Synthesis and antimicrobial activity of new (4,4,4-trihalo-3-oxo-but-1-enyl)-carbamic acid ethyl esters, (4,4,4-trihalo-3-hydroxy-butyl)-carbamic acid ethyl esters, and 2-oxo-6-trihalomethyl-[1,3]oxazinane-3-carboxylic acid ethyl esters

Green Synthetic Methods of Oxazine and Thiazine Scaffolds as Promising Medicinal Compounds: A Mini-review

Medical researchers have paid close attention to the green synthesis of oxazine and thiazine derivatives since they provided a lead molecule for the creation of numerous possible bioactive compounds. This review provides more information on green synthesis, which will be very helpful to researchers in creating the most effective, affordable, and clinically significant thiazine and oxazine derivatives that are anticipated to have strong pharmacological effects. This has resulted in the identification of several substances with a wide range of intriguing biological functions. This article's goal is to examine the numerous green chemical processes used to create oxazine and thiazine derivatives and their biological activity. We anticipate that researchers interested in oxazine and thiazine chemicals will find this material to be useful. We anticipate that medicinal chemists looking for new active medicinal components for drug discovery and advance progress will find this review of considerable interest.

Characterisation of the essential oil from Iphiona grantioides and investigation of its antibacterial and antioxidant properties

Iphiona grantioides (Boiss) Anderb. is a medicinal plant featuring several traditional uses. Nevertheless, this plant has not been widely investigated by modern medicinal chemistry yet, as also the properties of its extracts.In this study, we report the extraction of the essential oil by hydrodistillation from the leaves of I. grantioides. This was characterised by GC-MS analysis and ten chemical constituents were identified.Our findings demonstrate that the essential oil is effective in inhibiting the growth of bacterial strains, and of Klebsiela pneumonia and Staphylococcus aureus in particular. Additionally, its antioxidant properties were evaluated, and it showed radical scavenging activity in vitro.

Synthetic Methods and Pharmacological Potential of Different Oxazine Analogs

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Oxazine analog is a vital class of heterocyclic compounds and has attracted synthetic interest owing to their wide range of biological activities. Oxazine analogs are valuable in medicinal organic chemistry and exhibit different varieties of biological activities such as antimicrobial, anticancer, antimalarial, antitubercular, sedative, anticonvulsant, analgesic, anti-inflammatory, antipyretic, etc. Oxazine can be derived from benzene by appropriate substitution of carbon atoms of the ring by nitrogen and oxygen atoms. Nowadays, the development of drug resistance is a key problem, and to defeat this problem, it is crucial to synthesize novel compounds. So, novel oxazine analogs may play a crucial role to overcome these problems. Oxazine analogs are prepared by reaction of chalcone derivatives with thiourea in the presence of alcohol and sodium hydroxide. The present aims of this review are to give an outline of some different synthetic methods and different types of biological activities of oxazine analogs. We hope that this review will be motivating for researchers concerned with oxazine analogs.

Ultrastructural changes in methicillin-resistant Staphylococcus aureus (MRSA) induced by metabolites of thermophilous fungi Acrophialophora levis

Staphylococcus aureus and Methicillin-resistant S. aureus (MRSA) remains one of the major concerns of healthcare associated and community-onset infections worldwide. The number of cases of treatment failure for infections associated with resistant bacteria is on the rise, due to the decreasing efficacy of current antibiotics. Notably, Acrophialophora levis, a thermophilous fungus species, showed antibacterial activity, namely against S. aureus and clinical MRSA strains. The ethyl acetate extract of culture filtrate was found to display significant activity against S. aureus and MRSA with a minimum inhibitory concentration (MIC) of 1 μg/mL and 4 μg/mL, respectively. Scanning electron micrographs demonstrated drastic changes in the cellular architecture of metabolite treated cells of S. aureus and an MRSA clinical isolate. Cell wall disruption, membrane lysis and probable leakage of cytoplasmic are hallmarks of the antibacterial effect of fungal metabolites against MRSA. The ethyl acetate extract also showed strong antioxidant activity using two different complementary free radicals scavenging methods, DPPH and ABTS with efficiency of 55% and 47% at 1 mg/mL, respectively. The total phenolic and flavonoid content was found to be 50 mg/GAE and 20 mg/CAE, respectively. More than ten metabolites from different classes were identified: phenolic acids, phenylpropanoids, sesquiterpenes, tannins, lignans and flavonoids. In conclusion, the significant antibacterial activity renders this fungal strain as a bioresource for natural compounds an interesting alternative against resistant bacteria.

GC-MS-Based Metabolomics Analysis of Prawn Shell Waste Co-Fermentation by Lactobacillus plantarum and Bacillus subtilis

GC-MS-based metabolomics were used to investigate metabolic changes in prawn shell waste during fermentation. Microbial strains Lactobacillus plantarum and Bacillus subtilis were co-fermented in a shake flask comprising of 5% (w/v) prawn shell waste and 20% (w/v) glucose as a carbon source. Analysis of the prawn shell waste fermentation showed a total of 376 metabolites detected in the culture supernatant, including 14 amino acids, 106 organic acids, and 90 antimicrobial molecules. Results show that the liquid fraction of the co-fermentation is promising for harvesting valuable metabolites for probiotics application.

OC, Ahmad A, Burtoloso ACB. Synthesis of Oxazinanones: Intramolecular Cyclization of Amino Acid-Derived Diazoketones via Silica-Supported HClO4 Catalysis

A Brønsted acid catalyzed intramolecular cyclization of N-Cbz-protected diazoketones, derived from α-amino acids, is described. The reaction proceeds under metal-free conditions and is promoted by ecofriendly silica-supported HClO₄ as the catalyst and methanol as the solvent. This transformation enables the short synthesis of various 1,3-oxazinane-2,5-diones under mild reaction conditions and in good yields (up to 90%). The set-up is very simple; by just mixing all reagents together with no work-up necessary before purification, this protocol takes a greener approach.

1,5-Benzodiazepine derivatives as potential antimicrobial agents: design, synthesis, biological evaluation, and structure–activity relationships

36 novel 1,5-benzodiazepine derivatives were synthesized and evaluated for their in vitro antimicrobial activity. The results revealed that most of the 1,5-benzodiazepine derivatives exhibited considerable potency against all of the tested strains.

Reactions of CF3-enones with arenes under superelectrophilic activation: a pathway to trans-1,3-diaryl-1-CF3-indanes, new cannabinoid receptor ligands

CF₃-enones react with arenes in TfOH to givetrans-1,3-diaryl-1-CF₃indanes.

Reactions of β-diketone compounds with nitriles catalyzed by Lewis acids: a simple approach to β-enaminone synthesis

Aluminium chloride selectively promoted the nucleophilic attack of β-diketone compounds with nitriles to give enaminones.