Triphenylphosphonium-linked derivative of hecogenin with enhanced antiproliferative activity: Design, synthesis, and biological evaluation.

Hecogenin (HCG), a steroidal sapogenin, possesses good antitumor properties. However, the application of HCG for cancer treatment has been hindered primarily by its moderate potency. In this study, we incorporated triphenylphosphonium cation (TPP+) at the C-3 and C-12 positions through different lengths of alkyl chains to target mitochondria and enhance the efficacy and selectivity of the parent compound. Cytotoxicity screening revealed that most of the target compounds exhibited potent antiproliferative activity against five human cancer cell lines (MKN45, A549, HCT-116, MCF-7, and HepG2). Structure-activity relationship studies indicated that the TPP+ group significantly enhanced the antiproliferative potency of HCG. Among these compounds, 3c demonstrated remarkable potency against MKN45 cells with an IC50 value of 0.48 µM, significantly more effective than its parent compound HCG (IC50 > 100 µM). Further investigations into the mechanism of action revealed that 3c induced apoptosis of MKN45 cells through the mitochondrial pathway. In a zebrafish xenograft model, 3c inhibited the proliferation of MKN45 cells. Overall, these results suggest that 3c, with potent antiproliferative activity, may serve as a valuable scaffold for developing new antitumor agents.

Amperometric sensor based on ZIF/g-C3N4/RGO heterojunction nanocomposite for hydrazine detection.

A dense  zeolitic imidazolate framework (ZIF) nanosheet is for the first time molded by reduced graphite oxide (RGO) and graphitic carbon nitride (g-C3N4) to fabricate an original 2D/2D/2D heterojunction (ZIF/g-C3N4/RGO nanohybrid), which is pipetted onto carbon cloth electrode (CCE) (ZIF/g-C3N4/RGO/CCE) as an electrochemical sensor. Profiting from the renowned synergistic and coupling effects, the resulting nanohybrid endows excellent electrocatalytic activity towards hydrazine. Amperometric detection reveals that the hybrid sensor possesses a low detection limit of 32 nM (S/N = 3) in a monitoring range of 0.0001 to 1.0386 mM, along with a high sensitivity 93.71 µA mM-1 cm-2. Importantly, the minimum detection concentration of hydrazine in the actual sample is lower than the maximum allowable limit of the World Health Organization (WHO) and has high reproducibility (RSD = 4.82%). As expected, the high sensing capability  of ZIF/g-C3N4/RGO combines the advantages of abundant surface-active sites and high conductivity along with 2D interfaces between ZIF, g-C3N4, and RGO nanosheets. This study provides a promising to expand 2D-based ternary nanojunction as a bridge for promoting sensing performance.Graphical abstract.

Rapid analysis and characterization of multiple constituents of corn silk aqueous extract using ultra-high-performance liquid chromatography combined with quadrupole time-of-flight mass spectrometry.

Corn silk is a well-known traditional Chinese medicine that has been widely used for its antidiabetic, antioxidant, antihyperlipidemic, and other effects in China for thousands of years. Numerous studies have revealed that corn silk contains multiple bioactive constituents that are beneficial for human health. However, the constituents of corn silk in vivo remain ambiguous. In this study, high-throughput ultra-high-performance liquid chromatography combined with quadrupole time-of-flight mass spectrometry technology using multivariate statistical analysis was established to systematically investigate the constituents migrating into blood from corn silk aqueous extract. As a result, 76 compounds were identified, including caffeic acid and ten of its derivatives, (E)-p-coumaric acid and two of its derivatives, ferulic acid and four of its derivatives, and five flavones. Among the identified constituents, 21 constituents, including nine prototype components and 12 metabolites derived from eight components, were characterized in sequence. Based on the significance of the results, the applied approach was powerful for the accurate determination and rapid screening of bioactive components from corn silk aqueous extract. The obtained results are valuable for the in-depth understanding and further pharmacological study of corn silk aqueous extract.

Rapid discovery and global characterization of multiple components in corn silk using a multivariate data processing approach based on UHPLC coupled with electrospray ionization/quadrupole time-of-flight mass spectrometry.

Corn silk is an important traditional Chinese medicine which has been widely used as diuretic, antilithiasic, uricosuric, antiseptic, etc. for thousands of years. However, it is a pity that the chemical ingredients in corn silk, especially the constituents absorbed into blood, are unclear up to now. The aim of our study was to investigate the multiple components of corn silk in vitro and in vivo. In this present study, a sensitive and rapid method using ultra high performance liquid chromatography coupled with electrospray ionization/quadrupole time-of-flight tandem mass spectrometry and a multivariate data processing approach was established to detect the constituents of corn silk in vitro and in vivo. Consequently, total 41 ingredients in vitro and 19 of them absorbed into blood including luteolin, various C-glycosyl flavones, jasmonic acid, abscisic acid, gibberellin A, etc. were tentatively characterized in sequence. Furthermore, of particular importance, a kind of stable compound named C-glycosyl flavones is a great discovery in vivo, which can point the further pharmacological study target in future. In a word, this is the first serum pharmacochemistry study of corn silk, which played a critical role in exploring the pharmacological and effective data for further research.

Jolkinolide B induces cell cycle arrest and apoptosis in MKN45 gastric cancer cells and inhibits xenograft tumor growth in vivo.

Gastric cancer is one of the most common digestive carcinomas throughout the world and represents high mortality. There is an urgent quest for seeking a novel and efficient antigastric cancer drug. Euphorbia fischeriana Steud had long been used as a traditional Chinese medicine for the treatment of cancer. According to the basic theory of traditional Chinese medicine, its antitumor mechanism is 'to combat poison with poison'. However, its effective material foundation of it is still ambiguous. In our previous work, we studied the chemical constituents of E. fischeriana Steud. Jolkinolide B (JB) is an ent-abietane-type diterpenoid we isolated from it. The purpose of the present study was to investigate the antigastric effect and mechanism of JB. Results revealed that JB could suppress the proliferation of MKN45 cells in vitro and inhibit MKN45 xenograft tumor growth in nude mice in vivo. We further investigated its anticancer mechanism. On the one hand, JB caused DNA damage in gastric cancer MKN45 cells and induced the S cycle arrest by activating the ATR-CHK1-CDC25A-Cdk2 signaling pathway, On the other hand, JB induced MKN45 cells apoptosis through the mitochondrial pathway, and ultimately effectively inhibited the growth of gastric cancer cells. These results suggest that JB appears to be a promising candidate drug with antigastric cancer activity and warrants further research.

Ligands with 1,10-phenanthroline scaffold for highly regioselective iron-catalyzed alkene hydrosilylation.

Transition-metal-catalyzed alkene hydrosilylation is one of the most important homogeneous catalytic reactions, and the development of methods that use base metals, especially iron, as catalysts for this transformation is a growing area of research. However, the limited number of ligand scaffolds applicable for base-metal-catalyzed alkene hydrosilylation has seriously hindered advances in this area. Herein, we report the use of 1,10-phenanthroline ligands in base-metal catalysts for alkene hydrosilylation. In particular, iron catalysts with 2,9-diaryl-1,10-phenanthroline ligands exhibit unexpected reactivity and selectivity for hydrosilylation of alkenes, including unique benzylic selectivity with internal alkenes, Markovnikov selectivity with terminal styrenes and 1,3-dienes, and excellent activity toward aliphatic terminal alkenes. According to the mechanistic studies, the unusual benzylic selectivity of this hydrosilylation initiates from π-π interaction between the phenyl of the alkene and the phenanthroline of the ligand. This ligand scaffold and its unique catalytic model will open possibilities for base-metal-catalyzed hydrosilylation reactions.

[Voluntary HIV counseling and testing among peacekeepers in Liberia: acceptability and influential factors].

OBJECTIVE: To investigate the acceptability and influential factors of Voluntary HIV Counseling and Testing (VCT) among the Chinese and Ethiopian peacekeepers in Liberia so as to conduct more effective health education of AIDS and enhance the acceptance of VCT. METHODS: An anonymous questionnaire was used to investigate the attitudes to VCT among 518 Chinese (aged 23-51) and 648 Ethiopian (aged 25-49) peacekeepers in Liberia. RESULTS: The rates of those who claimed to have never heard of HIV/AIDS were 8.1% and 7.9% in the Chinese and Ethiopian subjects respectively, with no significant differences (P > 0.05) in between. Among those who had heard of HIV/ AIDS, 407 (85.5%) Chinese and 449 (75.2%) Ethiopians expressed their willingness to accept VCT, with a significant difference (P < 0.05) between the two groups. Statistic analysis indicated that the acceptance of VCT was as- sodiated with schooling and knowledge on HIV/AIDS in both groups as well as with the susceptibility to HIV among the Ethiopian subjects. CONCLUSION: The acceptability of VCT is obviously lower among those with less schooling and less knowledge of HIV/AIDS. It is important to carry out information-oriented education to increase VCT acceptability among the peacekeepers in the area with a high incidence of AIDS.

[An investigation on AIDS knowledge of Chinese peacekeepers in Liberia and effects of relevant health education].

OBJECTIVE: To investigate and analyze AIDS knowledge of the Chinese peacekeepers in Liberia and to evaluate the effects of AIDS education in order to conduct more effective health education of AIDS and increase AIDS knowledge among the Chinese peacekeepers in the areas with a high incidence of AIDS. METHODS: A questionnaire was designed on the basis of that recommended by WHO to investigate the knowledge of AIDS among the 528 Chinese peacekeepers in Liberia respectively before and after relevant health education, and the results were compared. RESULTS: There was an obvious deficiency in AIDS knowledge among the subjects before the education and an evident increase after it, and the difference was significant (P <0.01). CONCLUSION: The Chinese peacekeepers are deficient in AIDS knowledge, and the deficiency can be effectively improved by relevant health education, which is essential for the health of the Chinese peacekeepers in the areas with a high incidence of AIDS.

Environmentally friendly synthesis of highly hydrophobic and stable MIL-53 MOF nanomaterials.

The preparation of highly hydrophobic and stable MIL-53(Al) nanomaterials was achieved by an ionothermal synthesis strategy. The hydrophobicity of MIL-53(Al)it was studied by water adsorption; and the enhancement in this property was discussed with respect to its reference to MIL-53(Al)ht.