Fungal natural products have made important contributions to the history of human civilization. Mr. Liu Jikai has had a significant influence on the field of chemistry in fungal natural products, ...leading a large number of Chinese scholars engaged in related research. We would like to take this opportunity to thank Mr. Liu Jikai for his efforts on fungal natural products chemistry and hope that all colleagues will make great progress for the future.
For centuries, nature has been an inspirational source for the discovery of drugs used in modern medicine. Nowadays, natural-based treatments continue to be employed for primary health care, ...particularly playing a significant role in folk medicine. In addition, we are currently observing an increasing use of natural-products-based supplements from botanical and marine sources, making their standardization and scientific validation a priority to guarantee the safety of these products. Natural products and/or synthetic derivatives using their novel structures have also been of utmost importance in drug discovery and development in several clinical areas. After a period of discreditation and reduced investment, we are now witnessing a renewed interest from the pharmaceutical industry and scientific community due to the urgent need to develop new drugs. This reprint comprises 11 original and 6 review articles dedicated to plant and marine natural products research, contributing to the scientific validation of their use and opening new perspectives in drug discovery
We are very pleased to introduce the Book Version of our Special Issue in Molecules dedicated to the memory of the late Professor Dr. Charles D. Hufford. The issue has been a huge success, with 22 ...full-length peer-reviewed papers and a tribute by Professor Alice M.Clark. Authors, reviewers, and collaborators from many countries across the worldhave contributed to this endeavour, and we are truly grateful to all. This Special Issue isrepresentative of the broad impact that “Charlie” had on the field of bioactive naturalproducts. This Special Issue comprises papers from Professor Hufford’s former students,colleagues, and collaborators throughout the world who have utilized a wide array ofstate-of-the-art techniques to examine diverse natural sources to isolate and identify avariety of natural products with a wide spectrum of biological activities, including somenew microbial transformations and insights into bioactive molecules. Many new bioactive compounds are described and reported here for the first time. Bioactivities reportedinclude cytotoxicity, antimicrobial activity, anti-inflammatory activity, antileishmanialactivity, antitrypanosomal activity, antimalarial activity, analgesic activity, and beneficialliver activities, just to name a few. This Special Issue will undoubtedly have a lasting impact on the field of bioactive natural products, as exemplified by the career of Dr. Hufford.Lastly, without the timely and outstanding contributions from all of you, this Special Issue would not have been possible. We thank you all very much for your contributions and your time devoted to this Special Issue in memory of a special person. Finally, we express ourgratitude and thanks to the journal Molecules and their excellent team of expert reviewers for giving us the support and opportunity to make this Special Issue a huge success!
Hydrazide–hydrazones possess a wide spectrum of bioactivity, including antibacterial, antitubercular, antifungal, anticancer, anti-inflammatory, anticonvulsant, antidepressant, antiviral, and ...antiprotozoal properties. This review is focused on the latest scientific reports regarding antibacterial, antimycobacterial, and antifungal activities of hydrazide–hydrazones published between 2017 and 2021. The molecules and their chemical structures presented in this article are the most active derivatives, with discussed activities having a hydrazide–hydrazone moiety as the main scaffold or as a side chain. Presented information constitute a concise summary, which may be used as a practical guide for further design of new molecules with antimicrobial activity.
A new series of N–substituted 2–pyrazolines 9a–f, 10a–f, 11a–f, 12a–f and 13a–f were obtained from the cyclocondensation reaction of (7–chloroquinolin–4–yl)aminochalcones 8a–f with hydrazine hydrate ...and its derivatives. Fourteen of the synthesized compounds including the starting chalcones were selected by US National Cancer Institute (NCI) for testing their anticancer activity against 60 different human cancer cell lines, with the most important GI50 values ranging from 0.28 to 11.7 μM (0.13–6.05 μg/mL) and LC50 values ranging from 2.6 to > 100 μM (1.2 to > 51.7 μg/mL), for chalcones 8a,d and pyrazolines 10c,d. All compounds were assessed for antibacterial activity against wild type and multidrug resistant gram negative and gram positive bacteria, with MIC values ranging from 31.25 to 500 μg/mL. Additionally, the novel compounds were tested for antifungal and antiparasitic properties. Although these compounds showed mild activity against Candida albicans, chalcones 8a and 8e showed high activity against Cryptococcus neoformans with MIC50 = 7.8 μg/mL. For anti–Plasmodium falciparum activity the 2–pyrazoline 11b was the most active with EC50 = 5.54 μg/mL. Regarding the activity against Trypanosoma cruzi, compound 10a was highly active with EC50 = 0.70 μg/mL. Chalcone 8a had good activity against Leishmania panamensis amastigotes with EC50 = 0.79 μg/mL.
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•New series of 4,5–dihydro–1H–pyrazoles were synthesized from quinoline–chalcones.•Compounds 8c,d and 10a,c showed important anticancer activity with GI50 0.28–11.7 μM.•Chalcones 8a and 8e showed excellent anti–C. neoformans activity with MIC50 = 7.8 μg/mL.•Pyrazoline 9d selectively inhibited N. gonorrhoeae growth.•Compounds 8a, 10a and 11b were active to Leishmania, Trypanosoma and Plasmodium, respectively.
The cardioprotective vasodilator peptide adrenomedullin 2/intermedin (AM2/IMD) and the related adrenomedullin (AM) and calcitonin gene-related peptide (CGRP) signal through three heterodimeric ...receptors comprising the calcitonin receptor–like class B G protein–coupled receptor (CLR) and a variable receptor activity–modifying protein (RAMP1, -2, or -3) that determines ligand selectivity. The CGRP receptor (RAMP1:CLR) favors CGRP binding, whereas the AM1 (RAMP2:CLR) and AM2 (RAMP3:CLR) receptors favor AM binding. How AM2/IMD binds the receptors and how RAMPs modulate its binding is unknown. Here, we show that AM2/IMD binds the three purified RAMP–CLR extracellular domain (ECD) complexes with a selectivity profile that is distinct from those of CGRP and AM. AM2/IMD bound all three ECD complexes but preferred the CGRP and AM2 receptor complexes. A 2.05 Å resolution crystal structure of an AM2/IMD antagonist fragment–bound RAMP1–CLR ECD complex revealed that AM2/IMD binds the complex through a unique triple β-turn conformation that was confirmed by peptide and receptor mutagenesis. Comparisons of the receptor-bound conformations of AM2/IMD, AM, and a high-affinity CGRP analog revealed differences that may have implications for biased signaling. Guided by the structure, enhanced-affinity AM2/IMD antagonist variants were developed, including one that discriminates the AM1 and AM2 receptors with ∼40-fold difference in affinities and one stabilized by an intramolecular disulfide bond. These results reveal differences in how the three peptides engage the receptors, inform development of AM2/IMD-based pharmacological tools and therapeutics, and provide insights into RAMP modulation of receptor pharmacology.
The physiologic mechanisms by which the four activities of sleep, sedentary behavior, light-intensity physical activity, and moderate-to-vigorous physical activity (MVPA) affect health are related, ...but these relationships have not been well explored in adults. Research studies have commonly evaluated how time spent in one activity affects health. Because one can only increase time in one activity by decreasing time in another, such studies cannot determine the extent that a health benefit is due to one activity versus due to reallocating time among the other activities. For example, interventions to improve sleep possibly also increase time spent in MVPA. If so, the overall effect of such interventions on risk of premature mortality is due to both more MVPA and better sleep. Further, the potential for interaction between activities to affect health outcomes is largely unexplored. For example, is there a threshold of MVPA minutes per day, above which adverse health effects of sedentary behavior are eliminated? This article considers the 24-h Activity Cycle (24-HAC) model as a paradigm for exploring inter-relatedness of health effects of the four activities. It discusses how to measure time spent in each of the four activities, as well as the analytical and statistical challenges in analyzing data based on the model, including the inevitable challenge of confounding among activities. The potential usefulness of this model is described by reviewing selected research findings that aided in the creation of the model and discussing future applications of the 24-HAC model.
The research area of ambient assisted living has led to the development of activity recognition systems (ARS) based on human activity recognition (HAR). These systems improve the quality of life and ...the health care of the elderly and dependent people. However, before making them available to end users, it is necessary to evaluate their performance in recognizing activities of daily living, using data set benchmarks in experimental scenarios. For that reason, the scientific community has developed and provided a huge amount of data sets for HAR. Therefore, identifying which ones to use in the evaluation process and which techniques are the most appropriate for prediction of HAR in a specific context is not a trivial task and is key to further progress in this area of research. This work presents a systematic review of the literature of the sensor-based data sets used to evaluate ARS. On the one hand, an analysis of different variables taken from indexed publications related to this field was performed. The sources of information are journals, proceedings, and books located in specialized databases. The analyzed variables characterize publications by year, database, type, quartile, country of origin, and destination, using scientometrics, which allowed identification of the data set most used by researchers. On the other hand, the descriptive and functional variables were analyzed for each of the identified data sets: occupation, annotation, approach, segmentation, representation, feature selection, balancing and addition of instances, and classifier used for recognition. This paper provides an analysis of the sensor-based data sets used in HAR to date, identifying the most appropriate dataset to evaluate ARS and the classification techniques that generate better results.
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•AgGO with enhanced absorption in the visible spectrum through a single-step surfactant-free facile method was prepared.•WO3-x/AgrGO composite with better photocatalytic activity was ...prepared by doping WO3-x by AgGO via a hydrothermal process.•Better carrier separation and reduced impedance leading to RhB degradation and bacterial inactivation.•It exhibits versatilities for photocatalytic activities in visible regions.•Stability tests suggest its excellent reusability.
Suppressing charge recombination in semiconductors via triggering interfacial polarization and synergism provides an effective way to redeem multifunctionality and achieve environmental sustainability. Herein, we anchor a single-step facile synthesis of AgGO, providing bandgap control through varying oxidation time and subsequent simultaneous incorporation of Ag and rGO via the in situ hydrothermal method in WO3-x. The resulting WO3-x/AgrGO composite demonstrated a broadening of optical absorption and excellent suppression of carrier recombination, thereby improving the catalytic properties. The synergism and excellent conductivity of AgrGO enhance the interfacial polarization to store the carriers for longer times and help carriers carry most of their energy to the catalyst’s surface. When WO3-x/AgrGO was tested against RhB under visible light irradiation, its degradation constant reached 0.034/min, 7.4 times faster than pure WO3-x. It has left no viable bacteria during the photoinactivation of gram-negative E. coli bacteria, and even its inactivation rate is 1.07 times faster than AgGO. So, this study provides a direct method of metal-GO composite synthesis and subsequent introduction into WO3-x to broaden the versatility of environmental semiconductors.
The Achillea genus belongs to the Asteraceae family, which is mostly found in the northern hemisphere and is comprised of 115 species in the world. In Turkish flora, there are 52 species and 58 taxa, ...among them half of which are recorded as endemic. To the best of our knowledge, there has been no biological activity studied in this species until now, with the exception of one study of the antimicrobial activity of certain essential oils. This study focused primarily on the determination of antioxidant, antimicrobial, and enzyme-inhibition activity of aqueous ethanol extract of Turkish endemic Achillea cucullata by in vitro methods. The extract exhibited DPPH radical scavenging activity with an IC50 value of 132.55±0.026μg/mL, the total phenol content was 53.807±0.059 (mgGAE/g), and the total flavonoid content was 21.372±0.026 (mgQE/g), on the dry-weight basis. Antimicrobial activity was evaluated by a micro-dilution method focused on five microorganisms; two Gram-positive Staphylococcus aureus (ATCC 29213) and Enterococcus faecalis (ATCC 29212), two Gram-negative Pseudomonas aeruginosa (ATCC 27853) and Escherichia coli (ATCC 25922), and one fungal strain Candida albicans (ATCC 10231). Results show that the MIC value for the tested microorganism was higher than 5mg/mL. In this work, acetylcholinesterase (AChE), butyrylcholinesterase (BChE), and α-glucosidase enzymes were strongly inhibited by the A. cucullata extract, and the IC50 values for these enzymes were 2.4μg/mL, 0.26μg/mL, and 24.75μg/mL, respectively. Certain acetylcholinesterase inhibitors have been used for treatment of Alzheimer's disease in the past. α-Glucosidase inhibitors are strong drug candidates, as well as potential functional food agents, for deferring the postprandial absorbency of glucose.
•Ethanol extract was prepared from endemic plant - Achillea cucullata•In vitro antioxidant was evaluated by DPPH, TPC and TFC assay•Antimicrobial activity was determined by microdilution method against five microorganisms•Acetylcholinesterase, butyrylcholinesterase, α-glucosidase enzymes were impressively inhibited by the A. cucullata ethanol extract
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