL(3) = 2-(5,6-dihydro-4H-1,3-oxazolinyl)phenol]) and their characterization by various techniques such as UV-vis, IR, and EPR spectroscopy, mass spectrometry, cyclic voltammetry, and elemental analysis are reported. The novel oxazine (3) and complexes 4, 5, 8 and 9 were also characterized by X-ray crystallography. Oxazine 3 crystallizes in the monoclinic system with the P2(1)/n space group, complexes 4 and 9 crystallize in the monoclinic system with the P2(1)/c space group, and complexes 5 and 8 crystallize in the orthorhombic system with the C222(1) space group and the P2(1)2(1)2(1) chiral space group, respectively. The representative synthetic procedure involves the reaction of metal acetate or acetylacetonate derivatives with corresponding ligand in ethanol. Addition of Mn(OAc)(2).4H(2)O to an ethanol solution of 3 gave the unexpected complex Mn(L(3))(2).(CH(3)COO(-)) (9) where the acetate group is coordinated with the metal center in a bidentate fashion. The catalytic activity of complexes 4-9 for oxidation of styrene with tert-butyl hydroperoxide was tested. In all cases, benzaldehyde formed exclusively as the oxidation product.