Low-loss and high-resolution mechanical mode tuning in microspheres.

Lack of tunability impedes the wide application of optomechanical systems; however, little research exists on mechanical frequency tuning. Herein, ultra-fine low-loss dynamical mechanical frequency tuning is achieved by compressing a microsphere along the axial direction. The tuning resolution reaches approximately 4% of the mechanical linewidth, and the variation range of the mechanical quality factor (Qm) is within 2.9% of the untouched Qm. The roles of geometric deformation, spring effect, and stiffness were also evaluated through simulation and experimental analysis. Furthermore, sine function modulation was displayed, with a Pearson coefficient exceeding 99.3%, to achieve arbitrary-function mechanical resonance tuning. This method paves the way for scalable optomechanical applications, such as mechanical vibration synchronization or optomechanics-based optical wavelength conversion.

Effects of Isosorbide Incorporation into Flexible Polyurethane Foams: Reversible Urethane Linkages and Antioxidant Activity.

Isosorbide (ISB), a nontoxic bio-based bicyclic diol composed from two fuzed furans, was incorporated into the preparation of flexible polyurethane foams (FPUFs) for use as a cell opener and to impart antioxidant properties to the resulting foam. A novel method for cell opening was designed based on the anticipated reversibility of the urethane linkages formed by ISB with isocyanate. FPUFs containing various amounts of ISB (up to 5 wt%) were successfully prepared without any noticeable deterioration in the appearance and physical properties of the resulting foams. The air permeability of these resulting FPUFs was increased and this could be further improved by thermal treatment at 160 °C. The urethane units based on ISB enabled cell window opening, as anticipated, through the reversible urethane linkage. The ISB-containing FPUFs also demonstrated better antioxidant activity by impeding discoloration. Thus, ISB, a nontoxic, bio-based diol, can be a valuable raw material (or additive) for eco-friendly FPUFs without seriously compromising the physical properties of these FPUFs.

Effects of UV-B radiation on the survival, egg hatchability and transcript expression of antioxidant enzymes in a high-temperature adapted strain of Neoseiulus barkeri.

Biological control of spider mites in hot and dry weather is a serious technical issue. A high-temperature adapted strain (HTAS) of the predatory mite Neoseiulus barkeri Hughes was selected from its conventional strain (CS), via long-term heat acclimation and frequent heat hardenings in our previous studies. However, the environment of high temperature is usually associated with enhanced ultraviolet (UV) radiation. In the present study, the physiological effects of UV-B radiation on survival rate and egg damage of N. barkeri were investigated, as well as the activities and expression profiles of antioxidant enzymes to UV-B radiation stress. UV-B radiation had deleterious effects on egg hatchability and survival of N. barkeri. Adults of the HTAS strain were less UV-B resistant than those of the CS strain; they also had lower levels of enzymatic activity of superoxide dismutase (SOD) and catalase against oxidative damage and weaker upregulation of SOD genes. The mRNA expression of three SOD genes of CS adult females immediately increased whereas that of HTAS showed almost no difference under UV-B stress for 1 h. The results showed the HTAS of N. barkeri had lower fitness under UV-B stress compared with the CS of N. barkeri. These results suggested that long-term heat acclimation may exert a profound impact on the developmental physiology of N. barkeri.

Ethyl Rosmarinate Protects High Glucose-Induced Injury in Human Endothelial Cells.

Ethyl rosmarinate (RAE) is one of the active constituents from Clinopodium chinense (Benth.) O. Kuntze, which is used for diabetic treatment in Chinese folk medicine. In this study, we investigated the protective effect of RAE on high glucose-induced injury in endothelial cells and explored its underlying mechanisms. Our results showed that both RAE and rosmarinic acid (RA) increased cell viability, decreased the production of reactive oxygen species (ROS), and attenuated high glucose-induced endothelial cells apoptosis in a dose-dependent manner, as evidenced by Hochest staining, Annexin V⁻FITC/PI double staining, and caspase-3 activity. RAE and RA both elevated Bcl-2 expression and reduced Bax expression, according to Western blot. We also found that LY294002 (phosphatidylinositol 3-kinase, or PI3K inhibitor) weakened the protective effect of RAE. In addition, PDTC (nuclear factor-κB, or NF-κB inhibitor) and SP600125 (c-Jun N-terminal kinase, or JNK inhibitor) could inhibit the apoptosis in endothelial cells caused by high glucose. Further, we demonstrated that RAE activated Akt, and the molecular docking analysis predicted that RAE showed more affinity with Akt than RA. Moreover, we found that RAE inhibited the activation of NF-κB and JNK. These results suggested that RAE protected endothelial cells from high glucose-induced apoptosis by alleviating reactive oxygen species (ROS) generation, and regulating the PI3K/Akt/Bcl-2 pathway, the NF-κB pathway, and the JNK pathway. In general, RAE showed greater potency than RA equivalent.

Determination of a natural DNMT1 inhibitor, peperomin E, in rat plasma by UFLC-MS/MS and method application in a pharmacokinetic study.

Peperomin E (PepE), a naturally occurring secolignan isolated from Peperomia dindygulensis, has drawn much attention recently owing to its anticancer and DNA methyltransferase 1 (DNMT1) inhibitory activity. Here, a simple and sensitive ultra-fast liquid chromatography-tandem mass spectrometry method was developed and validated for the determination of PepE in rat plasma for the first time. Samples were prepared by simple protein precipitation. Separation was performed on an XBridge™ C18 column using a mobile phase of acetonitrile and 0.1% (v/v) aqueous formic acid. PepE and the internal standard arctigenin were detected in a positive-ion mode using multiple reaction monitoring of the transitions at m/z 413.2 → 261.0 and 373.2 → 137.2, respectively. The calibration curve for PepE was linear over the range of concentrations of 1.46-6000 ng/mL, with a lower limit of quantitation of 1.46 ng/mL. Both intra- and interday precisions were within 11.05%, and the accuracy ranged from -11.5 to 5.51%. The extraction recovery and matrix effect were within acceptable limits. Stability tests showed that PepE remained stable throughout the analytical procedure. The validated method was then used to analyze the pharmacokinetics of PepE administered to rats orally (12.5 and 25 mg/kg) or intravenously (6.25 and 12.5 mg/kg).

Triterpenoid Saponins with Potential Cytotoxic Activities from the Root Bark of Ilex rotunda Thunb.

A new 19-oxo-18,19-seco-ursane-type triterpeonoid saponin, laevigin E (8), together with 17 known compounds (1 - 7 and 9 - 18) were isolated from the root bark of Ilex rotunda Thunb. Their structures were determined by various spectroscopic analysis. Among them, compounds 6, 9, 11, and 18 were isolated from this species for the first time, while compounds 10 and 12 were firstly isolated from the family Aquifoliaceae. Biological activity assay showed that all triterpenoids exhibit moderate cytotoxic activities against MCF7, A549, HeLa and LN229 cell lines. The four triterpenoid saponins (3, 4, 6, and 8) exhibit slightly better activities compared to the four triterpenoid sapogenins (1, 2, 5, and 7). Compound 8 showed the best cytotoxicity against A549, HeLa and LN229 cell lines with IC50 of 17.83, 22.58 and 30.98 µm, respectively.

Peperomin E reactivates silenced tumor suppressor genes in lung cancer cells by inhibition of DNA methyltransferase.

Advanced lung cancer has poor prognosis owing to its low sensitivity to current chemotherapy agents. Therefore, discovery of new therapeutic agents is urgently needed. In this study, we investigated the antitumor effects of peperomin E, a secolignan isolated from Peperomia dindygulensis, a frequently used Chinese folk medicine for lung cancer treatment. The results indicate that peperomin E has antiproliferative effects, promoting apoptosis and cell cycle arrest in non-small-cell lung cancer (NSCLC) cell lines in a dose-dependent manner, while showing lower toxicity against normal human lung epidermal cells. Peperomin E inhibited tumor growth in A549 xenograft BALB/c nude mice without significant secondary adverse effects, indicating that it may be safely used to treat NSCLC. Furthermore, the mechanisms underlying the anticancer effects of peperomin E have been investigated. Using an in silico target fishing method, we observed that peperomin E directly interacts with the active domain of DNA methyltransferase 1 (DNMT1), potentially affecting its genome methylation activity. Subsequent experiments verified that peperomin E decreased DNMT1 activity and expression, thereby decreasing global methylation and reactivating the epigenetically silenced tumor suppressor genes including RASSF1A, APC, RUNX3, and p16INK4, which in turn activates their mediated pro-apoptotic and cell cycle regulatory signaling pathways in lung cancer cells. The observations herein report for the first time that peperomin E is a potential chemotherapeutic agent for NSCLC. The anticancer effects of peperomin E may be partly attributable to its ability to demethylate and reactivate methylation-silenced tumor suppressor genes through direct inhibition of the activity and expression of DNMT1.

[Water-soluble chemical constituents in flower buds of Lonicera macranthoides].

OBJECTIVE: To study the water-soluble chemical constituents of the flower buds of Lonicera macranthoides. METHODS: The chemical constituents were isolated and purified by means of chromatographic techniques and their structures were elucidated by spectroscopic methods. RESULTS: Six compounds were isolated and identified as trans-linalool-3,7-oxide-6-O-beta-D-glucopyranoside(1), secol oganoside(2), secoxyloganin(3),chlorogenic acid(4), caffeic acid(5), sucrose(6). CONCLUSION: Compound 1 is isolated from nature as a single compound for the first time, compounds 2-3 are isolated from this plant for the first time.

[Limonoids from fruits of Melia toosendan].

To study the chemical constituents of the fruits of Melia toosendan, three limonoids were isolated and purified by repeated silica gel column chromatography and preparative HPLC from the EtOAc extract of M. toosendan. Their structures were determined by their physico-chemical properties and spectroscopic data (1D-NMR, 2D-NMR) as: 24, 25, 26, 27-tetranorapotirucalla-(apoeupha)-1alpha-tigloyloxy-3alpha, 7alpha-dihydroxyl-12alpha-acetoxyl-14, 20, 22-trien-21, 23-epoxy-6, 28-epoxy (1), nimbolinin B (2), and trichilinin D (3), separately. Compound 1 is a new compound, and compound 2 is obtained from this plant for the first time.

Self-Healing and Mechanical Properties of Thermoplastic Polyurethane/Eugenol-Based Phenoxy Resin Blends via Exchange Reactions.

The possibility of exchange reactions and thermal self-healing in blends of thermoplastic polyurethane (TPU) and phenoxy resin was investigated herein. The analyses were based on characterization obtained via differential scanning calorimetry (DSC), Fourier transform infrared spectroscopy (FTIR), dynamic mechanical analysis (DMA), and tensile test. A new phenoxy resin was synthesized from eugenol, and blends with different types of TPU were prepared to investigate the exchange reaction, thermal self-healing, and mechanical properties. The influence of phenoxy resin content on the mechanical behavior and healing efficiency was studied. Improvement of storage modulus owing to the increase of phenoxy resin content was observed. Results suggest that the exchange reaction between phenoxy- and ester-type TPU occurred during thermal treatment. However, little exchange occurred between phenoxy resin and ether-type TPU. Specifically, only ester-type TPU exhibited a significant exchange reaction in the phenoxy resin blend. Furthermore, in the presence of a catalyst (e.g., zinc acetate), the exchange reaction readily occurred, and the healing efficiency improved by the addition of the catalyst and increase in the phenoxy content.

Novel N-containing rotenoid and seco-rotenoid from the root of Derris elliptica.

Two new rotenoids, 2-hydroxy-5-aminorotenonone (1) and elliptoic acid (2), were isolated from the roots of Derris elliptica collected in Guangdong Province, China. Their structures were established by extensive spectral analysis. Compound 1 is the first N-containing rotenoid and compound 2 is the third rotenoid with the cleavage of C(12)-C(12a).

Characteristics of Self-Healable Copolymers of Styrene and Eugenol Terminated Polyurethane Prepolymer.

With limited biomass that can be currently utilized as a renewable resource, it is important to develop a method to convert biomass into materials that can replace fossil fuel product. In this paper, eugenol, a bio-based allyl chain-substituted guaiacol, was used to synthesize self-healable copolymers. Eugenol terminated polyurethane prepolymer (ETPU) was synthesized from eugenol and polyurethane prepolymers terminated with isocyanate groups. ETPU contained two allyl groups. Self-healing copolymer networks were obtained by copolymerization of ETPU and styrene monomer via free radical polymerization. Effects of ETPU content on the properties of copolymers were then studied. These copolymers containing ETPU exhibited good thermal stability and mechanical properties. These copolymers showed higher tensile strength and elongation at break than PS. Their maximum tensile strength reached 19 MPa. In addition, these copolymers showed self-healing property at elevated temperature due to the reversible nature of urethane units in ETPU.

New Mycodiplosis gall midge (Diptera: Cecidomyiidae) feeding on fungal rusts (Fungi: Pucciniomycetes) that are pathogenic on cultured plants.

Larvae of a gall midge were found feeding on the fungal rust Maravalia pterocarpi (Pucciniomycetes: Pucciniales: Chaconiaceae) infesting the economically important sua tree Dalbergia tonkinensis (Fabaceae) on Hainan Island, China. The adults, pupae and larvae were collected, their morphology was studied and a segment of the Cytochrome Oxidase unit I (COI) mitochondrial gene was sequenced. The gall midge proved to be a species new to science that belongs to the genus Mycodiplosis (Diptera: Cecdiomyiidae). Comparison of the sequence to published Cecdiomyiidae sequences revealed that, despite being undescribed and unnamed, it was previously found in east and south-east Asia to feed on several rust species: Puccinia coronata (Pucciniomycetes: Pucciniales: Pucciniaceae) that develops on Lolium multiflorum (Poaceae), Puccinia sp. on Zea mays (Poaceae), Puccinia arachidis on Arachis hypogaea (Fabaceae) and Puccinia allii on Allium fistulosum (Amaryllidaceae). The new species is described and named here Mycodiplosis puccinivora Jiao, Bu Kolesik. It occurs in China, Japan, Thailand, Bangladesh and possibly Malaysia and Australia. In Hainan it has four to five generations per year.

Studies on chemical constituents of planted Taxus mairei (III).

From the chloroform-soluble fraction of the ethanol extracts of the whole plant of Taxus chinensis var. mairei (Lemee et Lev1), four compounds were isolated by using repeated column chromatography on silica gel and Sephadex LH-20. Based on spectroscopic data (UV, IR, ESI-MS, 1H NMR and 13C NMR), the compounds were identified as taxamairin K (1), 2alpha, 4alpha-dideacetoxy-7beta-benzoyloxy-5beta,20-epoxy-9alpha, 10beta, 13alpha, 15-tetrahydroxy-11(15-->1) abeotaxa-11-ene (2), 7beta-xylosyl-taxol (3), 10-deacetoxy-7-xylosyl-taxol (4). Among them, taxamairin K is a new compound.

[Studies on chemical constituents of rhizomes of Smilax china].

OBJECTIVE: To study the chemical constituents of the rhizomes of Smilax china. METHOD: The constituents of the rhizomes of S. china were isolated and purified by repeated silica gel and Sephadex LH-20 chromatography, and their structures were elucidated on the basis of spectral analysis. RESULT: Thirteen compounds were obtained and identified as kaemperol-7-O-beta-D-glucopyranoside (1), engeletin (2), isoengeletin (3), kaempferol (4), dihydrokaempferol (5), dihydrokaempferol-5-O-P-D-glucopyranoside (6), rutin (7), kaempferol- 5-O-beta-D-glucopyranoside (8), 3, 5, 4'-trihydroxystibene (9), vanillic acid (10), 3, 5-dimethoxy4-O-beta-D-glu-copyranosylcinnamic acid (11), beta-sitosterol (12), and beta-daucosterol (13) , respectively. CONCLUSION: Compounds 1, 3, 7, 8, and 11 were isolated from this plant for the first time, and compounds 8 and 11 were isolated from the genus Smilax for the first time.

Neo-clerodane diterpenes and phytoecdysteroids from Ajuga decumbens Thunb. and evaluation of their effects on cytotoxic, superoxide anion generation and elastase release in vitro.

Five novel compounds, including four neoclerodane diterpenoids, named ajugacumbins KN (1-4) along with a phytoecdysterone, named ajugacetalsterone E (5), were isolated from the whole herbs of Ajuga decumbens (Labiatae). Their structures were elucidated on the basis of detailed spectroscopic analysis including IR, HRESIMS, CD, 1D and 2D NMR spectroscopic experiments. Compounds 1-5 were evaluated for their cytotoxic activities and the effects on superoxide anion generation and elastase release in FMLP/CB-induced human neutrophils.

Chemical constituents from Agrimonia pilosa Ledeb. and their chemotaxonomic significance.

Phytochemical investigation of the ethanol extract from the whole plant of Agrimonia pilosa led to the isolation of 31 compounds, including 16 flavonoids (1-16), 5 triterpenes (17-21), 1 isocoumarin (22), 5 phenolic acids (23-27), 1 ceramide (28), 2 agrimols (29-30) and 1 fatty acid (31). Their structures were determined by various spectroscopic analyses. Compounds 5, 7 and 20 were firstly isolated from the genus Agrimonia, and compounds 6, 10-11, 15, 26, 28 and 31 were isolated from the family Rosaceae for the first time. Moreover, the chemotaxonomic significance of these compounds was summarised.

Two new limonoids isolated from the fuits of Melia toosendan.

In the present study, two new limonoids, 1α, 7α-dihydroxyl-3α-acetoxyl-12α-ethoxylnimbolinin (1) and 1α-tigloyloxy-3α-acetoxyl-7α-hydroxyl-12ß-ethoxylnimbolinin (2), together with other four known limonoids (3-6), were isolated from the fruits of Melia toosendan. Their structures were elucidated by means of extensive spectroscopic analyses (NMR and ESI-MS) and comparisons with the data reported in the literature. The isolated compounds were evaluated for their antibacterial activities. Compound 4 exhibited significant antibacterial activity against an oral pathogen, Porphyromonas gingivalis ATCC 33277, with an MIC value of 15.2 µg·mL(-1). Compound 2 was also active against P. gingivalis ATCC 33277, with an MIC value of 31.25 µg·mL(-1). In conlcusion, our resutls indicate that these compounds may provide a basis for future development of novel antibiotics.

Cytotoxic limonoids from the root bark of Dictamnus angustifolius.

Three novel limonoids, dictangustone G (1), dictangustone H (2), and dictangustone I (3) were isolated from the root bark of Dictamnus angustifolius. Their structures were elucidated on the basis of detailed spectroscopic analysis including UV, IR, HRESIMS, 1D and 2D NMR spectroscopic experiments. Compounds 1-3 were evaluated for their cytotoxic activities using Hela, A549, MCF7, and LN229 cell lines.