Graphene Oxide Catalyzed Synthesis of Fused Chromeno Spiro Pyrrolidine Oxindoles via Tandem Decarboxylation and 1,3-Dipolar Cycloaddition

A short and efficient multicomponent sequence for synthesizing fused novel polyheterocyclic chromeno spiro-pyrrolidine oxindoles via 1,3-dipolar cycloaddition reaction mediated by reactive azomethine ylides catalyzed by the Graphene Oxide (GO) is reported herein. This approach was utilized for synthesizing fused polyheterocyclic spiro-pyrrolothiazole and spiro-pyrrole oxindoles with yields ranging from good to excellent. A heterogeneous GO catalyst with an ultra-low catalytic loading of 0.05 wt% could proficiently catalyze the reaction without the formation of any side products and can also be visualized by the formation of solid mass in the reaction flask. The methodology is green in nature and the products were isolated by simple filtration without the use of any chromatographic techniques.

Chromatographic Techniques for the Analysis of Organophosphate Pesticides with their Extraction Approach: A Review (2015-2020)

In agriculture, a wide range of OPPs have been employed to boost crop yield, quality, and storage life. However, due to the ever-increasing population and rapid urbanization, pesticide use has...

Food Adulteration

Food adulteration is a prevalent issue in the food industry. It affects safety and quality of food and causes harm to the health of the consumer. To reduce incidence of adulteration in food, it is necessary to study adulterants being added to food. Food safety concerns arise when adulteration occurs for a variety of reasons. The act includes use of expired ingredients, deceptive adulterated food labels, addition of harmful compounds to food, and more. Tests and techniques for suspected food items that are commonly adulterated with certain food or non-food products are studied and described here. The detection of adulteration in food sectors can be done qualitatively and quantitatively. Various methods like chemical analysis, spectroscopic, and chromatographic techniques used to detect adulteration are reviewed. Various laws and regulations are in effect around the world in order to prevent adulteration and ensure food safety to protect the consumers. Regulatory agencies play an important role in putting a check to food adulteration by monitoring the quality of food and penalizing defaulters.

Pharmacognostic and Phytochemical Screening of Datura stramonium by TLC and GC-MS: A Forensic Approach

Forensic Botany helps in linking the location, type of crime, revealing modus Operandi, culprit as well as victim by various circumstantial facts. In the study, Datura stramonium was considered as major plant of Bundelkhand region encountered in poisoning cases in criminal Investigations. Datura plant was identified and its fresh leaves were washed to remove dirt, stored at 40C and were subjected to microscopic examination for botanical features, preliminary screening for alkaloids identification and chromatographic techniques such as TLC and GCMS for qualitative analysis of toxins present in the plant. The result showed that all techniques applied are suitable to identify the plant through botanical derived evidences such as leaf traces, resins, or plant extracts during the crime scene investigations. GCMS technique identified the main toxins and resulted that it contains high concentration of hyoscine and very fatal when administered eventually causes death.

Chemical composition and antioxidant activity of Psidium guajava L. leaves

Guava, Psidium guajava L., is well-known tropic tree which is abundantly grown for fruit. It belongs to phylum Magnoliophyta, class Magnoliopsida and Myrtaceae family and has been found a lot in the Mekong Delta of Viet Nam. Antioxidant activity of different extracts from Psidium guajava L. leaves revealed that ethyl acetate and n-butanol extracts have the good activities. Processing of these fractions using repeated column and thin layer chromatographic techniques resulted in the isolation of four compounds, which have identified their chemical structures by spectroscopic techniques including avicularin (1), kaempferol (2), gallic acid (3), and protocatechuic acid (4). All the isolated compounds showed antioxidant activity using DPPH and ABTS scavenging assays. These results suggest that the leaves of guava would be useful natural sources of antioxidants.

Sterigmatocystin Limits Plasmodium falciparum Proliferation and Transmission

As part of our drug discovery program against malaria, the Penicillium janthinellum extract was discovered to inhibit P. falciparum proliferation in blood and transmission to mosquitoes. Bioactivity-guided fractionation of P. janthinellum extraction was carried out using chromatographic techniques. We determined the activities of fractions against Plasmodium falciparum asexual stage parasite proliferation in culture and sexual stage parasite transmission to mosquitoes using standard membrane feeding assays (SMFA). One active compound was isolated. Based on mass spectrometry and nuclear magnetic resonance profiles, the compound was structurally determined to be sterigmatocystin. Sterigmatocystin inhibited P. falciparum proliferation in the blood with an IC50 of 34 µM and limited the sexual parasites to infect mosquitoes with an IC50 of 48 µM. Meanwhile, sterigmatocystin did not show any acute toxicity to human kidney cells at a concentration of 64 µM or lower. Sterigmatocystin can be used as a drug lead for malaria control and as a probe to understand molecular mechanisms of malaria transmission.

Hydroxyethyl Isoflavonoids from the Leaves of Maclura tricuspidata

: Maclura tricuspidata, which belongs to the Moraceae family, is widely distributed in Asia, including Korea. All parts of this plant, such as roots, fruits, and leaves, are rich in diverse bioactive compounds, especially xanthones and isoflavonoids. Investigation of the leaves of M. tricuspidata through various chromatographic techniques yielded fourteen compounds, including five new compounds. The new compounds were determined to comprise an isoflavonoid structure with hydroxyethyl moiety and defined as hydroxyethylisoflavones A-E (10-14) on the basis of 1D and 2D NMR and MS data. These compounds efficiently inhibited α-glucosidase activity.

Structure of the Cell-Wall-Associated Polysaccharides from the Deep-Sea Marine Bacterium Devosia submarina KMM 9415T

Two cell-wall-associated polysaccharides were isolated and purified from the deep-sea marine bacterium Devosia submarina KMM 9415T, purified by ultracentrifugation and enzymatic treatment, separated by chromatographic techniques, and studied by sugar analyses and NMR spectroscopy. The first polysaccharide with a molecular weight of about 20.7 kDa was found to contain d-arabinose, and the following structure of its disaccharide repeating unit was established: →2)-α-d-Araf-(1→5)-α-d-Araf-(1→. The second polysaccharide was shown to consist of d-galactose and a rare component of bacterial glycans-d-xylulose: →3)-α-d-Galp-(1→3)-β-d-Xluf-(1→.