Progressive Folding and Adaptive Multivalent Recognition of Alkyl Amines and Amino Acids in p-Sulfonatocalix[4]arene Hosts: Solid-State and Solution Studies.

Invited for this month's cover is the group of Dr. Mihail Barboiu from the Institut Europeen des Membranes of Montpellier, France and the Lehn Institute of Functional Materials at Sun-yat Sen University in Guangzhou, China. The cover picture shows the molecular recognition of folded 1,ω-amino-acids guests within p-sulfonatocalix[4]arene host anions stabilized with alternating hydrated cations and water molecules. Read the full text of the article at 10.1002/cplu.202000232.

Progressive Folding and Adaptive Multivalent Recognition of Alkyl Amines and Amino Acids in p-Sulfonatocalix[4]arene Hosts: Solid-State and Solution Studies.

Calix[4]arenes have the ability to encapsulate biomimetic guests, offering interesting opportunities to explore their molecular recognition, very close to biological scenarios. In this study, p-sulfonatocalix[4]arene (C4 A) anions and hydrated alkali cations have been used for the in situ recognition of cationic 1,ω-diammonium-alkanes and 1,ω-amino-acids of variable lengths. NMR spectroscopy illustrates that these systems are stable in aqueous solution and the interaction process involves several binding states or stabilized conformations within the C4 A anion, depending of the nature of the guest. DOSY experiments showed that monomeric 1 : 1 host-guest species are present, while the cation does not influence their self-assembly in solution. The folded conformations observed in the solid-state X-ray single-crystal structures shed light on the constitutional adaptivity of flexible chains to environmental factors. Futhermore, a comprehensive screening of 30 single crystal structures helped to understand the in situ conformational fixation and accurate determination of the folded structures of the confined guest molecules, with a compression up to 40 % compared with their linear conformations.

"Calix[4]-box" cages promote the formation of amide bonds in water in the absence of coupling reagents.

The present work shows that encapsulation can be used to promote amide bond formation in water under mild conditions, in the absence of carbodiimide coupling agents.

Bis-15-crown-5-ether-pillar[5]arene K+-Responsive Channels.

An artificial selective K+ channel is formed from the supramolecular organization on bis(benzo-15-crown-5- ether-ureido)-pillar[5]arene compound. This channel achieves a selectivity of SK+/Na+ = 5 for an initial transport rate of kK+ = 3.2 × 10-3 s-1. The cation-file diffusion occurs via selective macrocyclic-filters anchored on inactive supporting pillar[5]arene relays. The sandwich-type binding geometry of the K+ cation by two 15-crown-5 moieties sites is a key feature influencing channel efficiency.

"Pyrene Box" Cages for the Confinement of Biogenic Amines.

The complete structure of non-crystalline compounds can be determined by confining them in crystalline structures. The reduced motional degrees of freedom of encapsulated guests can be obtained through their anchoring to the host cages, which results in the reduction of a significant amount of disorder. The "pyrene box" cages that easily crystallize from aqueous solutions are recommended to achieve complete structure elucidation of compounds of biological interest. In this study, the "pyrene box" cages have been used for the in situ encapsulation of biogenic amines: histamine, dopamine, and serotonin. NMR spectroscopy illustrates that these systems are stable in aqueous solution. The X-ray single-crystal structure analysis reveals that the pyrene box/biogenic amine systems are stabilized through combined interactions, strongly contributing to in situ fixation and accurate determination of their crystal structures.

Diagnosis and treatment of micro-paragangliomas in urinary bladdler / 基础医学与临床

Objective To develope the diagnostic criteria and surgical methods to treat micro-paraganagliomas (<1 cm) of urinary bladder ( PUB) , we now report a case series study including 5 individual cases .Methods Clinical data of 5 patients with micro-PUBs who underwent surgical treatment were obtained and analyzed retrospectively . Two male patients and three female patients were included in our study with the mean age of 51 ( range from 41 to 65 years) .4 patients were reported as symptomatic due to hypercatecholaminemia , while the other was free of symptoms.24-hour urine catecholamine ( CA) examination was utilized to qualitatively diagnose PUB , positive in 75%patients.Ultrasonography(USG), CT, MRI, 111In-DTPA-Octreotide scintigraphy (OctreoScan) and 131 I-MIBG scintigraphy were used to locate the tumor , positive in 80%, 20%, 75%, 25%and 33%patients respectively .What's more, all 5 patients underwent transurethral resection of tumor .Overfilling of bladder and puncture following ultra-sonography guidance were performed to locate the tumors , when tumors were absent in surgical vision .Results All tumors were located and resected completely with no open conversions .It took 0.5 to 26 minutes to locate the tumor and another 3 to 10 minutes to resect the tumors .All lesions were diagnosed by histopathological confirma-tion, especially by immunohistochemical staining.Blood pressure return to normal level after the procedures.No local recurrence or distal metastasis were observed by performing 24-hour urine CA test , USG, cystoscopy and MRI within adequate follow-up.The mean follow-up duration was 38.6 months, ranging from 6 to 120 months.Conclu-sions USG and MRI examination were considered better in detecting micro PUB than CT-scan.Overfilling of blad-der and puncture following USG guidance may support more accurate tumor location intraoperatively if the tumors were not found in transurethral resection procedures .

Dynameric host frameworks for the activation of lipase through H-bond and interfacial encapsulation.

A facile lipase activation has been achieved by direct addition of multivalent amide dynameric frameworks into the reaction aqueous solutions, through the combined effects of lipase-host matrices, H-bonds and interfacial interactions.

Adaptive Encapsulation of ω-Amino Acids and Their Guanidinium-Amide Congeners.

The binding and the encapsulation of the 6-aminohexanoic acid (1) and 11-aminoundecanoic acid (2) are achieved in aqueous solution and in crystalline Pyrene-box cages. Unexpectedly, the amino-guanidinium AG+ and the amino acids 1 or 2 are reacting in aqueous solution in the absence and in the presence of Pyrene-box cages. The formation of an amide bond between a carboxylic acid and the amino-guanidine unit under mild acidic conditions in water without the use a coupling reagent is extremely interesting and unexpected. The resulted adducts AG1 and AG2 show adaptive binding behaviors and compressions.

Effects of platelet-rich fibrin extract on MC3T3-E1 cell / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To evaluate the effect of platelet-rich fibrin extract (PRFe) on proliferation and differentiation and F-actin cytoskeleton of osteoblasts.</p><p><b>METHODS</b>The experimental group used the α-minimum essential medium (α-MEM) containing PRFe (10% fetal bovine serum), and the control group used the α-MEM (10% fetal bovine serum). The number of the osteoblasts at 1st, 3rd, 5th d was detected by methyl thiazolyl tetrazolium (MTT) assay, and the differentiation of osteoblast at 1st, 3rd, 5th,7 th d detected by the activity of alkaline phosphatase (ALP).The alizarin red dye was used to observe the number of calcium nodus at 14th, 21st d. The F-actin cytoskeleton was evaluated by confocal laser scanning microscope(CLSM) at 3rd,6th,9th,12th h. The level of osteogenetic biomarkers osteocalcin (OCN) and core-binding factor α1(Cbfα1) at 3rd,7th d were quantified by real-time PCR.</p><p><b>RESULTS</b>A significant increase of absorbance at 1st, 3rd, 5th d was showed in experimental group (0.336 ± 0.011, 0.571 ± 0.039, 0.787 ± 0.050) compared to control group (0.300 ± 0.021, 0.387 ± 0.040, 0.527 ± 0.034) (P < 0.05). The absorbance of experimental group at 1st, 3rd, 5th, 7th d (0.146 ± 0.014, 0.199 ± 0.017, 0.390 ± 0.020, 0.492 ± 0.019) was significantly higher than that of control group (0.115 ± 0.014, 0.145 ± 0.015, 0.190 ± 0.015, 0.230 ± 0.026) (P < 0.05). The integrated absorbance of the calcium nodus in experimental group at 14th, 21st d (22.119 ± 3.694, 31.528 ± 3.162) was significantly higher than in control group (8.498 ± 2.041, 15.162 ± 2.526) (P < 0.05). The Cbfα1 and OCN gene expression in experimental group was higher than in control group (P < 0.05).</p><p><b>CONCLUSIONS</b>PRFe could enhance the proliferation and differentiation of osteoblasts and promote the spread of F-actin cytoskeleton.</p>