Monday, August 2, 2010

Bioactive cyclic heptapeptide cyclo

A new bioactive cyclic heptapeptide cyclo(Gly-Tyr-Val-Pro-Leu-Trp-Pro) was synthesized using the solution phase technique by cyclization of the linear peptide Boc- Gly-Tyr-Val-Pro-Leu-Trp-Pro after proper deprotection at carboxyl and amino terminals. All the coupling reactions were performed at room temperature utilizing dicyclohexylcarbodiimide (DCC) as the coupling agent and N-methylmorpholine (NMM) as the base. Structures of all new compounds were characterized by IR and 1HNMR. The synthesized cyclopeptide was screened for antimicrobial and anthelminitic activities and found to exhibit good antibacterial activity against Bacillus subtilis and moderate antifungal activity against Candida albicans and Asperigillus niger. In addition the cyclic peptide was found to exhibit good anthelminitic activity against earthworms Eudrilus species.

Cyclic congeners possess unusual or modified amino acid residues and exhibit there bioactivities through binding to corresponding enzyme. This characteristic feature can allow bioactive cyclopeptides to act as therapeutic agents in this resistant world. Cyclopepetides having multiple peptide bonds are concerned with a wide spectrum of biological activities such as antimicrobial, anti-inflammatory, antimalarial, cyctotoxic, and antifungal activities. Cyclic peptides are more important compounds for medicinal purposes and represent an important class of natural products. Since only minute quantities are obtained from natural resources many of these compounds were attempted to synthesize in the laboratory. Keeping in view the biological potential of cyclic peptide as well as to obtain a bioactive compound in a good yield, the present investigation aimed at synthesis of cyclic heptapeptide cyclo(Gly-Tyr-Val-Pro-Leu-Trp-Pro) in a convenient and economical manner. Synthesized cyclic heptapeptide was evaluated for pharmacological activities. The antibacterial and antifungal activities were carried out against variety of pathogenic microorganism like Escherichia coli, Staphylococcus aureus, Bacillus subtilis and Candida albicans, Asperigillus niger. The anthelminitic activity was carried out against Eudrilus species of earthworms.
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Bioelectronic DNA detection involves forming an electronic circuit mediated by nucleic acid hybridization and it serves as the basis for a DNA detection system called eSensor™ [1-4]. This system uses low-density DNA chips containing electrodes coated with DNA capture probes. Target DNA present in the sample hybridizes specifically both to capture probes and ferrocene labeled signal probes in solution thereby generating an electric current. Currente Sensor DNA chips contain as many as 36 electrodes for simultaneous detection of multiple pathogens from a single sample.

Many pathogens cause both acute and chronic disease at relatively low copy number and may be difficult or impossible to propagate in culture. Thus, most pathogen detection systems rely on nucleic acid amplification by using polymerase chain reaction (PCR). One highly effective amplification strategy targets conserved sequences among the family of organisms of interest. Such broad-range PCR strategies have been used to identify and characterize several known and previously uncharacterized bacteria [5,6] and viruses [7,8]. In order to maximize the utility of these effective pathogen nucleic acid amplification systems, amplification needs to be coupled with rapid, sensitive, and specific detection. Bioelectronic DNA detection by use of the eSensor chip might fulfill this need.

Human papillomaviruses (HPV) serve as an ideal model system for determining the efficiency and feasibility of eSensor DNA detection technology since there are at least 30 distinct genital HPV types that can be effectively amplified with broad-range consensus PCR primers. We designed two eSensor chips, each containing 14 probes specific for the conserved L1 region of the HPV genome. We evaluated clinical cervical cytology samples known to contain one or more HPV types. The eSensor DNA detection platform successfully detected the correct HPV type in most of these clinical samples, demonstrating that the system provides a rapid, sensitive, specific, and economical approach for multiple-pathogen detection and identification from a single sample.Background We used human papillomaviruses (HPV) as a model system to evaluate the utility of a nucleic acid, hybridization-based bioelectronic DNA detection platform (eSensor) in identifying multiple pathogens.