Bamboo leaf: A review of traditional medicinal property, phytochemistry, pharmacology, and purification technology.

ETHNOPHARMACOLOGICAL RELEVANCE: Bamboos are perennial evergreen plants that belong to the subfamily Bambusoideae of the true grass family Poaceae, with more than thousands of species distributed around the world. They are used as a traditional medicine with demonstrated effects of anti-oxidation, free radical scavenging, anti-inflammatory, liver protection and ameliorating cognitive deficits. Bamboo leaf is mainly used for the treatment of atherosclerotic, diabetic and nervous system diseases. AIM OF THE STUDY: This review aims to provide up-to-date information on the traditional medicinal properties, phytochemistry, pharmacology, and purification technologies of bamboo leaf. MATERIALS AND METHODS: Relevant information on bamboo leaf was obtained by an online search of worldwide accepted scientific databases (Web of Science, ScienceDirect, Elsevier, SpringerLink, ACS Publications, Wiley Online Library and CNKI). RESULTS: More than 100 chemical compounds, including flavonoids and flavonoid glycosides, volatile components, phenolic acids, polysaccharide, coenzyme Q10, phenylpropanoid and amino acids have been reported to be present. These compounds were usually extracted by column chromatography and membrane separation technologies. Preparative high performance liquid chromatography (PHPLC), high-speed counter-current chromatography (HSCCC), simulated moving bed chromatography (SMB) and dynamic axial compression chromatography (DAC) were the advanced separation technologies have been used to isolate C-glycosides from bamboo leaf flavonoid, the main bioactive ingredient of bamboo leaf. Currently, bamboo leaf is mainly used for the treatment of atherosclerotic, diabetic, hepatic diseases and nervous system related symptoms, which are attributed to the presence of bioactive components of bamboo leaf. CONCLUSIONS: Phytochemical and pharmacological analyses of bamboo leaf have been revealed in recent studies. However, most of the pharmacological studies on bamboo leaf have focused on bamboo leaf flavonoids. Further studies need to pay more attention to other phytochemical components of bamboo leaf. In addition, there is lack of sufficient clinical data and toxicity studies on bamboo leaf. Therefore, more clinical and toxicity researches on this plant and constituents are recommended.

A novel ultrasensitive and fast aptamer biosensor of SEB based on AuNPs-assisted metal-enhanced fluorescence.

A fluorescent biosensor strategy was developed in combination with immunomagnetic separation for rapid and sensitive detection of staphylococcal enterotoxin B (SEB). Magnetic nanoparticles (MNPs) modified with aptamer of SEB could capture the SEB. Then the gold nanoparticles (AuNPs) fluorescent probe was added and a "sandwich structure" was formed between AuNPs, SEB and MNPs. The MNPs-SEB-AuNPs structure could be separated with an additional magnetic field, which resulted the lower signals of AuNPs fluorescent probe. In optimal conditions, the current method displayed a broad quantitative range from 100 to 107 fg/mL and the limit of detection was 3.43 fg/mL. The recovery of SEB-spiked milk samples ranged from 92.00 to 119.00 %, which revealed that the developed method had great accuracy. Furthermore, the method was fast and economical for ultrasensitive detection. Therefore, the fluorescent biosensor based on MNPs-AuNPs is promising for the detection of other environmental and food pollutants.

Amyloid Cascade Hypothesis for the Treatment of Alzheimer's Disease: Progress and Challenges.

The amyloid cascade hypothesis has always been a research focus in the therapeutic field of Alzheimer's disease (AD) since it was put forward. Numerous researchers attempted to find drugs for AD treatment based on this hypothesis. To promote the research of anti-AD drugs development, the current hypothesis and pathogenesis were reviewed with expounding of ß-amyloid generation from its precursor protein and related transformations. Meanwhile, the present drug development strategies aimed at each stage in this hypothesis were also summarized. Several strategies especially immunotherapy showed the optimistic results in clinical trials, but only a small percentage of them eventually succeeded. In this review, we also tried to point out some common problems of drug development in preclinical and clinical studies which might be settled through multidisciplinary cooperation as well as the understanding that reinforces the amyloid cascade hypothesis.

Genome-Wide Identification and Characterization of Members of the ACS Gene Family in Cucurbita maxima and Their Transcriptional Responses to the Specific Treatments.

Ethylene biosynthesis and signal transduction play critical roles in plant sex differentiation. ACS (1-aminocyclopropane-1-carboxylic acid synthase) is a rate-limiting enzyme in ethylene biosynthesis. However, the understanding of the ACS gene family in Cucurbita maxima is limited. Here, we identified and characterized 13 ACS genes in the C. maxima genome. All ACS genes could be divided into three groups according to a conserved serine residue at the C-terminus. Thirteen CmaACS genes were found to be randomly distributed on 10 of the 20 chromosomes of C. maxima. The ACS gene exhibits different tissue-specific expression patterns in pumpkin, and four ACS genes (CmaACS1, CmaACS4, CmaACS7, and CmaACS9) were expressed specifically in both the female and male flowers of C. maxima. In addition, the expression levels of CmaACS4 and CmaACS7 were upregulated after ethephon and IAA treatments, which ultimately increased the number of female flowers, decreased the position of the first female flower and decreased the number of bisexual flowers per plant. These results provide relevant information for determining the function of the ACS genes in C. maxima, especially for regulating the function of ethylene in sex determination.

Isolation, Characterization of Bamboo Leaf Flavonoids by Size Exclusion Chromatography and Their Antioxidant Properties.

The utilization of bamboo industry exhibits varied but still needs to be improved. Bamboo leaf flavonoid (BLF) is an important resource of bamboo which has become a research focus. However, the isolation and purification techniques of four flavonoid carbon glycosides (orientin, isoorientin, vitexin, and isovitexin) from BLF were still confronted with difficulties due to their complex and similar structures, which obstructed the development of bamboo utilization. In this article, a purification technology of four flavonoid carbon glycosides from BLF by Sephadex LH-20 was improved. The results were evaluated by HPLC and pharmacological activity. Specifically, the eluent, flow rate, and loading amount were investigated, respectively. According to the results, the eluent would dominate the isolation effect among three factors. High concentration of isoorientin and four flavonoid carbon glycosides would be obtained under the optimized condition (The eluent was 70 % methanol, the loading amount was 1.5 g, and the flow rate was 0.5 mL/min). Meanwhile, the link between flavonoid carbon glycosides content and their antioxidant activity in vitro was also revealed. Overall, the results suggested that BLF may serve as potential functional food additives and medicine.

Development of a highly sensitive detection method for TTX based on a magnetic bead-aptamer competition system under triple cycle amplification.

We have established an assay that relies on aptamer and isothermal amplification for the tetrodotoxin (TTX)detection. The method uses triple cycle amplification (strand displacement amplification combined with catalytic hairpin assembly) and fluorescent reporter as an output signal. Free TTX and cDNA compete for binding to aptamer-modified magnetic beads. The cDNA collected by magnetic separation then used as a primer to trigger triple cycle amplification to obtain more ssDNA. The ssDNA combined with the reporter probe, and the original quenched fluorescence can be recovered. In addition, a linear relationship between fluorescence spectrum and different target concentrations is revealed. This method allows TTX to be detected by fluorometry with a detection limit as low as 0.265 pg mL-1. It was applied to clams and shellfish, achieving recoveries ranging from 100% to 107.33% and 99.67%-116.67%, respectively. The results were consistent with the commercial TTX ELISA kit. This assay is highly sensitive, reliable and has a good specificity. Therefore, it provides a better alternative to the standard method for quantitative detection of TTX.

MDL and RMSEP assessment of spectral pretreatments by adding different noises in calibration/validation datasets.

In multivariate calibration, the optimization of pretreatment methods is usually according to the prediction error and there is a lack of robustness evaluation. This study investigated the robustness of pretreatment methods by adding different simulate noises to validation dataset, calibration and validation datasets, respectively. The root mean squared error of prediction (RMSEP) and multivariate detection limits (MDL) were simultaneously calculated to assess the robustness of different pretreatment methods. The result with two different near-infrared (NIR) datasets illustrated that Multiplicative Scatter Correction (MSC) and Standard normal variate (SNV) were substantially more robust to additive noise with smaller REMSP and MDL value.

Synthesis of caffeic acid phenethyl ester derivatives, and their cytoprotective and neuritogenic activities in PC12 cells.

Twenty-one caffeic acid phenethyl ester (CAPE) derivatives were synthesized, and characterized by IR, HR-MS, (1)H and (13)C NMR analyses. All compounds were evaluated for their cytoprotective effects against H2O2-induced cytotoxicity and neuritogenic activities in the neurite outgrowth in PC12 cells. Compounds 1 and 20 exhibited stronger cytoprotective activities than their parent compound CAPE at 4 nM. Compounds 1, 4, 12 and 13 showed potential neuritogenic activities at 0.5 nM, while compounds 19 and 20 induced neurite outgrowth at 10 nM. The results from this study suggested that CAPE and its derivatives may be potential functional food ingredients for the prevention of neurodegenerative diseases.

Separation, identification, and quantitation of phenolic acids in Chinese waxberry (Myrica Rubra) juice by HPLC-PDA-ESI-MS.

A high-performance liquid chromatography coupled with photodiode-array spectrophotometry and electrospray ionization-mass spectrometry (HPLC-PDA-ESI-MS) method for separation and determination of phenolic acids in ethyl acetate extracts from Chinese waxberry (Myrica Rubra) juice was developed. Total of 4 phenolic acids (ferulic, caffeic, sinapic, and salicylic acids) were identified by comparing their HPLC retention times, UV-Vis absorption spectra, and simultaneously recorded mass spectra with authentic standards. Quantitation was carried out by the peak area method. The calibration curves are linear over the concentration range studied with the correlation coefficients, R(2), greater than 0.99. The contents of ferulic, caffeic, sinapic, and salicylic acids in waxberry juice samples studied were 2.76, 3.58, 2.89, and 1.92 mg/L, respectively, and they occur mainly in bound forms. All relative standard deviations were less than 4%. The recoveries range from 83.6% to 95.8% for the 4 analytes. To the authors' best knowledge, this is the first report for the identification of the sinapic and salicylic acids in Chinese waxberry products.

catena-Poly[[chloro(1,10-phenanthroline-kappa2N,N')copper(II)]-mu-imidazolato-kappa2N:N'].

In the polymeric title compound, [Cu(im)Cl(phen)](n), where im is the imidazolate anion (C(3)H(3)N(2)) and phen is 1,10-phenanthroline (C(12)H(8)N(2)), each Cu(II) ion is five-coordinated by four basal N atoms (two from two different im anions and two from one phen ligand) and one axial Cl atom, in a distorted square-pyramidal coordination geometry. Moreover, each im anion bridges two identical [CuCl(phen)](+) cations through its two N atoms, resulting in a one-dimensional zigzag chain along the crystallographic a axis. In addition, pairs of adjacent chains are staggered by pi-pi interactions, generating a two-dimensional layer, and neighbouring layers are further linked by two different kinds of C-H...Cl interactions, producing a three-dimensional network.

catena-Poly[diaquabis(5-chloropyridinium-2-olato-kappaO)copper(II)]-mu-pyrazine-kappa2N:N'] diperchlorate].

In the title compound, [Cu(C(5)H(4)ClNO)(2)(C(4)H(4)N(2))(H(2)O)(2)](ClO(4))(2), the Cu atom, which lies on an inversion centre, has an octahedral environment. The pyrazine ligand also lies about an inversion centre and links adjacent Cu atoms into a chain running along the b axis; perchlorate anions occupy the space between the chains, and the chains use the coordinated water molecules to link to the anions, resulting in a hydrogen-bonded ribbon structure. The donor 5-chloro-2-hydroxypyridine ligand exists in the zwitterionic form, i.e. 5-chloropyridinium-2-olate.

Mu1,3-azido-diazidotetrakis(1,10-phenanthroline)dicopper(II) azide tetrahydrate.

In the title compound, [Cu2(mu-(1,3)-N3)(N3)2(phen)4](N3)*4H2O (phen is 1,10-phenanthroline, C12H8N2), each of the two Cu atoms is surrounded by two N atoms of two azide anions and by four N atoms of two 1,10-phenanthroline ligands [Cu-N distances are 1.964 (3), 2.009 (3), 2.018 (3), 2.054 (3), 2.306 (3) and 2.759 (4) A], forming an elongated CuN6 octahedron. An ideally linear mu(1,3)-azide anion bridges two Cu atoms to form a dimeric structure with the central N atom located on a centre of inversion. Moreover, the adjacent dimeric units are connected by hydrogen-bond interactions to produce one-dimensional chains. A two-dimensional supramolecular array is formed by pi-pi interactions between the aromatic rings of 1,10-phenanthroline ligands of adjacent dimeric units.