Functional Supramolecular Gels Based on the Hierarchical Assembly of Porphyrins and Phthalocyanines

Supramolecular gels containing porphyrins and phthalocyanines motifs are attracting increased interests in a wide range of research areas. Based on the supramolecular gels systems, porphyrin or phthalocyanines can form assemblies with plentiful nanostructures, dynamic, and stimuli-responsive properties. And these π-conjugated molecular building blocks also afford supramolecular gels with many new features, depending on their photochemical and electrochemical characteristics. As one of the most characteristic models, the supramolecular chirality of these soft matters was investigated. Notably, the application of supramolecular gels containing porphyrins and phthalocyanines has been developed in the field of catalysis, molecular sensing, biological imaging, drug delivery and photodynamic therapy. And some photoelectric devices were also fabricated depending on the gelation of porphyrins or phthalocyanines. This paper presents an overview of the progress achieved in this issue along with some perspectives for further advances

Hierarchical Assembly of l‑Phenylalanine-Terminated Bolaamphiphile with Porphyrin Show Tunable Nanostructures and Photocatalytic Properties

Demands related to clean energy and environmental protection promote the development of novel supramolecular assemblies for photocatalysis. Because of the distinctive aggregation behaviors, bolaamphiphiles with two hydrophilic end groups could be theoretically the right candidates for the fabrication of high-performance photocatalysis. However, photocatalytic applications based on bolaamphiphilic assemblies were still rarely investigated. Especially, the relationship between diverse assembled nanostructures and the properties for different applications is urgently needed to be studied. Herein, we demonstrate that using the hierarchical assembly of bolaamphiphiles could correctly induce the porphyrin supramolecular architectures with much better photocatalytic performances than the aggregations containing 450 times of the porphyrin molecules, even though both molecular structures as well as the J-aggregations of porphyrin building blocks are same in two different systems. Thus, the co-assembly of l-phenylalanine terminated bolaamphiphile (Bola-F) and the porphyrin containing four hydroxyl groups (tetrakis-5,10,15,20-(4-hydroxyphenyl)­porphyrin) can form microtube in methanol and forms fibers/spheres in methanol/water mixture. For catalyzing the photodegradation of rhodamine B, the small amount of J-aggregated porphyrin within Bola-F microtubes show much better photocatalytic performance comparing with that of huge porphyrin J-aggregations in fibers/spheres. The supramolecular assemblies as well as the photocatalysis were thoroughly characterized by different spectroscopies and electron microscopy. It is demonstrated that the co-assembly with bolaamphiphiles could inhibit the energy transfer of porphyrin aggregation and subsequently benefit the electron transfer and corresponding photocatalysis under photo-irradiation. This work is not only useful for further understanding the hierarchically supramolecular assembly but also provides a new strategy for making novel functional supramolecular architectures based on the assembly of bolaamphiphiles and porphyrins

Identification and Functional Analysis of the Cell Proliferation Regulator, Insulin-like Growth Factor 1 (IGF1) in Freshwater Pearl Mussel (<i>Hyriopsis cumingii</i>)

Insulin-like growth factor 1 (IGF1) plays an important regulatory role in the regulation of growth, differentiation, and anabolism in a variety of cells. In this study, the full-length cDNA of the IGF1 gene was cloned from Hyriopsis cumingii, named HcIGF1. The expression level of HcIGF1 in six tissues (adductor muscle, foot, hepatopancreas, gill, mantle, and gonad) was determined. In addition, the localization of HcIGF1 in the mantle was analyzed by in situ hybridization, and finally the function of HcIGF1 was explored by RNA interference and prokaryotic expression. The results showed that the amino acid sequence contained a typical IIGF structural domain. The phylogenetic tree showed that HcIGF1 clustered with other marine bivalve sequences. Quantitative real-time PCR and in situ hybridization analysis showed that HcIGF1 was expressed in all tissues. The highest expression was in the foot and the lowest was in the mantle. In the mantle tissue, the hybridization signal was mainly concentrated in the outer mantle. After RNA interference, the expression of IGF1 was found to be significantly decreased (p IGF1R, AKT1, and cyclin D2 were downregulated, while MAPK1 were upregulated. The recombinant HcIGF1 protein was purified and its growth-promoting effect was investigated. The results showed that the recombinant HcIGF1 protein could significantly promote the proliferative activity of the mantle cells of mussels, with the best proliferative effect at 12.5 μg/mL. The results of this study provide a new method to solve the problem of weak proliferation of shellfish cells in vitro and lay the foundation for further understanding of the growth regulation mechanism of H. cumingii, as well as a better understanding of the physiological function of IGF1 in mollusks

Phthalocyanine-Triggered Helical Dipeptide Nanotubes with Intense Circularly Polarized Luminescence

Nanotubes with circularly polarized luminescence (CPL) are attracting much attention due to many potential applications, such as chiroptical materials, displays, and sensing. However, it remains a challenge to change the assemblies of ordinarily molecular building blocks into CPL supramolecular nanotubes. Herein, the regulation of quite common dipeptide (Fmoc-FF) assemblies into unprecedented helical nanotubes exhibiting intense CPL is reported by simply doping a few phthalocyanine (octakis(carboxyl)phthalocyaninato zinc complex (Pc)) molecules. Interestingly, altering the Fmoc-FF/Pc molar ratios over a wide range cannot change the nanotubes structures according to transmission electron microscopy (TEM) and atomic force microscope (AFM) measurements. Although molecular dynamics simulations suggest that the noncovalent interactions between Fmoc-FF and Pc are quite weak, few Pc molecules can still change the secondary structures of a large number of Fmoc-FF assemblies, which hierarchically form helical supramolecular nanotubes with long-range ordered molecular packing, leading to intense CPL signals with large luminescence dissymmetry factor (g(lum) = 0.04). Consequently, the chiral reorganization of Fmoc-FF assemblies is dependent on the coassembly between Pc molecule and Fmoc-FF supramolecular architectures. These results open the possibility for the fine-tuning of helix and supramolecular nanotubes with CPL properties by using a small number of cofactors

Tongue Coating and the Salivary Microbial Communities Vary in Children with Halitosis

Halitosis is a common symptom mainly caused by microbial activities in the oral cavity. Here, we used 16S rRNA gene pyrosequencing and metagenomic sequencing to examine oral microbial compositions and their functional variations in children with halitosis. We found that the tongue coating of subjects with halitosis had greater bacterial richness than those of healthy subjects. The relative abundance and prevalence of Leptotrichia wadei and Peptostreptococcus stomatis were higher in tongue coating samples from children with halitosis than those from children without halitosis; Prevotella shahii had higher relative abundance and prevalence in saliva samples from children with halitosis. We present the first comprehensive evaluation of the co-occurrence networks of saliva and tongue coating communities under healthy and halitosis conditions, and investigated patterns of significant differences between these communities. Moreover, we observed that bacterial genes associated with responses to infectious diseases and terpenoid and polyketide metabolism were enriched in subjects with halitosis, but not in healthy subjects. Hydrogen sulphide ( H2S)-related metabolic pathways suggested that there was higher microbial production and less usage of H2S in subjects with halitosis. Thus, the mechanism of halitosis was implied for the first time via metagenomic sequencing.National Natural Science Foundation of China [81200762, 81301475]; Peking University School of Stomatology [PKUSS20130210]; Scientific Research Foundation for Returned Overseas Chinese Scholars, State Education Ministry; Metagenopolis [ANR-11-DPBS-0001]SCI(E)[email protected]; [email protected]; [email protected]

Proteomic analysis of amino acid metabolism differences between wild and cultivated Panax ginseng

Background: The present study aimed to compare the relative abundance of proteins and amino acid metabolites to explore the mechanisms underlying the difference between wild and cultivated ginseng (Panax ginseng Meyer) at the amino acid level. Methods: Two-dimensional polyacrylamide gel electrophoresis and isobaric tags for relative and absolute quantitation were used to identify the differential abundance of proteins between wild and cultivated ginseng. Total amino acids in wild and cultivated ginseng were compared using an automated amino acid analyzer. The activities of amino acid metabolism-related enzymes and the contents of intermediate metabolites between wild and cultivated ginseng were measured using enzyme-linked immunosorbent assay and spectrophotometric methods. Results: Our results showed that the contents of 14 types of amino acids were higher in wild ginseng compared with cultivated ginseng. The amino acid metabolism-related enzymes and their derivatives, such as glutamate decarboxylase and S-adenosylmethionine, all had high levels of accumulation in wild ginseng. The accumulation of sulfur amino acid synthesis-related proteins, such as methionine synthase, was also higher in wild ginseng. In addition, glycolysis and tricarboxylic acid cycle-related enzymes as well as their intermediates had high levels of accumulation in wild ginseng. Conclusion: This study elucidates the differences in amino acids between wild and cultivated ginseng. These results will provide a reference for further studies on the medicinal functions of wild ginseng

Self-Assembled Zn(II) Coordination Complexes Based on Mixed V‑Shaped Asymmetric Multicarboxylate and N‑Donor Ligands

Hydrothermal reaction between Zn­(OAc)₂·2H₂O and three asymmetric semirigid V-shaped multicarboxylate ligands H₃L^1–3 with the help of a 4,4'-bipyridine (4,4'-bpy) or 1,4-bis­(imidazol-1-ylmethyl)­benzene (bix) linker led to the isolation of six new coordination polymers, including [Zn₃(L¹)₂(4,4′-bpy)₂]_<i>n</i>·(H₂O)_2<i>n</i> (<b>1</b>), [Zn₃(L²)₂­(4,4′-bpy)­(H₂O)₂]_<i>n</i>·(H₂O)_2<i>n</i> (<b>2</b>), [Zn₃(L³)₂­(4,4′-bpy)₂­(H₂O)₄]_<i>n</i>·(H₂O)_6<i>n</i> (<b>3</b>), [Zn₃(L¹)₂­(bix)₃]_<i>n</i>·(H₂O)_7<i>n</i> (<b>4</b>), [Zn₃(L²)₂­(bix)₃]_<i>n</i>·(H₂O)_4<i>n</i> (<b>5</b>), and [Zn₃(HL³)₂­(bix)₂]_<i>n</i> (<b>6</b>), where H₃L¹, H₃L², H₃L³ ligands represent 3-(2-carboxyphenoxy)­phthalic acid, 4-(2-carboxyphenoxy)­phthalic acid, 3-(4-carboxyphenoxy)­phthalic acid, respectively. Single crystal X-ray diffraction analysis reveals a three-dimensional (3D) network for <b>1</b> and <b>3</b>–<b>5</b> but a two-dimensional (2D) structure for <b>2</b> and <b>6</b>. Despite the construction from the polymetallic chains connected by the 4,4′-bpy ligands for both compounds <b>1</b> and <b>2</b>, a 3D architecture was revealed for the former species while a 2D configuration for the latter one. Complex <b>3</b> contains open nanotube building units composed of sole 44-numbered metallomacrocycles. For <b>4</b>, the 20-numbered metallomacrocycle subunits linked by Zn ions give a 1D chain, which further form a 3D polymeric structure with the help of the other cyclic-shaped subunits made from the bix ligands and Zn ions. A 3D framework of <b>5</b> is generated from the 2D sheets simplified as a (6,3) net bound by the bix ligands. Compound <b>6</b> shows a 2D corrugated framework simplified as a (4,4) net assembled by the bix ligand and dinuclear zinc unit as node. These results seem to suggest that the diversity in the building subunits formed in <b>1</b>–<b>6</b> actually originates from the intrinsic nature of the three asymmetric V-shaped tricarboxylate ligands together with the tunable coordination geometry and molecular configurations of ligands by the N-donor ligand employed. In addition, the thermal stability and luminescence properties for the series of six complexes have also been investigated