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Background: In this study, two novel hybrid series of artemisinin and quinazolinones were synthesized and evaluated in vitro cytotoxicity against two human cancer cell lines, including SKLu-1 (lung cancer), MCF- 7 (breast cancer). The bio-assay results indicated that most of the target compounds exhibited cytotoxic activities against both human cancer cell lines tested and seemed to be more cytotoxic toward the breast (MCF-7) cancer cells than lung (SKLu-1) cancer cells. Among the synthesized artemisinin hybrids, the compound 13d containing a quinazolinone conjugated system exhibited the most potent cytotoxicity against the SKLu-1 and MCF-7 cell lines with IC50 values of 1.62 and 0.77 μM, respectively. Objective: This study aims at developing novel hybrids of artemisinin and quinazolinones as anticancer agents. Method: A series of novel hybrids were designed, synthesized, and evaluated for cytotoxicity against two human cancer cell lines, including SKLu-1 and MCF-7, using the SRB method. Results: All thirteen hybrids of artemisinin with quinazolinone exhibited cytotoxic activity against two tested cancer cell lines, in which the compound 13d exhibited the most potent cytotoxicity against the SKLu-1 and MCF-7 cell lines with IC50 values of 1.62 and 0.77 μM, respectively. Conclusion: The research results suggest that some compounds could be considered as leads for future design of hybrids and have the potential for further studies in the field of anti-cancer agent development.

Methods: PLSR method is applied for 2D-QSAR determination of the (Z)-5-ethylidene-3-(4- methoxy-6-methyl-1,3,5-triazin-2-yl)-2-phenyl-3,5-dihydro-4H-imidazol-4-one (B1-B10). The designed compounds were synthesized and spectrally evicted by IR, 1H NMR, 13C NMR, and mass spectra data as well as biologically screened against the different antitubercular and antimicrobial species.

Background:Cytochrome P450 1B1 (CYP1B1) is specifically expressed in a variety of tumors which makes it a promising imaging target of tumor.Objective:We aimed to design and synthesize CYP1B1 targeted chelators for the potential application in positron emission tomography (PET) imaging of tumor.Methods:1,4,7-triazacyclononane-1,4-diiacetic acid (NODA) was connected to the CYP1B1 selective inhibitor we developed before through polyethylene glycol (PEG) linkers with different lengths. The inhibitory activities of chelators 6a-c against CYP1 family were evaluated by 7-ethoxyresorufin o-deethylation (EROD) assay. The manual docking between the chelators and the CYP1B1 was conducted subsequently. To determine the binding affinities of 6a-c to CYP1B1 in cells, we further performed a competition study at the cellular level.Results:Among three chelators, 6a with the shortest linker showed the best inhibitory activity against CYP1B1. In the following molecular simulation study, protein-inhibitor complex of 6a showed the nearest F-heme distance which is consistent with the results of enzymatic assay. Finally, the cell based competitive assay proved the binding affinity of 6a-c to CYP1B1 enzyme.Conclusion:We designed and synthesized a series of chelators which can bind to CYP1B1 enzyme in cancer cells.To our knowledge, this work is the first attempt to construct CYP1B1 targeted chelators for radiolabeling and we hope it will prompt the application of CYP1B1 imaging in tumor detection.

Substance use disorder remains a major, unmet medical need. Cocaine is one of the most commonly abused recreational drugs and in 2018, there were over 5.5 million cocaine users. There are no approved therapies for the treatment of cocaine use disorder, but the D3 dopamine receptor has been identified as a potential therapeutic target. Our initial lead compound (6) is a potent D3 ligand with a high level of selectivity for D3 over D2, but its solubility is low. We have identified a new series of functionalized 5-(4-arylpiperazin-1-yl)-N-arylpentanamides (7) that are potent D3 binders that have moderate to high selectivity for D3 over D2. Exemplary members of this series were also significantly more soluble than our initial lead compound (6).

Background: Over the years, the xanthone nucleus has been serving as an interesting scaffold for the design of derivatives aiming at anti-inflammatory drug development. Objective: The objective of the current work was to design and synthesize two series of novel 3- (5'-substituted pentyloxy)-1-hydroxy xanthone & 6-(5'-substituted pentyloxy)-1-hydroxy xanthone derivatives. The designed compounds were examined in vivo for anti-inflammatory activity. The effect of the synthesized xanthone derivatives on the serum expression of IL-10 and TNF-α was evaluated to understand the underlying molecular mechanisms. Method: The title compounds were virtually designed and screened for ADME/T properties and docked onto the COX-2 protein. The synthesis of the xanthone derivatives was achieved by the condensation of salicylic acid derivatives and a suitable phenol in the presence of a mixture of phosphorus pentoxide–methanesulfonic acid as an acylation catalyst. The compounds were evaluated for in vivo anti-inflammatory activity by carrageenan induced paw edema method and serum expression of cytokines was evaluated using ELISA assays. Results: The selected compounds exhibited docking scores ranging between -10.7 to -6.8 (Kcal/mol), respectively, as compared with standard Celecoxib (-7.9 Kcal/mol) and the nonselective COX inhibitor Indomethacin (-6.4 Kcal/mol). Among the tested compounds, 9u has shown the highest activity with 65.6 % reduction in edema (69.8% for Celecoxib). Immunoassay results showed a significant drop in serum TNF-α and an elevation in serum IL-10. Conclusion: The findings highlight that some of the synthesized xanthone derivatives displayed marked anti-inflammatory activity, which can be further investigated to render efficient and novel non-ulcerogenic anti-inflammatory agents.

Herein, we synthesized a series of novel benzimidazole derivatives 5a���k and screened their bioactivity as potent urease inhibitors. The structure of the 5a���k was elucidated using spectroscopic technics (1H-NMR, 13C-NMR, MS), elemental analysis, and melting point. The urease inhibition activity was evaluated using the urease enzyme inhibition kit. All 5a���k, except 5d, showed higher urease inhibition activity (0.77 to 6.25 ��M) in comparison to thiourea and hydroxyurea as standard (IC50: 22 and 100 ��M respectively). 5c and 5j exhibited the best activity with the IC50 value of 0.77 and 1.26 ��M respectively. A molecular docking study showed the mode of interactions between the most active compound and enzyme active site. To investigate the cytotoxicity profile of the target compounds, an MTT assay was done on two different cell lines which showed all 5a���k have IC50 values higher than 50 ��M on both tested cell lines.

We herein report the facile synthesis of a series of 3,5-substituted-1,2,4-oxadiazole derivatives in good to excellent yields. The anti-inflammatory potential of the newly synthesized compounds was evaluated by anti-denaturation assay using diclofenac sodium as the reference standard. Some of the compounds exhibited profound activity profile when compared to the standard drug. The molecular docking and SAR studies were carried out at the later stage for gaining more insights about the promising activity profile of the synthesized molecules.

Aims: This aims of this study was to synthesis new quinoxaline-based heterocycles and study its antibacterial properties. Objective: This study was designed to synthesis some 3-methyl-6-nitroquinoxaline-2-one with hydrazine moiety, characterize the synthesized compounds, and study their antibacterial properties on some bacterial strains. Materials and Methods: Six 3-methylquinoxaline-2-hydrazone derivatives were synthesized by reacting 2-hydrazinyl-3-methyl-6-nitroquinoxaline with various substituted acetophenones. The hydrazones were screened for their potential antibacterial properties. Results: All the test compounds were found to possessed promising antibacterial properties against a panel of bacterial strains screened for this study. The MIC values exhibited by these compounds ranged between 0.0313 and 0.250 mg/mL. The lowest MBC of the compounds against the test organism was 0.0625 mg/mL while the highest MBC was 0.250 mg/mL. Discussion and Conclusion: The study concluded that all the compounds exhibited appreciable bactericidal effects against all the bacterial strains, which is an indication that such synthetic compounds possessed broad spectrum activities and such compounds could be useful in formulation of antibacterial compounds which could be used to mitigates infections caused by pathogens that are now developing resistance against the available antibiotics.

Aims: To synthesize some phthalimides derivatives and evaluate the compounds for their possible biological properties. Methods: The substituted phenylisoindoline-1,3-dione were synthesized from the reactions of N-phenyl phthalimide with different substituted aromatic aldehyde. The synthesized compounds were characterized using nuclear magnetic resonance spectroscopic analysis. The Nitric oxide and Ferric reducing antioxidant properties (FRAP) were determined by spectrophochemical method. Results: The IC50 values for all the synthesized compounds were lower than standard, eserine (IC50 = 15 ± 2 µg/mL) against Nitric oxide inhibition. Compounds 3 (FRAP = 205±8 µg/ML) and 6 (FRAP = 118±1 µg/ML) were found to exhibit higher FRAP analysis results which were comparable to the results obtained for serine. (FRAP = 202±7 µg/ML). Conclusion: The considerable activity of the compounds shown by its Nitric oxide and Ferric reducing antioxidant properties (FRAP) makes them good candidates for the development of selective acetylcholinesterase and butyryl cholinesterase inhibitors.

16,17-Dihydroheronamide C (8) and ent-heronamide C (ent-1) were designed as probes for the mode-of-action analysis of heronamide C (1). These molecules were synthesized by utilizing a highly modular strategy developed in the preceding paper. The evaluation of the antifungal activity of these compounds revealed the exceptional importance of the C16-C17 double bond for the antifungal activity of heronamide C and the existence of chiral recognition between heronamide C (1) and cell membrane components.

Blockade of immune checkpoint PD-1/PD-L1 has been a promising anticancer strategy; however, clinically available PD-1/PD-L1 small-molecule inhibitors are lacking. In view of the high potency of compound 2 (BMS-1002), structural fine tuning of the methoxy linkage together with diverse modification in the solvent interaction region was conducted. A series of novel derivatives featuring a difluoromethyleneoxy linkage were designed. Compound 43 was identified as the most promising PD-1/PD-L1 inhibitor with an IC50 value of 10.2 nM in the HTRF assay. This compound is capable of promoting CD8+ T cell activation through inhibiting PD-1/PD-L1 cellular signaling. Moreover, in the Hepa1-6 syngeneic mouse model, administration of compound 43 at 1 mg/kg dosage promoted CD8+ T cell activation and delayed the tumor growth with good tolerance. Notably, the tumor in one mouse of the compound 43-treated group was completely regressed. These results indicate that compound 43 is a promising candidate worthy of further investigation.

Neuroplasticity allows the human nervous system to adapt and relearn motor control following stroke. Rehabilitation therapy, which enhances neuroplasticity, can be made more effective if assisted by robotic tools. In this paper, a novel 4-SPS parallel robot has been developed to provide recovery of wrist movements post-stroke. The novel mechanism presented here was inspired by the forearm anatomy and can provide the rotational degrees of freedom required for all wrist movements. The robot design has been discussed in detail along with the necessary constructional, kinematic, and static analyses. The spatial workspace of the robot is estimated considering various dimensional and application-specific constraints besides checking for singular configurations. The wrist robot has been further evaluated using important performance indices such as condition number, actuator forces, and stiffness. The pneumatic artificial muscles exhibit varying stiffness, and therefore, workspace points are reached with different overall stiffness of the robot. It is essential to assess robot workspace points that can be reached with positive forces in actuators while maintaining a positive definite overall stiffness matrix. After the above analysis, design optimization has been carried out using an evolutionary algorithm whereby three critical criteria are optimized simultaneously for optimal wrist robot design.

[Image: see text] Herein a novel series of APN and AKT dual inhibitors were derived from the clinical AKT inhibitor AZD5363. It was demonstrated that most compounds exhibited remarkable APN inhibitory activities with the most potent compound 8b (IC(50) = 0.05 ± 0.01 μM) being over 70-fold more potent than the approved APN inhibitor bestatin (IC(50) = 3.64 ± 0.56 μM). The moderate AKT inhibitory potencies of target compounds were also confirmed, with 5f and 5h possessing AKT1 IC(50) values of 0.12 and 0.27 μM, respectively. More importantly, the APN IC(50) values of 5f and 5h were 0.96 and 0.21 μM, respectively, indicating their balanced APN and AKT dual inhibition. HUVEC tube formation assays confirmed the superior APN inhibitory activities of 5f and 5h relative to bestatin at the cellular level. Western blot analysis demonstrated that 5h could effectively inhibit the phosphorylation of GSK3β, the intracellular substrate of AKT.

Aims: This aims of this study was to continue the effort to synthesis new quinoxaline-based heterocycles and study its antibacterial properties. Objective: This study was designed to reacts 3,6-dimethylquinoxaline-2-hydrazine with some substituted aromatic ketones and study their antibacterial properties on some locally and clinically isolated bacterial strains. Materials and Methods: Five 3,6-dimethylquinoxaline-2-hydrazone derivatives were synthesized from the reactions of 3,6-dimethylquinoxaline-2-hydrazine with various substituted aromatic ketones. The products were then tested for their potential antibacterial properties. Results: All the synthesized compounds were found to be active against all the bacterial strains investigated in this study. It was observed that the zones of inhibition observed for the synthesized compounds against the test organisms ranged between 15 mm and 38 mm. The MIC observed for the synthesized compounds ranged between 0.0313mg/mL and 0.125 mg/mL, while that of the standard antibiotic, streptomycin, varied between 0.0313 mg/mL and 0.500 mg/mL and those observed for tetracycline falls between 0.0313 mg/mL and 0.500 mg/mL. The minimum bactericidal concentrations exhibited by the synthesized compounds ranged between 0.0625 mg/mL and 0.250 mg/mL Discussion and conclusion: The study concluded that all the compounds exhibited appreciable bactericidal effects against all the bacterial strains, which is an indication that such synthetic compounds possessed broad spectrum activities and such compounds could be useful in formulation of antibacterial compounds which could be used to mitigates infections caused by pathogens that are now developing resistance against the available antibiotics.

Protein tyrosine phosphatase 1B (PTP1B) is a member of the phosphotyrosine phosphatase family and plays an important role in the signal transduction of diabetes. Inhibition of PTP1B activity can increase insulin sensitivity and reduce blood sugar levels. Therefore, it is urgent to find compounds with novel structures that can inhibit PTP1B. This study designed imidazolidine-2,4-dione derivatives through the computer-aided drug design (CADD) strategy, and the Comp#10 showed outstanding inhibitory ability. (IC50 = 2.07 μM) and selectivity. The inhibitory mechanism at molecular level of Comp#10 on PTP1B was studied by molecular dynamics simulation. The results show that the catalytic region of PTP1B protein is more stable, which makes the catalytic sites unsuitable for exposure. Interestingly, the most obvious changes in the interaction between residues in the P-loop region (such as: His214, Cys215, and Ser216). In short, this study reported for the first time that imidazolidine-2,4-dione derivatives as novel PTP1B inhibitors had good inhibitory activity and selectivity, providing new ideas for the development of small molecule PTP1B inhibitors.

The development of new classes of antimicrobial is urgently needed due to the widespread occurrence of multi-resistant pathogens. In this study, three novel ruthenium complexes: [Ru(dmob)2(BTPIP)](PF6)2 (Ru(II)-1), [Ru(dbp)2(BTPIP)](PF6)2 (Ru(II)-2), and [Ru(dpa)2(BTPIP)](PF6)2 (Ru(II)-3) (dpa = 2,2’-dipyridylamine, dmob = 4,4’-dimethoxy-2,2’-bipyridyl, dbp = 4,4’-di- tert-butyl-2,2’-dipyridyl, BTPIP = 4-(benzo[ b]thiophen-2-yl)phenyl-1 H-imidazo[4,5- f][1,10]phenanthroline) are synthesized and investigated as antimicrobial metallodrugs. We demonstrate that all three complexes have significant antimicrobial activity against Staphylococcus aureus by testing their minimal inhibitory concentrations = 0.0015–0.0125 mg/mL. The antibacterial activity of the best active complex Ru(II)-3 is 13 times that of ofloxacin (minimal inhibitory concentration = 19.5 μg/mL). Importantly, Ru(II)-3 not only increases the susceptibility of Staphylococcus aureus to existing common antibiotics but also shows noticeably delayed and decreased resistance in Staphylococcus aureus since the minimal inhibitory concentration values of Ru(II)-3 only increased eightfold times after 20 passages. Furthermore, the biofilms formation and rabbit erythrocyte hemolysis assays verified that Ru(II)-3 also efficiently inhibit the biofilm formation and toxin secretion of Staphylococcus aureus.

Gaucher disease (GD) is a lysosomal storage disorder caused by inherited deficiencies in beta-glucocerebrosidase (GBA). Current treatments require rapid disease diagnosis and a means of monitoring therapeutic efficacy, both of which may be supported by the use of GBA-targeting activity-based probes (ABPs). Here, we report the synthesis and structural analysis of a range of cyclophellitol epoxide and aziridine inhibitors and ABPs for GBA. We demonstrate their covalent mechanism-based mode of action and uncover binding of the new N-functionalised aziridines to the ligand binding cleft. These inhibitors became scaffolds for the development of ABPs; the O6-fluorescent tags of which bind in an allosteric site at the dimer interface. Considering GBA's preference for O6- and N-functionalised reagents, a bi-functional aziridine ABP was synthesized as a potentially more powerful imaging agent. Whilst this ABP binds to two unique active site clefts of GBA, no further benefit in potency was achieved over our first generation ABPs. Nevertheless, such ABPs should serve useful in the study of GBA in relation to GD and inform the design of future probes.

In this study, a series of novel thiochromanone derivatives containing an acylhydrazone moiety were designed and synthesized. Their structures were characterized by 1H NMR, 13C NMR, and HRMS. Bioassay results indicated that most of the target compounds exhibited good in vitro antibacterial activities against Xanthomonas oryzae pv. oryzae (Xoo), Xanthomonas oryzae pv. oryzicolaby (Xoc), and Xanthomonas axonopodis pv. citri (Xac). Especially, compound methyl 6-chloro-4-(2-(4-fluorobenzoyl)hydrazineylidene)thiochromane-2-carboxylate (4f) revealed the best antibacterial activities against Xoo, Xoc, and Xac, with the EC50 values of 15, 28, and 24 ��g/mL, respectively, compared with Bismerthiazol and Thiodiazole copper. As far as we know, this is the first report on the antibacterial activity of this series of novel thiochromanone derivatives containing an acylhydrazone moiety.

Thiazole-substituted pyrazole is an important structural feature of many bioactive compounds, including antiviral, antitubercular, analgesic and anticancer agents. Herein we describe an efficient and facile approach for the synthesis of two series of 36 novel N-bridged pyrazole-1-phenylthiazoles. The antiproliferative activity of a set of representative compounds was evaluated in vitro against different human cancer cell lines. Among the identified compounds, compound 18 showed potent anticancer activity against the examined cancer cell lines. The in silico molecular docking study revealed that compound 18 possesses high binding affinity toward both SK1 and CDK2. Overall, these results indicate that compound 18 is a promising lead anticancer compound which may be exploited for development of antiproliferative drugs.

A series of 2-heteroaryl benzimidazole-chalcone hybrids were synthesized and the anticancer activity was estimated by MTT assay in human breast, lung, colon, and ovarian cancer cell lines. The biological results indicate that the compounds showed good anticancer activity with IC50 value in the range of 0.056-19.5 μM. Compound 11b with hexa methoxy groups, bearing three methoxy groups on each terminal aryl ring exhibited a significant IC50 value (56 nM) against human breast carcinoma cells, which is 37 times higher potency in comparison with the reference Etoposide. Further compounds substituted variably with methoxy and nitro groups on the phenyl ring of chalcone showed more promising anticancer activity than the compounds with unsubstituted phenyl ring or variably alkyl-substituted phenyl ring of chalcone. The molecular docking results indicate that the synthesized compounds bind in the active site of Abl tyrosine kinase, the target of anticancer drug Imatinib. The present study provides the synergistic effect of hybrids, benzimidazole-chalcones as potential anticancer agents that will aid in the discovery of new anticancer agents.

Schiff's Bases were synthesized from the reaction of p-amino benzoic acid and alkoxybenzaldehyde in absolute ethanol and reacted with (E)-3-((4-hydroxybenzylidene) amino) phenol used DCC (N,N'-Dicyclocarbodiimide) and DAMP (4-(Dimethylamino) pyridine ) to 3-(((E)-4-((4-(((E)-4 alkoxy benzylidene) amino) benzoyl) oxy) benzylidene) amino) phenyl4- (E)- 4-alkoxy benzyli dene ) amino) benzoate. The structures of the products were confirmed by their melting points, FT-IR, 1HNMR spectra.

The 90 kDa heat shock proteins (Hsp90) are molecular chaperones that are responsible for the folding and/or trafficking of ~400 client proteins, many of which are directly associated with cancer progression. Consequently, inhibition of Hsp90 can exhibit similar activity as combination therapy as multiple signaling nodes can be targeted simultaneously. In fact, seventeen small-molecule inhibitors that bind the Hsp90 N-terminus entered clinical trials for the treatment of cancer, all of which exhibited pan-inhibitory activity against all four Hsp90 isoforms. Unfortunately, most demonstrated undesired effects alongside induction of the pro-survival heat shock response. As a result, isoform-selective inhibitors have been sought to overcome these detriments. Described herein is a structure-based approach to design Hsp90β-selective inhibitors along with preliminary SAR. In the end, compound 5 was shown to manifest ~370-fold selectivity for Hsp90β versus Hsp90α, and induced the degradation of select Hsp90β-dependent clients. These data support the development of Hsp90β-selective inhibitors as a new paradigm to overcome the detriments associated with pan-inhibition of Hsp90.

To better understand the role of bromodomain and extra-terminal domain (BET) proteins in epigenetic mechanisms, we developed a series of thienodiazepine-based derivatives and identified two compounds, 3a and 6a, as potent BET inhibitors. Further in vivo pharmacokinetic studies and analysis of in vitro metabolic stability of 6a revealed excellent brain penetration and reasonable metabolic stability. Compounds 3a and 6a were radiolabeled with fluorine-18 in two steps and utilized in positron emission tomography (PET) imaging studies in mice. Preliminary PET imaging results demonstrated that [18F]3a and [18F]6a have good brain uptake (with maximum SUV = 1.7 and 2, respectively) and binding specificity in mice brains. These results show that [18F]6a is a potential PET radiotracer that could be applied to imaging BET proteins in the brain. Further optimization and improvement of the metabolic stability of [18F]6a are still needed in order to create optimal PET imaging probes of BET family members.

Typical engineering design tasks require the effort to modify designs iteratively until they meet certain constraints, i.e., performance or attribute requirements. Past work has proposed ways to solve the inverse design problem, where desired designs are directly generated from specified requirements, thus avoid the trial and error process. Among those approaches, the conditional deep generative model shows great potential since 1) it works for complex high-dimensional designs and 2) it can generate multiple alternative designs given any condition. In this work, we propose a conditional deep generative model, Range-GAN, to achieve automatic design synthesis subject to range constraints. The proposed model addresses the sparse conditioning issue in data-driven inverse design problems by introducing a label-aware self-augmentation approach. We also propose a new uniformity loss to ensure generated designs evenly cover the given requirement range. Through a real-world example of constrained 3D shape generation, we show that the label-aware self-augmentation leads to an average improvement of14% on the constraint satisfaction for generated 3D shapes, and the uniformity loss leads to a 125% average increase on the uniformity of generated shapes' attributes. This work laid the foundation for data-driven inverse design problems where we consider range constraints and there are sparse regions in the condition space.

A novel series of 4,5-dihydroisoxazole-5-carboxamide derivatives were designed, synthesized and evaluated for their anti-cancer activity against two different human cancer cell lines. Most of the synthesized compounds showed anti-cancer activity with IC50 values ranging from 4.03 to 104.45 ��M. Further, compounds 17h, 17i, 17e, and 18e were showed potent inhibitory activity against two cancer cell lines, with IC50 values close to that of standard drug. It is important to note that compound 17h was more potent than the standard drug cisplatin with IC50 values of 4.11 and 4.03 ��M against Hela cell line and MCF-7 cell line respectively.

Leishmaniasis is one of today's most neglected diseases. The emergence of new anti-leishmanial therapies emphasizes several study groups funded by the World Health Organization. The present investigation will focus on the research to determine a few new potential derivatives of β-carboline ester derivatives against leishmaniasis. The

Due to a lack of therapeutic options for the pathological condition of leishmaniasis, which is characterized by polymorphic lesions and skin surface infections, Leishmania genus parasites damaged dermis and mucosa. There was a need to synthesize and characterize some new complexes. This study evaluated the biological activities preferably anti-Leishmanial activity of organotin (IV) containing sulphonyl hydrazide derivatives. A series of six new organotin (IV) complexes 1–6 labeled as R2SnL2; R = Methyl (1), Butyl (2), Phenyl (3) and R3SnL; R = Methyl (4), Butyl (5), Phenyl (6) has been synthesized as reflux method derived from N'‐ (2,4‐dinitrophenyl)‐4‐methylphenylsulfonylhydrazide (L). All compounds were characterized through FT-IR, 1HNMR, 13CNMR, and elemental analysis. Structural analysis confirms the formation of six complexes (1–6). All derivatives have been screened for their pharmacological activities. Interestingly, compound 1 showed promising activity against leishmania promastigotes with low cytotoxicity. All results were further elaborated through docking studies performed on leishmania donovoni synthetase PDB: ID 3QW3 that acts as an essential building block for the viability of Leishmania promastigotes. This research effectively synthesized sulphonyl hydrazide ligand and its six new organotin (IV) derivatives, which were tested for biological properties such as antibacterial, anti-fungal, anti-oxidant, and ideally anti-leishmanial activity and cytotoxicity. Studies have confirmed that these compounds have the potency to be a good candidate against leishmaniasis. Computational studies were carried out to recognize the binding affinities for leishmania donovoni synthetase. Communicated by Ramaswamy H. Sarma

Purpose The purpose of this paper is to present a novel retractable main landing gear for a light amphibious airplane, while the design, synthesis and analysis are given in details for constructing the main landing gear. Design/methodology/approach The constraint three-position synthesis has given the correct path of all linkages that suitably fit the landing gear into the compartment. The additional lock-link is introduced into the design to ensure the securement of the mechanism while landing. Having the telescopic gas-oil shock strut as a core element to absorb the impact load, it enhances the ability and efficiency to withstand higher impact than others type of light amphibious airplane. Findings By kinematics bifurcation analysis, the optimized value of the unlock spring stiffness at 90 N/m can be found to tremendously reduce the extended-retracted linear actuator force from 500 N to 150 N at the beginning of the retraction sequence. This could limit the size and weight of the landing gear actuator of the light amphibious airplane. Practical implications The drop test of the landing gear to comply with the ASTM f-2245 (Standard Specification for Design and Performance of a Light Sport Airplane) reveals that the novel landing gear can withstand the impact load at the drop height determined by the standard. The maximum impact loading 4.8 G occurs at the drop height of 300 mm, and there is no sign of any detrimental or failure of the landing gear or the structure of the light amphibious airplane. The impact settling time response reaches the 2% of steady-state value in approximately 1.2 s that ensure the safety and stability of the amphibious airplane if it subjects to an accidentally hard landing. Originality/value This paper presents unique applications of a retractable main landing gear of a light amphibious airplane. The proposed landing gear functions properly and complies with the drop test standard, ensuring the safety and reliability of the airplane and exploiting the airworthiness certification process.

Thirty-eight novel ferulic amide 1-aminocyclohexane carboxylic acid (Ac6c) derivatives D1-D19 and E1-E19 were designed and synthesized, and their antibacterial, antifungal, and insecticidal activities were tested. Most of the synthesized compounds displayed excellent activity againstXanthomonas oryzae pv. oryzae (Xoo), with EC50 values ranging from 11.6 to 83.1 μg/mL better than that of commercial bismerthiazol (BMT, EC50 = 84.3 μg/mL), as well as much better performance compared to that of thiediazole copper (TDC, EC50 = 137.8 μg/mL). D6 (EC50 = 17.3 μg/mL), D19 (EC50 = 29.4 μg/mL), E3 (EC50 = 29.7 μg/mL), E9 (EC50 = 27.0 μg/mL), E10 (EC50 = 18.6 μg/mL), and E18 (EC50 = 20.8 μg/mL) showed much higher activity on Xanthomonas oryzae pv. oryzicola compared with BMT (EC50 = 80.1 μg/mL) and TDC (EC50 = 124.7 μg/mL). In relation to controlling the fungus, Rhizoctonia solani, E1, E10, and E13 had much lower EC50 values of 0.005, 0.140, and 0.159 μg/mL compared to hymexazol at 74.8 μg/mL. Further in vivo experiments demonstrated that E6 and E12 controlled rice bacterial leaf blight disease better than BMT and TDC did. Scanning electron microscopy (SEM) studies revealed that E12 induced the Xoo cell membrane collapse. Moreover, D13 (73.7%), E5 (80.6%), and E10 (73.4%) also showed moderate activity against Plutella xylostella. These results indicated that the synthesized ferulic amide Ac6c derivatives showed promise as candidates for treating crop diseases.

[Image: see text] The absolute structure of an indole alkaloid (+)-cinchonaminone by total synthesis of both (+)-cinchonaminone and its enantiomer was determined. The main focus of the study was the enantioselective synthesis of both enantiomers of a chiral cis-3,4-disubstituted piperidine. We also evaluated monoamine oxidase (MAO) inhibitory activities of these enantiomers. Furthermore, its structurally simplified derivatives were synthesized that did not have any chiral center. Two of these derivatives showed stronger MAO inhibitory activities than that of (+)-cinchonaminone.

Purpose The purpose of this paper is to study the influence of different factors on mud performance, find the best conditions and synthesize a new type of anti-collapse drilling polymer mud with higher stability. The anti-collapse mechanism of drilling polymer mud was also suggested. Design/methodology/approach Exploring the influence of different molecular weight thickeners, filtrate reducers, soda ash addition and film-forming components on the mud performance, so as to obtain the best ratio of anti-collapse drilling polymer mud. Findings The results show that the use of vegetable glue, sulfonate copolymer and vegetable fiber powder can synthesize a high-viscosity, high-stability, collapse-resistant mud. When the mass ratio of vegetable fiber powder: vegetable glue: sulfonate copolymer is 40:1:2, the mud viscosity is 21.2 s, the fluid loss in 30 min is only 12.5 mL, and the mud film thickness is 1.5 mm, which is one ideal anti-collapse polymer mud. Originality/value Compared with ordinary polymer mud and bentonite mud, this anti-collapse polymer mud not only uses vegetable glue instead of traditional tackifiers but also effectively uses vegetable fiber powder produced from waste wood, which is environmentally friendly and highly stable specialty. It can effectively improve the safety and quality of construction during drilling in water-sensitive geology.