Methicillin‐resistant Staphylococcus aureus (MRSA)‐infected skin wounds have caused a variety of diseases and seriously endanger global public health. Therefore, multidimensional strategies are ...urgently to find antibacterial dressings to combat bacterial infections. Antibacterial hydrogels are considered potential wound dressing, while their clinical translation is limited due to the unpredictable risks and high costs of carrier excipients. it is found that the natural star antibacterial and anti‐inflammatory phytochemicals baicalin (BA) and sanguinarine (SAN) can directly self‐assemble through non‐covalent bonds such as electrostatic attraction, π–π stacking, and hydrogen bonding to form carrier‐free binary small molecule hydrogel. In addition, BA‐SAN gel exhibited a synergistic inhibitory effect on MRSA. And its plasticity and injectability allowed it to be applied as a wound dressing. Due to the matched physicochemical properties and synergistic therapeutic effects, BA‐SAN gel can inhibit bacterial virulence factors, alleviate wound inflammation, promote wound healing, and has good biocompatibility. The current study not only provided an antibacterial hydrogel with clinical value but also opened up new prospects that carrier‐free hydrogels can be designed and originated from clinically used small‐molecule phytochemicals.
Small molecule baicalin (BA) and sanguinarine (SAN) binary carrier‐free self‐assembled hydrogels derived from natural plants can promote wound healing by inhibiting bacterial virulence factors and alleviating the inflammatory response.
(di-)Thioacetals and (di-)thioketals serve commonly as protecting groups of carbonyls and alcohols in organic synthesis, and therefore require highly efficient and chemoselective methods for ...desulfurization into carbonyls or alcohols. Although many approaches have been developed for such deprotection reactions, they usually employ toxic and/or expensive reagents under harsh conditions with a relatively long reaction time. Reported is a green catalytic approach that exploits Fenton-like chemistry (FLC: CeBr
3
-H
2
O
2
) for the oxidative desulfurization of thioacetals and thioketals, which has many competitive advantages including (1) high efficiency (15 min, up to 97% yield), (2) high chemoselectivity with broad substrate scope, (3) greenness (H
2
O as the sole waste) with outstanding green chemistry metrics, and (4) low cost. Detailed mechanistic studies revealed that the reactive brominating species (RBS, HOBr) generated
in situ
using Fenton-like chemistry (
i.e.
, HO&z.rad;) and bromide reacted with sulfide (thioacetals or thioketals) to form the bromosulfonium intermediate (RR'S-Br), which was attacked by a heteroatom such as sulfur, oxygen or nitrogen to initiate the hydrolysis to carbonyls or alcohols. The released bromide ion (Br
−
) could be oxidized again by Fenton-like chemistry to generate RBS for the next catalytic cycle. This highly efficient, chemoselective, and green approach for oxidative desulfurization is expected to find wide applications in organic synthesis.
The catalytic deprotection of thioacetals/thioketals with Fenton-halide H
2
O
2
/CeBr
3
(cat): reactive brominating species (RBS) generated
in situ
from Fenton-like chemistry are highly effective for the oxidative desulfurization of thioacetals and thioketals.
Pomegranate seeds are a potential source of bioactive compounds. Nonetheless, most pomegranate seeds are discarded in the food processing industry, likely due to the lack of convincing data on their ...component analysis.
To reveal the main chemical constituents of pomegranate seeds, a reliable and sensitive method based on ultra-high-performance supercritical fluid chromatography coupled with electrospray ionization and quadrupole time-of-flight mass spectrometry (MS) was developed. A time-dependent MS
data acquisition mode was applied to acquire the mass spectrometric data. The chemical constituents were identified by an automatic retrieval of a traditional Chinese medicine library and relevant literature.
A total number of 59 compounds, including fatty acids, sterols, vitamins, cerebrosides, phospholipids, flavonoids, phenylpropanoids, and others, were tentatively identified. Their possible fragmentation pathways and characteristic ions were proposed and elucidated.
The findings of this study, along with the developed methodology, could provide a reference for basic research on the pharmacodynamic substances of pomegranate seeds and shed light on their potential nutritional and therapeutic applications in the future.
The self‐assembly of phytochemicals with multiple chiral centers is receiving significant attention for its potential in biomedical applications. However, the impact of single chiral center ...epimerization on molecular self‐assembly remains unexplored. Herein, the self‐assembly behavior and bioactivities of 1,2,3,4,6‐penta‐O‐galloyl‐α‐D‐glucose (α‐D‐PGG) and 1,2,3,4,6‐penta‐O‐galloyl‐β‐D‐glucose (β‐D‐PGG) is examined, a pair of natural ellagitannins abundant in plants. Interestingly, β‐D‐PGG formed a hydrogel without modification, while α‐D‐PGG does not. This occurred due to the balanced distribution of aromatic rings and phenolic hydroxyl groups in β‐D‐PGG, facilitating self‐assembly via hydrogen bonding and π–π stacking into nanofibers. In contrast, α‐D‐PGG's self‐assembly is inhibited by steric hindrance. Notably, β‐D‐PGG hydrogel demonstrated exceptional antibacterial activity and by regulating macrophage polarization toward the M2 phenotype, thereby reducing inflammation. This study not only reveals the distinct self‐assembly behaviors of glucose derivatives but also offers new insights into their potential in biomedical applications, such as wound healing.
β‐D‐PGG can self‐assemble into hydrogels in deionized water without any chemical modification or pretreatment, whereas its epimer α‐D‐PGG does not self‐assemble. β‐D‐PGG hydrogel not only exhibits great antibacterial activity, anti‐inflammatory activity, and promotes wound healing by reducing M1 macrophage expression and increasing M2 macrophage expression, but also exhibits stability, injectability, self‐healing, and thermosensitivity, making it potentially an ideal wound dressing.
A Rh(i)-catalyzed trideuteromethylation of heteroarenes with inexpensive and readily available deuterated acetic acid (CD3CO2D) with the aid of a N-containing directing groups is developed. The ...oxidant-free reaction is applicable to a wide range of heteroarene substrates, including 2-pyridones, indoles, aryl rings, pyrroles and carbazoles. It allows installation of CD3 groups under straightforward reaction conditions. It is expected that the salient and practical features of this trideuteromethylation protocol will be of use to academic and industrial researchers.
Rh(I)‐catalyzed C8‐selective C−H alkenylation and arylation of 1,2,3,4‐tetrahydroquinolines with alkenyl and aryl carboxylic acids under microwave assistance have been realized. Using Rh(CO)2(acac) ...as the catalyst and Piv2O as the acid activator, 1,2,3,4‐tetrahydroquinolines undergo C8‐selective decarbonylative C−H alkenylation with a wide range of alkenyl and aryl carboxylic acids, affording the C8‐alkenylated or arylated 1,2,3,4‐tetrahydroquinolines. This method enables the synthesis of C8‐alkenylated 1,2,3,4‐tetrahydroquinolines that would otherwise be difficult to access by means of conventional C−H alkenylation protocols. Moreover, this catalytic system also works well in C8‐selective decarbonylative C−H arylation of 1,2,3,4‐tetrahydroquinolines with aryl carboxylic acids. The catalytic activity strongly depends on the choice of the N‐directing group, with the readily installable and removable N‐(2‐pyrimidyl) group being optimal. The catalytic pathway is elucidated by mechanistic experiments.
et Rhizoma is regarded as one of the most popular and commonly used herbal medicines and has been used in traditional Chinese medicine (TCM) prescriptions for over 2000 years. Pentacyclic triterpene ...saponins are common secondary metabolites in these plants, which are synthesized via the isoprenoid pathway to produce a hydrophobic triterpenoid aglycone containing a hydrophilic sugar chain. This paper systematically summarizes the chemical structures of triterpene saponins in
et Rhizoma and reviews and updates their main biological activities studies. Furthermore, the solubilization characteristics, influences, and mechanisms of
et Rhizoma are elaborated. Solubilization of the triterpene saponins from
et Rhizoma occurs because they contain the nonpolar sapogenin and water-soluble sidechain. The possible factors affecting the solubilization of
et Rhizoma are mainly other crude drugs and the pH of the decoction. Triterpene saponins represented by glycyrrhizin from
et Rhizoma characteristically form micelles due to amphiphilicity, which makes solubilization possible. This overview provides guidance regarding a better understanding of
et Rhizoma and its TCM compatibility, alongside a theoretical basis for the further development and utilization of
et Rhizoma.
The application of nanotechnology for antimicrobial delivery has capacity to improve antibacterial efficacy. Currently, the usage of various inorganic and organic carriers, such as metal ions, ...nano-silicon and surfactants, might increase the potential toxicity of nanoparticles and make their clinical transformation more difficult. Herein, a nano-delivery system was constructed by direct self-assembly of antibacterial phytochemicals (berberine and rhein) originated from traditional Chinese medicine Coptis chinensis Franch. and Rheum palmatum L., respectively. Combining X-ray single crystal diffraction, nuclear magnetic resonance and other spectra characterizations, the stacked structure of nanoparticles was profoundly demonstrated. Briefly, rhein acted as the layered backbone and berberine embedded in it. In vitro bacteriostasis experiment showed the minimum bactericidal concentration of nanoparticles was 0.1 μmol/mL, which was lower than that of berberine and rhein. The results of confocal laser scanning microscope, biofilm quantitive assay and scanning electron microscopy indicated that nanoparticles had strong inhibitory effects on Staphylococcus aureus biofilm. More importantly, transmission electron microscopy and mass spectra indicated the further bacteriostatic mechanism of nanoparticles. Meanwhile, the nanoparticles had well biocompatibility and safety. Current study will open up new prospect that the design of self-assemblies between active phytochemicals can be originated from traditional Chinese medicine combination.
Ber-Rhe nanoparticles (NPs) were formed by direct self-assembly of Ber and Rhe. Combining X-ray single crystal diffraction and spectral analyses, the self-assembly mechanism of NPs had been demonstrated. Meanwhile, Ber–Rhe NPs demonstrated the inhibitory effect against Staphylococcus aureus by destroying the cell wall & membrane and cleaning the biofilm. Display omitted
Diarrhea-predominant irritable bowel syndrome (IBS-D) is one common chronic functional disease of the digestive system with limited treatments. The microbiota–gut–brain axis (MGBA) has a central ...function in the pathogeny of IBS-D, which includes the participation of many various factors, such as brain-gut peptides (BGPs), immune inflammation, and intestinal flora. Inspired by the drug combination in traditional Chinese medicine (TCM), our previous study discovered that berberine (BBR) and baicalin (BA) could form natural self-assemblies as BA-BBR nanoparticles (BA-BBR NPs) and showed synergistic effects against IBS-D. Here, we investigated the synergistic effects of BA-BBR NPs on IBS-D model mice induced by chronic restraint stress plus Senna alexandrina Mill decoction with the influence on MGBA. BA-BBR NPs showed the best therapeutic effect on improving visceral hypersensitivity and diarrhea on IBS-D model mice, compared with BBR, BA, and BA/BBR mixture. Furthermore, BA-BBR NPs significantly (
P
<0.05) reduced the levels of 5-hydroxytryptamine (5-HT), vasoactive intestinal polypeptide (VIP) and choline acety transferase (CHAT) in colon tissues or of serum from BGPs; it lowered the expressions of the nuclear factor kappa-B (NF-κB) in colon tissues and changed the levels of basophil granulocyte (BASO) and leukomonocyte (LYMPH) in whole blood from immune inflammation; it altered the intestinal flora of Bacteroidia, Deferribacteres, Verrucomicrobia, Candidatus_Saccharibacteria, and Cyanobacteria from intestinal flora. In conclusion, BA-BBR NPs, after forming the natural self-assembly between BBR and BA, promoted the synergistic effect on IBS-D mice than the sum of BBR and BA effects, based to the formation of self-assemblies rather than the simple mixing. It further proved that synergistic effect of BA-BBR NPs on IBS-D mice might be related to BGPs, immune inflammation, and intestinal flora from three important interrelated components of MGBA. This study will provide a novel idea for the interpretation of TCM compatibility theory and provide the basis for BA-BBR NPs as a medicinal plant-derived natural and efficient nanomaterial for clinical use.
Ulcerative colitis (UC) is a chronic inflammatory illness affecting the colon and rectum, with current treatment methods being unable to meet the clinical needs of ulcerative colitis patients. ...Although nanomedicines are recognized as promising anti‐inflammatory medicines, their clinical application is limited by their high cost and unpredictable safety risks. This study reveals that two natural phytochemicals, berberine (BBR) and hesperetin (HST), self‐assemble directly to form binary carrier‐free multi‐functional spherical nanoparticles (BBR‐HST NPs) through noncovalent bonds involving electrostatic interactions, π–π stacking, and hydrogen bonding. Because of their synergistic anti‐inflammatory activity, berberine–hesperetin nanoparticles (BBR‐HST NPs) exhibit significantly better therapeutic effects on UC and inhibitory effects on inflammation than BBR and HST at the same dose by regulating the immune microenvironment and repairing the damaged intestinal barrier. Furthermore, BBR‐HST NPs exhibit good biocompatibility and biosafety. Thus, this study proves the potential of novel natural anti‐inflammatory nanoparticles as therapeutic agents for UC, which could promote the progress of drug development for UC and eventually benefit patients who suffering from it.
This study introduces berberine and hesperetin nanoparticles (BBR‐HST NPs), binary carrier‐free self‐assembly nanoparticles, as a potential treatment for ulcerative colitis. Demonstrating efficacy in dextran sodium sulfate (DSS)‐induced colitis mice, BBR‐HST NPs also restore the intestinal barrier, microbiota, and immune system. This research offers a promising ulcerative colitis treatment and advances carrier‐free nanodrug development.
PDF
