Valorization of organic fruit peel wastes for Aedes aegypti control: A green chemistry approach integrating in vitro and in silico studies

Vector-borne diseases affect millions of people worldwide, with a significant impact on children below five years. The infections transmitted by mosquitoes cause an estimate of 219 million cases globally, resulting in more than 400,000 deaths every year. As per WHO protocol, spraying of synthetic larvicides over the stagnant drainages and water systems is being one of the most common and effective techniques in the process of disease control. In parallel, the awareness on organic waste pollution had led to the increased practice of sustainable valorization to tackle daily needs. The present study focuses on mixed fruit peel liquid (MFPL) production through anaerobic fermentation of fruit peel wastes and evaluation of its larvicidal efficacy against Aedes aegypti. The in vitro assay revealed that higher concentrations of MFPL and exposure period increased larval mortality, with LC50 values ranging from 1.4% at 6 h to 0.3% at 24 h. Among the twenty bioactive compounds identified through GC-MS analysis of MFPL, n-hexadecanoic acid,2(1H) - quinolinone hydrazone and benzofuran, had significant glide scores of. -12.3 kcal/mol, -7.1 kcal/mol and -5.7 kcal/mol against the target protein 1PZ4 and -11.1 kcal/mol, -7.2 kcal/mol and -5.2 kcal/mol against 1YIY during molecular docking. The stability and interactions of three bioactive compounds were then assessed using DFT and molecular dynamics simulations, in which n-hexadecanoic acid was significantly stable with optimal hydrogen bond interactions. The novel findings of the study confirm MFPL's potential as an effective larvicide which could substitute commercial larvicides that are harmful to the ecosystem.

Synthesis and modification of novel thiazole-fused quinoxalines as new insecticidal agents against the cotton leafworm Spodoptera litura: design, characterization, in vivo bio-evaluation, toxicological effectiveness, and study their mode of action

Herein, novel thiazolo[4,5-b]quinoxalin-2-ones 2-6 and thiazolo[4,5-b]quinoxalin-2(3H)-imines 7-9 were synthesized and characterized using elemental analysis, IR spectroscopy, and 1H/13C NMR to confirm their structures. The efficacy of the newly designed thiazolo-quinoxalines 2, 3, 4, 5, 7, 8, and 9 against the cotton leafworm S. litura (2nd and 4th instar larvae) was evaluated, and results revealed insecticidal activity with variable and good mortality percentages. A SAR study was also discussed. Additionally, compound 3 exhibited the highest insecticidal activity, with mortality% values ranging from 86% ± 7.21% to 97% ± 1.52% and from 66.00% ± 6.24% to 86.33% ± 6.90% at concentrations of 625-2500 mg L-1 against the 2nd and 4th instar larvae, respectively. The probit analysis revealed that the thiazolo[4,5-b]quinoxalin-2(3H)-one derivative 3, after 5 days of treatment, exhibited LC50 values of 141.02 and 366.73 mg L-1 for the 2nd and 4th instar larvae, respectively. The LT50 values ranged from 0.52 to 1.92 days for the 2nd larval instar and from 1.95 to 2.47 days for the 4th larval instar. The corresponding toxicity index (TI) values were 86.21% for the 2nd instar and 78.47% for the 4th instar larvae. The mode of action of compound 3 was assessed through physiological, histological, and SEM analyses on the 4th larval instar. The physiological bioassay revealed a significant increase in total carbohydrate and protein levels compared to the control group. However, the enzymatic study showed a significant decrease (P < 0.05) in the levels of aspartate aminotransferase (AST/GOT), alanine aminotransferase (ALT/GPT), and alkaline phosphatase (AlP), while acetylcholinesterase (AChE) levels significantly increased. SEM analysis revealed malformations in the external body, while histological examination demonstrated severe damage to the gut epithelium and regenerative cells in the midgut tissues.

In-silico Studies, Design, and Synthesis of Pyrimidine-linked Benzothiazoles for its Anticonvulsant Potential

BACKGROUND

The objective of the study was to design and synthesize a series of N-(6-substituted- 1, 3-benzothiazole-2-yl)-2-{[6-(3-substitutedphenyl)-5-cyano-2-sulfanylpyrimidine-4-yl)]amino} acetamide derivatives BPD (1-15) that contains key pharmacophores required for anticonvulsant action.

METHODS

The titled compounds (BPD 1-15) were synthesized by reacting 2-substituted-N-(6-chlorobenzo[ d]thiazol-2-yl)acetamide with 4-amino-6-(4-substituted phenyl)-2-mercapto pyrimidine 5-carbonitrile in the presence of potassium carbonate and dry acetone. The synthesized compounds BPD (1-15) were assessed in vivo by the maximum electric shock (MES) test and the subcutaneous pentylenetetrazol (scPTZ) test in mice. The neurotoxicity test was performed by the rotarod test. A molecular docking study of title compounds with a sodium channel receptor (PDB ID: 1BYY) was carried out using the SP Docking protocol of the Glide module of the Maestro. Pharmacophore modeling was used to qualitatively identify the chemical characteristics for ligand binding and their spatial configurations in the 3D space of the active site.

RESULT

Among the studied compounds, BPD-15 and BPD-5 compounds showed significant action in both the MES and scPTZ models, with no neurotoxicity. BPD-15 & BPD-5 were relatively safe in acute toxicity testing. Compounds BPD-15 and BPD-5 showed good dock scores of -6.434 and -6.191, respectively.

CONCLUSION

Thus, the compounds BPD-15 and BPD-5 have shown a considerable affinity towards the sodium channel as compared to the standard drug Riluzole. Compound BPD-14 showed good drug compatibility, and compounds BPD-1, BPD-2, BPD-11, BPD-12, BPD-13, BPD-14, BPD-15 showed good ADME values.

Beauveria bassiana (Hypocreales: Clavicipitaceae) Volatile Organic Compounds (VOCs) Repel Rhynchophorus ferrugineus (Coleoptera: Dryophthoridae)

The entomopathogenic fungus Beauveria bassiana (Bb) is used to control the red palm weevil (RPW) Rhyncophorus ferrugineus (Oliver). Beuveria bassiana can infect and kill all developmental stages of RPW. We found that a solid formulate of B. bassiana isolate 203 (Bb203; CBS 121097), obtained from naturally infected RPW adults, repels RPW females. Fungi, and entomopathogens in particular, can produce volatile organic compounds (VOCs). VOCs from Bb203 were analyzed using gas chromatography-mass spectrometry (GC-MS). GC-MS identified more than 15 VOCs in B. bassiana not present in uninoculated (control) formulate. Both ethenyl benzene and benzothiazole B. bassiana VOCs can repel RPW females. Our findings suggest that B. bassiana and its VOCs can be used for sustainable management of RPW. They could act complementarily to avoid RPW infestation in palms.

Synthesis of biologically active derivatives of 2-aminobenzothiazole

The minireview considers the current trends in the synthesis of some biologically active compounds based on 2-aminobenzothiazole. The presented information covers publications of the last five years.

Modern Approaches to the Synthesis and Transformations of Practically Valuable Benzothiazole Derivatives

The review is devoted to modern trends in the chemistry of 2-amino and 2-mercapto substituted benzothiazoles covering the literature since 2015. The reviewed heterocycles belong to biologically active and industrially demanded compounds. Newly developed synthesis methods can be divided into conventional multistep processes and one-pot, atom economy procedures, realized using green chemistry principles and simple reagents. The easy functionalization of the 2-NH2 and 2-SH groups and the benzene ring of the benzothiazole moiety allows considering them as highly reactive building blocks for organic and organoelement synthesis, including the synthesis of pharmacologically active heterocycles. The review provides a summary of findings, which may be useful for developing new drugs and materials and new synthetic approaches and patterns of reactivity.