Study of Amino Acid-Derived 3-Acyltetramic Acids as Herbicidal Agents.

The growing problem of herbicide resistance necessitates the development of novel herbicidal active ingredients, together with other integrated weed management approaches. Natural products are a major source of inspiration for novel actives. In previous research, we identified a 3-acyltetramic acid of microbial origin that inhibited algal growth in marine biofilms, at least in part through inhibition of photosystem II. In this work, we demonstrate the herbicidal effect of this lead compound and construct multiple libraries to test the impact of the different substituents of the central scaffold in order to study the structure-activity relationships. Among these analogues, the highest activities were found for medium- to long-chain acyl groups and apolar secondary amino acid residues. Finally, we provide first insights into the herbicidal mechanisms and present preliminary field-trial and ecotoxicological results for TA12-Pro, the most active analogue in our library. Together, this research shows the potential of 3-acyltetramic acids for herbicide development.

Recent Advances in Naturally Occurring [4+2] Type Terpenoid Dimers Assembled through Unmatched-electron-demand Cycloaddition.

Terpenoid dimers of the [4+2] type, which are naturally occurring compounds biosynthetically derived from the [4+2] cycloaddition of two synthons, have garnered considerable attention due to their complex molecular structures, diverse biological activities, and intriguing biosynthetic pathways. We have previously summarized the advancements in three types of [4+2] terpenoid dimers. In this review, we will focus on the lesser-explored class of [4+2] terpenoid dimers which assembled from two electron-deficient synthons via the unmatched-electron-demand Diels-Alder reaction  (UMEDDA). We will summarize their sources, biological activities, proposed biosynthesis, and chemical syntheses. Finally, a summary and outlook for this fascinating class of compounds will be presented.

Unveiling FM-1088: A Breakthrough in Isoindolinone-Based Acaricide Development.

The increasing resistance of agricultural pests to existing acaricides presents a significant challenge to sustainable agriculture. Therefore, this study introduced FM-1088, a novel isoindolinone-based phenyl trifluoroethyl thioether derivative generated through an innovative design strategy combining bioisosterism and novel cyclization methods. We synthesized several compounds and evaluated their acaricidal efficacy against Tetranychus cinnabarinus in greenhouses and Panonychus citri in field settings. FM-1088 emerged as a standout candidate, demonstrating a lower median lethal concentration (LC50) of 0.722 mg/L compared to the commercial acaricide, cyetpyrafen. Notably, 30 days after application, FM-1088 showed a field control efficacy of 96.4% against P. citri, highlighting its potential for broader applications. The results underscore the utility of the isoindolinone scaffold in pesticide development, offering a promising solution to combat pest resistance with implications for enhanced crop protection and agricultural productivity. Future studies should explore the detailed mode of action of FM-1088 and its potential applicability across diverse agricultural settings, further confirming its role as a sustainable solution for pest management.

Natural and synthetic 5-(3'-indolyl)oxazoles: Biological activity, chemical synthesis and advanced molecules.

5-(3'-Indolyl)oxazole moiety is a privileged heterocyclic scaffold, embedded in many biologically interesting natural products and potential therapeutic agents. Compounds containing this scaffold, whether from natural sources or synthesized, have demonstrated a wide array of biological activities. This has piqued the interest of synthetic chemists, leading to a large number of reported synthetic approaches to 5-(3'-indolyl)oxazole scaffold in recent years. In this review, we comprehensively overviewed the different biological activities and chemical synthetic methods for the 5-(3'-indolyl)oxazole scaffold reported in the literatures from 1963 to 2024. The focus of this study is to highlight the significance of 5-(3'-indolyl)oxazole derivatives as the lead compounds for the lead discovery of anticancer, pesticidal, antimicrobial, antiviral, antioxidant and anti-inflammatory agents, to summarize the synthetic methods for the 5-(3'-indolyl)oxazole scaffold. In addition, the reported mechanism of action of 5-(3'-indolyl)oxazoles and advanced molecules studied in animal models are also reviewed. Furthermore, this review offers perspectives on how 5-(3'-indolyl)oxazole scaffold as a privileged structure might be exploited in the future.

Rethinking Nanoparticle Synthesis: A Sustainable Approach vs. Traditional Methods.

This review portrays a comparison between green protocols and conventional nanoparticle (NP) synthesis strategies, highlighting each method's advantages and limitations. Various top-down and bottom-up methods in NP synthesis are described in detail. The green chemistry principles are emphasized for designing safe processes for nanomaterial synthesis. Among the green biogenic sources plant extracts, vitamins, enzymes, polysaccharides, fungi (Molds and mushrooms), bacteria, yeast, algae, and lichens are discussed. Limitations in the reproducibility of green protocols in terms of availability of raw material, variation in synthetic protocol, and selection of material due to geographical differences are elaborated. Finally, a conclusion is drawn utilizing green chemical principles, & a circular economy strategy to minimize waste generation, offering a promising framework for the synthesis of NPs emphasizing sustainability.

Exploring the Mutated Kinases for Chemoenzymatic Synthesis of N4-Modified Cytidine Monophosphates.

Nucleosides, nucleotides, and their analogues are an important class of molecules that are used as substrates in research of enzymes and nucleic acid, or as antiviral and antineoplastic agents. Nucleoside phosphorylation is usually achieved with chemical methods; however, enzymatic phosphorylation is a viable alternative. Here, we present a chemoenzymatic synthesis of modified cytidine monophosphates, where a chemical synthesis of novel N4-modified cytidines is followed by an enzymatic phosphorylation of the nucleosides by nucleoside kinases. To enlarge the substrate scope, multiple mutant variants of Drosophila melanogaster deoxynucleoside kinase (DmdNK) (EC:2.7.1.145) and Bacillus subtilis deoxycytidine kinase (BsdCK) (EC:2.7.1.74) have been created and tested. It has been determined that certain point mutations in the active sites of the kinases alter their substrate specificities noticeably and allow phosphorylation of compounds that had been otherwise not phosphorylated by the wild-type DmdNK or BsdCK.

Catalytic divergence of O-methyltransferases shapes the chemo-diversity of polymethoxylated bibenzyls in Dendrobium catenatum.

Erianin, crepidatin, and chrysotobibenzyl are typical medicinal polymethoxylated bibenzyls (PMBs) that are commercially produced in Dendrobium species. PMBs' chemo-diversity is mediated by the manifold combinations of O-methylation and hydroxylation in a definite order, which remains unsolved. To unequivocally elucidate the methylation mechanism of PMBs, 15 possible intermediates in the biosynthetic pathway of PMBs were chemically synthesized. DcOMT1-5 were highly expressed in tissues where PMBs were biosynthesized, and their expression patterns were well-correlated with the accumulation profiles of PMBs. Moreover, cell-free orthogonal tests based on the synthesized intermediates further confirmed that DcOMT1-5 exhibited distinct substrate preferences and displayed hydroxyl-group regiospecificity during the sequential methylation process. The stepwise methylation of PMBs was discovered from SAM to dihydro-piceatannol (P) in the following order: P → 3-MeP → 4-OH-3-MeP → 4-OH-3,5-diMeP → 3,3'(4'),5-triMeP → 3,4,4',5-tetraMeP (erianin) or 3,3',4,5-tetraMeP (crepidatin) → 3,3',4,4',5-pentaMeP (chrysotobibenzyl). Furthermore, the regioselectivities of DcOMTs were investigated by ligand docking analyses which corresponded precisely with the catalytic activities. In summary, the findings shed light on the sequential catalytic mechanisms of PMB biosynthesis and provide a comprehensive PMB biosynthetic network in D. catenatum. The knowledge gained from this study may also contribute to the development of plant-based medicinal applications and the production of high-value PMBs.

Evaluation of Thiazolidine Derivatives with Potential Anti-ZIKV Activity.

OBJECTIVE: In this study, we have synthesized 19 Thiazolidine (TZD) derivatives to investigate their potential anti-ZIKV effects. METHODS: Nineteen thiazolidine derivatives were synthesized and evaluated for their cytotoxicity and antiviral activity against the ZIKA virus. RESULTS: Among them, six demonstrated remarkable selectivity against the ZIKV virus, exhibiting IC50 values of <5µM, and the other compounds did not demonstrate selectivity for the virus. Interestingly, several derivatives effectively suppressed the replication of ZIKV RNA copies, with derivatives significantly reducing ZIKV mRNA levels at 24 hours post-infection (hpi). Notably, two derivatives (ZKC-4 and -9) stood out by demonstrating a protective effect against ZIKV cell entry. Informed by computational analysis of binding affinity and intermolecular interactions within the NS5 domain's N-7 and O'2 positions, ZKC-4 and FT-39 displayed the highest predicted affinities. Intriguingly, ZKC-4 and ZKC-9 derivatives exhibited the most favorable predicted binding affinities for the ZIKV-E binding site. CONCLUSION: The significance of TZDs as potent antiviral agents is underscored by these findings, suggesting that exploring TZD derivatives holds promise for advancing antiviral therapeutic strategies.

Identification of Novel Isatin Derivative Bearing a Nitrofuran Moiety as Potent Multi-Isoform Aldehyde Dehydrogenase Inhibitor.

Aldehyde dehydrogenases (ALDHs) are a family of enzymes that aid in detoxification and are overexpressed in several different malignancies. There is a correlation between increased expression of ALDH and a poor prognosis, stemness, and resistance to several drugs. Several ALDH inhibitors have been generated due to the crucial role that ALDH plays in cancer stem cells. All of these inhibitors, however, are either ineffective, very toxic, or have yet to be subjected to rigorous testing on their effectiveness. Although various drug-like compounds targeting ALDH have been reported in the literature, none have made it to routine use in the oncology clinic. As a result, new potent, non-toxic, bioavailable, and therapeutically effective ALDH inhibitors are still needed. In this study, we designed and synthesized potent multi-ALDH isoform inhibitors based on the isatin and indazole pharmacophore. Molecular docking studies and enzymatic tests revealed that among all of the synthesized analogs, compound 3 is the most potent inhibitor of ALDH1A1, ALDH3A1, and ALDH1A3, exhibiting 51.32%, 51.87%, and 36.65% inhibition, respectively. The ALDEFLUOR assay further revealed that compound 3 acts as an ALDH broad spectrum inhibitor at 500 nM. Compound 3 was also the most cytotoxic to cancer cells, with an IC50 in the range of 2.1 to 3.8 µM for ovarian, colon, and pancreatic cancer cells, compared to normal and embryonic kidney cells (IC50 7.1 to 8.7 µM). Mechanistically, compound 3 increased ROS activity due to potent multi-ALDH isoform inhibition, which increased apoptosis. Taken together, this study identified a potent multi-isoform ALDH inhibitor that could be further developed as a cancer therapeutic.

Synergistic Photocatalysis by α-MoO3 Nanostructures and SWCNT Nanocomposites for Efficient Cross-Linking and Oxidative Degradation of Polystyrene Nanoplastics.

Nanoplastics (NPs) generated from plastic debris weathering pose a significant threat to ecosystems. The ubiquity of plastics driven by their advantageous physical properties, necessitates the development of efficient degradation and removal methods. Polystyrene (PS), a common and hazardous aquatic NP is a long-chain hydrocarbon with alternating phenyl groups. This study investigates the photooxidative degradation of PS NPs under UV light irradiation using synthesized MoO3 nanoflakes, nanobelts, and MoO3/SWCNT nanocomposites. Raman spectroscopy, X-ray diffraction, atomic force microscopy, high-resolution transmission electron microscopy, energy dispersive X-ray, Brunauer-Emmett-Teller, and UV-vis spectroscopy were employed to characterize the photocatalyst. Field emission scanning electron microscopy was used to visualize morphological changes in the spherical PS NPs upon interaction with the photocatalysts. MoO3 nanoflakes acting as a photocatalyst under UV irradiation for 24 h achieved an impressive degradation efficiency exceeding 19%. This treatment significantly reduced the average diameter of PS NPs from 220 to 178 nm. Notably, even higher degradation efficiencies were observed with MoO3 nanobelts and nanocomposites as a complete change in the spherical morphology of PS NPs is observed. Fourier transform infrared spectroscopy elucidated the chemical transformations of PS during degradation. The observed changes in PS NPs structure due to photocatalytic oxidation at different time intervals indicate a promising approach.

A bioactive sprite: Recent advances in the application of vinyl sulfones in drug design and organic synthesis.

Vinyl sulfones, with their exceptional chemical properties, are known as the "chameleons" of organic synthesis and are widely used in the preparation of various sulfur-containing structures. However, their most alluring feature lies in their biological activity. The vinyl sulfone skeleton is ubiquitous in natural products and drug molecules and boasts a unique molecular structure and drug activity when compared to conventional drug molecules. As a result, vinyl sulfones have been extensively studied, playing a critical role in organic synthesis and pharmaceutical chemistry. In this review, we present a comprehensive analysis of the recent applications of vinyl sulfone structures in drug design, biology, and chemical synthesis. Furthermore, we explore the prospects of vinyl sulfones in diverse fields, offering insight into their potential future applications.

[Advances in the synthesis of cytidine-5'-diphosphate choline].

Cytidine-5'-diphosphate choline (CDP-choline) plays a crucial role in the formation of the phospholipid bilamolecular layer in cell membranes and the stabilization of the neurotransmitter system, acting as a precursor to phosphatidylcholine and acetylcholine. CDP-choline has been found effective in treating functional and consciousness disorders resulting from brain injury, Parkinson's disease, depression and glaucoma, and other conditions. As such, CDP-choline is widely utilized in clinical medicine and health care products. The conventional chemical synthesis process of CDP-choline is gradually being replaced by biosynthesis due to the expensive and toxic reagents involved, the production of various by-products, and the high cost of industrial production. Biosynthesis of CDP-choline offers two strategies: microbial fermentation and biocatalysis. Microbial fermentation utilizes inexpensive raw materials but results in a relatively low conversion rate and requires a complex separation and purification process. Biocatalysis, on the other hand, involves two stages: the growth of a living "catalyst" and the conversion of the substrate. Although the synthetic process in biocatalysis is more complex, it offers a higher conversion ratio, and the downstream processing technique for extraction is relatively less costly. Consequently, biocatalysis is currently the primary strategy for the industrial production of CDP-choline. This review aims to summarize the progress made in both chemical synthesis and biosynthesis of CDP-choline, with particular focus on the metabolic pathway and the synthetic processes involved in biocatalysis, in order to provide insights for the industrial production of CDP-choline.

[Advances in synthesis of 2-phenylethanol].

2-phenylethanol (2-PE), an aromatic alcohol with a rose fragrance, is the second most widely used flavoring substance in the world. It is widely used in the cosmetic, food, and pharmaceutical industries. This paper introduces the chemical synthesis methods of 2-PE and the synthetic pathways in plants and microorganisms, summarizes the strategies to improve the microbial synthesis of 2-PE, reviews the research progress in de novo synthesis of 2-PE in microorganisms, and makes an outlook on the research prospects, aiming to provide a theoretical basis for the industrial production of 2-PE.

Optimized Synthesis and Antioxidant Activity of Anthocyanins Delphinidin-3-O-glucoside and Petunidin-3-O-glucoside.

The chemical synthesis of anthocyanins, especially delphinidin-3-O-glucoside and petunidin-3-O-glucoside, is preferable due to the challenges associated with their extraction and purification. However, the reported methods for the synthesis are scarce and intricate. Our research focused on exploring a one-step ester-to-ketone process and optimizing the ring formation reaction, simplifying and improving the overall synthesis strategy. Through these attempts, we were able to achieve higher production yields of delphinidin-3-O-glucoside and petunidin-3-O-glucoside. According to the results of DPPH, ABTS, and FRAP, the antioxidant activity of anthocyanins was increased with the number of B ring hydroxyl substituent. Additionally, both delphinidin-3-O-glucoside and petunidin-3-O-glucoside exhibited no cytotoxicity effects, highlighting their potential for safe application in various fields.

Quality control, safety assessment and preparation approaches of low molecular weight heparin.

Low Molecular Weight Heparins (LMWHs) are well-established for use in the prevention and treatment of thrombotic diseases, and as a substitute for unfractionated heparin (UFH) due to their predictable pharmacokinetics and subcutaneous bioavailability. LMWHs are produced by various depolymerization methods from UFH, resulting in heterogeneous compounds with similar biochemical and pharmacological properties. However, the delicate supply chain of UFH and potential contamination from animal sources require new manufacturing approaches for LMWHs. Various LMWH preparation methods are emerging, such as chemical synthesis, enzymatic or chemical depolymerization and chemoenzymatic synthesis. To establish the sameness of active ingredients in both innovator and generic LMWH products, the Food and Drug Administration has implemented a stringent scientific method of equivalence based on physicochemical properties, heparin source material and depolymerization techniques, disaccharide composition and oligosaccharide mapping, biological and biochemical properties, and in vivo pharmacodynamic profiles. In this review, we discuss currently available LMWHs, potential manufacturing methods, and recent progress for manufacturing quality control of these LMWHs.

Advances in the synthesis and application of silver nanoparticles for laser mass spectrometry: A mini-review.

Silver nanoparticles are used in laser mass spectrometry to replace organic matrices. Thanks to their unique properties, they enable effective desorption/ionization of samples of various polarities and ionization abilities. This review presents new methods for the synthesis of monoisotopic silver nanoparticles and the use of targets coated with these nanoparticles for qualitative and quantitative analyses of various small-molecule compounds. Additionally, the results of progress in the application of AgNPs for metabolomics analyses were presented.

Synthesis and analytical characterization of 1-(2-thienoyl)-6-allyl-nor-d-lysergic acid diethylamide (1T-AL-LAD).

Lysergic acid diethylamide (LSD) analogs have emerged as new psychoactive substances (NPS) since the mid-2010s, and new compounds continue to emerge for recreational use. Since the end of 2023, "1D-AL-LAD" appeared on X (formerly Twitter) and other websites. As for the compound "1D-LSD" (which also has "1D" in the name), several studies show that the ingredient of seized blotter paper printed "1D-LSD" was actually 1-(2-thienoyl)-LSD (1T-LSD). However, there are no reports of seizures of 1-(1,2-dimethylcyclobutanecarbonyl)-LSD (1D-LSD). Accordingly, it was considered that all or at least a certain percentage of "1D-AL-LAD (1-(1,2-dimethylcyclobutanecarbonyl)-6-allyl-nor-LSD)" is actually 1-(2-thienoyl)-6-allyl-nor-LSD (1T-AL-LAD). This compound is handled by a number of distributors as of April 2024; therefore, it should be characterized in advance if seized. In this study, 1T-AL-LAD was synthesized and characterized using nuclear magnetic resonance spectroscopy, Fourier transform-infrared spectroscopy, liquid chromatography/high-resolution mass spectrometry (LC/HRMS) and gas chromatography/MS (GC/MS). This compound was easily distinguished from previously reported lysergamides. There were some differences in the detectability of 1T-AL-LAD compared with other lysergamides using GC/MS and the fragmentation patterns in LC/HRMS. These differences can be reasonably explained. This information will be of help to determine this substance in seized materials should it emerge on the market.

Concise Synthesis of 11-Noriridoids via Pauson-Khand Reaction.

Iridoids, which are a class of monoterpenoids, are attractive synthetic targets due to their diversely substituted cis-fused cyclopenta[c]pyran skeletons. Additionally, various biological activities of iridoids raise the value of synthetic studies on this class of compounds. Here, our synthetic efforts toward 11-noriridoids; (±)-umbellatolide B (6), (±)-10-O-benzoylglobularigenin (9) and 1-O-pentenylaucubigenin (34) are described. For the efficient synthesis of target compounds, common synthetic intermediates (tricyclic enones 17 and 26) were prepared by the Pauson-Khand reaction. The cleavage of the acetal bond on the tricyclic enones and 1,2-reduction introduced the two hydroxy groups on the cyclopentane ring of the core scaffold. Furthermore, the C3-C4 olefin part was constructed by the syn-elimination of a thiocarbonate moiety to obtain 34. The developed synthetic routes for 6, 9, and 34 will be useful for the preparation of iridoid analogs that have a polyfunctionalized core skeleton.

Microscopic Raman-based rapid detection of submicron/nano polypropylene plastics in tea and tea beverages.

Polypropylene (PP) is suitable for a broad range of applications and represents the most extensively utilized plastic in food packaging. Micro- and nano-PP plastics are prevalent categories of microplastics (MPs). However, the majority of MPs particles currently utilized in laboratory studies are man-made polystyrene (PS) spheres, and there has been limited research on micrometer- and nanoscale PP plastic particles. This study aims to employ a top-down approach in crafting micro/nanoparticle (M/NPs) models of PP particles, ensuring their enhanced relevance to real-world environments. Micro/nano PP particles, featuring a negatively charged particle size ranging from 203 to 2101 nm, were synthesized through variations in solution concentration and volume. Simultaneously, the devised MPs model was employed to develop a Raman-based qualitative and quantitative detection method for micro/nano PP particles, considering diverse sizes and concentrations. This method integrates Raman spectroscopy and microscopy to measure PP particles with varying sizes, utilizing the coffee ring effect. The Limit of detection (LOD) for 203 nm PP reached 31.25 µg/mL, while those for 382-2101 nm PP were approximately 3.9 µg/mL. The method underwent quantitative analysis by introducing 203 nm PP nanospheres into real food media (i.e., tea beverages, tea leaves), revealing a minimum LOD of approximately 31.25 µg/mL.

Bifunctional glycosphingolipid (GSL) probes to investigate GSL-interacting proteins in cell membranes.

Glycosphingolipids (GSLs) are abundant glycolipids on cells and essential for cell recognition, adhesion, signal transduction, and so on. However, their lipid anchors are not long enough to cross the membrane bilayer. To transduce transmembrane signals, GSLs must interact with other membrane components, whereas such interactions are difficult to investigate. To overcome this difficulty, bifunctional derivatives of II3-ß-N-acetyl-D-galactosamine-GA2 (GalNAc-GA2) and ß-N-acetyl-D-glucosamine-ceramide (GlcNAc-Cer) were synthesized as probes to explore GSL-interacting membrane proteins in live cells. Both probes contain photoreactive diazirine in the lipid moiety, which can crosslink with proximal membrane proteins upon photoactivation, and clickable alkyne in the glycan to facilitate affinity tag addition for crosslinked protein pull-down and characterization. The synthesis is highlighted by the efficient assembly of simple glycolipid precursors followed by on-site lipid remodeling. These probes were employed to profile GSL-interacting membrane proteins in HEK293 cells. The GalNAc-GA2 probe revealed 312 distinct proteins, with GlcNAc-Cer probe-crosslinked proteins as controls, suggesting the potential influence of the glycan on GSL functions. Many of the proteins identified with the GalNAc-GA2 probe are associated with GSLs, and some have been validated as being specific to this probe. The versatile probe design and experimental protocols are anticipated to be widely applicable to GSL research.