A new species of Misopates Raf. (Scrophulariaceae, Antirrhineae)

Misopates pontiense sp. nov. is described from one population located in the north-west of the Iberian Peninsula. It is an annual, living on charred soils. Its distinguishing characteristics include its seeds, which have a carinate dorsal face and an encircling rounded ridge with cylindrical papillae, but lack a median ridge on the ventral face. Morphological characters and taxonomic affinities are discussed.     

Meristic variation in Potamogeton flowers

Flowers of Potamogeton normally have a completely tetramerous plan. Deviations from this norm occur quite commonly in the uppermost flowers of the inflorescence; these variations have been reported before and usually involve a reduction in number of parts. Cases have now been found where the gynoecium of all or many flowers differs from the normal tetracarpellate arrangement; some species regularly have fewer and others more than four carpels. The developmental bases of meristic variation have been explored and quantitative studies of gynoecia and developing gynoecia have been undertaken. The data are used to evaluate the control and correlation of floral development in Potamogeton in general, and in particular the relationship between the gynoecium and the rest of the flower. The developing flower passes through two successive phases of organ initiation: one in which the perianth and stamen primordia arise, and one in which the gynoecial primordia arise. There seems to be little developmental relationship between the two phases except phyllotactic continuity. During the perianth/stamen phase each stamen primordium arises directly above a perianth member, and the presence of a perianth member seems to be a prerequisite for initiation of the stamen. The perianth/stamen phase seems to be rather stable so that normally four perianth/stamen associations are initiated, except in flowers at the tip of the inflorescence. In the gynoecial phase the number of carpel primordia initiated seems to depend on the relative size of carpel primordia and floral apex, and on whether or not the floral apex continues to grow while initiating carpel primordia.     

A new species of Globularia L. (Globulariaceae) from South Anatolia

A new species of Globularia L., G. hedgei H. Duman sp. nov., is described and illustrated. The species is restricted to the south of Sütçüler (Isparta) and grows on calcareous rocky cliffs. It is suggested that its IUCN category is Critically Endangered (CR). Diagnostic morphological characters for a detailed discrimination from the most closely similar taxa are discussed.     

Curcuminoids as inhibitors of thioredoxin reductase: A receptor based pharmacophore study with distance mapping of the active site

Curcumin is the yellow pigment of turmeric that interacts irreversibly forming an adduct with thioredoxin reductase (TrxR), an enzyme responsible for redox control of cell and defence against oxidative stress. Docking at both the active sites of TrxR was performed to compare the potency of three naturally occurring curcuminoids, namely curcumin, demethoxy curcumin and bis-demethoxy curcumin. Results show that active sites of TrxR occur at the junction of E and F chains. Volume and area of both cavities is predicted. It has been concluded by distance mapping of the most active conformations that Se atom of catalytic residue SeCYS498, is at a distance of 3.56 from C13 of demethoxy curcumin at the E chain active site, whereas C13 carbon atom forms adduct with Se atom of SeCys 498. We report that at least one methoxy group in curcuminoids is necessary for interation with catalytic residues of thioredoxin. Pharmacophore of both active sites of the TrxR receptor for curcumin and demethoxy curcumin molecules has been drawn and proposed for design and synthesis of most probable potent antiproliferative synthetic drugs.     

Synthesis and antimicrobial studies of hydrazone derivatives of 4-[3-(2,4-difluorophenyl)-4-formyl-1H-pyrazol-1-yl]benzoic acid and 4-[3-(3,4-difluorophenyl)-4-formyl-1H-pyrazol-1-yl]benzoic acid

Microbial resistance to antibiotics is an unresolved global concern, which needs urgent and coordinated action. One of the guidelines of the Centers for Disease Control and Preventions (CDC) to combat antibiotic resistance is the development of new antibiotics to treat drug-resistant bacteria. In our effort to find new antibiotics, we report the synthesis and antimicrobial studies of 30 new pyrazole derivatives. These novel molecules have been synthesized by using readily available starting materials and benign reaction conditions. Some of these molecules have shown activity with MIC values as low as 0.78?µg/mL against four bacterial strains; Staphylococcus aureus, methicillin-resistant S. aureus, Bacillus subtilis, and Acinetobacter baumannii. Furthermore, active molecules are non-toxic to mammalian cell line.

     

Novel compounds with potent CDK9 inhibitory activity for the treatment of myeloma

Cyclin-dependent kinases (CDKs) and Polo-like kinases (PLKs) play key role in the regulation of the cell cycle. The aim of our study was originally the further development of our recently discovered polo-like kinase 1 (PLK1) inhibitors. A series of new 2,4-disubstituted pyrimidine derivatives were synthesized around the original hit, but their PLK1 inhibitory activity was very poor. However the novel compounds showed nanomolar CDK9 inhibitory activity and very good antiproliferative effect on multiple myeloma cell lines (RPMI-8226).