Photodegradation of Flucetosulfuron, a Sulfonylurea-Based Herbicide in the Aqueous Media Is Influenced by Ultraviolet Irradiation

Photodegradation (photolysis) causes the breakdown of organic pesticides molecules by direct or indirect solar radiation energy. Flucetosulfuron herbicide often encounters water bodies. For this reason, it is important to know the behavior of the compound under these stressed conditions. In this context, photodegradation of flucetosulfuron, a sulfonylurea-based herbicide, has been assessed in aqueous media in the presence of photocatalyst TiO2 and photosensitizers (i.e., H2O2, humic acid, and KNO3) under the influence of ultraviolet (UV) irradiation. The influence of different water systems was also assessed during the photodegradation study. The photodegradation followed the first-order reaction kinetics in each case. The metabolites after photolysis were isolated in pure form by column chromatographic method and characterized using the different spectral data (i.e., XRD, IR, NMR, UV-VIS, and mass spectrometry). The structures of these metabolites were identified based on the spectral data and the plausible photodegradation pathways of flucetosulfuron were suggested. Based on the findings, photocatalyst TiO2 with the presence of ultraviolet irradiation was found effective for the photodegradation of toxic flucetosulfuron residues under aqueous conditions.

Facile and Straightforward Synthesis of Racemic Version of Substituted 3-[3-(2-Hydroxyphenyl)-3-oxo-1-arylpropyl]-4-hydroxycoumarins: Easy Access to a Series of Biorelevant Warfarin Analogues

The present communication deals with a straightforward, efficient, and green synthesis of a series of racemic version of 3-[3-(2-hydroxyphenyl)-3-oxo-1-arylpropyl]-4-hydroxycoumarins as biologically interesting warfarin analogues upon decarboxylative hydrolysis of bis-coumarin derivatives in aqueous potassium hydroxide solution. The salient features of this practical method are operational simplicity, avoidance of any organic solvents and tedious column chromatographic purification, clean reaction profiles, excellent yields, and gram-scale synthetic applicability.

A General Method for the Synthesis of 11H-indeno[1,2-b]quinoxalin-11-ones and 6H-indeno[1,2-b]pyrido[3,2-e]pyrazin-6-one Derivatives using Mandelic Acid as an Efficient Organo-catalyst at Room Temperature

Aims: Synthesis of 11H-indeno[1,2-b]quinoxalin-11-ones as well as 6H-indeno[1,2-b]pyrido[3,2-e]pyrazin-6-one derivatives under greener conditions. Background: Quinoxaline and related skeletons are very common in naturally occurring bioactive compounds. Objective: Design a facile, green and organo-catalyzed method for the synthesis of 11H-indeno[1,2-b]quinoxalin-11-ones as well as 6H-indeno[1,2-b]pyrido[3,2-e]pyrazin-6-one derivatives. Methods: Both the scaffolds were synthesized via the condensation of ninhydrin and o-phenylenediamines or pyridine-2,3-diamines respectively by using a catalytic amount of mandelic acid as an efficient, commercially available, low cost, organo-catalyst in aqueous ethanol at room temperature. Results: Mild reaction conditions, use of metal-free organocatalyst, non-toxic solvent, ambient temperature, and no column chromatographic separation are some of the notable advantages of our developed protocol. Conclusion: In conclusion, we have developed a simple, mild, facile and efficient method for the synthesis of structurally diverse 11H-indeno[1,2-b]quinoxalin-11-one derivatives via the condensation reactions of ninhydrin and various substituted benzene-1,2-diamines using a catalytic amount of mandelic acid as a commercially available metal-free organo-catalyst in aqueous ethanol at room temperature. Under the same optimized reaction conditions, synthesis of 6H-indeno[1,2-b]pyrido[3,2-e]pyrazin-6-one derivatives was also accomplished with excellent yields by using pyridine-2,3-diamines instead of o-phenylenediamine.

A practical and scalable synthesis of KRN7000 using glycosyl iodide as the glycosyl donor

KRN7000 is particularly useful because it is a powerful and specific CD1d agonist and has prompted intense interest in the context of immunology in the past 25 years. Its limited commercial availability and high price has led to the publication of many different syntheses. However, almost all of them focused on the methodology development rather than a scalable synthesis. Herein, we have described a practical and scalable procedure for the synthesis of KRN7000 basing on the glycosyl iodide method. This procedure involves total of eight steps to obtain the highly pure product KNR7000 on gram scale from the commercially available starting materials (d-galactose and the phytosphingosine) with only three column chromatographic purifications.

Isolation and Analysis of Methanol Extract of Leaf of Senna siamea

This study aimed at isolation and characterization of biochemical constituents of the leaf extract of Senna siamea. The fresh leaves of Senna siamea were air-dried, pulverized and extracted using methanol by maceration method. The extract was screened for phytochemicals using standard methods. Fifty grammas (50 g) of the crude extract was defatted using n-hexane; 20 g was subjected to column chromatographic (CC) analysis using ethyl acetate and n-butanol fractions with similar retardation factor (Rf) were pooled and coded. Subsequently purification of fraction SSM5 was carried out using CC with solvent [Toluene and n-butanol (4:1) as mobile phase]. The collection was based on colour bands) and TLC was carried out where a sub-fraction SSM54 amongst other fractions gave a single spot on TLC and the Rf value was 0.71. It was then subjected to UV, IR and GC-MS analysis. The extract by maceration yielded 12.60% w/w and the defatted extract yielded 10.0% w/w. The result of the UV-visible gave a wavelength of 289 nm and an absorbance of 4.268. The result of infrared spectroscopy revealed functional groups thus O-H, N-H, C-H stretching group at 3385.8 cm-1, -CHO at 2955.8 cm-1, -CHO stretching at 2926.0 cm-1,-NH3+ at 1640.0 cm-1, carboxylate ion–CO2- for amino acid at 1449.9cm-1, -N=N- at 1401.5 cm-1, -N+O-=N- at 1315.8 cm-, C-O-C at 1189 cm-1, Si-O at 1084 cm-1 and S=O at 1013.8. The GC-MS analysis of SSM54 revealed the presence of Diisoctyl phthalate, Purine-2,6-dione, 8-(3-Ethoxypropylamino)-1,3-dimethyl-3, 9-dihydro-, a-Pinene, 10-(dimethylaminomethyl), 1H-indene-2-ethanamine, N, N- dimethyl-3-[1-(2-pyrindinyl) ethyl] -, Benzene, 1, 2- bis(2,5 dimethylphenylaminomethyl)-3,6- dimethyl- and Cinnamic acid, p-(trimethylsiloxy)-, methyl ester were among the probable bioactive compounds.