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Attitude estimation plays a major role in the autonomy of unmanned aerial vehicles and requires fusion of different sensor measurements. This paper describes an adaptive estimation scheme in which the weight parameter for the complementary filter (CF) is varied over time. The adaptive mechanism proposed here is inspired from the multiple model adaptive estimation (MMAE) scheme used for varying noise parameters in the Kalman filter structure. In this paper, the linear complementary filters are used as elementary blocks in the MMAE structure and their weights are modified probabilistically to obtain an accurate orientation estimate. It avoids the problem of manual selection of weight factor for complementary filter and provides a robust orientation estimate against varying system dynamics. The proposed MMAE based adaptive CF scheme is modular in nature and is dependent on the residual error between estimated and the measured orientation angle. It is applied on the real world datasets logged from inertial sensors and the performance of MMAE based CF structure is found to work promisingly as compared to the non-linear complementary filter versions and the extended Kalman filter framework. [ABSTRACT FROM AUTHOR]

Exploiting the competitive ability of crops is essential to develop cost-effective and sustainable weed management practices. Reduced row spacing, increased seeding rates, and selection of competitive cultivars can potentially manage crop–weed competition in cotton, soybean, wheat, and corn. These cultural weed management practices facilitate a more rapid development of crop canopy that adversely affect the emergence, density, growth, biomass, and subsequently the seed production of weeds during a growing season. These cultural practices can also favour the weed suppressive ability of the crop by influencing the canopy architecture traits (plant height, canopy density, leaf area index, rate of leaf area development, and leaf distribution). These crop-competition attributes can potentially reduce the risk of crop yield losses due to interference from weed cohorts that escape an early- or a late-season post-emergence herbicide application. Furthermore, reduced row spacing, increased seeding rates, and weed-competitive cultivars are effective in reducing reliance on a single site-of-action herbicides, thereby reducing the selection pressure for development of herbicide-resistant weed populations in a cropping system. [ABSTRACT FROM AUTHOR]

Background: Posterior-stabilized rotating-platform (PSRP) knee was designed with the purpose of improving postoperative flexion and stability. Its long-term performance has limited reports, which could show whether this purpose has been realized without deleterious effect. We report its long-term results at 10-13 years, of a previously studied cohort, evaluated longitudinally.Methods: A total of 133 consecutive PSRP implants, selected for 118 patients were studied. Twenty-one patients (24 knees) were deceased and 11 patients (12 knees) were lost to follow-up after 10 years. Eighty patients (97 knees) completed clinical evaluation, of whom 78 patients (88 knees) also completed radiological evaluation.Results: Mean flexion improved from 106.8° (30°-150°) to 127° (90°-155°). Forty-three percent patients could sit crosslegged, 32.5% could sit on floor, and 3.4% could squat. Mean knee subscore of Knee Society Score improved from 28 (1-59) to 96 (67-100). Mean function subscore improved from 53 (5-81) to 78 (-10 to 100). After 10 years, 5 patients had zero function score because of developing other debilitating medical illnesses. Twenty-one dead patients (24 knees), at their last follow-up (7.7 years), had satisfactory scores. No patient had spinout or revision. Radiologically, alignment was satisfactory and there was no osteolysis. Kaplan-Meier analysis showed 100% implant survival.Conclusion: PSRP design, evaluated after 10 years of implantation in selected patients, had 100% survival with good flexion. Addition of post and cam to the original rotating platform design has provided good stability without untoward effects of wear or osteolysis at 10-13 years. [ABSTRACT FROM AUTHOR]

The recent evolution of glyphosate-resistant (GR) Kochia scoparia (kochia) is a potential threat to the sustainability of GR cropping systems, including GR sugar beet in the northwestern United States. The lack of effective and economical, alternative herbicide programs for K. scoparia control in GR sugar beet further exacerbates the problem. Therefore, it is critical to understand the population dynamics and demographics of K. scoparia in response to the glyphosate application timing, and their overall impact on the replenishment of the weed seed bank in the soil, and on GR sugar beet yields. To fulfill this objective, field experiments were conducted at the Montana State University Southern Agricultural Research Center near Huntley, Montana, USA in 2012 and 2013. Glyphosate timing treatments included a single application at the 2-leaf (lf), 6-lf, or 10-lf stage of sugar beet or sequential applications at 2-lf followed by (fb) 6-lf, 6-lf fb 10-lf, 2-lf fb 6-lf fb 10-lf, or 6-lf fb 10-lf fb canopy closure (CC) stage of sugar beet. K. scoparia survival, biomass, and seed production were monitored in three cohorts that emerged at different growth stages of sugar beet during the season. K. scoparia plants in cohort 1 and 2 were more competitive (greater biomass and seed production) than those in cohort 3. Compared with a single glyphosate timing, sequential applications of glyphosate at 6-lf fb 10-lf stages of sugar beet prevented survival, biomass and seed production in cohort 1 and cohort 2. K. scoparia plants in cohort 3 that emerged after the glyphosate application at the 10-lf stage of sugar beet, produced up to 1123 seeds m −2 . A follow-up application of glyphosate at the CC stage of sugar beet was needed to prevent biomass and seed production from cohort 3 survivors. Irrespective of timing, sequential applications of glyphosate provided higher root and sucrose yields than the single glyphosate applications in GR sugar beet. Growers should utilize three applications of glyphosate applied sequentially at 6-lf fb 10-lf fb CC stages of sugar beet to prevent season-long K. scoparia interference and seed additions in GR sugar beet. [ABSTRACT FROM AUTHOR]

Regional variations in environmental conditions, cultivars, and management practices necessitate locally derived tools for crop water use estimation and irrigation scheduling. A study was conducted in northeast Louisiana (mid-south US) aimed at estimating daily crop evapotranspiration (ET c ) and reference evapotranspiration (ET o ) and thus, developing local crop coefficient ( K c ) curves for irrigated upland cotton. ET c was determined using paired weighing lysimeters installed near the middle of a 1-ha cotton field and planted with cotton as in the rest of the surrounding field, while ET o was calculated using the Standardized Reference Evapotranspiration Equation (SREE) developed by the American Society of Civil Engineers (ASCE), using estimates of weather variables from a nearby standard reference weather station. Stage-specific K c values averaged over 2 years were 0.42, 1.25 and 0.70 for initial, midseason, and end season stages of cotton, respectively. The initial-stage K c value was approximately 26% lower than the Food and Agricultural Organization (FAO)-adjusted initial K c value. The mid- and end-season K c values obtained in the study were approximately 6% and 11% greater, respectively, than the FAO-adjusted K c values for the corresponding stages. The observed differences among the local stage-specific K c values (especially at initial growth stage of cotton) and the FAO-adjusted initial K c values could be attributed to regional variations in environmental conditions, cultivars, and management practices. The ET c and K c values obtained from this study provide research-based information for future studies and the development of K c -based irrigation tools in this region. [ABSTRACT FROM AUTHOR]

Field, greenhouse, and laboratory experiments were conducted at the Montana State University Southern Agricultural Research Center, Huntley, MT, USA, in 2012 and 2013, to evaluate the effectiveness of various postharvest-applied herbicides on late-season control, fecundity, seed viability, and progeny fitness of Kochia scoparia (kochia) in wheat stubble. Paraquat + atrazine, paraquat + linuron, and paraquat + metribuzin applied at the early bloom stage were the most effective postharvest treatments for late-season control (100%) at 28 d after treatment (DAT), biomass reduction (70–73%), and seed prevention of K. scoparia , and did not differ from glyphosate, glufosinate, saflufenacil + 2, 4-D, saflufenacil + atrazine, tembotrione + atrazine, or topramezone + atrazine treatments. Dicamba alone, dicamba + 2, 4-D, or diflufenzopyr + dicamba + 2, 4-D applied at the early bloom stage were ineffective, with <70% late-season control, <45% biomass reduction, and <55% seed reduction of K. scoparia . In the absence of a postharvest herbicide, uncontrolled kochia plants at a density of 8–10 plants m −2 contributed >100,000 seeds m −2 . Addition of atrazine to dicamba improved late-season control (80%) and seed reduction (78%) compared to dicamba alone, and reduced seed viability and 100-seed weight. There was no significant effect of any of the dicamba-containing herbicides applied at the early bloom stage on K. scoparia progeny fitness, including height, width, primary branches, and shoot dry weight of seedlings at 42 d after planting (DAP). The effective postharvest-applied herbicides investigated in this research should be utilized to prevent late-season K. scoparia seed bank replenishment in wheat, and as a component of herbicide resistance management program for the containment of glyphosate- and/or acetolactate synthase (ALS)-inhibitor-resistant K. scoparia in wheat-based crop rotations in the US Great Plains. [ABSTRACT FROM AUTHOR]

Field and laboratory experiments were conducted in SC, USA, in 2004/2005 and 2006/2007 to determine the effect of temperature, light, and spring burial on Ipomoea purpurea (L.) Roth. seed germination over a 12-month period after seed maturation in the field. The seed collections used for the temperature and light studies had physical dormancy (water-impermeable), with 10–23% and 17–46% germination, respectively, of the freshly matured viable seeds. Freshly matured seeds used for the temperature study germinated to higher percentages at 15–25 °C constant. During winter (3 months after seed maturation), seed germination was higher at 30 °C constant or 22.5/37.5 °C fluctuating. During spring (6 months after seed maturation), there was a widening of thermal range (10–40 °C constant or 2.5/17.5 to 27.5/42.5 °C fluctuating) for germination. Germination of surface-lying or buried seeds was higher at 35–40 °C constant or 22.5/37.5–27.5/42.5 °C fluctuating in late summer (9 months after maturation) and autumn (12 months after maturation). Light had minimal influence on germination of surface or buried seeds of the tested population over the 12-month after-ripening period. A temperature-mediated annual dormancy continuum of I. purpurea seed has been proposed in this research, which will contribute to the development of weed emergence models aimed at improving strategies for I. purpurea control in the field. [ABSTRACT FROM AUTHOR]

Highlights: [•] β-Lactam-synthon-interceded intramolecular cyclization of ω-alkenyl oximes. [•] Convenient access to synthetically arduous cyclic (E)-endo-aldonitrones. [•] Reaction with DMAD resulted in tandem 1,3-dipolar cycloaddition-N–O bond cleavage. [Copyright &y& Elsevier]

Abstract: Synthesis of functionally enriched hydantoins has been developed and validated via base-assisted intramolecular amidolysis of C-3 functionalized β-lactams. [Copyright &y& Elsevier]

Abstract: We describe herein the synthetic utility of β-lactam synthon protocol for the convenient and diastereoselective synthesis of functionally decorated hexahydroisoquinolines, hexahydroisoquinolones and hexahydroisochromones. Since the described protocol does not include the use of highly functionalized intermediates, stringent conditions or toxic reagents, the developed methodology does not suffer from the typical intricacies associated with the conventional protocols. [Copyright &y& Elsevier]

Abstract: Natural products remain a rich source of novel molecular scaffolds for novel antimalarial agents in the fight against malaria. This has been well demonstrated in the case of quinine and artemisinin both of which have served as templates for the development of structurally simpler analogues that either served or continue to serve as effective antimalarials. This review will expound on these two natural products as well as other selected natural products that have served either as antimalarial agents or as potential lead compounds in the development of antimalarial drugs. [Copyright &y& Elsevier]

Abstract: New analogues of the potent antihelmintic meclonazepam were prepared and evaluated against Schistosoma mansoni. The biological data suggests substitution at positions 2 and 4 of meclonazepam could provide promising analogues for prophylactic and therapeutic activity against S. mansoni. [Copyright &y& Elsevier]

Abstract: The chemo- as well as regioselective aza Diels–Alder reactions of 5-dienyl pyrimidinones with N-arylimines in the presence of a Lewis acid catalyst resulting in novel quinoline derivatives are reported. [Copyright &y& Elsevier]

Abstract: A systematic approach through computer assisted design to identify novel quinazolines having anxiolytic and GABAergic activity has been reported. [Copyright &y& Elsevier]

Abstract: A solvent-free and catalyst-free approach towards the selective synthesis of quinazolines and benzo[g] quinazolines has been developed using conventional microwave oven with excellent yields and reproducibilty. [Copyright &y& Elsevier]

The synthesis and transformation of previously unknown 3-aryl-2-phenyl-5-prop-2-ynylsulfanyl-3H-pyrimidin-4-ones to novel thieno[3,2-d]pyrimidin-4-ones are reported. [Copyright &y& Elsevier]

• Prevalence of any new menstrual disturbance after Covishield vaccine was 20%. • The cycles were mostly affected by less than 7 days, reversing within 1–3 cycles. • Previous SARS-CoV-2 infection was not associated with menstrual disturbance. • Emotional disturbance and previous dysmenorrhea are associated with menstrual disturbance. The association between covid-19 vaccine and menstrual disturbance is unclear. An in-person cross-sectional survey among female members ≥ 18 years enrolled in an ongoing Zero TB prospective cohort in Northern India who had received one or two doses of covid-19 vaccine was conducted to study the characteristics and association of menstrual disturbance within six months of receiving Covishield. Between June 29 and September 5, 2021, 339 females ≥ 18 years of age were administered the survey. Median age was 30 (IQR: 22–39) years; 84 % were between 18 and 49 and 16 % were ≥ 50 years old. There were 152 college students, 27 healthcare workers, and 160 nuns. Forty-two women (12 %) had received one dose and 297 (88 %) had received two doses of Covishield. Overall, 66 (20 %) women reported experiencing menstrual disturbance after receiving Covishield vaccine. The problems included early menstruation: 6 % (n = 19/339); late menstruation: 4 % (n = 14/339); and heavier bleeding: 5 % (n = 17/339). Disturbances lasted for less than seven days and cycles normalized in 1–3 months. There was no post-menopausal bleeding. There was no significant difference in menstrual disturbance based on receiving one vs. two doses of Covishield (OR: 1.58; 95 % CI: 0.55–4.57; p = 0.381). History of SARS-CoV-2 infection was not associated with the development of menstrual disturbance among the vaccinees (OR: 0.63; 95 % CI: 0.24–1.73; p = 0.379). Presence of emotional disturbance at baseline (OR: 31; 95 % CI: 3.52–267; p = 0.002) or previous history of dysmenorrhea (OR: 41; 95 % CI: 8.7–196; p < 0.001) was associated with menstrual disturbance in the vaccinees, indicating their potential to confound or bias study results. Menstrual problems were reported by Covishield vaccinees, but they were minor and reversible within three months and do not constitute a ground for vaccine hesitancy. Studies designed to assess causal link taking care to avoid selection bias or confounding are needed. [ABSTRACT FROM AUTHOR]

Microwave promoted high yielding synthesis of 4-aminoquinoline-phthalimides was developed with an aim to evaluate their anti-plasmodial potential. The scaffolds with longer spacer length (n = 6, 8) between two pharmacophores and a halogen substituent on the phthalimide ring displayed good antiplasmodial activity. Compound 5w , with an optimum combination of hexyl chain as spacer along with a tetra-bromophthalimide ring proved to be most potent and non-cytotoxic among the series exhibiting an IC 50 value of 0.10 μM. [ABSTRACT FROM AUTHOR]

This paper aims to develop an Adaptive Sliding Kalman Filter (ASKF) by fusing the concept of change detection in a data stream, adapting noise covariance matrices and the Sliding Kalman filter (SKF). Adaptive Kalman filtering (AKF) scheme modifies the noise covariance matrix ( Q and R ) value based on a window of past innovation sequence whereas SKF is a window based filtering technique which uses past information to obtain the present state estimate. However, the length of the window chosen for SKF and AKF is arbitrary and a scheme has been devised here to adapt this window length according to the data stream statistics. The change detection scheme chosen here does not make any assumption on the data distribution and is sequential in nature, such that a change is triggered whenever the underlying statistics of data crosses a pre-determined threshold. The key contribution of this work is toward the formulation of a mechanism by which the window length is made adaptive such that whenever a change is detected, the window length for SKF and AKF is curtailed and restarted in an oscillatory windowing fashion. The suggested filter is robust against temporary uncertainties and appropriate for reliable estimation of signals that may arise in many engineering areas. Real world experimental results demonstrate better estimation accuracy of the proposed method than that of others. [ABSTRACT FROM AUTHOR]

Selective electrochemical sensors based on newly synthesized ferrocene appended quinoline-triazole (FAQT) derivative for Fe (III) ions have been developed. The cyclic voltammetry (CV) of FAQT exhibited reversible voltammogram corresponding to ferrocene/ferrocenium redox process in the potential range of −0.4 to 0.6 V vs Ag/Ag + . The CV of FAQT undergoes electrochemical perturbation on addition of Fe (III) ions and results in the shift of voltammogram toward more positive potential (anodic shift) which ascribed the formation of FAQT-Fe (III) complex. The binding behavior and 1:1 stoichiometry of FAQT-Fe (III) complex was further confirmed by employing fluorescence and UV-visible techniques. The high binding constant (1.82 × 10 3 M −1 ) and negative free energy change (−18.6 kJ mol −1 ) indicates the stability and feasibility of FAQT-Fe (III) complex. The voltammetric sensor works within the concentration range of 1.0 × 10 −4 –5.0 × 10 −6 M with detection limit of 2.33 × 10 −7 M. The potentiometric solid contact electrode exhibits the Nernstian slope of 18.7 mV decade −1 for Fe (III) ions in concentration range of 1.0 × 10 −1 –1.0 × 10 −7 M with the detection limit of 2.94 × 10 −8 M. These proposed sensors showed high selectivity toward Fe (III) ions and therefore, used for quantification of Fe (III) ions in different sample matrices. [ABSTRACT FROM AUTHOR]

Highly selective and unprecedented 4-aminoquinoline-β-lactam (AQL) based electrochemical (voltammetric & potentiometric) sensors for the selective recognition of Zn (II) ions have been developed. Preliminary, the complexation behavior of AQL towards various metal ions was investigated by employing the UV-visible and fluorescence techniques. The voltammetry of AQL exhibits two anodic peaks at 0.85 V and 1.25 V which get shifted toward more positive potential (anodic shift) on addition of Zn (II) ions in the potential range of 0.40 V to 1.60 V vs Ag/Ag+ due to formation of AQL-Zn (II) complex. Voltammetric sensor exhibited linear response in the wide concentration range of 5.0 × 10 −5 to 6.0 × 10 −4 M with detection limit of 2.5 × 10 −6 M. Potentiometrically, the polyvinyl chloride based solid contact coated graphite electrode (CGE-1) showed the Nernstian slope of 28.9 mVdecade −1 in concentration range of 1.0 × 10 −1 to 1.0 × 10 −7 M with detection limit of 8.26 × 10 −8 M. The high binding constant and negative value of free energy calculated by using the Benesi-Hildebrand equation confirmed the formation of AQL-Zn (II) complex and further validated via 1 H-NMR and mass spectrometry. The developed electrochemical sensors exhibited high selectivity and reproducibility toward Zn (II) ions. The analytical utilities of proposed sensors were confirmed by the quantification of Zn (II) content in various sample matrices. [ABSTRACT FROM AUTHOR]

The chromogenic, voltammetric and potentiometric sensors based upon the novel ferrocene appended chalcone (FAC) have been developed for the selective detection of Cu (II) ions. In UV/visible measurements, the addition of Cu (II) ion into the FAC resulted in the disappearance of low energy band associated with hypsochromic shift of 30 nm of the high energy band. This perturbation in the absorption spectrum is well appreciated by naked eye inspection. The chromogenic sensor exhibited the concentration range of 3.00 × 10 −5 to 3.50 × 10 −6 M with detection limit of 6.00 × 10 −7 M. The cyclic voltammetry (CV) of FAC showed a reversible redox couple (Fe 2+ /Fe 3+ ), when scanned in between the potential range of 0.4 V to -0.2 V vs . Ag/Ag + . The CV of FAC undergoes electrochemical changes due to the formation of FAC-Cu (II) complex on addition of Cu (II) ions. The voltammetric sensor can work within the concentration range of 5.00 × 10 −5 to 4.00 × 10 −4 M with detection limit of 2.00 × 10 −6 M. The potentiometric response of polyvinylchloride (PVC) based solid contact coated graphite electrode (CGE-1) was linear within the Cu (II) ions concentration range of 1.00 × 10 −1 to 5.00 × 10 −7 M and showed near Nernstian slope of 28.5 mV/decade with the detection limit of 1.78 × 10 −7 M. No significant interference was observed from other diverse metal ions. The analytical usefulness of proposed sensors has been validated further by estimating the Cu (II) ions in various sample matrices with excellent results. [ABSTRACT FROM AUTHOR]

Chalcones represent key structural motif in the plethora of biologically active molecules including synthetic and natural products. Synthetic manipulations of chalcones or their isolation from natural sources are being investigated worldwide for the development of more potent and efficient drugs for the treatment of several dreadful diseases such as cancer, diabetes, HIV, tuberculosis, malaria etc. Over the past few years, a large volume of research papers and review articles highlighting the significance of chalcone derivatives has been compiled in the literature. The present review article focuses on the recent developments (2010–2014) on various pharmacological and medicinal aspects of chalcones and their analogues. [ABSTRACT FROM AUTHOR]

Abstract: A facile diastereoselective synthesis of 2,3-disubstituted 1-arylazetidines has been reported via NaBH4-promoted reduction of C-3 functionalized azetidin-2-ones. Since the developed protocol does not involve the use of a Lewis acid, the methodology does not suffer from typical drawbacks of the conventional protocol. [Copyright &y& Elsevier]

Abstract: The manuscript explicates simple and convenient protocols for the diastereoselective synthesis of functionally decorated thioxo-imidazolidines, imidazolidin-2-ones, piperazine-5,6-diones and 4,5-dihydroimidazoles using β-lactam synthon approach with an extension towards one-pot synthesis. Since the developed methodology does not employ either the use of Lewis acid conditions or Pd-catalyzed customary procedures, the developed route can be easily modulated for the synthesis of functionalized imidazoles with acid-sensitive functionalities and do not suffer from typical intricacies associated with conventional methods. [Copyright &y& Elsevier]

Abstract: Malaria and HIV are among the most important global health problems of our time and together are responsible for approximately 3 million deaths annually. These two diseases overlap in many regions of the world including sub-Saharan Africa, Southeast Asia and South America, leading to a higher risk of co-infection. In this study, we generated and characterized hybrid molecules to target Plasmodium falciparum and HIV simultaneously for a potential HIV/malaria combination therapy. Hybrid molecules were synthesized by the covalent fusion of azidothymidine (AZT) with dihydroartemisinin (DHA), a tetraoxane or a 4-aminoquinoline derivative; and the small library was tested for antiviral and antimalarial activity. Our data suggests that compound 7 is the most potent molecule in vitro, with antiplasmodial activity comparable to that of DHA (IC50 =26nM, SI>3000), a moderate activity against HIV (IC50 =2.9μM; SI>35) and not toxic to HeLa cells at concentrations used in the assay (CC50 >100μM). Pharmacokinetics studies further revealed that compound 7 is metabolically unstable and is cleaved via O-dealkylation. These studies account for the lack of in vivo efficacy of compound 7 against the CQ-sensitive Plasmodium berghei N strain in mice, when administered orally at 20mg/kg. [Copyright &y& Elsevier]

Abstract: To check the gamma ray shielding properties of selected low-Z building materials such as Soil-I, Soil-II, Dolomite, Gypsum, Igneous Rock and Lime Stone, some parameters of dosimetric interest have been investigated in the energy range 0.015–15MeV. The photon interactions with the samples have been discussed mainly in terms of mass attenuation coefficient, equivalent atomic number and exposure buildup factor. From the present investigations, it has been concluded that the values of exposure buildup factors are very large in the medium energy region and Soil-I acts as best gamma ray shielding material among the selected samples. [Copyright &y& Elsevier]

Abstract: The manuscript describes the synthesis of novel 1,2,3-triazole tethered β-lactam-chalcone bifunctional hybrids via click chemistry approach utilizing azide-alkyne cycloaddition reactions and their evaluation as anticancer agents against four human cancer cell lines. The presence of a cyclohexyl substituent at N-1 of β-lactam ring and methoxy substituents, preferably ortho on ring A and para on ring B on chalcones markedly improved the anticancer profiles of the synthesized scaffolds with the most potent of the test compound exhibiting an IC50 value of <1, 67.1, <1 and 6.37 μM against A-549(lung), PC-3(prostate), THP-1(leukemia), and Caco-2(colon) cell lines, respectively. [Copyright &y& Elsevier]

Abstract: The manuscript pertains to the synthesis and in vitro cytotoxic evaluation of a series of N-alkylbromo and N-alkylphthalimido-isatins against four different human cancer cell lines namely Colon: HCT-15; Liver: Hep-2; Lung: A-549 and Leukemia: THP-1 at 10 and 100μM concentrations. The active compounds based on preliminary studies were evaluated for their IC50 value against six cell lines viz. Colo-205, HCT-15 (Colon), THP-1 (Leukemia), A-549 (Lung), PC-3 (Prostate) and HeLa (Cervix). The active analogue IS-4 exhibited IC50 values of 4.57, 10.90, 11.75, 12.40 and 54.20μM against HeLa, PC-3, HCT-15, THP-1 and Colo-205, respectively. [Copyright &y& Elsevier]

Abstract: The regioselective nitroso Diels–Alder (NDA) cycloadditions of 3-dienyl-2-azetidinones with nitrosobenzene to generate oxazine-substituted β-lactams in excellent yields are reported. The amidiolytic ring opening of the cycloadducts with sodium methoxide followed by iodocyclization using I2/K2CO3 etiquette to capitulate previously unknown, multisubstituted pyrroloxazine in outstanding yields is also accounted. [Copyright &y& Elsevier]

Abstract: The present Letter describes the use of β-lactams for the synthesis of functionalized β-amino esters and their transformation to trisubstituted octahydroisoquinolone derivatives in good yields with an extension to their one-pot synthesis. [Copyright &y& Elsevier]

The success in exploring anti-tubercular potency of nitroimidazole and quinoline, the core moieties of recently approved anti-tubercular drugs instigated us to synthesize a series of alkylated/aminated 2-methyl-5-nitroimidazoles and nitroimidazole-7-chloroquinoline conjugates and to evaluate them for their activities against Mycobacterium tuberculosis as well as for their cytotoxicity towards the J774 murine macrophage cell line. Although the synthesized compounds did not surpass the activity of the standard drug Isoniazid, they have appreciable activities with minimal cytotoxicity. The synthesized nitroimidazole-7-chloroquinoline conjugate, 11c, having butyl chain as linker, proved to be the most potent among the series with an MIC 50 value of 2.2 μg/mL. [ABSTRACT FROM AUTHOR]

In spite of the development of a large number of novel anticancer drugs over the years, Cancer remains as a prominent cause of death, worldwide. Numerous drugs that are currently in clinical practice have developed multidrug resistance along with fatal side effects. Therefore, the utilization of single-target therapy is incapable of providing an effective control on the malignant process. Molecular hybridization, involving a combination of two or more pharmacophores of bioactive scaffolds to generate a single molecular architecture with improved affinity and activity, in comparison to their parent molecules, has emerged as a promising strategy in recent drug discovery research. Hybrid anticancer drugs are of great therapeutic interests since they can potentially overcome most of the pharmacokinetic drawbacks encountered with conventional anticancer drugs. Strategically, the design of anticancer drugs involved the blending or linking of an anticancer drug with another anticancer drug or a carrier molecule which can efficiently target cancer cells with improved biological potential. Major advantages of hybrid anticancer drugs involved increased specificity, better patient compliance, and lower side effects along with reduction in chemo-resistance. The successful utilization of this technique in design and synthesis of novel anticancer hybrids has been well illustrated and documented in the literature. The purpose of the present review article will be to provide an emphasis on the recent developments (2015–16) in anticancer hybrids with insights into their structure-activity relationship (SAR) and mechanism of action. [ABSTRACT FROM AUTHOR]

1 H -1,2,3-triazole linked 4-aminoquinoline-chalcone/- N -acetylpyrazoline conjugates were synthesized and evaluated against cultured chloroquine (CQ) resistant strain. Antiplasmodial activities of the synthesized conjugates revealed dependence of activity on the length of the alkyl chain as well as on the presence of methoxy substituents on ring A/ring B of the chalcone. The most potent and non-cytotoxic conjugate showed comparable antiplasmodial activity with that of CQ, with an IC 50 value of 53.7 nM. [ABSTRACT FROM AUTHOR]

A series of aliphatic and aromatic substituted 1 H -1,2,3-triazole-tethered 4-amino-quinoline-ferrocenylchalcone conjugates has been synthesized and evaluated for anti-plasmodial activity. The conjugates with flexible aliphatic (aminoethanol or aminopropanol) substituents on the quinoline ring showed better anti-plasmodial activities compared to those with cyclic (piperazine or aminophenol) substituents. The conjugate 17j was the most potent and non-cytotoxic, with an IC 50 value of 0.37 μM against the chloroquine-resistant W2 strain of Plasmodium falciparum. [ABSTRACT FROM AUTHOR]