(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