Development of aviation biofuels has attracted great attention worldwide because that the shortage of fossil resources has become more and more serious. In the present paper, the development background, synthesis technologies, current application status and existing problems of aviation biofuels were reviewed. Several preparation routes of aviation biofuels were described, including Fischer-Tropsch process, catalytic hydrogenation and catalytic cracking of bio-oil. The status of flight tests and commercial operation were also introduced. Finally the problems for development and application of aviation biofuels were stated, and some accommodation were proposed.
Aviation ; methods ; Biofuels ; Chemistry Techniques, Synthetic ; methods

Compound libraries and chemical synthesis play important roles in drug discovery and development, and efficient synthetic techniques can greatly facilitate the drug research. This review highlights the application of some efficient synthetic techniques in drug research including microwave chemistry, click chemistry, combinatorial chemistry, cascade reactions and multicomponent reactions, as well as the construction of diverse and drug-like compound libraries.
Click Chemistry ; Combinatorial Chemistry Techniques ; methods ; Drug Discovery ; methods ; Microwaves ; Pharmaceutical Preparations ; chemical synthesis

A practical approach to the synthesis of the A, B and C-ring subunit of cyclopamine has been developed. This synthetic tactic highlights the utility of mandelate acetal-mediated resolution of the fused ring ketone (±)-4 and IBX-mediated oxidation cascades from 12 to 9. The availability of advanced intermediates from enantiomerically pure (+)-4 and 2 could provide efficient access to biologically active and structurally diverse C-nor-D-homo-steroidal alkaloids such as cyclopamine.
Chemistry Techniques, Synthetic ; methods ; Molecular Structure ; Organic Chemistry Phenomena ; Stereoisomerism ; Steroids ; chemistry ; Veratrum Alkaloids ; chemical synthesis ; chemistry

OBJECTIVETo investigate the in situ extraction effect of macroporous resins on tanshinones in Salvia miltiorrhiza hairy root.

METHODMacroporous resins were added to S. miltiorrhiza hairy root culture and the contents of three major tanshinones (crypotanshinone, tanshinone I and tanshinone II(A)) in root, medium and resin were analyzed by HPLC.

RESULTThe macroporous resin X - 5 had the best adsorption effect on total tanshinones among three chosen resins (X - 5, AB - 8, XAD - 4) during the S. miltiorrhiza hairy root culture. The adsorption reached equilibrium after four hours with the addition of the resin X -5. The saturation of X - 5 on total tanshinones was 1.2 mg g)-1) resin and the adsorption ratio reached 92.4%.

CONCLUSIONThe macroporous resin X -5 could extract tanshinones in situ effectively during S. miltiorrhiza hairy root culture and simplify the further separation process.

Adsorption ; Diterpenes, Abietane ; Phenanthrenes ; analysis ; isolation & purification ; Plant Roots ; chemistry ; growth & development ; Plants, Medicinal ; chemistry ; growth & development ; Resins, Synthetic ; Salvia miltiorrhiza ; chemistry ; growth & development ; Tissue Culture Techniques ; methods

Correct diagnosis and successful therapy are extremely important to enjoy a healthy life when suffering from a disease. To achieve these aims, various cutting-edge technologies have been designed and fabricated to diagnose and treat specific diseases. Among these technologies, aptamer–nanomaterial hybrids have received considerable attention from scientists and doctors because they have numerous advantages over other methods, such as good biocompatibility, low immunogenicity and controllable selectivity. In particular, aptamers, oligonucleic acids or peptides that bind to a specific target molecule, are regarded as outstanding biomolecules. In this review, several screening techniques for aptamers, also called systematic evolution of ligands by exponential enrichment (SELEX) methods, are introduced, and diagnostic and therapeutic aptamer applications are also presented. Furthermore, we describe diverse aptamer–nanomaterial conjugate designs and their applications for diagnosis and therapy.
Diagnosis ; Mass Screening ; Peptides ; SELEX Aptamer Technique

Ligustrazine, one of the major effective components of the Chinese traditional medicinal herb Ligusticum Chuanxiong Hort, has been reported plenty of biological activities, such as protect cardiovascular and cerebrovascular, neuroprotection and anti-tumor, et al. Because of its remarkable effects, studies on structural modification of ligustrazine have attracted much attention. Ligustrazine synthetic derivatives reported in recent decades are mainly derived from four primary intermediates (TMP-COOH, TMP-OH, TMP-NH2, HO-TMP-OH). To explore the neuroprotection activitiy of ligustrazine intermediates, six ligustrazine intermediates (2, 5, 8, 11, 12, 13) were synthesized and their protective effects against CoCl2-induced neurotoxicity in differentiated PC12 cells were studied. The target compounds were prepared via different chemical methods, including oxidation, substitution, esterification and amidation without changing the structure nucleus of ligustrazine. Compared with TMP (EC50 = 56.03 micromol x L(-1)), four compounds (2, 5, 12 and 13) exhibited higher activity (EC50 < 50 micromol x L(-1)) respectively, of which, compound 2 displayed the highest protective effect against the damaged PC12 cells (EC50 = 32.86 micromol x L(-1)), but target compounds 8 and 11 appeared lower activity (EC50 > 70 micromol x L(-1)). By structure-activity relationships analysis, the introduction of carboxyl, amino to the side chain of ligustrazine and appropriately increase the proportion of ligustrazine may contribute to enhance its neuroprotective activity, which provides a reference for the design, synthesis and activity screening of relevant series of ligustrazine derivatives in the future.
Animals ; Cell Differentiation ; drug effects ; Chemistry Techniques, Synthetic ; Cobalt ; toxicity ; Drugs, Chinese Herbal ; chemistry ; Neuroprotective Agents ; chemical synthesis ; chemistry ; pharmacology ; Neurotoxins ; toxicity ; PC12 Cells ; Pyrazines ; chemical synthesis ; chemistry ; pharmacology ; Rats

Targeting of complex system such as human cells rather than biochemically pure molecules will be a useful approach to massively identify ligands specific for the markers associated with human disease such as cancer and simultaneously discover the specific molecular markers. In this study, we developed in vitro selection method to identify nuclease-resistant nucleic acid ligands called RNA aptamers that are specific for human cancer cells. This method is based on the combination of the cell-based selection and subtractive systematic evolution of ligands by exponential enrichment (SELEX) method. These aptamers will be useful for cancer-specific ligands for proteomic research to identify cancer-specific molecular markers as well as tumor diagnosis and therapy.
Aptamers, Nucleotide ; Diagnosis ; Humans ; Ligands* ; Proteomics ; SELEX Aptamer Technique

SELEX technology (Systematic Evolution of Ligand by Exponential Enrichment) is a new in vitro screening technology appeared and developed in the past 20 years. SELEX integrate library technology and screening techniques, screening a nucleic acid molecule from nucleic acid library by ligand-aptamer interaction. Similar to the antibodies, aptamers bind with the specific target substance. SELEX screening technology develops rapidly, and aptamer have been widely applied in biomedical field. This article briefly-overviewed the progress and its applications of SELEX technology in recent years.
Animals ; Gene Library ; Humans ; Oligonucleotides ; genetics ; SELEX Aptamer Technique ; methods

The computer information technology that has penetrated into every aspect of our lives, can not only assist the screening of drugs, but also simulate the effect of drugs. At present, computer-aided technologies have been used to screen aptamers, which play an important role in improving the screening efficiency and screening high affinity binding aptamers. This review summarized the screening methods of aptamers through computer-aided sequence evaluation, structural analysis and molecular docking.
Aptamers, Nucleotide ; Computers ; Molecular Docking Simulation ; SELEX Aptamer Technique/methods*

Hypericin, a red-colored naphtodianthrone, is a natural product synthesized in the medicinal plant Hypericum perforatum, commonly known as St. John's wort. Hypericin has attracted a growing attention of the pharmaceutical industry because of its potential application to various therapies, including the treatment of depression and remarkable antiviral and photodynamic activities, hyp-1 gene encodes for phenolic coupling protein which catalyzes in vitro direct and specific conversion of emodin to hypericin which, however, has not formed common opinion so far. Six pairs of primers specific to hyp-1 gene were synthesized. The rapid cloning of hyp-1 gene was performed based on step-by-step extension of a short region of the gene through a series of PCR reactions. All cloned sequences were confirmed by DNA sequencing. A vector named pET32ahyp containing hyp-1 gene was constructed and was transformed into E. coli to induce heterologous expression. SDS-PAGE and Western blot results showed the recombinant Hyp-1 protein was expressed successfully in E. coli. The soluble fraction was used to test the function of the recombinant Hyp-1. Hypericin was detected by LC-MS/MS with emodin as a substrate under in vitro conditions. The above results corroborated the Hyp-1 function, a confusing question, which lay a material foundation for the synthesis of hypericin by synthetic biotechnology.
Antidepressive Agents ; isolation & purification ; metabolism ; Antiviral Agents ; isolation & purification ; metabolism ; Chemistry Techniques, Synthetic ; Emodin ; metabolism ; Escherichia coli ; metabolism ; Gene Expression Regulation, Plant ; Genes, Plant ; Genetic Vectors ; Hypericum ; chemistry ; Peptide Synthases ; genetics ; isolation & purification ; metabolism ; Perylene ; analogs & derivatives ; isolation & purification ; metabolism ; Plant Proteins ; genetics ; isolation & purification ; metabolism ; Plants, Medicinal ; chemistry ; Recombinant Proteins ; genetics ; metabolism ; Transformation, Genetic