C. A. De Simone

Synthesis and structural study of arylidene thiazolidine and benzothiazine compounds

Synthesis and physico-chemical properties of some 5-arylidene-3-(2-biphenyl-4-yl-2-oxo-ethyl)- and 3-(4-bromo-benzyl)-4-thioxo-thiazolidin-2-ones, 5-arylidene-3-(4-chloro-benzyl)-4-thioxo- and 4-oxo-thiazolidin-2-ones and 2-arylidene-6-benzoyl-amino- or 6-amino-4 H -benzo[1,4]thiazin-3-ones are described. These arylidene thiazolidines and benzothiazines compounds were prepared by Knoevenagel condensation with benzaldehydes.

The influence of electronic and steric effects in the structure–activity relationship (SAR) study of quinone compounds with biological activity against Trypanosoma cruzi

Abstract A set of 14 quinone compounds with anti-trypanocidal activity was studied by using the AM1 semi-empirical method in order to calculate atomic and molecular properties (variables or descriptors) to be correlated to the biological activity. Principal component analysis (PCA), hierarchical cluster analysis (HCA), stepwise discriminant analysis (SDA) and the K th nearest neighbor (KNN) method were employed to obtain possible relationships between the calculated descriptors and the biological activity studied and to predict the anti-trypanocidal activity of new quinone compounds from a prediction set. The atomic and molecular descriptors responsible for the separation between the active and inactive compounds were: total energy ( E T ), polarizability ( α ) and the charge on the R 1 atom ( Q 4 ). These descriptors give information on the kind of interaction that can occur between the compounds and the biological receptor. The prediction study was done with a set of three new compounds by using the PCA, HCA, SDA and KNN methods and two of them were predicted as active against T. cruzi .

A pimpinellin monomer and dimer isolated from the roots of Esenbeckia grandiflora.

X-ray diffraction studies carried out on single crystals of the monomeric, viz. 5,6-dimethoxy-2H-furo[2,3-h][1]benzopyran-2-one, C(13)H(10)O(5), and dimeric, viz. 5,5,6,6-tetramethoxy-3,3,4,4-tetrahydro-2H,2H-3,3:4,4-bi(furo[2,3-h][1]benzopyran)-2,2-dione, C(26)H(20)O(10), forms of pimpinellin have revealed that, following cyclodimerization, the carbonyl groups are head-to-head with respect to one another. In the monomer, the heterocyclic ring is planar, but it exhibits a twisted-boat conformation in the dimer. Both the monomer and the dimer interact through C-H...O interactions.

3-Bromo-β-lapachone

In the title compound, C15H13BrO3, the benzo and quinone rings are planar, while the heterocycle is in a distorted half-chair conformation.

rac-4-Meth­oxy-6-phenyl-5,6-dihydro-2-pyrone

In the title compound, C12H12O3, the heterocyclic ring adopts a half-chair conformation. C–H⋯O hydrogen bonds form a three-dimensional network.

14b-Chloro-4a-meth­oxy-3,3-dimethyl-2,3,4a,14b-tetra­hydro-1H-benzo[a]pyrano[2,3-c]phenazine: a new active structural type against Mycobacterium tuberculosis

The title compound, C22H21ClN2O2, obtained from the reaction of the phenazine of β-lapachone with trichloroxadisocyanuric acid, showed a minimum inhibitory concentration of 6.25u2005ngu2005ml−1 in tuberculostatic assays against Mycobacterium tuberculosis and established a new structural type with potential interxadest in medicinal chemistry. The dihydroxadpyran ring adopts a pure chair conformation, while the ring fused to it has a half-chair conformation. The two substituents, OMe and Cl, are in axial positions, due to anomeric effects towards the methxadoxy derivative.

Crystal structure of 3β-[5-phenyl-(2E,4E)-penta-2,4-dienoyloxy]- olean-12-ene, C41H58O2, from Peltastes peltatus

C41H58O2, monoclinic, C121 (no. 5), a = 25.573(3) A, £>= 10.453(1) A, c = 14.159(2) A,/3 = 113.674(8), V = 3466.3 A, Ζ = 4, Rp(F) = 0.069, wR^F) = 0.180, T= 120 K. Source of material The crystals of the 3/H5-phenyl-(2£,4E)-penta-2,4-dienoyloxy]olean-12-ene were obtained by recrystallization from MeOH at room temperature.

Crystal structure of 4-hydroxy-6-propenyl-5,6-dihydro-pyran-2-one, C8H10O3

Abstract C8H10O3, monoclinic, P121/c1 (no. 14), a = 5.1640(2) Å, b = 19.979(1) Å, c = 7.5840(4) Å, β = 104.540(2)°, V = 757.4 Å3, Z = 4, Rgt(F) = 0.049, wRref(F2) = 0.169, T = 293 K.