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Aromatic nitro compounds are an increasing concern worldwide due to their potential toxicity, prompting a quest for efficient removal approaches.

Weeds are becoming increasingly resistant to our current herbicides, posing a significant threat to agricultural production. Therefore, new herbicides with novel modes of action are urgently needed. In this study, we exploited a novel herbicide target, dihydrodipicolinate synthase (DHDPS), which catalyses the first and rate-limiting step in lysine biosynthesis. The first class of plant DHDPS inhibitors with micromolar potency against Arabidopsis thaliana DHDPS was identified using a high-throughput chemical screen. We determined that this class of inhibitors binds to a novel and unexplored pocket within DHDPS, which is highly conserved across plant species. The inhibitors also attenuated the germination and growth of A. thaliana seedlings and confirmed their pre-emergence herbicidal activity in soil-grown plants. These results provide proof-of-concept that lysine biosynthesis represents a promising target for the development of herbicides with a novel mode of action to tackle the global rise of herbicide-resistant weeds.

In this experiment, we aimed to fabricate SWCNT conjugated with tamoxifen and evaluated its anticancer potential against human breast cancer cells (MCF-7). The results showed that SWCNT was synthetized successfully using chemical vapor deposition (CVD) method. The results of Raman spectroscopy, SEM, and TEM analyses confirmed the synthesis of highly pure SWCNT. The functionalization of SWCNT was performed by oxidizing of SWCNT, attachment of polyethylene glycol (PEG) to oxidized SWCNT, and attachment of azelaic acid to the polyethylene glycol group. As a result, the SWCNT with free functional carboxylic acid and hydroxyl groups (SWCNT-PEG) was developed. The SWCNT-PEG was then conjugated with tamoxifen (SWCNT-PEG-TAM). The FT-IR together with NMR results confirmed the conjugation of tamoxifen to functionalized SWCNT (SWCNT-PEG-TAM). The cytotoxic concentrations (CC50) of SWCNT-PEG, tamoxifen, and SWCNT-PEG-TAM were >100, 12.67±2.69, and 5.49±1.34μg/ml, respectively. Linking tamoxifen to functionalized SWCNT enhanced the cytotoxic action of tamoxifen against breast cancer cells up to 2.3 times. The results of the morphological examination and caspase-3 activity confirmed the higher cytotoxic action of SWCNT-PEG-TAM as compared to free tamoxifen. The results obtained in this study indicated that this delivery system enhanced the therapeutic effects and anticancer potential of tamoxifen against human breast cancer cells.

Dihydrodipicolinate synthase (DHDPS), responsible for the first committed step of the diaminopimelate pathway for lysine biosynthesis, has become an attractive target for the development of new antibacterial and herbicidal agents. Herein, we report the discovery and exploration of the first inhibitors of E. coli DHDPS which have been identified from screening lead and are not based on substrates from the lysine biosynthesis pathway. Over 50 thiazolidinediones and related analogues have been prepared in order to thoroughly evaluate the structure-activity relationships against this enzyme of significant interest.

To investigate the influence of pH on the size and distribution of silver nanoparticles (Ag-NPs) as well as the antibacterial activity and catalytic performance of rice straw/silver nanocomposites (RS/Ag-NCs), Ag-NPs were synthesized on the surface of rice straw (RS) with various percentages of Ag-NPs (1.0, 5.0, 10.0, and 20.0 wt.%) under different temperatures and diverse pH values. The ultraviolet-visible spectroscopy of synthesized RS/Ag-NCs became noticeable with increased pH, and the peaks were blue-shifted to lower wavelengths. X-ray powder diffraction (PXRD) demonstrated the presence of pure Ag-NPs. Transmission electron microscopy (TEM) showed that the diameters of Ag-NPs on RS were between 7.78 and 2.84 nm at pH values of 8 to 10. The antibacterial activity of various sizes of Ag-NPs on RS was examined using Gram-negative bacteria (Escherichia coli) and Gram-positive bacteria (Staphylococcus aureus) based on the well diffusion technique. Higher antibacterial activity was detected as the loading percentage of RS/Ag-NCs increased and particle size decreased. The superior catalytic performance of 20.0 wt.% RS/Ag-NCs was considered in a test reaction in 4-nitrophenol (4-NP) reduction in the presence of sodium borohydride (NaBH4) in an eco-friendly solvent at ambient temperature. The results represented the high-performance catalytic activity of 20.0 wt.% RS/Ag-NCs.

Some new oleic acid, linoleic acid, lauric acid derivatives of 5-aminosalicylic acid were produced in order to enhance bioactivity properties of 5-aminosalicylic acid. All new compounds’ structures were confirmed by spectroscopic methods. Moreover, in vitro antibacterial, anticancer, and anti-inflammatory activities of new synthesized compounds were investigated. Antibacterial activity was studied against pathogenic Gram-negative bacteria, Escherichia coli and Gram-positive bacteria, Staphylococcus aureus via disc diffusion method. Additionally, all derivatives’ anti-inflammatory activity were evaluated through NO suppression assay using interferon gamma (IFN-γ)/lipopolysaccharide (LPS)-stimulated RAW264.7 macrophages. Furthermore, in vitro cytotoxicity assay was probed using MTT test against 3T3 and HT-29 cell lines. In another effort, docking studies were performed to predict the possible interactions and binding energy of new compounds against cyclooxygenase (COX-1/COX-2) and lipoxygenase (5-LOX) proteins. In conclusion, all new compounds exhibited moderate to better bioactivity improvements in comparison with parent drug. Also study of interactions between the new derivatives with active sites of proteins presented greater binding affinities than 5-aminosalicylic acid.

A novel and simple organocatalyst derived from proline was designed, synthesized and tested for its catalytic potential in a direct asymmetric aldol reaction between 4-nitrobenzaldehyde and cychlohexanone in aqueous media. The relatively inexpensive and safe solvent, water stabilized the transition state, and increased reactivity and selectivity of catalyst. The diastereo- and enantio-selective products of the reaction were obtained in excellent yields.

pH-responsive virus-like nanoparticles (VLNPs) hold promising potential as drug delivery systems for cancer therapy. In the present study, hepatitis B virus (HBV) VLNPs harbouring His-tags were used to display doxorubicin (DOX) via nitrilotriacetic acid (NTA) conjugation. The His-tags served as pH-responsive nanojoints which released DOX from VLNPs in a controlled manner. The His-tagged VLNPs conjugated non-covalently with NTA-DOX, and cross-linked with folic acid (FA) were able to specifically target and deliver the DOX into ovarian cancer cells via folate receptor (FR)-mediated endocytosis. The cytotoxicity and cellular uptake results revealed that the His-tagged VLNPs significantly increased the accumulation of DOX in the ovarian cancer cells and enhanced the uptake of DOX, which improved anti-tumour effects. This study demonstrated that NTA-DOX can be easily displayed on His-tagged VLNPs by a simple Add-and-Display step with high coupling efficiency and the drug was only released at low pH in a controlled manner. This approach facilitates specific attachment of any drug molecule on His-tagged VLNPs at the very mild conditions without changing the biological structure and native conformation of the VLNPs.

The promiscuous aldo–ketoreductase (AKR) enzyme is used as a sustainable biocatalyst for the first time to catalyze asymmetric aldol reactions in aqueous medium. The reactions between aromatic aldehydes and cyclic/acyclic ketones give the corresponding products in moderate yields and enantioselectivities in the presence of water. The influence of solvents, the mole ratio of substrates, and enzyme concentration are investigated. The mechanism of the AKR1A1-catalyzed aldol reaction is also discussed.

Peptides as a kind of important chiral scaffold are broadly identified for their obvious advantages, diverse structures and accessibility. Based on promiscuous aldo-keto-reductase enzymes, several mimetic peptides were designed which were synthesized and tested as multifunctional organocatalysts in direct asymmetric aldol reactions. The corresponding aldol products were produced with high yields (up to 97%) and excellent diastereoselectivities (up to 99/1) and enantioselectivities (>98%) under mild reaction selectivity and enantioselectivity. The secondary structures of peptide catalysts provide an understanding of their mechanism.

This work reports the effectiveness of short polar peptides as asymmetric catalysts in Michael reactions to attain good yields of enantio- and diastereoselective isomers. In a comparison, glutamic acid and histidine produced greater ee and yields when they were applied as the second amino acid in short trimeric peptides. These short polar peptides were found to be efficient organocatalysts for the asymmetric Michael addition reaction in water. Supplemental materials are available for this article. Go to the publisher's online edition of Synthetic Communications® to view the free supplemental file.

A series of tripeptide organocatalysts containing a secondary amine group and two amino acids with polar side chain units were developed and evaluated in the direct asymmetric intermolecular aldol reaction of 4-nitrobenzaldehyde and cyclohexanone. The effectiveness of short polar peptides as asymmetric catalysts in aldol reactions to attain high yields of enantio- and diastereoselective isomers were investigated. In a comparison, glutamic acid and histidine produced higher % ee and yields when they were applied as the second amino acid in short trimeric peptides. These short polar peptides were found to be efficient organocatalysts for the asymmetric aldol addition reaction in aqueous media.

Inflammatory bowel disease (IBD) is the main risk factor for developing colorectal cancer which is common in patients of all ages. 5-Aminosalicylic acid (5-ASA), structurally related to the salicylates, is highly active in the treatment of IBD with minor side effects. In this study, the synthesis of galactose and fructose esters of 5-ASA was planned to evaluate the role of glycoconjugation on the bioactivity of the parent drug. The antibacterial activity of the new compounds were evaluated against two Gram-negative and two Gram-positive species of bacteria, with a notable effect observed against Staphylococcus aureus and Escherichia coli in comparisons with the 5-ASA. Cytotoxicity testing over HT-29 and 3T3 cell lines indicated that the toxicity of the new products against normal cells was significantly reduced compared with the original drug, whereas their activity against cancerous cells was slightly decreased. The anti-inflammatory activity test in RAW264.7 macrophage cells indicated that the inhibition of nitric oxide by both of the monosaccharide conjugated derivatives was slightly improved in comparison with the non-conjugated drug.

In this work, three forms of a novel octapeptide have been evaluated as asymmetric catalysts for the Michael reaction. Low quantity catalyst loading, ecofriendly solvents, and reusability of organocatalyst successfully applied to attain excellent yields and moderate enantioselectivities in the Michael reaction. [Supplementary materials are available for this article. Go to the publisher's online edition of Synthetic Communications® for the following free supplemental resources: Full experimental and spectral details.]

Hypercholesterolemia is one of the most common chronic diseases in human. Along with chemical therapy traditional medication is used as hypocholesterolemic remedy, however, with unfavorable side effects. Recently,Monascusfermented product (MFP) has become a popular hypocholesterolemic natural supplement. In the present study, the hypocholesterolemic activity ofMonascus purpureusFTC5391 fermented product ethanolic extract (MFPe) was investigated in hypercholesterolemic rats. Results showed that MFPe not only reduced the serum total cholesterol (TC), LDL-C, TG concentration, and TC/HDL-C ratio but also increased the HDL-C. Further, solid phase extraction (SPE) was carried out to obtain the hypocholesterolemic bioactive fraction. The high polar fraction of SPE increased the HDL-C (42%) and decreased the TC (53.3%), LDL-C (47%), and TG (50.7%) levels as well as TC/HDL-C ratio (69.1%) in serum. The GC-MS results of the active fraction revealed two main compounds, isosorbide and erythritol, which act as coronary vasodilator compounds.

A series of tripeptide organocatalysts containing a secondary amine group and two amino acids with polar side chain units were developed and evaluated in the direct asymmetric intermolecular aldol reaction of 4-nitrobenzaldehyde and cyclohexanone. The effectiveness of short polar peptides as asymmetric catalysts in aldol reactions to attain high yields of enantio- and diastereoselective isomers were investigated. In a comparison, glutamic acid and histidine produced higher % ee and yields when they were applied as the second amino acid in short trimeric peptides. These short polar peptides were found to be efficient organocatalysts for the asymmetric aldol addition reaction in aqueous media.