Isolation of Lactococcus garvieae NEP21 from raw cow (Bos indicus) milk in Nepal.

Lactococcus garvieae is an emerging zoonotic pathogen impacting both humans and animals. Infection of this bacterium is known to cause mastitis in cattle, and endocarditis, osteomyelitis, liver abscess, and gastrointestinal problems are reported in immunocompromised and elderly people that regularly consume or handle raw meat, milk, dairy products, and seafood. This study aimed at investigating and detecting lactic acid bacteria in raw cow (Bos indicus) milk samples from a smallholder farm in Nepal. Based on the plate culture, biochemical tests, and molecular sequencing of 16 s ribosomal RNA coding nuclear DNA region followed by phenotypic and genotypic analyses, L. garvieae NEP21 was detected and identified for the first time in Nepal in raw cow milk samples. This finding suggests the prevalence of L. garvieae NEP21 in raw cow milk and recommends further research and surveillance for understanding the extent of its presence in Nepal and globally for informed management of its infection in cattle and humans.

Preparation and characterization of chitin benzoic acid esters.

Chitin benzoic acid esters were prepared using a phosphoryl mixed anhydride method. The products were characterized by 1H-NMR and FT-IR spectroscopy. FT-IR analysis revealed that the degree of O-acyl substitution of the products was in a range of 1.17-1.83. Morphological surface changes in the parent molecule due to the introduction of benzoic acid moieties were observed by scanning electron microscopy. The surface of the products was porous, in contrast to the sheet-shape of the parent molecules. The solubility of the products, which improved with increased degree of acid substitution, was tested in various organic solvents.

Preparation of chitin butyrate by using phosphoryl mixed anhydride system.

Acylation of chitin with butyric acid was performed in the presence of trifluoroacetic anhydride/phosphoric acid mediated system. The products were characterized by (1)H NMR and FT-IR spectroscopy and their solubility was tested in different organic solvents. Inclusion of butyric acid moieties into the parent molecule was confirmed from the (1)H NMR and FT-IR spectra. FT-IR analysis revealed that the degree of acid substitution (DS) of the products was in a range of 1.9-2.38, which increased with increasing the amounts of butyric acid added to the reaction system. Degree of N-deacetylation (DD) of the products, as determined by (1)H NMR was between 54.2% and 65.6%. The products with DS >2.0 were soluble in dimethyl sulfoxide, N,N-dimethylformamide, tetrahydrofuran, methanol, acetone, chloroform, and acetic acid.

Synthesis of chitin cycloalkyl ester derivatives and their physical properties.

A series of acylated chitin derivatives was prepared by reacting chitin in a solution of trifluoroacetic anhydride and each of the cyclopropyl, cyclobutyl, cyclopentyl, and cyclohexyl carboxylic acids. The degree of O-acyl substitution was in a range of 1.1-1.4 depending upon the nature of the cyclic acid added, as determined by FT-IR analysis. The solubility of the products in the organic solvents of DMF and THF increased with an increase in the cyclic chain length of the carboxylic acid. Thermal gravimetric analysis indicated that the products were stable up to 220 degrees C for chitin cyclopropanoate and cyclobutanoate, and 250 degrees C for chitin cyclopentanoate and cyclohexanoate. The surface morphology of the products by scanning electron microscopic analysis revealed porous and globular surface for chitin cyclobutanoate, cyclopentanoate, and cyclohexanoate, contrast to the dense and smooth organization for the cyclopropanoate.

Anti-human rhinovirus activity of gallic acid possessing antioxidant capacity.

Human rhinoviruses (HRVs) are a major cause of the common cold and until now there is no registered clinically effective antiviral chemotherapeutic agent for treatment of diseases caused by HRVs. Our previous report showed that gallic acid from Woodfordia fruticosa flowers possessed antioxidant activity. Many studies reported that antioxidants possess antiviral activities against various viruses. Therefore, we examined antiviral activity of gallic acid against HRVs and mode of its actions by observing the effect of gallic acid on HRV-induced cytopathic effect (CPE) and the infectivity of HRV particles, and then carried out a time-addition study. As a result, gallic acid actively inhibited HRV2 and -3 replications with antiviral activity more than 55% without cytotoxicity in human epitheloid carcinoma cervix (HeLa) cells at a concentration of 100 mug/mL. Also, ribavirin showed lower anti-HRV3 activity than gallic acid and similar anti-HRV3 activity to it. The addition of gallic acid to HRV-infected HeLa cells directly reduced the formation of a visible CPE. Furthermore, gallic acid did directly interact or activate with HRV particles. Collectively, we concluded that the inhibition of HRV production by gallic acid is mainly due to a general action as an antioxidant and the mode of action derived from the inhibition of virus absorption.

A chalcone glycoside from the fruits of Sorbus commixta Hedl.

Sorbus commixta Hedl. (Rosaceae) has been traditionally used in oriental countries for the treatment of asthma and other bronchial disorders. In this study, a chalcone glycoside was isolated from the ethyl acetate extract of the fruits of this plant. The compound was identified as neosakuranin based on the spectroscopic analysis and comparison with literature data. This is the first report of isolation of neosakuranin from Sorbus commixta.