Context:Ocimum basilicum L. (Lamiaceae) commonly known as sweet basil, has been used as a traditional medicinal plant for the treatment of headaches, coughs, diarrhea, constipation, warts, worms, and kidney malfunctions.Materials and Methods:The essential oil of the flowering aerial parts of O. basilicum growing in the Western Ghats region of North West Karnataka, India, was obtained by hydro-distillation and analyzed by gas chromatography equipped with flame ionization detector and gas chromatography coupled to mass spectrometry (GC–MS). The oil was tested against six Gram-positive, eight Gram-negative bacteria, and three fungi by the tube-dilution method at a concentration range of 5.00-0.009 mg/mL.Results:Twenty-five constituents were identified in the essential oil of O. basilicum. The major constituents were identified as methyl eugenol (39.3%) and methyl chavicol (38.3%), accounting for 98.6% of the total oil. The oil was found to be active against Gram-positive, Gram-negative bacteria, and fungi with minimal bactericidal concentration values in the range of 0.143 ± 0.031 to 0.572 ± 0.127 mg/mL, 0.781 ± 0.382 to 1.875 ± 0.684 mg/mL, and 0.312 ± 0.171 to 0.442 ± 0.207 mg/mL, respectively.Conclusion:The essential oil of O. basilicum of this region contains methyl eugenol/methyl chavicol chemotype and has bactericidal properties.

Cysteine residues and disulfide bonds are important for protein structure and function. We have developed a simple and sensitive method for determining the presence of free cysteine (Cys) residues and disulfide bonded Cys residues in proteins (<100 pmol) by liquid chromatography/electrospray ionization tandem mass spectrometry (LC/ESI-MS/MS) in combination with protein database searching using the program Sequest. Free Cys residues in a protein were labeled with PEO-maleimide biotin immediately followed by denaturation with 8 M urea. Subsequently, the protein was digested with trypsin or chymotrypsin and the resulting products were analyzed by capillary LC/ESI-MS/MS for peptides containing modified Cys and/or disulfide bonded Cys residues. Although the MS method for identifying disulfide bonds has been routinely employed, methods to prevent thiol-disulfide exchange have not been well documented. Our protocol was found to minimize the occurrence of the thiol-disulfide exchange reaction. The method was validated using well-characterized proteins such as aldolase, ovalbumin, and beta-lactoglobulin A. We also applied this method to characterize Cys residues and disulfide bonds of beta 1,4-galactosyltransferase (five Cys), and human blood group A and B glycosyltransferases (four Cys). Our results demonstrate that beta 1,4-galactosyltransferase contains one free Cys residue and two disulfide bonds, which is in contrast to work previously reported using chemical methods for the characterization of free Cys residues, but is consistent with recently published results from x-ray crystallography. In contrast to the results obtained for beta 1,4-galactosyltransferase, none of the Cys residues in A and B glycosyltransferases were found to be involved in disulfide bonds.

Abstract:The chemical composition, antioxidant, cytotoxic and antiviral activities of the essential oil obtained by hydrodistillation from the aerial parts of Teucrium pseudochamaepitys (Lamiaceae) collected from Zaghouan province of Tunisia are reported. The essential oil was analyzed by gas chromatography equipped with a flame ionization detector (GC-FID) and gas chromatography coupled with mass spectrometry (GC/MS). Thirty-one compounds were identified representing 88.6% of the total essential oil. Hexadecanoic acid was found to be the most abundant component (26.1%) followed by caryophyllene oxide (6.3%), myristicin (4.9%) and α-cubebene (3.9%). The antioxidant capacity of the oil was measured on the basis of the scavenging activity to the stable 2,2-diphenyl-1-picrylhydrazyl (DPPH). The IC 50 value of the oil was evaluated as 0.77 mg¨mL´1. In addition, the essential oil was found to possess moderate cytotoxic effects on the HEp-2 cell line (50% cytotoxic concentration (CC 50 ) = 653.6 µg¨mL´1). The potential antiviral effect was tested against Coxsackievirus B (CV-B), a significant human and mouse pathogen that causes pediatric central nervous system disease, commonly with acute syndromes. The reduction of viral infectivity by the essential oil was measured using a cytopathic (CPE) reduction assay.

No abstract