Introduction to RSC Advances themed collection on Nanoarchitectonics Advances: Bridge over Nanotechnology and Materials Science.

A passport to a method for everything in materials science.

Bioactive alkaloids from Nepalese Corydalis chaerophylla D.C. acting on the regulation of PCSK9 and LDL-R in vitro.

Four new alkaloids Chaeronepaline-A (1), Chaeronepaline-B (2), Chaeronepaline-C (3), and Chaeronepaline-D (4) were isolated from Corydalis chaerophylla D.C. collected from Nepal and their structures were elucidated by spectroscopic data, 1D, 2D NMR and mass spectrometry. The structures were established as 3,12- Dimethoxy-5,6-dihydroisoquinolino [2,1-b] isoquinolin- 7- ium- 2, 9- diol (1), 7-methyl-5, 6, 7, 8-tetrahydroisoquinoline- 2, 3- methylenedioxy- (8-> 9)- 10, 12- methylenedioxy- benzoic-16-acid (2), 7- methyl-5, 6, 7, 8- tetrahydro- 8H-spiro-9,14-dihydroxy-11,12-methylenedioxy-indane-isoquinoline (3) and 7- methyl-5, 6, 7, 8- tetrahydro- 8H-spiro-9,14-dihydroxy-11,12-methylenedioxy-indane-isoquinoline-N-oxide (4). The new alkaloids were tested in human hepatoma cell line to assess their ability to modulate the expression of low-density lipoprotein receptor (LDL-R), of proprotein convertase subtilisin/kexin 9 (PCSK9) and to affect cellular cholesterol biosynthesis with the aim to evaluate their potential hypocholesterolemic effect. Results indicated that compounds 2 and 3 upregulate the LDLR, and inhibited the cholesterol biosynthesis with compound 2, which also reduced the secretion of PCSK9 by Huh7 cells. These in vitro data indicated a potential hypocholesterolemic effect of compound 2 that requires further in vivo validation.

Liquid-Liquid and Liquid-Solid Interfacial Nanoarchitectonics.

Nanoscale science is becoming increasingly important and prominent, and further development will necessitate integration with other material chemistries. In other words, it involves the construction of a methodology to build up materials based on nanoscale knowledge. This is also the beginning of the concept of post-nanotechnology. This role belongs to nanoarchitectonics, which has been rapidly developing in recent years. However, the scope of application of nanoarchitectonics is wide, and it is somewhat difficult to compile everything. Therefore, this review article will introduce the concepts of liquid and interface, which are the keywords for the organization of functional material systems in biological systems. The target interfaces are liquid-liquid interface, liquid-solid interface, and so on. Recent examples are summarized under the categories of molecular assembly, metal-organic framework and covalent organic framework, and living cell. In addition, the latest research on the liquid interfacial nanoarchitectonics of organic semiconductor film is also discussed. The final conclusive section summarizes these features and discusses the necessary components for the development of liquid interfacial nanoarchitectonics.

Metal-Organic Framework on Fullerene (MOFOF) as a Hierarchical Composite by the Integration of Coordination Chemistry and Supramolecular Chemistry.

There is a synergy between coordination chemistry and supramolecular chemistry that has led to the development of innovative hierarchical composites with diverse functionalities. Here, we present a novel approach for the synthesis and characterization of a metal-organic framework on fullerene (MOFOF) composites, achieved through the integration of coordination chemistry and supramolecular chemistry principles. The hierarchical nature of the MOFOF harnesses the inherent properties of metal-organic frameworks and fullerenes. The two-step synthesis procedure involves controlled assembly of fullerenes as tube-like nanostructures (fullerene nanotube: FNT), their surface functionalization, and the on-surface growth of the MOF (in this case, ZIF-67). The method permits the precise tuning of morphology, effective distribution of MOF-on-FNT, and tight compositional control. The materials were comprehensively structurally characterized using electron microscopy, spectroscopic techniques, and other methods to elucidate the unique features and interactions within the MOFOF composites. The main findings reveal that the novel synthesis and characterization of MOFOF composites demonstrate the successful integration of coordination chemistry and supramolecular chemistry for the designing and fabricating of advanced hierarchical composites with tailored properties, including micro- and mesopore channels, interfacial facets, and defect sites. These properties are expected to lead to numerous potential applications such as gas storage and separation, catalysis, sensing, energy storage, and environmental remediation. However, only the capability of acid vapor sensing was tested and is described here.

Bio-gel nanoarchitectonics in tissue engineering.

Given the creation of materials based on nanoscale science, nanotechnology must be combined with other disciplines. This role is played by the new concept of nanoarchitectonics, the process of constructing functional materials from nanocomponents. Nanoarchitectonics may be highly compatible with applications in biological systems. Conversely, it would be meaningful to consider nanoarchitectonics research oriented toward biological applications with a focus on materials systems. Perhaps, hydrogels are promising as a model medium to realize nanoarchitectonics in biofunctional materials science. In this review, we will provide an overview of some of the defined targets, especially for tissue engineering. Specifically, we will discuss (i) hydrogel bio-inks for 3D bioprinting, (ii) dynamic hydrogels as an artificial extracellular matrix (ECM), and (iii) topographical hydrogels for tissue organization. Based on these backgrounds and conceptual evolution, the construction strategies and functions of bio-gel nanoarchitectonics in medical applications and tissue engineering will be discussed.

Interface-Interactive Nanoarchitectonics: Solid and/or Liquid.

The methodology of nanoarchitectonics is to construct functional materials using nanounits such as atoms, molecules, and nanoobjects, just like architecting buildings. Nanoarchitectonics pursues the ultimate concept of materials science through the integration of related fields. In this review paper, under the title of interface-interactive nanoarchitectonics, several examples of structure fabrication and function development at interfaces will be discussed, highlighting the importance of architecting materials with nanoscale considerations. Two sections provide some examples at the solid and liquid surfaces. In solid interfacial environments, molecular structures can be precisely observed and analyzed with theoretical calculations. Solid surfaces are a prime site for nanoarchitectonics at the molecular level. Nanoarchitectonics of solid surfaces has the potential to pave the way for cutting-edge functionality and science based on advanced observation and analysis. Liquid surfaces are more kinetic and dynamic than solid interfaces, and their high fluidity offers many possibilities for structure fabrications by nanoarchitectonics. The latter feature has advantages in terms of freedom of interaction and diversity of components, therefore, liquid surfaces may be more suitable environments for the development of functionalities. The final section then discusses what is needed for the future of material creation in nanoarchitectonics.

Phosphorous - Containing Activated Carbon Derived From Natural Honeydew Peel Powers Aqueous Supercapacitors.

The introduction of phosphorous (P), and oxygen (O) heteroatoms in the natural honeydew chemical structure is one of the most effective, and practical approaches to synthesizing activated carbon for possible high-performance energy storage applications. The performance metrics of supercapacitors depend on surface functional groups and high-surface-area electrodes that can play a dominant role in areas that require high-power applications. Here, we report a phosphorous and oxygen co-doped honeydew peel-derived activated carbon (HDP-AC) electrode with low surface area for supercapacitor via H3PO4 activation. This activator form phosphorylation with cellulose fibers in the HDP. The formation of heteroatoms stabilizes the cellulose structure by preventing the formation of levoglucosan (C6H10O5), a cellulose combustion product, which would otherwise offer a pathway for a substantial degradation of cellulose into volatile products. Therefore, heteroatom doping has proved effective, in improving the electrochemical properties.  The improved performance is attributed to the high phosphorous doping with a hierarchical porous structure, which enables the transportation of ions at higher current rates. The high specific capacitance of 486, and 478 F/g at 0.6, and 1.3 A/g in 1M H2SO4 electrolyte with a prominent retention of 98% is observed for 2M H3PO4 having an impregnation ratio of 1:4.

Adsorptive avidity of Prussian blue polypyrrole nanocomposite for elimination of water contaminants: a case study of malachite green and isoniazid.

Persistent water contaminants include a variety of substances that evade natural cleaning processes posing severe risks to ecosystems. Their adsorptive elimination is a key approach to safer attenuation. Herein we present the design and development of Prussian blue incorporated polypyrrole (PPY/PB) hybrid nanocomposite as a high-performance adsorbent for the elimination of malachite green (M.G.), isoniazid (INH) and 4-nitrophenol (4-NP) water contaminants. The nanocomposite synthesis was favored by strong dopant-polymer interactions, leading to a PPY/PB material with enhanced electro-active surface area compared to pristine PPY. The structure-activity response of the nanocomposite for the adsorption of target contaminants was unveiled by evaluating its maximum adsorption capacities under environmentally viable conditions. In-depth analysis and optimization of adsorption influencing factors (pH, temperature, and adsorbent dose) were performed. Using equilibrium studies, kinetic model fitting, aided with FTIR analysis, a multi-step mechanism for the adsorption of target contaminants on the nanocomposite was proposed. Furthermore, the PPY/PB nanocomposite also acts as a catalyst, enabling contaminant elimination following a synergistic scheme that was demonstrated using 4-NP contaminant. The synergetic adsorption and catalytic degradation of 4-NP using PPY/PB as adsorbent and catalyst was demonstrated in the presence of NaBH4 as a reducing agent in absence of light. In summary, this work highlights the targeted design of adsorbent, its optimization for adsorptive avidity, and the synergistic role of adsorption trapping in the catalytic degradation of persistent contaminants.

Molecular machines working at interfaces: physics, chemistry, evolution and nanoarchitectonics.

As a post-nanotechnology concept, nanoarchitectonics combines nanotechnology with advanced materials science. Molecular machines made by assembling molecular units and their organizational bodies are also products of nanoarchitectonics. They can be regarded as the smallest functional materials. Originally, studies on molecular machines analyzed the average properties of objects dispersed in solution by spectroscopic methods. Researchers' playgrounds partially shifted to solid interfaces, because high-resolution observation of molecular machines is usually done on solid interfaces under high vacuum and cryogenic conditions. Additionally, to ensure the practical applicability of molecular machines, operation under ambient conditions is necessary. The latter conditions are met in dynamic interfacial environments such as the surface of water at room temperature. According to these backgrounds, this review summarizes the trends of molecular machines that continue to evolve under the concept of nanoarchitectonics in interfacial environments. Some recent examples of molecular machines in solution are briefly introduced first, which is followed by an overview of studies of molecular machines and similar supramolecular structures in various interfacial environments. The interfacial environments are classified into (i) solid interfaces, (ii) liquid interfaces, and (iii) various material and biological interfaces. Molecular machines are expanding their activities from the static environment of a solid interface to the more dynamic environment of a liquid interface. Molecular machines change their field of activity while maintaining their basic functions and induce the accumulation of individual molecular machines into macroscopic physical properties molecular machines through macroscopic mechanical motions can be employed to control molecular machines. Moreover, research on molecular machines is not limited to solid and liquid interfaces; interfaces with living organisms are also crucial.

Mild selective photochemical oxidation of an organic sulfide using OxP-polyimide porous polymers as singlet oxygen generators.

A series of porous organic polymers based on a singlet oxygen generating oxoporphyinogen ('OxP') has been successfully prepared from a pseudotetrahedral OxP-tetraamine precursor (OxP(4-NH2Bn)4) by its reaction with tetracarboxylic acid dianhydrides under suitable conditions. Of the compounds studied, those containing naphthalene (OxP-N) and perylene (OxP-P) spacers, respectively, have large surface areas (~530 m2 g-1). On the other hand, the derivative with a simple benzene spacer (OxP-B) exhibits the best 1O2 generating capability. Although the starting OxP-tetraamine precursor is a poor 1O2 generator, its incorporation into OxP POPs leads to a significant enhancement of 1O2 productivity, which is largely due to the transformation of NH2 groups to electron-withdrawing diimides. Overall 1O2 production efficacy of OxP-POPs under irradiation by visible light is significantly improved over the common reference material PCN-222. All the materials OxP-B, OxP-N and OxP-P promote oxidation of thioanisole involving conversion of ambient triplet state oxygen to singlet oxygen under visible light irradiation and its reaction with the sulfide. Although the reaction rate of the oxidation promoted by OxP POPs is generally lower than for conventional materials (such as PCN-222) or previously studied OxP derivatives, undesired overoxidation of the substrate to methyl phenyl sulfone is suppressed. For organic sulfides, selectivity of oxidation is especially important for detoxification of mustard gas (bis(2-chloroethyl)sulfide) or similarly toxic compounds since controlled oxidation leads to the low toxicity bis(2-chloroethyl)sulfoxide while overoxidation leads to intoxification (since bis(2-chloroethyl)sulfone presents greater toxicity to humans than the sulfide substrate). Therefore, OxP POPs capable of promoting selective oxidation of sulfides to sulfoxides have excellent potential to be used as mild and selective detoxification agents.

Oxoporphyrinogen (OxP) is a unique chromophore compound in that it is intrinsically de-aggregated allowing large quantum yields of singlet oxygen generation. Due to its structure, OxP is also an ideal building block for porous systems. In this work, we describe the first incorporation of OxP in highly stable microporous polymers strongly enhanced singlet oxygen generation for selective oxidation of organic sulfides to sulfoxides (as a model reaction) under heterogeneous conditions. The novelty of this work lies in the high stability and easy recovery of the materials, the synergetic enhancement of singlet oxygen generation in the polymers over the starting OxP, and the excellent selectivity for the oxidation reaction.

Cell-derived nanomaterials for biomedical applications.

The ever-growing use of nature-derived materials creates exciting opportunities for novel development in various therapeutic biomedical applications. Living cells, serving as the foundation of nanoarchitectonics, exhibit remarkable capabilities that enable the development of bioinspired and biomimetic systems, which will be explored in this review. To understand the foundation of this development, we first revisited the anatomy of cells to explore the characteristics of the building blocks of life that is relevant. Interestingly, animal cells have amazing capabilities due to the inherent functionalities in each specialized cell type. Notably, the versatility of cell membranes allows red blood cells and neutrophils' membranes to cloak inorganic nanoparticles that would naturally be eliminated by the immune system. This underscores how cell membranes facilitate interactions with the surroundings through recognition, targeting, signalling, exchange, and cargo attachment. The functionality of cell membrane-coated nanoparticles can be tailored and improved by strategically engineering the membrane, selecting from a variety of cell membranes with known distinct inherent properties. On the other hand, plant cells exhibit remarkable capabilities for synthesizing various nanoparticles. They play a role in the synthesis of metal, carbon-based, and polymer nanoparticles, used for applications such as antimicrobials or antioxidants. One of the versatile components in plant cells is found in the photosynthetic system, particularly the thylakoid, and the pigment chlorophyll. While there are challenges in consistently synthesizing these remarkable nanoparticles derived from nature, this exploration begins to unveil the endless possibilities in nanoarchitectonics research.

We have highlighted the Cell-derived Nanomaterials for Biomedical Applications through the lenses of our team who have experiences with working on cell membrane, thylakoids, and studying the impact of nanoparticles on biological phenomenon such as nanomaterialsinduced endothelial leakiness (NanoEL). In this review, we have discussed the progress and the wide potential of nanoarchitectonics in plant systems, animal cells and microorganisms. Due to our unique backgrounds, our take on this topic may be the novelty of the review.

Confined Space Nanoarchitectonics for Dynamic Functions and Molecular Machines.

Nanotechnology has advanced the techniques for elucidating phenomena at the atomic, molecular, and nano-level. As a post nanotechnology concept, nanoarchitectonics has emerged to create functional materials from unit structures. Consider the material function when nanoarchitectonics enables the design of materials whose internal structure is controlled at the nanometer level. Material function is determined by two elements. These are the functional unit that forms the core of the function and the environment (matrix) that surrounds it. This review paper discusses the nanoarchitectonics of confined space, which is a field for controlling functional materials and molecular machines. The first few sections introduce some of the various dynamic functions in confined spaces, considering molecular space, materials space, and biospace. In the latter two sections, examples of research on the behavior of molecular machines, such as molecular motors, in confined spaces are discussed. In particular, surface space and internal nanospace are taken up as typical examples of confined space. What these examples show is that not only the central functional unit, but also the surrounding spatial configuration is necessary for higher functional expression. Nanoarchitectonics will play important roles in the architecture of such a total system.

2D Materials Nanoarchitectonics for 3D Structures/Functions.

It has become clear that superior material functions are derived from precisely controlled nanostructures. This has been greatly accelerated by the development of nanotechnology. The next step is to assemble materials with knowledge of their nano-level structures. This task is assigned to the post-nanotechnology concept of nanoarchitectonics. However, nanoarchitectonics, which creates intricate three-dimensional functional structures, is not always easy. Two-dimensional nanoarchitectonics based on reactions and arrangements at the surface may be an easier target to tackle. A better methodology would be to define a two-dimensional structure and then develop it into a three-dimensional structure and function. According to these backgrounds, this review paper is organized as follows. The introduction is followed by a summary of the three issues; (i) 2D to 3D dynamic structure control: liquid crystal commanded by the surface, (ii) 2D to 3D rational construction: a metal-organic framework (MOF) and a covalent organic framework (COF); (iii) 2D to 3D functional amplification: cells regulated by the surface. In addition, this review summarizes the important aspects of the ultimate three-dimensional nanoarchitectonics as a perspective. The goal of this paper is to establish an integrated concept of functional material creation by reconsidering various reported cases from the viewpoint of nanoarchitectonics, where nanoarchitectonics can be regarded as a method for everything in materials science.

Interaction of vascular endothelial cells with hydrophilic fullerene nanoarchitectured structures in 2D and 3D environments.

The interaction between diverse nanoarchitectured fullerenes and cells is crucial for biomedical applications. Here, we detailed the preparation of hydrophilic self-assembled fullerenes by the liquid-liquid interfacial precipitation (LLIP) method and hydrophilic coating of the materials as a possible vascularization strategy. The interactions of vascular endothelial cells (ECs) with hydrophilic fullerene nanotubes (FNT-P) and hydrophilic fullerene nanowhiskers (FNW-P) were investigated. The average length and diameter of FNT-P were 16 ± 2 µm and 3.4 ± 0.4 µm (i.e. aspect ratios of 4.6), respectively. The average length and diameter of FNW-P were 65 ± 8 µm and 1.2 ± 0.2 µm (i.e. aspect ratios of 53.9), respectively. For two-dimensional (2D) culture after 7 days, the ECs remained viable and proliferated up to ~ 420% and ~ 400% with FNT-P and FNW-P of 50 µg/mL, respectively. Furthermore, an optimized chitosan-based self-healing hydrogel with a modulus of ~400 Pa was developed and used to incorporate self-assembled fullerenes as in vitro three-dimensional (3D) platforms to investigate the impact of FNT-P and FNW-P on ECs within a 3D environment. The addition of FNW-P or FNT-P (50 µg/mL) in the hydrogel system led to proliferation rates of ECs up to ~323% and ~280%, respectively, after 7 days of culture. The ECs in FNW-P hydrogel displayed an elongated shape with aligned morphology, while those in FNT-P hydrogel exhibited a rounded and clustered distribution. Vascular-related gene expressions of ECs were significantly upregulated through interactions with these fullerenes. Thus, the combined use of different nanoarchitectured self-assembled fullerenes and self-healing hydrogels may offer environmental cues influencing EC development in a 3D biomimetic microenvironment, holding promise for advancing vascularization strategy in tissue engineering.

Self-assembled fullerenes with large aspect ratios modulate the morphology and gene expression of endothelial cells within a soft biomimetic 3D microenvironment, representing a promising new vascularization strategy in tissue engineering.

Ionic Liquid Interface as a Cell Scaffold.

In sharp contrast to conventional solid/hydrogel platforms, water-immiscible liquids, such as perfluorocarbons and silicones, allow the adhesion of mammalian cells via protein nanolayers (PNLs) formed at the interface. However, fluorocarbons and silicones, which are typically used for liquid cell culture, possess only narrow ranges of physicochemical parameters and have not allowed for a wide variety of cell culturing environments. In this paper, it is proposed that water-immiscible ionic liquids (ILs) are a new family of liquid substrates with tunable physicochemical properties and high solvation capabilities. Tetraalkylphosphonium-based ILs are identified as non-cytotoxic ILs, whereon human mesenchymal stem cells are successfully cultured. By reducing the cation charge distribution, or ionicity, via alkyl chain elongation, the interface allows cell spreading with matured focal contacts. High-speed atomic force microscopy observations of the PNL formation process suggest that the cation charge distribution significantly altered the protein adsorption dynamics, which are associated with the degree of protein denaturation and the PNL mechanics. Moreover, by exploiting dissolution capability of ILs, an ion-gel cell scaffold is fabricated. This enables to further identify the significant contribution of bulk subphase mechanics to cellular mechanosensing in liquid-based culture scaffolds.

Materials Nanoarchitectonics at Dynamic Interfaces: Structure Formation and Functional Manipulation.

The next step in nanotechnology is to establish a methodology to assemble new functional materials based on the knowledge of nanotechnology. This task is undertaken by nanoarchitectonics. In nanoarchitectonics, we architect functional material systems from nanounits such as atoms, molecules, and nanomaterials. In terms of the hierarchy of the structure and the harmonization of the function, the material created by nanoarchitectonics has similar characteristics to the organization of the functional structure in biosystems. Looking at actual biofunctional systems, dynamic properties and interfacial environments are key. In other words, nanoarchitectonics at dynamic interfaces is important for the production of bio-like highly functional materials systems. In this review paper, nanoarchitectonics at dynamic interfaces will be discussed, looking at recent typical examples. In particular, the basic topics of "molecular manipulation, arrangement, and assembly" and "material production" will be discussed in the first two sections. Then, in the following section, "fullerene assembly: from zero-dimensional unit to advanced materials", we will discuss how various functional structures can be created from the very basic nanounit, the fullerene. The above examples demonstrate the versatile possibilities of architectonics at dynamic interfaces. In the last section, these tendencies will be summarized, and future directions will be discussed.

Layer-by-layer designer nanoarchitectonics for physical and chemical communications in functional materials.

Nanoarchitectonics, as a post-nanotechnology concept, constructs functional materials and structures using nanounits of atoms, molecules, and nanomaterials as materials. With the concept of nanoarchitectonics, asymmetric structures, and hierarchical organization, rather than mere assembly and organization of structures, can be produced, where rational physical and chemical communications will lead to the development of more advanced functional materials. Layer-by-layer assembly can be a powerful tool for this purpose, as exemplified in this feature paper. This feature article explores the possibility of constructing advanced functional systems based on recent examples of layer-by-layer assembly. We will illustrate both the development of more basic methods and more advanced nanoarchitectonics systems aiming towards practical applications. Specifically, the following sections will provide examples of (i) advancement in basics and methods, (ii) physico-chemical aspects and applications, (iii) bio-chemical aspects and applications, and (iv) bio-medical applications. It can be concluded that materials nanoarchitectonics based on layer-by-layer assembly is a useful method for assembling asymmetric structures and hierarchical organization, and is a powerful technique for developing functions through physical and chemical communication.

Two-Dimensional Nanoarchitectonics for Two-Dimensional Materials: Interfacial Engineering of Transition-Metal Dichalcogenides.

Transition-metal dichalcogenides (TMDs) have attracted increasing attention in fundamental studies and technological applications owing to their atomically thin thickness, expanded interlayer distance, motif band gap, and phase-transition ability. Even though TMDs have a wide variety of material assets from semiconductor to semimetallic to metallic, the materials with fixed features may not show excellence for precise application. As a result of exclusive crystalline polymorphs, physical and chemical assets of TMDs can be efficiently modified via various approaches of interface nanoarchitectonics, including heteroatom doping, heterostructure, phase engineering, reducing size, alloying, and hybridization. With modified properties, TMDs become interesting materials in diverse fields, including catalysis, energy, electronics, transistors, and optoelectronics.

Chemical Characterization of Corydalis chaerophylla D.C. Extracts and Preliminary Evaluation of Their in Vitro and in Vivo Biological Properties.

Genus Corydalis is a rich source of isoquinoline alkaloids reported to having potential bioactivities. Corydalis chaerophylla collected from Nepal at an altitude of 2400-4800 m was extracted using hexane, methanol and chloroform as solvents. The resulting hexane, methanol and chloroform extracts were subjected to LC-DAD-MSn analysis to yield fifteen different alkaloids. To assess any potential pharmacological properties, antimicrobial activity against two Gram-positive, two Gram-negative bacterial strains and one fungal strain was assessed, revealing significant inhibitive action of the methanol and chloroform extracts. Of the extracts obtained using chloroform contained the highest content of phenolic compounds at 113 mg GAE/g, while the highest total flavonoid content was found for the hexane extract with a value of 46.45 mg QE/g. The chloroform extract also exhibited a considerable antioxidant activity at IC50 value, 261.5±3 µg/mL, for the DPPH assay. Conversely, the methanol extract exhibited the highest LC50 value for Brine Shrimp cytotoxicity at 196±3 µg/mL being least potential for the test. The methanol extract was found to be the most active against α-amylase inhibition with an IC50 of 51.52±2 µg/mL. In an in vivo acute oral toxicity study against mice, methanol and chloroform extracts presented harmful effects with 1000.36 mg/kg BW and 515 mg/kg BW for LD50 , respectively. By analyzing all the results of the solvents used, the chloroform extract was found to be the most active, a feature that will be used in future isolation procedures and other pharmacological tests.

Kinetic study of NADPH activation using ubiquinone-rhodol fluorescent probe and an IrIII-complex promoter at the cell interior.

Nicotine adenine dinucleotide derivatives NADH and NADPH are intimately involved in energy and electron transport within cells. The fluorescent ubiquinone-rhodol (Q-Rh) probe is used for NADPH activation monitoring. Q-Rh reacts with NADPH yielding its quenched hydroquinone-rhodol (H2Q-Rh) form with concurrent NADPH activation (i.e. NADP+ formation). NADPH activation can be enhanced by the addition of an IrIII-complex (i.e. [(η5-C5Me5)Ir(phen)(H2O)]2+) as a promoter. The rate of the Q-Rh fluorescence quenching process is proportional to the NADPH activation rate, which can be used to monitor NADPH. Experiments were performed in phosphate-buffered saline (PBS) solution and on HeLa cell cultures to analyze the kinetics of Q-Rh reduction and the influence of the IrIII-complex promoter on the activation of NADPH (in PBS) and of other intracellular reducing agents (in HeLa cells). There is a substantial increase in Q-Rh reduction rate inside HeLa cells especially after the addition of IrIII-complex promoter. This increase is partly due to a leakage process (caused by IrIII-complex-induced downstream processes which result in cell membrane disintegration) but also involves the nonspecific activation of other intracellular reducing agents, including NADH, FADH2, FMNH2 or GSH. In the presence only of Q-Rh, the activation rate of intracellular reducing agents is 2 to 8 times faster in HeLa cells than in PBS solution. When both Q-Rh and IrIII-complex are present, the rate of the IrIII-complex catalyzed reduction reaction is 7 to 23 times more rapid in HeLa cells. Concentration- and time-dependent fluorescence attenuation of Q-Rh with third-order reaction kinetics (reasonably approximated as pseudo-first-order in Q-Rh) has been observed and modelled. This reaction and its kinetics present an example of "bioparallel chemistry", where the activation of a molecule can trigger a unique chemical process. This approach stands in contrast to the conventional concept of "bioorthogonal chemistry", which refers to chemical reactions that occur without disrupting native biological processes.