Two new dimeric naphthoquinones, 5',8'-dihydroxy-6,6'-dimethyl-7,3'-binaphthyl-1,4,1',4'-tetraone (1; Di-naphthodiospyrol D) and 5',8'-dihydroxy-5,8-dimethoxy-6,6'-dimethyl-7,3'-binaphthyl-1,4,1',4'-tetraone (2; Di-naphthodiospyrol E), along with known naphthoquinones diospyrin (3) and 8-hydroxy diospyrin (4) were isolated from the chloroform fraction of extract of Diospyros lotus roots. Their structures were elucidated by advanced spectroscopic analyses, including HSQC, HMBC, NOESY, and J-resolved NMR experiments. The fractions and compounds 1-4 were evaluated for urease activity and phosphodiesterase-I, carbonic anhydrase-II and α-chymotrypsin enzyme inhibitory activities. Compounds 1 and 2 and their corresponding fractions showed significant and selective inhibitory effects on urease activities. The IC values of 1 and 2 were 260.4 ± 6.37 and 381.4 ± 4.80 µmol·L, respectively, using thiourea (IC = 21 ± 0.11 µmol·L) as the standard inhibitor. This was the first report demonstrating that the naphthoquinones class showed urease inhibition.
Biological Assay ; Diospyros ; chemistry ; Enzyme Inhibitors ; chemistry ; isolation & purification ; pharmacology ; Molecular Structure ; Naphthoquinones ; chemistry ; isolation & purification ; pharmacology ; Plant Extracts ; chemistry ; pharmacology ; Plant Roots ; Urease ; antagonists & inhibitors

OBJECTIVE: Scandix pecten-veneris L. is a less studied wild edible herb and is considered an extinct plant species in many parts of the world. This study was designed to evaluate its phytochemical composition and biological potential of S. pecten-veneris L. METHODS: Phytochemicals including alkaloids, flavonoids, polyphenols, and tannins were determined in extracts of S. pecten-veneris. Antioxidant activity was determined using 2,2-diphenyl-1-picrylhydrazyl (DPPH), while reducing power was tested by ferric reducing/antioxidant power (FRAP) assay. Antimicrobial activity against seven bacterial and four fungal strains was evaluated using agar well diffusion assay. Enzymes inhibition study was performed for urease, phosphodiesterase-I, and catalase-II. RESULTS: S. pecten-veneris showed moderate antiradical activity and reducing potential of hydroxyl radicals to about 20% of the initial value. The antioxidant activity of various extracts of S. pecten-veneris showed a linear correlation with total phenolic contents in the order of water>n-butanol>chloroform>ethyl acetate>methanol extracts. S. pecten-veneris leaves showed the highest inhibitory activity against Staphylococcus aureus while the highest antifungal activity was observed against Candida albicans. The plant extract was most potent against urease enzymes but showed moderate activity against phosphodiestrase-I and carbonic anhydrase-II. CONCLUSIONS Our data demonstrate that in addition to its culinary uses, S. pecten-veneris has good medicinal potential and hence could be used for treating some specific health ailments.
Animals ; Anti-Infective Agents/pharmacology* ; Antioxidants/pharmacology* ; Apiaceae/chemistry* ; Enzyme Inhibitors/pharmacology* ; Phosphodiesterase Inhibitors/pharmacology* ; Phytochemicals/analysis* ; Plant Extracts/pharmacology* ; Plants, Edible/chemistry* ; Staphylococcus aureus/drug effects* ; Urease/antagonists & inhibitors*

OBJECTIVETo establish an effective method for purification of Helicobacter pylori UreB fragment and conduct functional analysis of the purified protein.

METHODSThe protein fragment expression was induced by IPTG and the expressed protein was purified through affinity chromatography and ion-exchange chromatography. The purity of the fragment was determined by high-performance liquid chromatography (HPLC), and the specific biological activity of the purified fragment was assayed by urease activity inhibition test.

RESULTSThe protein fragment was highly expressed in E. coli with a purity over 91%. The protein fragment showed highly specific biological activity and the specific antibody induced by this fragment in rabbits could inhibit the activity of urease in a dose-dependent manner.

CONCLUSIONThe UreB fragment with high purity and biological activity can be applied for further studies.

Amino Acid Sequence ; Animals ; Antibody Specificity ; Bacterial Proteins ; chemistry ; Bacterial Vaccines ; biosynthesis ; chemistry ; immunology ; isolation & purification ; Chromatography, High Pressure Liquid ; Electrophoresis ; Escherichia coli ; genetics ; Helicobacter pylori ; genetics ; immunology ; Molecular Sequence Data ; Peptide Fragments ; biosynthesis ; chemistry ; immunology ; isolation & purification ; Rabbits ; Urease ; antagonists & inhibitors