GC-MS and GC-FID analysis of volatile secondary metabolites of the root of Anaphalis contorta Hook F. from India

  ABSTRACT. The chemical composition of hydro-distilled essential oil of dried roots of Anaphalis contorta Hook F. was analyzed for the first time by using gas chromatography equipped with flame ionization detector (GC-FID) and gas chromatography coupled with mass spectrometry (GC-MS). The compounds of essential oil were identified according to their mass spectra and their relative retention indices determined on a capillary GC column (non-polar stationary phase). Twenty-seven compounds were identified representing 94.8% of the total oil. The major constituents were 2,2-dimethyl-2[2,4,6-trimethylphenyl] acetic acid (12.1%), labda-8,14-dien-13-ol (8.4%), δ-cadinene (8.1%), labda-7,14-dien-13-ol (6.9%), α-gurjunene (6.7%), viridiflorene (5.1%), and caryophyllene oxide (4.9%). The root essential oil of A. contorta produced different chemotypes.                 KEY WORDS: Anaphalis contorta Hook F., Essential oil composition, 2,2-Dimethyl-2[2,4,6-trimethylphenyl] acetic acid.  labda-8,14-dien-13-ol, GC/MS Bull. Chem. Soc. Ethiop. 2022, 36(1), 235-240.                                                                DOI: https://dx.doi.org/10.4314/bcse.v36i1.19                                                                                           &nbsp

Distance Dependent Resonance Energy Transfer Between Molecular Machine and Plasmonic Nanostructure

poster abstractPhotoswitchable molecules (molecular machines) have attracted a great deal of attention over the past few years for the design of molecular sensors. Among photoswitchable molecules, azobenzene is widely studied due to its trans-cis photoisomerization, which produces a simple structure and optical and Raman spectra, and is photo and electrochemically active, and can be utilized for optical storage and other applications. Localized surface plasmon resonance (LSPR) properties of the metal nanostructures in conjunction with the photoswitching properties of the azobenzene molecules allow the nanoscale environment to be more controlled and to ultimately improve the sensing abilities of the metallic nanostructure. Herein, we develop an ultrasensitive molecular sensor by functionalizing the gold nanoprism with a selfassembled monolayer of alkanethiols containing azobenzenes. This is the first study where light-induced reversible switching of azobenzenes to cis and trans conformations was detected by monitoring the LSPR of gold nanoprisms-based sensing platforms. It was found that the LSPR red shift was observed as the light exposure was switched from UV to blue light due to the cis to trans isomerization of the azobenzene. This shift is consistent with the increase in thickness of the local dielectric environment (0.6 nm) surrounding the nanoprisms with perhaps a contribution from electronic interaction between the nanoprisms and azobenzene. We hypothesize that this electronic interaction is the nearfield resonance energy transfer (NF-RET). Changing the alkanethiol chain length altered the distance between the nanoprisms’ surface to the azobenzene. The LSPR red shift decreases as the distance between azobenzenes and nanoprisms increases due to the decrease in NF-RET. The LSPR shift was found to be reversible as the light source was switched back and forth several times from UV to blue light. The effects of the azobenzene conformational change and its photoreversibility were also probed through surface enhanced Raman spectroscopy (SERS) demonstrating that the NF-RET between the nanoprisms and bound azobenzenes in their cis conformation significantly enhances the intensity of the Raman bands of the azobenzenes and is highly dependent on the distance of azobenzene from the surface of the nanoprisms. The SERS data suggested that the isomerization was controlled by first-order kinetics with a rate constant of 1.0 x 10−4 s−1. Our demonstration of light-induced photoreversibility of this type of molecular machine is the first step toward eliminating current limitations on detection of molecular motion in solid-state devices using LSPR spectroscopy with nanoprisms. Modulating the LSPR position and controlling energy transfer across the nanostructure organic molecule interface are very important for the fabrication of plasmonic-based nanoscale devices

Nanoplasmonic sensor for the detection of cardiac Troponin

poster abstractThe Isoform of troponin I is uniquely produce in the adult human myocardium and it overexpress at myocardial injury. Accordingly, Iso troponin 1 level in plasma and other biological fluids can serve as diagnostic and prognostic disease biomarkers. Our study focus on the design of a label free ultrasensitive nanoplasmonic sensor by utilizing unique localized surface Plasmon resonance (LSPR) property of highly sensitive gold nanoprisms. Herein our study reveals that chemically synthesized nanoprisms with 42 nm average edge lengths can be used in nanoplasmonic sensor fabrication for the troponin detection. The limit of detection has been found to be sub-picomolar concentrations in PBS buffer and we will explore this sensing mechanism to detect Troponin I of myocardial infarction patient’s samples

DESIGNING EFFICIENT LOCALIZED SURFACE PLASMON RESONANCE-BASED SENSING PLATFORMS: OPTIMIZATION OF SENSOR RESPONSE BY CON-TROLLING THE EDGE LENGTH OF GOLD NANOPRISMS

poster abstractOver the last few years, the unique localized surface plasmon resonance (LSPR) properties of plasmonic nanostructures have been used to design la-bel-free biosensors. In this research, we demonstrate that it is the difference in edge length of gold nanoprisms that significantly influences their bulk re-fractive index sensitivity and local sensing efficiency. Nanoprisms with edge lengths in the range of 28-51 nm were synthesized by the chemical-reduction method and sensing platforms were fabricated by chemisorptions of these nanoprisms onto silanized glass substrates. The plasmonic nanosensors prepared from 28 nm edge length nanoprisms exhibited the largest sensitivity to change in bulk refractive index with a value of 647 nm/RIU. The refractive index sensitivity decreased with increasing edge length, with nanoprisms of 51 nm edge lengths displaying a sensitivity of 384 nm/RIU. In contrast, we found that the biosensing efficiency of sensing platforms modified with biotin increased with increasing edge length, and the sensing platforms fabricated from 51 nm edge length nanoprisms displaying the highest local sensing efficiency. The lowest concentration of streptavidin that could be measured reliably was 1.0 pM and the limit of detection for the sensing platforms fabricated from 51 nm edge length nanoprisms was 0.5 pM, which is much lower than found with gold bipyramids, nanostars, and nanorods

Reduced regional brain cortical thickness in patients with heart failure.

AimsAutonomic, cognitive, and neuropsychologic deficits appear in heart failure (HF) subjects, and these compromised functions depend on cerebral cortex integrity in addition to that of subcortical and brainstem sites. Impaired autoregulation, low cardiac output, sleep-disordered-breathing, hypertension, and diabetic conditions in HF offer considerable potential to affect cortical areas by loss of neurons and glia, which would be expressed as reduced cortical thicknesses. However, except for gross descriptions of cortical volume loss/injury, regional cortical thickness integrity in HF is unknown. Our goal was to assess regional cortical thicknesses across the brain in HF, compared to control subjects.Methods and resultsWe examined localized cortical thicknesses in 35 HF and 61 control subjects with high-resolution T1-weighted images (3.0-Tesla MRI) using FreeSurfer software, and assessed group differences with analysis-of-covariance (covariates; age, gender; p<0.05; FDR). Significantly-reduced cortical thicknesses appeared in HF over controls in multiple areas, including the frontal, parietal, temporal, and occipital lobes, more markedly on the left side, within areas that control autonomic, cognitive, affective, language, and visual functions.ConclusionHeart failure subjects show reduced regional cortical thicknesses in sites that control autonomic, cognitive, affective, language, and visual functions that are deficient in the condition. The findings suggest chronic tissue alterations, with regional changes reflecting loss of neurons and glia, and presumably are related to earlier-described axonal changes. The pathological mechanisms contributing to reduced cortical thicknesses likely include hypoxia/ischemia, accompanying impaired cerebral perfusion from reduced cardiac output and sleep-disordered-breathing and other comorbidities in HF

Ayuvedic approach in Primary Biliary Cholangitis (PBC): A case study

Despite of countless facilities and highly developed technologies for the treatment of diseases in modern medical science, there are many diseases which has no medical cure other than prophylactic treatment while the disease is progressing and needs organ transplant in last stage, one such disease is Primary Biliary Cholangitis (PBC). A 65 year old female patient presenting with pain in upper abdomen (Udarshool), decrease appetite (Agnimandhyata), weakness (Daurbalyata), distension of abdomen (Kuchheradmanam), bilateral mild pedal edema (Ubhaypaad-shoth), itching (Kandu), muscular and bony pain (Mansasthishool) diagnosed as Yakritpleehodar Roga, a subtype of Udar roga was brought to Hospital National Institute of Ayurveda, Jorawarsingh Gate, Jaipur, Rajasthan. The patient was treated on the basis of Ayurvedic principles of treatment of Udar roga. According to Ayurveda, the principle of treatment of Udar roga includes Nitya Virechan (purgation), Agnideepan (increasing appetite), Yakituttejan (stimulation of Liver), Mutra Virechan (diuresis) and Ksheer Prayoga (use of milk as diet) for Balprapti (increasing strength of patient). Appreciable result were observed in the form of decreased abdominal pain, decreased abdominal girth, decreased pedal edema, decreased weakness, decreased  muscular and bone pain, increased appetite, decrease in fibrotic changes of Liver, resolution of Ascites, decrease in size of Spleen along with significant improvement in other laboratory investigations. Keywords- Ksheer Prayoga, Jalodar, Primary Biliary Cholangitis, Udar roga, Yakritpleehodar Roga

Label-Free Nanoplasmonic-Based Short Noncoding RNA Sensing at Attomolar Concentrations Allows for Quantitative and Highly Specific Assay of MicroRNA-10b in Biological Fluids and Circulating Exosomes

MicroRNAs are short noncoding RNAs consisting of 18-25 nucleotides that target specific mRNA moieties for translational repression or degradation, thereby modulating numerous biological processes. Although microRNAs have the ability to behave like oncogenes or tumor suppressors in a cell-autonomous manner, their exact roles following release into the circulation are only now being unraveled and it is important to establish sensitive assays to measure their levels in different compartments in the circulation. Here, an ultrasensitive localized surface plasmon resonance (LSPR)-based microRNA sensor with single nucleotide specificity was developed using chemically synthesized gold nanoprisms attached onto a solid substrate with unprecedented long-term stability and reversibility. The sensor was used to specifically detect microRNA-10b at the attomolar (10(-18) M) concentration in pancreatic cancer cell lines, derived tissue culture media, human plasma, and media and plasma exosomes. In addition, for the first time, our label-free and nondestructive sensing technique was used to quantify microRNA-10b in highly purified exosomes isolated from patients with pancreatic cancer or chronic pancreatitis, and from normal controls. We show that microRNA-10b levels were significantly higher in plasma-derived exosomes from pancreatic ductal adenocarcinoma patients when compared with patients with chronic pancreatitis or normal controls. Our findings suggest that this unique technique can be used to design novel diagnostic strategies for pancreatic and other cancers based on the direct quantitative measurement of plasma and exosome microRNAs, and can be readily extended to other diseases with identifiable microRNA signatures