R. K. Agarwal

Essential Oils as Natural Food Antimicrobial Agents: A Review

Food-borne illnesses pose a real scourge in the present scenario as the consumerism of packaged food has increased to a great extend. Pathogens entering the packaged foods may survive longer, which needs a check. Antimicrobial agents either alone or in combination are added to the food or packaging materials for this purpose. Exploiting the antimicrobial property, essential oils are considered as a “natural” remedy to this problem other than its flavoring property instead of using synthetic agents. The essential oils are well known for its antibacterial, antiviral, antimycotic, antiparasitic, and antioxidant properties due to the presence of phenolic functional group. Gram-positive organisms are found more susceptible to the action of the essential oils. Essential oils improve the shelf-life of packaged products, control the microbial growth, and unriddle the consumer concerns regarding the use of chemical preservatives. This review is intended to provide an overview of the essential oils and their role as natural antimicrobial agents in the food industry.

Rapid Detection of Salmonella enterica Subspecies enterica serovar Typhimurium by Loop Mediated Isothermal Amplification (LAMP) Test From Field Chicken Meat Samples

Considering the importance of Salmonella enterica subsp. enterica serovar Typhimurium in the foodborne diseases, a Typhimurium specific loop mediated isothermal amplification (LAMP) test was standardized for its rapid detection in chicken meat. The Optimum results were obtained at 64oC and 70 min temperature-time combination. The sensitivity of LAMP and PCR were compared with serial 10-fold dilution of the 100 ng of DNA. The LAMP test detected 2 pg DNA per reaction tube, whereas PCR detected 200 pg DNA per reaction. Therefore, the LAMP test was considered 100 times more sensitive than the PCR. The specificity of LAMP and PCR analyzed with six different isolates of non-Salmonella and 22 serovars of non-Typhimurium. None of these isolates were found positive by both LAMP and PCR. Twenty-eight pure isolates of Salmonella Typhimurium from diverse sources were also examined by Typhimurium specific LAMP and were all found positive. Two-hundred twenty-five field chicken meat samples were screened by cultural, PCR, and LAMP methods. The LAMP and PCR tests were performed by using DNA isolated from 8 h and 18 h enrichment samples, respectively. Typhimurium specific LAMP was shown to be in 100% correlated with cultural and PCR methods. However, LAMP test delivered the results within 26 h without sophisticated equipment while PCR and cultural methods took 48 h and 6 d, respectively. The LAMP test developed in this study has potential to detect and as well as differentiate S. Typhimurium from other Salmonella serovars.

Infrared and thermal behaviour of thorium(IV) and oxozirconium(IV) complexes of dibenzyl sulphoxide

Abstract A series of complexes of thorium(IV) and oxozirconium(IV) with dibenzyl sulphoxide having the general compositions ThX 4 ·2BzSO (X = Cl, Br, NCS or NO 3 ), ThI 4 ·4BzSO, Th(ClO 4 ) 4 ·6BzSO, ZrOX 2 ·2BzSO (X = Cl, Br, I, NCS, NCSe or BPh 4 ) and ZrO(ClO 4 ) 2 · 6BzSO were synthesised and characterized by elemental analyses, electrolytic conductivity, moleculer weight, IR, and magnetic susceptibility measurements. TG and DTA of the complexes were also studied.

Altered Expression of Sphingosine-1-Phosphate Metabolizing Enzymes in Oral Cancer Correlate With Clinicopathological Attributes

ABSTRACT We have determined the gene expression of sphingosine-1-phosphate (S1P) metabolizing enzymes (SphK1, SphK2, SGPL1, SGPP1, SGPP2, PPAP2A, PPAP2B, and PPAP2C) by quantitative real-time polymerase chain reaction in tumor tissues and adjacent normal tissues of 50 oral squamous cell carcinoma (OSCC) patients. Expression of SphK1 and SGPP1 genes was up-regulated significantly in 70% and 75% OSCC tumors respectively. Importantly, expression of SphK2 and PPAP2B was down-regulated in the tumor tissues of 70% OSCC patients. Expression of SphK2 and PPAP2B negatively correlated with tumor-node-metastasis (TNM) staging and tumor volume respectively. Furthermore, LPP1 is an independent predictor of TNM staging and lymph node ratio.

Emerging role of sphingosine-1-phosphate signaling in head and neck squamous cell carcinoma

Head and neck squamous cell carcinoma (HNSCC) is the sixth most frequent cancer type, with an annual incidence of approximately half a million people worldwide. It has a high recurrence rate and an extremely low survival rate. This is due to limited availability of effective therapies to reduce the rate of recurrence, resulting in high morbidity and mortality of patients with advanced stages of the disease. HNSCC often develops resistance to chemotherapy and targeted drug therapy. Thus, to overcome the problem of drug resistance, there is a need to explore novel drug targets. Sphingosine-1-phosphate (S1P) is a bioactive sphingolipid involved in inflammation, tumor progression, and angiogenesis. S1P is synthesized intracellularly by two sphingosine kinases (SphKs). It can be exported to the extracellular space, where it can activate a family of G-protein-coupled receptors. Alternatively, S1P can act as an intracellular second messenger. SphK1 regulates tumor progression, invasion, metastasis, and chemoresistance in HNSCC. SphK1 expression is highly elevated in advanced stage HNSCC tumors and correlates with poor survival. In this article, we review current knowledge regarding the role of S1P receptors and enzymes of S1P metabolism in HNSCC carcinogenesis. Furthermore, we summarize the current perspectives on therapeutic approaches for targeting S1P pathway for treating HNSCC.

Infrared and thermal study of 5,6-benzoquinoline complexes of some higher valent metal ions

Abstract The synthesis and physical properties of crystalline ZrO 2+ , Th 4+ and UO 2+ 2 complexes of 5,6-benzoquinoline (Benzqn), ThX 4 ·4Benzqn (X = Cl, Br, I, NCS), Th(NO 3 ) 4 ·2Benzqn, Th(ClCO 4 ) 4 ·6Benzqn, ZrOX 2 · 4Benzqn (X = Cl, Br, I, NCS), ZrO(NC 3 ) 2 ·2Benzqn, ZrO(ClO 4 ) 2 ·6Benzqn, UO 2 X 2 ·4Benzqn (X = Cl, Br, I, NCS), UO 2 (NO 3 ) 2 ·2Benzqn and UO 2 (ClO 4 ) 2 ·6Benzqn are reported, together with their IR spectra, molar conductivity, molecular weights and TGA data. In all the complexes, Benzqn is bonded to metal via nitrogen.

Infrared and thermal studies of 5,6-benzoquinoline N-oxide complexes of oxozirconium(IV)

We have recently reported the infrared and thermal properties of 5,6-benzoquinoline complexes of higher valent metal ions including oxozirconium(IV) [l]. Aromatic amine N-oxides are potential coordinating agents [2-51. Thus, it is worthwhile to study the coordinating ability of 5,6-benzoquinoline N-oxide. In the present communication, we describe the synthesis, infrared and thermal behaviour of oxozirconium(IV) complexes of 5,6-benzoquinoline N-oxide (Benzquo).

Magneto, spectral and thermal investigations of some oxovanadium(IV) chelates of 2-ethoxycarbonylamino pyridine n-oxide

Abstract Some oxovanadium(IV) chelates of 2-ethoxycarbonylamino pyridine N -oxide (ECAPO) with general compositions VOX 2 ·ECAPO (X = Cl, Br, I, NO 3 , NCS or 0.5C 2 O 4 ) and VO(C1O 4 ) 2 ·2ECAPO have been isolated and characterized through chemical analyses, conductance, molar weight, magnetic susceptibility, infrared and electronic spectra. Magnetic susceptibilities measured at room temperature (30°C) of the chelates indicate the absence of metal-metal interaction between vanadium atoms. Except the perchlorato complex, all other complexes behave like non-electrolytes in nitrobenzene. In the case of the perchlorate complex, the molar conductance value suggests the 1:2 electrolytic nature of the complex. Ir data indicate that ECAPO is bonded to the vanadium atom through oxygens of the carbonyl group and N -oxygen forming a seven-membered ring. It is suggested that penta-coordinates oxovanadium(IV) compounds can have a tetragonal pyramidal structure. Thermal properties of the chelates are also discussed.