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Covalent organic frameworks (COFs) characterized by structural diversity, face-to-face stacking and open channels exhibit unique advantages as photothermal materials but have rarely been applied in...

Metal–organic frameworks (MOFs) with high porosity and variable structure have attracted extensive attention in the field of electrochemistry, but their poor conductivity and stability have limited their development. Materials derived from MOFs can maintain the structural diversity and porosity characteristics of MOFs while improving their electrical conductivity and stability. Metal phosphides play an important role in electrochemistry because they possess rich active sites, unique physicochemical properties, and a porous structure. Published results show that MOF-derived metal-phosphides materials have great promise in the field of electrochemistry due to their controllable structure, high specific surface area, high stability and excellent electrical conductivity. MOF-derived metal-phosphides with significant electrochemical properties can be obtained by simply, economical and scalable synthetic methods. This work reviews the application of MOF-derived metal phosphides in electrochemistry. Specifically, the synthesis methodology and morphological characterization of MOFs derived metal-phosphides and their application in electrochemistry are described. Based on recent scientific advances, we discuss the challenges and opportunities for future research on MOF-derived metal-phosphides materials.

Background Despite, a large number of bioactive anthraquinones (AQs) isolated from host-living fungi, only plant-derived AQs were introduced in the global consumer markets. Host-living fungi represents renewable and extendible resources of diversified metabolites to be exploited for bioactives production. Unique classes of AQs from fungi include halogenated and steroidal AQs, and absent from planta are of potential to explore for biological activity against urging diseases such as cancer and multidrug-resistant pathogens. The structural diversity of fungal AQs, monomers, dimers, trimers, halogenated, etc… results in a vast range of pharmacological activities. Aim of review The current study capitalizes on uncovering the diversity and distribution of host-living fungal systems producing AQs in different terrestrial ecosystems ranging from plant endophytes, lichens, animals and insects. Furthermore, the potential bioactivities of fungal derived AQs i.e., antibacterial, antifungal, antiviral (anti-HIV), anticancer, antioxidant, diuretic and laxative activities are assembled in relation to their structure activity relationship (SAR). Analyzing for structure–activity relationship among fungal AQs may facilitate bioengineering of more potential analogues. Withal, elucidation of AQs biosynthetic pathways in fungi is discussed from different fungal hosts to open up new possibilities for potential biotechnological applications. Such comprehensive review unravels terrestrial host-living fungal systems as a treasure trove in drug discovery, in addition to future perspectives and trends for their exploitation in pharmaceutical industries. Key Scientific Concepts of Review Such comprehensive review unravels terrestrialhost-living fungal systems as a treasure trove in drug discovery, in addition to future perspectives and trends for their exploitation in pharmaceutical industries.

Natural products have remarkable structural diversity and biological characteristics, providing researchers with more possibilities to develop novel drugs for disease therapeutics. Andrographolide, an ent-labdane diterpenoid from traditional Chinese medicines, Andrographis paniculata, exhibits a broad range of biological activities, which has been a hot area of research for several years. Up to now, lots of its derivatives with multiple bioactivities have been prepared through chemical modification. This review summarizes andrographolide derivatives prepared in the last ten years (2006-present), classifies them by different biological activities, and provides some discussion about the design of novel and potent derivatives.

Abstract: 10,11-Dehydrocurvularin is a natural benzenediol lactone (BDL) with a 12-membered macrolide fused to a resorcinol ring produced as a secondary metabolite by many fungi. In this review, we summarized the pieces of literature regarding biosynthesis, chemical synthesis, biological activities, and assumed work mechanisms of 10,11-dehydrocurvularin, which presented a potential for agricultural and pharmaceutical uses.

The spread of antibiotic-resistant bacteria and exhausted drug leads render some infections untreatable now and in the future. To deal with these "new challenges", scientists tend to re-pick up "old antibiotics". Fusidane-type antibiotics have been known for nearly 80 years as potent antibacterial agents against gram-positive bacteria, especially Staphylococci, and represent the only triterpene-derived antibiotic class in clinical setting. These attractive characteristics have drawn renewed attention on fusidane-type antibiotics in recent decades. Isolation, characterization, biological evaluation, as well as chemical modifications of fusidane-type antibiotics are increasingly being reported. Combinatorial biosynthesis of this type of antibiotics has been successfully utilized not only for elucidating the biosynthetic pathways, but also for expanding their structural diversity. Some isolated and synthetic compounds exhibit comparable or even more potent biological activity than fusidic acid. This review provides an overview of progress on the studies of structure and biology of fusidane-type antibiotics from 1943 to April 2021. The informative structure-activity relationship is also highlighted.

The textile and dyeing industry have shown dramatic growth alongside synthetic chemistry in the last century. With operations and economic importance, challenges also increase, including environmental pollution, work safety, and consumer health. Change of perspectives in the industry is on the rise, so environmentally-friendly solutions for safer processes and more circularity are urgently sought-after. A possible solution for the pressing issue of textile dyeing is the use of natural colourants obtained in fermentation processes. In this contribution, a comparison between biologically-derived dyes and their synthetic counterparts is conducted on several levels. The structural diversity of biogenic dyes is potentially high enough to pose an alternative on a broad front. Matching fundamental properties concerning dyeing, (bio)synthesis and toxicity give an impression of the advantages of developing this natural alternative. The most important topics for the future are outlined. Major challenges and potential solutions that limit the implementation of biogenic dyes into the textile dyeing value chain are discussed. Biotechnology offers numerous methods to increase reliable production or engineer molecular properties elegantly. The biggest advantage from a Green Chemistry perspective is the possibility to switch to renewable starting materials and obtain more biodegradable dyes. A more sustainable alternative in textile dyeing is afoot. It needs to be embraced and developed to provide the world population with a sustainable way into the future.

Background Poly-γ-glutamic acid (γ-PGA) is a chiral biopolymer composed of either l -glutamic acid or d -glutamic acid or both monomers in different ratios and repeating frequency. It is biodegradable, water-soluble, environmentally friendly, and edible, and has versatile industrial applications. Depending on the microbial producers, the molecular weights and stereochemical compositions of γ-PGA differ substantially, and exhibit great application diversity. It is crucial to control the structural diversity to produce tailor-made γ-PGA. Scope and approach This review presents advances in γ-PGA synthesis in microorganisms and metabolic engineering strategies used to improve γ-PGA diversity. The fascinating roles of structural diversity in various applications and future research directions in γ-PGA bio-production are also discussed in this review. Key findings and conclusions Obtaining the γ-PGA with specific stereoisomer and molecular weight is an indispensable step in the expanded uses of γ-PGA. With the development of metabolic engineering and synthetic biology, the production of tailored γ-PGA in a single host is possible.

Background Grifola frondosa is a valuable fungus with high health and medicinal value, and it plays an important role in the treatment of diseases as traditional Chinese medicine. Among them, the active ingredient that plays the main function was polysaccharides. Although some work had summarized the structure, physicochemical properties and biological activities of G. frondosa polysaccharides (GFPs), it was not systematic and in-depth enough. Now, a detailed summary of GFPs with the new light is necessary to address their future aspects and application. Scope and approach This review provides new light and updated overview of GFPs and their derivatives on extraction methods, structural diversity and as being biological response modifiers. This work will further improve the understanding of the structural diversity, biological activities and structure-activity relationship of GFPs, and provide a reference for its further development and application. Key founds and conclusion Numerous studies had focused on the extraction, structural characterization and biological activities of GFPs. However, the active mechanism of GFPs is not very clear. The elucidation of the active mechanism of GFPs is of great significance for its application in the field of biomedicine. Besides, GFPs play an important role in the regulation of a variety of physiological processes as biological response modifiers, but other potential effects still need further to be developed.

Covalent organic frameworks (COFs) have emerged as highly crystalline porous organic materials and proved to be the potential candidates for various interesting applications, such as gas adsorption and separation, catalysis, energy storage, and sensing, etc. Fluorescence-based sensing has gained great attention due to its high selectivity, rapid response time, and real-time monitoring. Lately, luminescent COFs have come to the fore as sensing probes to detect the various target molecules. In this review, we have targeted a comprehensive account of the chronological development of the field of COFs starting from 2005 till date. We have described the design principle with a focus on various topologies reported, classification of their structural diversity on the basis of thirty-two linkages and dimensionality, methods of synthesis with examples, and the use of various characterization techniques. Interestingly, almost one-half of the COFs contains linkages that are nitrogen-rich. With a background in different processes involved for fluorescence sensing, we have illustrated the potential applicability of nitrogen-rich COFs as sensors for numerousanalytes, such as explosives, volatile organic molecules, pH, temperature, toxic anions, metal ions and biomolecules from different media utilizing the striking features of COFs with predesigned structures and diverse functionality.

This review surveys recent progress in the chemistry of polycyclic heteroaromatic molecules with a focus on structural diversity and synthetic methodology. The article covers literature published during the period of 2016–2020, providing an update to our first review of this topic (Chem. Rev.2017, 117 (4), 3479–3716).

15 p.-3 fig.-1 tab., Bacterial biopolymers such as bacterial cellulose (BC), alginate or polyhydroxyalkanotes (PHAs) have aroused the interest of researchers in many fields, for instance biomedicine and packaging, due to their being biodegradable, biocompatible and renewable. Their properties can easily be tuned by means of microbial biotechnology strategies combined with materials science. This provides them with highly diverse properties, conferring them non-native features. Herein we highlight the enormous structural diversity of these macromolecules, how are they produced, as well as their wide range of potential applications in our daily lives. The emergence of new technologies, such as synthetic biology, enables the creation of next-generation-advanced materials presenting smart functional properties, for example the ability to sense and respond to stimuli as well as the capacity for self-repair. All this has given rise to the recent emergence of biohybrid materials, in which a synthetic component is brought to life with living organisms. Two different subfields have recently garnered particular attention: hybrid living materials (HLMs), such as encapsulation or bioprinting, and engineered living materials (ELMs), in which the material is created bottom-up with the use of microbial biotechnology tools. Early studies showed the strong potential of alginate and PHAs as HLMs, whilst BC constituted the most currently promising material for the creation of ELMs., Research on polymer biotechnology at the lab of Auxi Prieto is supported by the European Union’s Horizon 2020 Research and Innovation Programme under grant agreements no. 745737 (Afterlife), no. 760994 (Engicoin),no. 870294 (Mix-Up), no. 814418 (SinFonia) and no. 101000733 (Promicon). At National level, the lab is supported by grants from the Community of Madrid (P2018/NMT4389), the Spanish Ministry of Science and Innovation under research grants BIOCIR (PID2020-112766RB-C21), REVOLUZION (PLEC2021-008188) and the Juan de la Cierva aid of Cristina Campano (FJC2019-040298-I).

Over the past years, Pd(II)-catalyzed oxidative couplings have enabled the construction of molecular scaffolds with high structural diversity via C–C, C–N and C–O bond-forming reactions. In contrast to the use of stoichiometric amounts of more common oxidants, such as metal salts (Cu and Ag) and benzoquinone derivatives, the use of molecular oxygen for the direct or indirect regeneration of Pd(II) species presents itself as a more viable alternative in terms of economy and sustainability. In this review, we describe recent advances on the development of Pd-catalyzed oxidative cyclizations/functionalizations, where molecular oxygen plays a pivotal role as the sole stoichiometric oxidant.1 Introduction2 Oxidative C–C and C–Nu Coupling2.1 Intramolecular Oxidative C–Nu Heterocyclization Reactions2.1.1 C–H Activation2.1.2 Wacker/Aza-Wacker-Type Cyclization2.1.3 Tandem Wacker/Aza-Wacker and Cyclization/Cross-Coupling Reactions2.2 Intermolecular Oxidative C–Nu Heterocoupling Reactions2.3 Intramolecular Oxidative (C–C) Carbocyclization Reactions2.4 Intermolecular Oxidative C–C Coupling Reactions2.4.1 Cyclization Reactions2.4.2 Cross-Coupling Reactions2.4.3 Homo-Coupling Reactions3 Aerobic Dehydrogenative Coupling/Functionalization4 Oxidative C–H Functionalization5 Summary

The structural diversity and designability of metal–organic frameworks (MOFs) make these porous materials a strong candidate for NH3 uptake. However, to achieve a high NH3 capture capacity and good...

Computational databases and tools in recent times have been proved to provide an essential aid for anticancer studies in the field of oncology. Molecular docking studies facilitate the structural diversity of plant-derived phytomolecules having anticancer properties against receptor proteins involved in cancer signaling pathways. The current study involves the investigation of phytocompounds-agasthisflavone, anacardic acid, zoapatanolide A, a purified product of the plant extract Amarogopinois546 were subjected to docking studies on p38-α MAPK and EGFR Kinase domain. The effectiveness of this study was evaluated by comparing the docking interactions of a standard drug, doxorubicin against the receptor molecules. The docking study is analyzed by compound estimated with lowest binding energy is considered to have the highest affinity towards the active site of the receptor proteins. The isolated plant compound Amarogopinois546 displayed the least binding score with a large number of hydrogen bonds and hydrophobic interactions towards the P38α MAP kinase receptor in comparison with the EGFR kinase domain. This preliminary result can strongly be supported for carrying out experimental evaluation in near future.

Many prominent social scientists have advocated for random-draw lotteries as a solution to the “problem” of elite college admissions. They argue that lotteries will be fair, equitable, eliminate corruption, reduce student anxiety, restore democratic ideals, and end debates over race-conscious admissions. In response, we simulate potential lottery effects on student enrollment by race, gender, and income, using robust simulation methods and multiple minimum thresholds for grades and standardized tests. In the overwhelming majority of lottery simulations, the proportions of low-income students and students of color drop precipitously. With a GPA minimum, we find the proportion of men could drop as low as one third. Admissions lotteries with minimum bars for GPA and/or standardized tests do not appear to produce more equitable outcomes.

Soil microbiome is a dynamic micro-ecosystem driving and fine-tuning several biological processes in the global macro-ecosystems. Its tremendous potential towards mediating sustainability in the ecosystem necessitates the urgent need to store it optimally and efficiently as "next-generation biologicals" for future applications via soil transplantation. The challenge, therefore, is to devise a strategy for the storage of soil microbiome such that its "functionality" is preserved for later application. This review discusses the current endeavours made towards storage of the soil microbiome. The methods for assessing the integrity of soil microbiome by targeting the structural diversity and functional potential of the preserved microbiomes have also been discussed. Further, the success stories related to the storage of fecal microbiome for application in transplants have also been highlighted. This is done primarily with the objective of learning lessons, and parallel application of the knowledge gained, in bringing about improvement in the research domain of soil microbiome storage. Subsequently, the limitations of current techniques of preservation have also been delineated. Further, the open questions in the area have been critically discussed. In conclusion, possible alternatives for storage, comprehensive analyses of the composition of the stored microbiome and their potential have been presented.

Nanotechnology is a top priority research area in a plethora of technological and scientific fields due to its economic impact and versatile capability. Among various applications, water treatment is considered among the most prospective utilization of nanotechnology, where a large number of nanostructured materials can remediate water using several different mechanistic ways. For achieving this, nanomaterials can be combined and modified with active moieties to develop different nanocomposites with structural diversity and unique physicochemical attributes. In addition, they have also been designed and integrated into membranes for improving water treatment performance. In this review, we provide an up-to-date overview of various nanostructured materials as nanoadsorbents, such as carbon-based nanomaterials, nanocomposites, and nanomembranes for remediating pesticide-based pollutants from aqueous systems using CNTs. Notably, nanomaterials are capable of efficiently removing environmental pollutants given their substantial surface area, high absorptive ability, and excellent environmental selectivity and compatibility.

Metal-organic frameworks (MOFs) with structural diversity and functionality have attracted incredible research interest, while their practical applications are hampered due to their intrinsic fragi...

Languages vary according to which morphosyntactic forms of embedding are present in the grammar as well as to which of these forms allow recursive embedding. The present study examines how German-s...

Multifunctional stimuli-responsive fluorophores showing bright environment-sensitive emissions have fueled intense research due to their innovative applications in the fields of biotechnologies, optoelectronics, and materials. A strong structural diversity is observed among molecular materials, which has been enriched over the years with a growing responsiveness to stimuli. Boron dipyrromethene (BODIPY) dyes have long been the flagship of emissive boron complexes due to their outstanding properties until a decade ago when analogues based on N^O, N^N, or N^C π-conjugated chelates emerged. The finality of developing borate dyes was to compensate for BODIPYs’ lack of solid-state fluorescence and small Stokes shifts while keeping their excellent optical properties in solution. Among them, the borate complexes based on a salicylaldimine ligand, called by the acronym boranils appear as the most promising, owing to their facile synthesis and dual-state emission properties. Boranil dyes have proven to be good alternatives to BODIPY dyes and have been applied in applications such as bioimaging, bioconjugation, and detection of biosubstrates. Meanwhile, ab initio calculations have rationalized experimental results and provided insightful feedback for future designs. This review article aims at providing a concise yet representative overview of the chemistry around the boranil core with the subsequent applications.

Through the European Lead Factory model, industry-standard high-throughput screening and hit validation are made available to academia, small and medium-sized enterprises, charity organizations, patient foundations, and participating pharmaceutical companies. The compound collection used for screening is built from a unique diversity of sources. It brings together compounds from companies with different therapeutic area heritages and completely new compounds from library synthesis. This generates structural diversity and combines molecules with complementary physicochemical properties. In 2019, the screening library was updated to enable another 5 years of running innovative drug discovery projects. Here, we investigate the physicochemical and diversity properties of the updated compound collection. We show that it is highly diverse, drug-like, and complementary to commercial screening libraries.

Single-atomic nanocatalysts/nanozymes (SACs/SAEs) have emerged as a research frontier on account of the maximum atom-utilization efficiency and well-defined localized structure. Metal-organic frameworks (MOFs) featuring the structural diversity and functional tunability are promising host materials in constructing SACs/SAEs. Further pyrolysis of MOF precursors under certain conditions can lead to the formations of MOF-derived SACs/SAEs. In this review, we first introduce the classification and enzymatic mechanisms of nanozymes, comprehensive characterization techniques for SACs/SAEs, and various synthetic methodologies of MOF-based SACs/SAEs. Next, we highlight the recent advances of MOF-based SACs/SAEs in the enzymatic healthcare area, i.e., cancer treatment, biosensing, anti-bacteria, reactive oxygen species scavenger, and environmental protection. Finally, we summarize the insights we gain from these studies, and discuss possible design principles and future challenges for a deeper understanding of this emerging field, thus offering great opportunities to leap over conventional nanozymes into a new era of next-generation biosafe SACs/SAEs. Agency for Science, Technology and Research (A*STAR) National Research Foundation (NRF) Submitted/Accepted version The work was supported by the Singapore Agency for Science, Technology and Research (A*STAR) AME IRG grant (A20E5c0081) and the Singapore National Research Foundation Investigatorship (NRF-NRFI2018-03).

Many insects depend on symbiont(s) for survival. This is particularly the case for sap-feeding hemipteran insects. In this study, we revealed that symbionts harboured in cicadas are diverse and complex, and the yeast-like fungal symbionts (YLS) are present in most cicada species, but Hodgkinia is absent. During vertical transmission, Sulcia became swollen with the outer membrane drastically changed, while Hodgkinia became shrunken and changed from irregular to roughly spherical. Sulcia and/or Hodgkinia were exocytosed from the bacteriocytes to the intercellular space of bacteriomes, where they gathered together and were extruded to haemolymph. YLS and associated facultative symbiont(s) in the fat bodies were released to the haemolymph based on bacteriocyte disintegration. The obligate symbiont(s) were endocytosed and exocytosed successively by the epithelial plug cells of the terminal oocyte, while associated facultative symbiont(s), and possibly also YLS, may take a 'free ride' on the transmission of obligate symbiont(s) to gain entry into the oocyte. Then, the intermixed symbionts formed a characteristic 'symbiont ball' in the oocyte. Our results suggest that YLS in cicadas represent a new example of a relatively early stage of symbiogenesis in insects and contribute to a better understanding of the diversity and transmission mechanisms of symbionts in insects.

Protein tyrosine phosphatase 1B (PTP1B) is an intractable target for drug discovery due to its conservative and cationic catalytic site. Targeting alternative allosteric sites of PTP1B is a promising strategy to achieve specificity and bioavailability. A hierarchical virtual screening based on a previously identified allosteric site was applied to search for potential PTP1B inhibitors with better pharmacological profiles. Four potent PTP1B inhibitors (H1, H3, H7, and H9) with structures distinct from known inhibitors were identified. Among them, H3 and H9 demonstrated evident selectivity to PTP1B over homologous T-cell protein tyrosine phosphatase (TCPTP) and SHP2. Molecular dynamics simulations and molecular mechanics-generalized Born surface area (MM-GBSA) calculations recognized Phe280, Phe196, Leu192, and Asn193 as key residues responsible for potent allosteric inhibition and excellent PTP selectivity. The results not only expand the structural diversity but also aid the future molecular design of PTP1B allosteric inhibitors.

Most Neotropical Malpighiaceae species are characterized by having zygomorphic flowers and oil glands in the sepals called elaiophores; these floral characteristics are associated with a particular pollination syndrome through oil-collecting bees. This work proposes a study about the structural characteristics of elaiophores in 18 species of Malpighiaceae present in Argentina. The main objectives are to describe the morphology and anatomy of the elaiophores, to detect variation in the number of glands, to compare similarities or differences in elaiophores of species belonging to different lineages, and to know about the potential pollinators and their association with the structural traits of the elaiophores. The morphology and the anatomy were studied using traditional methods of scanning electron and bright-field microscopes. Field trips were carried out to capture oil-collecting bee species on flowers, in different natural populations. Different measurements were taken in the flowers, elaiophores, and oil-collecting bees and were statistically analyzed. Although elaiophores showed a common pattern, some particularities in number, morphology, and anatomy were detected; few of these seem to be restricted to some groups of species phylogenetically related. As regards pollinators, a positive tendency was observed between the size of the flowers, elaiophores, and oil-collecting bees. However, the thickness of the cuticle presented a negative association with the size of the elaiophore and consequently with the floral diameter, which could be presumably related to the foraging behavior and/or the structure of oil-collecting apparatus of the bee species.

College graduation rates for racially minoritized students are adversely affected by structural barriers and hostile campus racial climates, which lead to notable equity gaps within and across inst...

Lipids, serving as the structural components of cellular membranes, energy storage, and signaling molecules, play the essential and multiple roles in biological functions of mammals. Mass spectrometry (MS) is widely accepted as the first choice for lipid analysis, offering good performance in sensitivity, accuracy, and structural characterization. However, the untargeted qualitative profiling and absolute quantitation of lipids are still challenged by great structural diversity and high structural similarity. In recent decade, chemical derivatization mainly targeting carboxyl group and carbon-carbon double bond of lipids have been developed for lipidomic analysis with diverse advantages: (i) offering more characteristic structural information; (ii) improving the analytical performance, including chromatographic separation and MS sensitivity; (iii) providing one-to-one chemical isotope labeling internal standards based on the isotope derivatization regent in quantitative analysis. Moreover, the chemical derivatization strategy has shown great potential in combination with ion mobility mass spectrometry and ambient mass spectrometry. Herein, we summarized the current states and advances in chemical derivatization-assisted MS techniques for lipidomic analysis, and their strengths and challenges are also given. In summary, the chemical derivatization-based lipidomic approach has become a promising and reliable technique for the analysis of lipidome in complex biological samples.

Forested wetlands are an integral but understudied part of heterogeneous landscapes in Atlantic Canada, although they are known to provide habitat for species at risk. Our objectives were to explore patterns of forest structure across edges between forested wetland and upland forest, to locate changes in vegetation structure and to assess multivariate relationships in vegetation structure. Our study sites were in temperate (Acadian) forested wetland landscapes. We sampled trees and recorded canopy cover every 20 m along 120-m-long transects. We estimated the cover of trees, saplings, shrubs in three height classes, Sphagnum, other bryophytes, lichens, graminoids, ferns, and forbs in contiguous 1 m × 1 m quadrats. We calculated structural diversity using the Shannon index and used wavelet analysis to assess spatial patterns. We found few clear patterns except for lower tree structural diversity at the edge of forested wetlands. Structural diversity was not a reliable measure for distinguishing forested wetland from upland forest. Forested wetlands are an integral part of many forested landscapes in Atlantic Canada, but their detection and differentiation from surrounding ecosystems can be difficult. Policy should err on the side of caution when mapping forested wetlands and include them in wetland protection.

Over 3 billion years, photosynthetic algae have evolved complex uses for cellulose, the most abundant polymer worldwide. A major cell-wall component of lignocellulosic plants, seaweeds, microalgae, and bacteria, cellulose can be processed to nanocellulose, a promising nanomaterial with novel properties. The structural diversity of macro- and microalgal nanocelluloses opens opportunities to couple low-impact biomass production with novel, green-chemistry processing to yield valuable, sustainable nanomaterials for a multitude of applications ranging from novel wound dressings to organic solar cells. We review the origins of algal cellulose and the applications and uses of nanocellulose, and highlight the potential for microalgae as a nanocellulose source. Given the limited state of current knowledge, we identify research challenges and strategies to help to realise this potential.

Fluostatins belong to the atypical angucyclinone aromatic polyketides featuring a distinctive tetracyclic benzo[a]fluorene skeleton. To understand the formation of the heavily oxidized A-ring in fluostatins, a flavin adenine dinucleotide-binding oxidoreductase-encoding gene flsP was inactivated, leading to the production of an unprecedented 1,4-oxazepine-linked seco-fluostatin heterodimer difluostatin I (7) and five new fluostatin-related derivatives, fluostatins T-X (8-12). Their structures were elucidated by mass spectrometry, nuclear magnetic resonance, X-ray diffraction analysis, and biosynthetic considerations. Difluostatin I (7) represents the first example with an A-ring-cleaved 3',4'-seco-fluostatin skeleton. The absolute configuration of fluostatin T (8) was determined by X-ray diffraction analysis. Fluostatin W (11) contains an uncommon isoxazolinone ring. These findings highlight the structural diversity of fluostatins.

Molecular activatable probes with near-infrared (NIR) fluorescence play a critical role in in vivo imaging of biomarkers for drug screening and disease diagnosis. With structural diversity and high fluorescence quantum yields, hemicyanine dyes have emerged as a versatile scaffold for the construction of activatable optical probes. This Review presents a survey of hemicyanine-based NIR activatable probes (HNAPs) for in vivo imaging and early diagnosis of diseases. The molecular design principles of HNAPs towards activatable optical signaling against various biomarkers are discussed with a focus on their broad applications in the detection of diseases including inflammation, acute organ failure, skin diseases, intestinal diseases, and cancer. This progress not only proves the unique value of HNAPs in preclinical research but also highlights their high translational potential in clinical diagnosis. Ministry of Education (MOE) K.P. thanks Singapore Ministry of Education, Academic Research Fund Tier 1 (2019-T1-002-045, RG125/19, RT05/20), Academic Research Fund Tier 2 (MOE2018-T2-2-042), and A*STAR SERC AME Programmatic Fund (SERCA18A8b0059) for the financial support.

Current studies in the Li-battery field are focusing on building systems with higher energy density than ever before. The path toward this goal, however, should not ignore aspects such as safety, stability, and cycling life. These issues frequently originate from interfacial instability, and therefore, precise surface chemistry that allows for accurate control of material surface and interfaces is much in demand for advanced battery research. Molecular self-assembly as a surface chemistry tool is considered to surpass many conventional coating techniques due to its intrinsic merits such as spontaneous organization, molecular-scale uniformity, and structural diversity. Recent publications have demonstrated the power of self-assembled monolayers (SAMs) in addressing pressing issues in the battery field such as the chemical stability of Li, but many more investigations are needed to fully explore the potential and impact of this technique on energy storage. This perspective is the first of its kind devoted to SAMs in batteries and related materials. Recent research progress on SAMs in batteries is reviewed and mainly falls in two categories, including the improvement of chemical stability and the regulation of nucleation in conversion electrode reactions. Future applications and consideration of SAMs in energy storage are discussed. We believe these summaries and outlooks are highly stimulative and may benefit future advancements in battery chemistry.

Stuffed tridymites AM2O4 composed of a condensed MO4-tetrahedra-based framework have been widely investigated due to their structural diversity and rich physical properties. Herein, the strategy of stuffing mixed Ca2+ and Sr2+ cations into the [Ga2O4]2- framework in (Ca1-xSrx)Ga2O4 (CSGO, 0 ≤ x ≤ 1) is utilized to manipulate the phase formation behavior with different structure types at particular annealing temperatures. Five derivatives, including α- and β-CaGa2O4, β- and γ-SrGa2O4, and new CSGO-type structures, were observed. The distinctive feature of the CSGO-structure is the coexistence of UUDDUD- and UDUDUD-type six-membered rings, where U (up) and D (down) denote the orientations of GaO4-tetrahedra with respect to the plane grids, in a ratio of 2:1. Single-phase α-Ca1-xSrxGa2O4 (x 0.67) could be obtained at low temperatures. Biphasic regions, including α-Ca1-xSrxGa2O4/CSGO (0.2 ≤ x ≤ 0.67), γ-Ca1-xSrxGa2O4/CSGO (0.67 < x ≤ 0.8), and β-Ca1-xSrxGa2O4/CSGO (0.8 < x < 1), were observed at the intermediate temperature region and evolve irreversibly into the CSGO single-phase region upon elevating the temperature. Moreover, the structure-property relationship of the new CSGO-phase was further studied by doping coordination-sensitive Bi3+ activators to advance the development and applications of stuffed tridymites.

Two undescribed shikimic acid derivatives named shikimerans B and C (1 and 2), one new natural compound shikimeran D (3), as well as five known compounds 4−8 were obtained from the EtOAc extract of the endophytic fungus Chaetomium sp. FZ-4. Their structures were determined by the NMR spectroscopy and HRESIMS examination, while the absolute configurations of compounds 1−3 were clarified based on the electronic circular dichroism (ECD) experiment. These new compounds enriched the structural diversity of shikimic acid analogues and also expanded the chemical diversity of the metabolites of Chaetomium sp..

Biomolecular condensates comprised of specific proteins and nucleic acids are now recognized as one of the key organizing mechanisms in eukaryotic cells. However, the specific roles played by the nucleic acid secondary structure and sequence in biomolecular phase separation are still not clear. Here, utilizing giant membrane vesicles (GMVs) as a protocell model, we found that single-stranded DNA (ssDNA) with a parallel G-quadruplex structure could functionally cooperate with a G-quadruplex-binding protein to form speckle-like puncta inside the GMVs. The clustering behavior is dependent on the structural diversity of G-quadruplexes, and the reversible clustering behavior implicated a new pathway in dynamically regulating the formation of biomolecular condensates. This finding represents a potential link between G-quadruplex-binding proteins and the resulting G-quadruplex-mediated biomolecular phase separation, which would gain insight into a wide range of biological processes associated with nucleic acid-modulated phase separation inside living cells.

An efficient nickel(0)-catalyzed addition of benzyl nitriles to terminal vinyl ketones via C(sp3)-H functionalization has been developed. The reaction provides a novel and efficient protocol for the synthesis of α-functionalized benzyl nitriles with a wide range of structural diversity under mild reaction conditions while obviating the use of a strong base. The work might be potentially useful toward the development of an enantioselective variant using chiral nitrogen ligands.

The paper analyzes the siderophore biosynthesis genes that are located in the ysu and ynp loci of only Y. pestis and Y. pseudotuberculosis, have variable structure between different strains of both species and contain previously unknown variable number tandem repeats (VNTR). The purpose of the study was to assess the possibility of using these VNTR as genetic markers for intra-and interspecific differentiation of pathogenic Yersinia. Based on the novel VNTR-markers, three pairs of primers (ysu-interF/R, ilp1F/R и ilp2F/R) were designed and used for the in silico and in vitro PCR analysis of various Y.pestis and Y. pseudotuberculosis strains. All studied Y. pestis strains of the main subspecies (ssp pestis), unlike the strains of non-main subspecies and Y. pseudotuberculosis, did not give amplicon with ilp1F/R primers, since the area between them contains an IS100 element. To identify the strains of the main subspecies, the fourth pair of primers ilp1F-is100R was designed, allowing the most dangerous ssp pestis strains to be distinguished from the not dangerous non-main ssp strains. Y. pseudotuberculosis strains were characterized by a significant variety of amplicons with three pairs of primers, and which made it possible to carry out intraspecies strain genotyping. At the same time, for those strains whose serotype is known, the correlation between the serogroup and the genotype of the strains was observed. Analysis of the 1 serotype strains representing most sequenced Y. pseudotuberculosis strains allowed us to separate two gene groups differing from the rest of 1 serotype gene groups. The first one included the serotype 1a strains isolated from people in Europe, which are known to have the greatest pathogenetic potential. The other one was formed by serotype 1b strains isolated from people in Siberia and Primorye, which are characterized by the high epidemic potential. Thus, four pairs of primers designed in this study can be used to develop additional tests for the identification and differential diagnostics of the most dangerous Y. pestis ssp pestis and Y. pseudotuberculosis serotype 1a and 1b strains.

Secondary metabolites have been recognized for centuries as medicinal agents, in particular monoterpenes which have been the target of research in the discovery of antineoplastic drugs, as they have potential antitumor effect and low toxicity and are used as additives in foods and cosmetics. Another advantage of monoterpenes is structural diversity, which gives greater plasticity when interacting with cells. The purpose of this review was to summarize and critically discuss the anticancer potential of monoterpenes and their respective mechanisms of action. A systematic review of articles in the MEDLINE/PubMed, Web of Science, Scopus and Science Direct electronic databases was independently conducted by three reviewers using the combination of the following keywords: monoterpenes AND anticancer AND in vitro. Restriction in selecting articles followed pre-established inclusion and exclusion criteria by the reviewers, and also a time limitation with works published between 2015 and 2019 being selected. In total, 39 works were deemed eligible for inclusion in the final review. Monoterpenes have cytotoxic activity in a wide variety of tumor cell lines, and mainly appear to exert this effect by inducing apoptosis caused by oxidative stress. In addition, improved use of monoterpenes when used in drug delivery systems and the synergistic effect with conventional chemotherapeutic drugs are reported. These findings validate this class of compounds as a promising source of chemotherapeutic drugs yet to be explored.

The natural polysaccharides, due to their structural diversity, commonly present very distinct solubility and physical chemical properties and additionally have intrinsic biological activities that, gene-rally, reveal themselves in a light way. The chemical modification of the molecular structure can improve these parameters. In this review, original articles that approached the quaternization of polysaccharides for purposes of biological application were selected, without limitation of year of publication, in the databases Scopus, Web of Science and PubMed. The results obtained from the bibliographic survey indicate that the increase in positive charges caused by quaternization improves the interaction between modified polysaccharides and structures that have negative charges on their surface, such as the cell wall of microorganisms and some cells in the human body, such as the DNA. This greater interaction is reflected as an increase in the biological activity of all polysaccharides broached in this study. Another important data obtained was the fact that the chemical changes did not affect or irrelevantly affect the toxicity of almost all of the polysaccharides that were quaternized. Therefore, polysaccharide quaternization is a safe and effective way to obtain improvements in the biological behavior of these macromolecules.

Photosynthetic reaction centers (RC) catalyze the conversion of light to chemical energy that supports life on Earth, but they exhibit substantial diversity among different phyla. This is exemplified in a recent structure of the RC from an anoxygenic green sulfur bacterium (GsbRC) which has characteristics that may challenge the canonical view of RC classification. The GsbRC structure is analyzed and compared with other RCs, and the observations reveal important but unstudied research directions that are vital for disentangling RC evolution and diversity. Namely, (1) common themes of electron donation implicate a Ca2+ site whose role is unknown; (2) a previously unidentified lipid molecule with unclear functional significance is involved in the axial ligation of a cofactor in the electron transfer chain; (3) the GsbRC features surprising structural similarities with the distantly-related photosystem II; and (4) a structural basis for energy quenching in the GsbRC can be gleaned that exemplifies the importance of how exposure to oxygen has shaped the evolution of RCs. The analysis highlights these novel avenues of research that are critical for revealing evolutionary relationships that underpin the great diversity observed in extant RCs. Supplementary Information The online version contains supplementary material available at 10.1007/s11120-021-00857-9.

10 pags., 5 figs., 4 tabs., Silver(I) coordination compounds display an interesting geometrical diversity, the possibility of having distinct coordination numbers (typically from 2 to 4) and the capability of forming argentophilic (Ag⋅⋅⋅Ag) interactions. These properties complicate the accurate prediction of structures of silver complexes under certain experimental conditions. In this work, we show how subtle modifications in thiolate and phosphine ligands exert important effects on the nuclearity and geometry of phosphine caped clusters [Ag(SR)] (n=4, 6 and 8). We rationalize these effects in terms of the electronic environment of silver centers by analyzing the electronic density of the single-crystal X-ray structures via the Quantum Theory of Atoms in Molecules (QTAIM) and the Non-Covalent Interaction (NCI)-Index. Furthermore, we characterized attractive and repulsive argentophilic contacts by means of the Interacting Quantum Atoms (IQA) energy partition. Our results provide insights on the effects of ancillary ligands in controlling the structure of silver-thiolate clusters. Such control is relevant towards a bottom-up approach to the atomic precise construction of higher nuclearity clusters., We acknowledge fundingby DGAPA-UNAM project IN210818,andby CONACYT-Mexico through the postdoctoral grant 740732. We are also thankful for the instrumental support of the Unit for Industryand Research Support (USAII)at the School of Chemistry at UNAM, Mexico and for the computer time provided by DGTIC/UNAMproject LANCAD-DGTIC-UNAM-250.G.M.-A acknowledges the RSC-Chemists’CommunityFund support

Fusidane-type antibiotics, represented by helvolic acid, fusidic acid and cephalosporin P1, are fungi-derived antimicrobials with little cross-resistance to commonly used antibiotics. Generation of new fusidane-type derivatives is therefore of great value, but this is hindered by available approaches. Here, we developed a stochastic combinational strategy by random assembly of all the post-tailoring genes derived from helvolic acid, fusidic acid, and cephalosporin P1 biosynthetic pathways in a strain that produces their common intermediate. Among a total of 27 gene combinations, 24 combinations produce expected products and afford 58 fusidane-type analogues, of which 54 are new compounds. Moreover, random gene combination can induce unexpected activity of some post-tailoring enzymes, leading to a further increase in chemical diversity. These newly generated derivatives provide new insights into the structure‒activity relationship of fusidane-type antibiotics. The stochastic combinational strategy established in this study proves to be a powerful approach for expanding structural diversity of natural products., Graphical abstract Chemical diversification of fusidane-type antibiotics was accomplished using a stochastic combinational strategy through random assembly of all the post-tailoring genes derived from helvolic acid, fusidic acid and cephalosporin P1 pathways.Image 1

Protein misfolding and aggregation are associated with human diseases and aging. However, microorganisms widely exploit the self-propagating properties of misfolded infectious protein particles, prions, as epigenetic information carriers that drive various phenotypic adaptations and encode molecular information. Microbial prion research has faced a paradigm shift in recent years, with breakthroughs that demonstrate the great functional and structural diversity of these agents. Here, we outline unorthodox examples of microbial prions in yeast and other microorganisms, focusing on their noncanonical functions. We discuss novel molecular mechanisms for the inheritance of conformationally-encoded epigenetic information and the evolutionary advantages they confer. Lastly, in light of recent advancements in the field of molecular self-assembly, we present a hypothesis regarding the existence of non-proteinaceous prion-like entities.