8 research outputs found
(5R*,11R*)-5-Methyl-1,2-dihydro-5,11-methano-5H,11H-1,3-thiazolo[2,3-d][1,3,5]benzoxadiazocine
The title compound, C13H14N2OS, crystallizes as a racemate in a non-chiral space group. It represents a conformationally restricted analogue of so-called Biginelli compounds known to exhibit multiple pharmacological activities and was selected for a single-crystal X-ray analysis in order to probe the chemical and spatial requirements of some kinds of activity. It was found that the state of hybridization of the formally aminic nitrogen of the heterocycle is between sp
2 and sp
3 with the lone-pair electrons partially delocalized through conjugation with the sulfur atom rather than the double bond of the pyrimidine nucleus. As a result, the thiazolo ring adopts a flat-envelope conformation and the puckering of the central pyrimidine ring is close to a half-chair. The critical phenyl ring is fixed in a pseudo-axial and perpendicular [dihedral angle 84.6 (1)°] orientation with respect to the pyrimidine ring via an oxygen bridge
rac-2-Methyl-3,4,5,6-tetrahydro-2H-2,6-methano-1,3-benzoxazocin-4-one
The title compound, C12H13NO2, represents a conformationally restricted 2-pyridone analogue of 1,4-dihydropyridine-type calcium antagonists and was selected for a crystal structure determination in order to explore some aspects of drug-receptor interaction. In the molecule, two stereogenic centres are of opposite chirality, whereas a racemate occurs in the crystal. It was found that the formally aminic N atom of the heterocycle is essentially sp
2-hybridized with the lone-pair electrons partially delocalized through conjugation with the adjacent carbonyl bond. As a result, the central pyridone ring assumes an unsymmetrical half-chair conformation. The critical 4-phenyl ring is fixed in a pseudo-axial and perpendicular orientation [dihedral angle 85.8 (1)°] with respect to the pyridone ring via an oxygen bridge. In the crystal a pair of centrosymmetric N—H⋯O hydrogen bonds connect molecules of opposite chirality into a dimer. The dimers are packed by hydrophobic van der Waals interactions
Ethyl 6-ethoxycarbonylmethyl-4-(2-hydroxyphenyl)-2-oxo-1,2,3,4-tetrahydropyrimidine-5-carboxylate
The title compound, C17H20N2O6, belongs to the monastrol-type of anticancer agents and was selected for crystal structure determination in order to confirm its molecular structure and explore some aspects of its structure–activity relationships. The central tetrahydropyrimidine ring has a flat-envelope conformation. The 4-hydroxyphenyl group occupies a pseudo-axial position and is inclined at an angle of 87.7 (2)° to the mean plane of the heterocyclic ring. Of the two ethyl ester groups, one (in the 5-position) is in a coplanar and the other (in the 6-position) is in a perpendicular orientation with respect to the heterocyclic plane. There is a three-dimensional hydrogen-bonding network in which all hydrogen-bond donors and acceptors are involved
Monastrol analogs : a synthesis of pyrazolopyridine, benzopyranopyrazolopyridine, and oxygen-bridged azolopyrimidine derivatives and their biological screening
A synthesis of novel pyrazolopyridine, benzopyranopyrazolopyridine, and oxygen-bridged pyrazolo-, tetrazolo-, benzimidazo-, and thiazolopyrimidines via Hantzsch- and Biginelli-like condensations has been developed. The ability of these compounds to inhibit Eg5 activity has been examined. The results indicate that synthetic manipulations in the monastrol thiourea moiety are inefficient
<i>Lycopus europaeus</i>: phenolic fingerprint, antioxidant activity and antimicrobial effect on clinical <i>Staphylococcus aureus</i> strains
<div><p><i>Lycopus europaeus</i> L. leaves water extract (LEL) was subjected to phytochemical analysis, and evaluated for its antibacterial and antioxidant effects. Antibacterial activity testing was performed on <i>Staphylococcus aureus</i> clinical strains from catheter-related and skin infections by broth microdilution test. LEL showed bactericidal activity at concentrations from 2500 to 5000 μg/mL against all, including methicillin resistant and polyresistant nosocomial, strains. Antioxidant activity was examined using DPPH and ABTS (11.3 and 9.8 μg/mL, respectively) and by ferric reducing ability of the plasma method (891 μmol AAE/g dry extract). Phytochemical analysis of LEL was performed by LC-DAD-MS/MS. Ten phenolic compounds were identified; two minor compounds (glucopyranosyl rosmarinic acid and sagerinig acid) have not been described in <i>Lycopus</i> yet. The major compounds, considered to be responsible for biological activities detected in the study, were determined as rosmarinic acid (76 mg/g) and luteolin-7-<i>O</i>-glucuronide (23 mg/g). <i>L. europaeus</i> arises from our study as a promising source of antibacterial agent for topical usage.</p></div