Four Natural Compounds Separated from Folium Isatidis: Crystal Structures and Antibacterial Activity

Abstract

Four natural compounds were obtained by concentrating, separating and purifying from the Folium isatidis. These natural compounds have been characterized by elemental analysis, IR spectrum, NMR and single-crystal X-ray diffraction analysis. The results show that these natural compounds are 4(3H)-quinazolinone (I), 2,4(1H,3H)-quinazolinedione (II), methyl 3,4-dihydro-4-oxoquinazoline-2-carboxylate (III) and ethyl 3,4-dihydro-4-oxoquinazoline-2-carboxylate (IV). The antibacterial activity experiment showed that I and II had better activity against Staphylococcus aureus, Escherichia coli, Bacillus subtilis and Salmonella than III, IV and other multiple components, because III and IV have long branches and steric hindrance effect. Compounds I and II have planar structure, which can more easily combine with these bacteria and kill them. The above results have good guiding significance for studying the antibacterial activity for single components or mixtures from natural origin.

Crystal structures of 6-nitroquinazolin-4(3H)-one, 6-aminoquinazolin-4(3H)-one and 4-aminoquinazoline hemihydrochloride dihydrate

“…The nitro group is rotated slightly with respect to the quinazoline ring system, the C5-C6-N9-O3 and C7-C6-N9-O2 torsion angles being 6.0 (3) and 4.9 (4) , respectively. All bond lengths and angles are normal and in good agreement with those reported previously (Liao et al, 2018;Yong et al, 2008). Fig.…”

“…The crystal structures of quinazolin-4(3H)-one and its first metal coordination compound have also been reported [BIHJIO (Liao et al, 2018) and NALFEN (Turgunov & Englert, 2010)].…”

Inhibitors of Fumarylacetoacetate Hydrolase Domain Containing Protein 1 (FAHD1)

“…The oxalamic acid derivative 1a was cyclized at an elevated temperature or upon treatment with acetic acid anhydride to a 4-oxo-4 H -benzo[ d ]-[1,3]oxazine derivative 17a [ 17 ]. Analogously, the ortho -amide-bearing methyl ester 18a was cyclized to methyl 4-oxo-1,4-dihydroquinazoline-2-carboxylate 19a [ 18 ]. The latter one was saponified to the acid congener 19b ( Figure 8 ).…”

Development of the Species-Specific Multiplex PCR and DNA Sequencing Methods for Rapid Authentication of Isatidis Folium and its Adulterants

“…It is a common traditional herbal medicine with the effect of detoxification. In addition, several studies had revealed several pharmacologic functions including anti-bacterial [ 2 ], anti-inflammatory [ 3 ] and anti-viral [ 4 – 6 ] activities. However, “Daqingye “ is an easily confused herb and its adulteration often occurs in markets.…”