Characterization of the metabolism of aloin A/B and aloesin in rats using ultra-high performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry.

Aloin A/B and aloesin are the major bioactive constituents in Aloe vera, with diverse pharmacological activities, including anti-bacterial, anti-tumour, anti-inflammatory and intestinal regulation. However, the in vivo metabolism of aloin A/B and aloesin is still unclear. In this study, the metabolic processes of aloin A/B and aloesin in rats were investigated using ultra-high performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF/MS) and MetaboLynx™ software with the mass defect filter technique. Based on the proposed method, the prototype components of three compounds were all detected in rat plasma, urine and feces. Meanwhile, 25 aloin A/B metabolites (six phase I, three phase II, 16 phase I combined with phase II) and three aloesin metabolites (two phase I and one phase II) were detected in rats after oral administration of aloin A, aloin B and aloesin, and the main biotransformation reactions were hydroxylation, oxidation, methylation, acetylation and glucuronidation. In addition, aloin A and aloin B can be transformed into each other in vivo and the metabolic profiles of aloin A and aloin B are identical. These results provide essential data for further pharmaceutical research and clinical application of aloin A/B and aloesin.

New caffeoyl derivatives from Elephantopus scaber.

Three new caffeoyl derivatives (1-3), together with two known ones (4-5), were isolated from the whole plant of Elephantopus scaber Linn. The structures of the new compounds were elucidated using detailed spectroscopic analysis. Compound 4 was obtained and its NMR data were given for the first time. All isolates were evaluated for their anti-inflammatory activity against lipopolysaccharide (LPS)-stimulated nitric oxide (NO) production and pro-inflammatory cytokines release in RAW 264.7 cells. Compounds 2-5 showed mild inhibitory activities with IC50 values ranging from 64.78 to 87.21 µM, and 3-4 could inhibit LPS-induced tumor necrosis factor-α (TNF-α) production.

Machine learning for reparameterization of four-site water models: TIP4P-BG and TIP4P-BGT.

Parameterizing an effective water model is a challenging issue because of the difficulty in maintaining a comprehensive balance among the diverse physical properties of water with a limited number of parameters. The advancement in machine learning provides a promising path to search for a reliable set of parameters. Based on the TIP4P water model, hence, about 6000 molecular dynamics (MD) simulations for pure water at 1 atm and in the range of 273-373 K are conducted here as the training data. The back-propagation (BP) neural network is then utilized to construct an efficient mapping between the model parameters and four crucial physical properties of water, including the density, vaporization enthalpy, self-diffusion coefficient and viscosity. Without additional time-consuming MD simulations, this mapping operation could result in sufficient and accurate data for high-population genetic algorithm (GA) to optimize the model parameters as much as possible. Based on the proposed parameterizing strategy, TIP4P-BG (a conventional four-site water model) and TIP4P-BGT (an advanced model with temperature-dependent parameters) are established. Both the water models exhibit excellent performance with a reasonable balance among the four crucial physical properties. The relevant mean absolute percentage errors are 3.53% and 3.08%, respectively. Further calculations on the temperature of maximum density, isothermal compressibility, thermal expansion coefficient, radial distribution function and surface tension are also performed and the resulting values are in good agreement with the experimental values. Through this water modeling example, the potential of the proposed data-driven machine learning procedure has been demonstrated for parameterizing a MD-based material model.

Pharmacokinetics of costunolide and dehydrocostuslactone after oral administration of Radix aucklandiae extract in normal and gastric ulcer rats.

Costunolide and dehydrocostuslactone are the main active ingredients of Radix Aucklandiae (RA). An accurate and sensitive LC-MS/MS method was established to simultaneously determine contents of costunolide and dehydrocostuslactone in plasma. There were significant differences in pharmacokinetic parameters (AUC0-t, Cmax,1, Cmax,2, Tmax,1, Vd, and CL) of costunolide and dehydrocostuslactone between RA group and costunolide group or dehydrocostuslactone group. The relative bioavailability of costunolide or dehydrocostuslactone of RA extract was improved. As compared to normal group, the Tmax,2 values of dehydrocostuslactone of RA in gastric ulcer group were prolonged, while the Cmax,1, Cmax,2, and AUC0-t values decreased.

Chemical profiling of Di-Wu-Yang-Gan Granules by ultra performance liquid chromatography coupled to quadrupole time-of-flight mass spectrometry with MSE technology.

Di-Wu-Yang-Gan Granules is a Traditional Chinese Medicine prescription used for the treatment of HBeAg-negative chronic hepatitis B patients in China. It consists of five commonly used Chinese herbs. However, the chemical constituents of the whole prescription had not been clarified yet. Hence, in this study, the chemical profiling of Di-Wu-Yang-Gan Granules was explored by ultra performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry, which can provide accurate molecular weight within 5-ppm error and sufficient MS/MS fragment ions without the need for precursor ion selection. As a result, 116 compounds were identified, including lignans, triterpenesaponins, flavonoids, coumarins, iridoids, nortriterpenoids, phenolic acids, and sesquiterpenes. All compounds were further assigned to the individual herbs. In conclusion, this established method was reliable and effective for the separation and identification of the constituents in Di-Wu-Yang-Gan Granules. The findings are beneficial for quality control of the prescription during production and provide helpful chemical information for exploring its efficacy and the mechanism of action. The fragmentation regularity summarized in this study also provided important information for the rapid identification of the chemical composition in herbal medicines or their prescription.

Three New Highly Oxygenated Germacranolides from Carpesium Divaricatum and Their Cytotoxic Activity.

Three new highly oxygenated (2⁻4), and two known (1 and 5) germacranolides, were isolated from the whole plant of Carpesium divaricatum. The planar structures and relative configurations of the new compounds were determined by detailed spectroscopic analysis. The absolute configuration of 1 was established using the circular dichroism (CD) method and X-ray diffraction, and the stereochemistry of the new compounds 2⁻4 were determined using similar CD spectra with 1. The new compound 2 and the known compound 5 exhibited potent cytotoxicity against hepatocellular cancer (Hep G2) and human cervical cancer (HeLa) cells, superior to those of the positive control cis-platin.

Trichoderpyrone, a Unique Polyketide Hybrid with a Cyclopentenone-Pyrone Skeleton from the Plant Endophytic Fungus Trichoderma gamsii.

Trichoderpyrone (1), a unique polyketide with a cyclopentenone-pyrone hybrid skeleton, was isolated from the plant endophytic fungus Trichoderma gamsii. The structure of 1 was determined by detailed analysis of NMR data together with comparison of chemical shift values of similar fragments. The relative and absolute configurations were established by NOESY correlations and CD experiment. Trichoderpyrone (1) displayed weak cytotoxic activities against A549, HepG2, and HeLa cancer cell lines. 1 might originate from a hybrid biosynthetic pathway through two nonreduced (NR) polyketide megasynthetases.

Semisynthetic and SAR Studies of Amide Derivatives of Neocrotocembraneic Acid as Potential Antitumor Agents.

A series of novel amide derivatives of cembranoid neocrotocembraneic acid were designed and synthesized. The antiproliferative activities of these derivatives were evaluated against three human tumor cell lines (the human cervical cancer cell line HeLa, chronic myeloid leukemia cell line K562 and leukemia multidrug-resistant cell line K562/A02). Some of the synthesized compounds exhibited moderate to good activity against all three cancer cell lines. Particularly, compound 8a exhibited more potent antiproliferative activity than the reference drug etoposide against drug-resistant cell line K562/A02, indicating that it possessed a great potential for further development as a multidrug resistance modulator by structural modification.

Cabozantinib reverses multidrug resistance of human hepatoma HepG2/adr cells by modulating the function of P-glycoprotein.

BACKGROUND & AIMS: Cabozantinib, a small-molecule multitargeted tyrosine kinase inhibitor, has entered into a phase III clinical trial for the treatment of hepatocellular carcinoma (HCC). This study assessed the mechanistic effect of cabozantinib on the reversal of P-glycoprotein (P-gp)-mediated multidrug resistance (MDR). METHODS: CCK-8 assays and tumour xenografts were used to investigate the reversal of MDR in vitro and in vivo respectively. Substrate retention assays were evaluated by fluorescence microscope and flow cytometry. Western blotting was used to detect protein expression levels. mRNA expression was determined by qPCR. The ATPase activity of P-gp was investigated using Pgp-Glo(™) assay systems. The binding mechanism of cabozantinib to P-gp at the molecular level was evaluated using docking analysis. RESULTS: Cabozantinib enhanced the cytotoxicity of P-gp substrate drugs in HepG2/adr and HEK293-MDR1 cells but had no effect on non-P-gp substrates. In addition, cabozantinib increased the accumulation of P-gp substrates in HepG2/adr cells but had no effect in HepG2 cells. Furthermore, cabozantinib did not alter the expression of P-gp mRNA or protein but did stimulate the activity of P-gp ATPase. The docking study indicated that cabozantinib and verapamil may partially share a binding site on P-gp. The reversal concentrations of cabozantinib did not affect the expression of MET, AKT and ERK1/2. Significantly, cabozantinib increased the inhibitory efficacy of doxorubicin in P-gp-overexpressing HepG2/adr cell xenografts in nude mice. CONCLUSION: Cabozantinib reverses P-gp-mediated MDR by directly inhibiting the efflux function of P-gp, indicating that cabozantinib may help to reverse P-gp-mediated MDR in HCC and other cancer chemotherapy.

A new dihydroagarofuranoid sesquiterpene from the roots of Tripterygium hypoglaucum.

A new sesquiterpene ester (1) has been isolated from the root bark of Tripterygium hypoglaucum. The structure was determined as 1α-acetoxy-6ß,9ß-dibenzoyloxy-4ß-hydroxy-dihydroagarofuran by the extensive analysis of NMR data, and the absolute configurations were established as 1R, 4R, 6S, and 9R by application of the CD excitation chirality method. Compound 1 exhibited weak cytotoxicity against HeLa cells, with an IC50 value of 30.2 µM.

Selective recognition of Triamterene in biological samples by molecularly imprinted monolithic column with a pseudo template employed.

Melamine (MAM) was employed as a pseudo template to prepare a molecularly imprinted polymer monolithic column which presents the ability of selective recognition to Triamterene (TAT), whose structure was similar to that of MAM. Methacrylic acid and ethylene glycol dimethacrylate were applied as functional monomer and cross-linker, respectively, during the in situ polymerization process. Chromatographic behaviors were evaluated, the results indicated that the molecularly imprinted polymer monolithic column possessed excellent affinity and selectivity for TAT, and the imprinting factor was high up to 3.99 when 7:3 of ACN/water v/v was used as mobile phase. In addition, the dissociation constant and the binding sites were also determined by frontal chromatography as 134.31 µmol/L and 132.28 µmol/g, respectively, which demonstrated that the obtained molecularly imprinted polymer monolith had a high binding capacity and strong affinity ability to TAT. Furthermore, biological samples could be directly injected into the column and TAT was enriched with the optimized mobile phase. These assays gave recovery values higher than 91.60% with RSD values that were always less than 3.5%. The molecularly imprinted monolithic column greatly simplified experiment procedure and can be applied to preconcentration, purification, and analysis of TAT in biological samples.

[Children primary intestinal inflammatory myofibroblastic tumor: a case report].

Children intestinal inflammatory myofibroblastic tumor (IMT) is rare, and its clinical differential is very difficult to the malignant tumor. Its diagnosis depends on pathology, and operation is the most effective therapy method. We preset here a case of a 5-year-old girl who was admitted to the hospital for intestinal obstruction. A malignant tumor in the intestinal wall showed on the enhanced CT. Exploratory laparotory found the tumor and then it was resected. Postoperative pathology and immunohistochemistry proved that it was an intestinal IMT. Three months' follow-up found no tumor recurrence and metastasis.

Water diffusion inside carbon nanotubes: mutual effects of surface and confinement.

The mutual effects of two crucial features of carbon nanotubes (CNTs) (surface and confinement) on the temperature-dependent water diffusion are studied through molecular dynamics simulations. A two-stage diffusion mechanism is detected in the CNTs of diameter smaller than 12.2 Å, which becomes obscure as the temperature increases. This peculiar phenomenon can be ascribed to the cooperation of the small confinement and the periodic surface. The diffusion coefficient of the confined water exhibits a nonmonotonic dependence on the confinement size and an unexpected increase inside the large CNTs (compared to that of bulk water). These anomalous behaviors can be attributed to the competition of the smooth surface and the small confinement. Considering the mutual effects, an empirical formula is proposed on the basis of two groups of numerical examples, whose results indicate that the confinement effect will dominate over the surface effect until the CNT diameter increases up to ~16 Å, whereas thereafter the surface effect becomes dominant and finally both of them vanish gradually.

Supramolecular aggregation/disaggregation-based molecular sensing: a review focused on investigations from China.

Supramolecular aggregation and disaggregation induced by external stimuli can impact the optical or electrical signals of the aggregates/constituting units (receptors). Therefore, manipulating supramolecular aggregation/disaggregation has recently been employed to construct novel and promising photoluminescence (PL)-based sensing and recognition systems. The sensing systems were capable of substantially enhancing the sensitivity, relying on cooperative interactions occurring in the assembly/disassembly processes (mostly operating in emission turned-on or emission-enhanced mode). This review focuses mainly on recent advances in the new emerging PL-based sensing platforms, based on manipulating the behaviours of supramolecular aggregation/disaggregation, including aggregation-induced emission (AIE), metallophilic interactions-related sensing (metallophilic interactions-induced aggregation/disaggregation), metal coordination polymers-related sensing, and other sensing systems involving supramolecular aggregation/disaggregation. In particular, those sensing systems developed by scientists in China are summarized and highlighted.

A simulation study on nanoscale holes generated by gold nanoparticles on negative lipid bilayers.

Understanding the interactions of gold nanoparticles (AuNPs) with cellular compartments, especially cell membranes, is of fundamental importance in obtaining their control in biomedical applications. An effort is made in this paper to investigate the interactions of 2.2 nm core AuNPs with negative model bilayer membranes by coarse-grained (CG) molecular dynamics (MD) simulation. The CG model of lipid bilayer was taken from Marrink et al. ( J. Phys. Chem. B 2004, 108, 750-760 ), whereas the CG AuNPs model was developed on the basis of both atomistic MD simulations and experimental data. It was found that AuNPs functionalized with cationic ligands penetrated into the negative bilayer membranes and generated significant disruptions on bilayers. The lipids surrounding the nanoparticle were highly disordered and the bulk surface of the bilayer exhibits some defective areas. Most importantly, it is observed that a nanoscale hole can be formed and expanded spontaneously on the peripheral regions of the 20 × 20 nm bilayer. The expansion of the hole is on the time scale of hundreds of nanosceonds. The fully expanded hole had a radius of ∼5.5 nm and could transport water molecules at a rate of up to ∼1100 molecule/ns. However holes could not be formed on a larger bilayer (28 × 28 nm). The factors that can eliminate hole formation on the bilayer also include the decrease of cationic lignads on the AuNP, the reduction of negative lipids in the bilayer, the release of bilayer surface tension, the lowering of temperature, and the addition of a high concentration of salt. The results suggest that a hole can only be formed on living cell membranes under extreme conditions.

[Design push-pull osmotic pump tablets of famotidine based on an expert system for the formulation design of osmotic pump of poor water-soluble drug].

The purpose of this study is to design push-pull osmotic pump (PPOP) tablets of famotidine using the expert system for the formulation design of osmotic pump of poor water-soluble drug which had been established by the authors. Firstly, the parameters which were requisite of the system input were obtained from literatures and experimental tests. Then the parameters were input into the system, and the program was run. The system displayed the designed formulations sequential. Finally, famotidine PPOP was prepared according to the designed formulations and the in vitro dissolution was carried out. It was found out that the target formulation of famotidine PPOP which could release for 24 hours was obtained in a very short period. Meanwhile, the practicability of the established expert system was proved.

New phenolic acids from the whole herb of Elephantopus scaber Linn. and their anti-inflammatory activity.

Two new phenolic acids, ethyl 3,3',4,4'-tetrahydroxy-δ-truxinate (1), 3-O-p-coumaroyl-4-O-caffeoyl quinic acid methyl ester (2), together with three known compounds (3-5) were isolated from the whole plant of Elephantopus scaber Linn. The structures of the new compounds were elucidated using detailed spectroscopic analysis. Compound 3 was obtained and given its NMR data for the first time. All isolates were evaluated for their anti-inflammatory activity via inhibiting the production of nitric oxide (NO) in lipopolysaccharide (LPS)-stimulated murine macrophage RAW 264.7 cells, and 1, 4 and 5 showed a moderate inhibition with IC50 values ranging from 11.85 to 20.62 µM.

Anti-inflammatory constituents in the root and rhizome of Polygonum cuspidatum by UPLC-PDA-QTOF/MS and lipopolysaccharide-activated RAW264.7 macrophages.

The root and rhizome of Polygonum cuspidatum (Hu-Zhang) has been used for treatment of various inflammatory disorders in China. In our pervious study, we found that three fractions (HZE-30, HZE-60 and HZE-95) from the ethanol extract of Hu-Zhang (HZE) all could inhibit NO production, and HZE-60 shows the most potent anti-inflammatory activity. In order to understand the major contribution constituents of Hu-Zhang responsible for its anti-inflammatory effect, quantitative composition-activity relationship method was performed. Firstly, the constituents in HZE-60 were characterized using an ultra-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF/MS) approach. Second, quantitative analyzed five major constituents identified in HZE-60 and compare the difference of five major constituents in HZE and three anti-inflammatory activity fractions. Finally, evaluated the anti-inflammatory effects of major constituents in lipopolysaccharide (LPS)-activated RAW264.7 macrophages. The results showed that a total of 31 compounds were identified from HZE-60, including 12 anthraquinones, 7 diphenylethenes, 9 phenols and 3 others. The contents of five major constituents (polydatin (6), resveratrol (7), emodin-1-O-ß-d-glucoside (15), emodin-8-O-ß-d-glucoside (21) and emodin (31)) were simultaneously determined by UPLC-PDA with good linearity (correlation coefficients > 0.9990) and satisfactory repeatability (RSD < 0.99 %), precision (RSD < 0.01 %), stability (RSD < 0.67 %) and recoveries (99.52 %-101.23 %, RSD < 0.91 %). All five major constituents could be detected in HZE and HZE-60 fraction, but only 6 was detected in HZE-30, and 31 in HZE-95. Moreover, 7, 15 and 21 exhibited significant anti-inflammatory activity via suppressing supernatant pro-inflammatory mediators, such as NO, tumor Necrosis Factor-α (TNF-α), interleukin-6 (IL-6) and monocyte chemotactic protein-1 (MCP-1). Therefore, we conclude that the bioactivity of HZE is the syngeneic effect of its constituents, and 7, 15 and 21 should make great contributions for the anti-inflammatory effect of Hu-Zhang. The findings define the anti-inflammatory chemical constituents of Hu-Zhang, which will benefit further investigation on its quality control and the mechanism of action.

Flavonoids from the stems of Croton caudatus Geisel. var. tomentosus Hook.

A new flavone, named crotoncaudatin (1), was isolated from the stems of Croton caudatus Geisel. var. tomentosus Hook., together with nine known analogues: 3,5,6,7,8,3',4'-heptamethoxyflavone (2), tangeretin (3), nobiletin (4), 5,6,7,4'-tetramethoxy-flavone (5), sinensetin (6), kaempferol (7), tiliroside (8), kaempferol-3-O-rutinoside (9) and rutin (10). The structures of the above compounds were established by a combination of spectroscopic methods, including HR-ESI-MS, 1H-NMR, 13C-NMR, HMQC and HMBC spectra. All compounds were isolated from and identified in this species for the first time and compounds 1-6 are new for the genus Croton.

Advances in the role of exosomal non-coding RNA in the development, diagnosis, and treatment of gastric cancer (Review).

Exosomes are small vesicles secreted by a variety of cells that contain vrious biological macromolecules, including RNA, non-coding RNA and protein. An increasing number of studies have demonstrated that exosomes and particularly the non-coding RNAs they contain, serve important roles in many cellular processes, including the transmission of information. It is well established that the occurrence and development of gastric cancer, one of the four most common malignant tumors worldwide, involves the transmission of information. Based on the urgent need for the elucidation of the mechanism involved in this process, as well as advances in the diagnosis and treatment of gastric cancer, numerous reports have assessed the association between non-coding RNAs in exosomes and gastric cancer. The purpose of the present review was to summarize recent evidence on certain non-coding RNAs associated with the development, diagnosis and treatment of gastric cancer.