Neurophysins: molecular and cellular aspects.

Neurophysins are linear cystine-rich proteins containing 93–95 amino acid residues which like the neurohypophysial hormones oxytocin and vasopressin are formed in the hypothalamus and travel from there to the hypophysial posterior lobe. A species usually contains two (or three) neurophysins which differ only slightly in chain length and/or sequence. Many observatios suggest that both oxytocin and one of the neurophysins as well as vasopressin and the other neurophysin have a common precursor whose long chain is split into neurophysin and hormone. It can be shown on rats having considerable diabetes insipidus that a single gene controls the biosynthesis of the vasopressin and one of the neurophysins.     

The hormonal system of plants

Higher plants generate active substances, termed phytohormones, having the character of tissue hormones. Some of these compounds have been isolated and identified, namely ethylene, heteroauxins, and gibberellic acids. Cell-elongation inhibitors have been detected, but not yet isolated or identified. Natural and synthetic substances with hormone-analogous effects and those with a hormone-antagonistic effect have become known; evidently, they act on the hormonal system of plants which regulates growth, differentiation, and development and can serve as model substances for as yet unknown phytohormones. Certain physiological phenomena suggest the existence of additional phytohormones.     

Cool Temperature Enhances Growth,Ferulic Acid and Flavonoid Biosynthesis While Inhibiting Polysaccharide Biosynthesis in Angelica sinensis

Angelica sinensis, a perennial herb that produces ferulic acid and phthalides for the treatment of cardio-cerebrovascular diseases, prefers growing at an altitude of 1800–3000 m. Geographical models have predicted that high altitude, cool temperature and sunshade play determining roles in geo-authentic formation. Although the roles of altitude and light in yield and quality have been investigated, the role of temperature in regulating growth, metabolites biosynthesis and gene expression is still unclear. In this study, growth characteristics, metabolites contents and related genes expression were investigated by exposing A. sinensis to cooler (15 °C) and normal temperatures (22 °C). The results showed that plant biomass, the contents of ferulic acid and flavonoids and the expression levels of genes related to the biosynthesis of ferulic acid (PAL1, 4CLL4, 4CLL9, C3H, HCT, CCOAMT and CCR) and flavonoids (CHS and CHI) were enhanced at 15 °C compared to 22 °C. The contents of ligustilide and volatile oils exhibited slight increases, while polysaccharide contents decreased in response to cooler temperature. Based on gene expression levels, ferulic acid biosynthesis probably depends on the CCOAMT pathway and not the COMT pathway. It can be concluded that cool temperature enhances plant growth, ferulic acid and flavonoid accumulation but inhibits polysaccharide biosynthesis in A. sinensis. These findings authenticate that cool temperature plays a determining role in the formation of geo-authentic and also provide a strong foundation for regulating metabolites production of A. sinensis.     

Synthesis of Peptide Hormones using Recombinant DNA Techniques

Recombination of genetic material enables the creation of new bacterial strains which can synthesize specific proteins in large amounts. Such bacteria permit the production of previously inaccessible proteins. They can therefore be used as starting materials for the production of drugs which will open up new paths for therapy. Several proteins produced by bacteria after DNA recombination are presently undergoing clinical trials while others are already being produced on a large scale. Thus, in the area of recombinant DNA techniques the transition from the research laboratory to industrial exploitation has occurred much faster than was anticipated several years ago. The methods, possibilities and problems encountered in the synthesis of peptide hormones by bacteria after DNA recombination are outlined, using insulin, somatostatin, and growth hormone as examples. Great emphasis is placed on the molecular biological aspects of this approach.     

Separation of potentially therapeutic peptide hormones by liquid chromatography. Optimisation of the composition and pH of the mobile phase

The aim of this work is to optimise the proportion of the organic modifier and the pH of the mobile phase, in order to separate a series of peptide hormones with therapeutic interest in the molecular mass range from 500 to 6000. The composition of the mobile phase was optimised by establishing relationships between retention parameters and either the scale of solvent polarity, or the Kamlet–Taft multiparameter solvent scale of the eluent, using linear solvation energy relationships. Likewise, linear correlations between the chromatographic retention and Reichardt’s E^N_T parameter were obtained. These relationships allowed an important reduction of the experimental retention data needed for developing a given separation. In addition, a model describing the effect of the correctly measured pH of the mobile phase on retention in LC was established and tested for the series of selected peptides using an octadecylsilica column. The proposed equations permit the prediction of the optimum pH and also permit the determination of the acidity constants of the peptides in the hydro-organic mixtures using a minimum number of measurements.     

The Role of Birth Control in the Survival of the Human Race

Analysis of the growth of the world's population shows that if no trenchant measures are taken, the number of the earth's inhabitants is likely to double to 8 billion people within as few as 35 years. Hormonal contraception is presently the best method available which would be capable of counteracting this trend. 6.5 tons of estrogen and 32 tons of progestogen would in theory be sufficient to protect the 500 million women of child-bearing age from unwanted pregnancies for one year.—In addition, the history, industrial methods of synthesis, mode of action and side effects of steroid contraceptives as well as the possible future developments are briefly mentioned.     

Uncommon Terpenoids from Salvia Species: Chemistry,Biosynthesis and Biological Activities

The search for new bioactive compounds from plant sources has been and continues to be one of the most important fields of research in drug discovery. However, Natural Products research has continuously evolved, and more and more has gained a multidisciplinary character. Despite new developments of methodologies and concepts, one intriguing aspect still persists, i.e., different species belonging to the same genus can produce different secondary metabolites, whereas taxonomically different genera can produce the same compounds. The genus Salvia L. (Family Lamiaceae) comprises myriad distinct medicinal herbs used in traditional medicine worldwide that show different pharmacological activities due to the presence of a variety of interesting specialized metabolites, including mono-, sesqui-, di-, sester-, tri-, tetra-, and higher terpenoids as well as phenylpropanoids, phenolic acid derivatives, lignans, flavonoids, and alkaloids. We herein summarize the research progress on some uncommon terpenoids, isolated from members of the genus Salvia, which are well recognized for their potential pharmacological activities. This review also provides a current knowledge on the biosynthesis and occurrence of some interesting phytochemicals from Salvia species, viz. C₂₃-terpenoids, sesterterpenoids (C₂₅), dammarane triterpenoids (C₃₀), and uncommon triterpenoids (C₂₀+C₁₀). The study was carried out by searching various scientific databases, including Elsevier, ACS publications, Taylor and Francis, Wiley Online Library, MDPI, Springer, Thieme, and ProQuest. Therefore, 106 uncommon terpenoids were identified and summarized. Some of these compounds possessed a variety of pharmacological properties, such as antibacterial, antiviral, antiparasitic, cytotoxic and tubulin tyrosine ligase inhibitory activities. Due to the lack of pharmacological information for the presented compounds gathered from previous studies, biological investigation of these compounds should be reinvestigated.     

Separation and characterization of multicomponent peptide mixtures by liquid chromatography-electrospray ionization mass spectrometry. Application to crude products of the synthesis of leuprolide

Leuprolide is a synthetic structural analogue of luteinizing hormone-releasing hormone used for the treatment of a large number of diseases related with the regulation of sexual hormones. Solid-phase peptide synthesis is used to obtain leuprolide peptidic hormone, but this synthetic procedure results in complex mixtures that need separation and characterization. Here, liquid chromatography coupled with mass spectrometry using electrospray ionization, (LC–ES-MS), was used for the separation and characterization of multicomponent peptide mixtures of crudes of synthesis of leuprolide. To optimize the LC separation process, the method of linear solvation energy relationships was applied and the powerful coupling LC–ES-MS permitted rapid and reliable characterization of the reaction product.     

DDA在硫酸介质中的存在状态与缓蚀行为的关系

利用电化学方法、物理检测技术及表面分析技术，针对十二烷基胺（DDA）作用于FeNiSiB非晶合金表面时，在不同浓度范围内，缓蚀效率与缓蚀剂浓度存在不同的对应关系的现象，探讨了DDA的存在状态与其缓烛行为的关系．利用物理测量技术对临界浓度前后DDA的存在状态进行了分析，利用扫描隧道显微镜捕获了高浓度时DDA在非晶合金表面的典型结构，详细阐述了DDA对非晶合金的微观缓蚀机制．     

DDA在碱酸介质中的存在状态与缓蚀行为的关系

利用电化学方法、物理检测技术及表面分析技术，针对十二烷基胺（ＤＤＡ）作用于ＦｅＮｉＳｉＢ非晶合金表面时，在不同浓度范围内，缓蚀效率与缓蚀剂２在不同的对应关系的现象、探讨了ＤＤＡ的存在状态与其缓蚀行为的关系，利用物理测量技术对临界浓度前后ＤＤＡ的存在状态进行了分析，利用扫描隧道显微镜捕获了高浓度时ＤＤＡ在非晶合金表面的典型结构，详细阐述了ＤＤＡ对非晶合金的微观缓蚀机制。     

The chemistry and biochemistry of insulin

The protein hormone insulin occurs widely in the animal kingdom. Although its biological function is always the same, its amino-acid composition varies widely. Insulin consists of two polypeptide chains, which are linked by three cystine residues to form a bicyclic system with a 20-membered and an 85-membered ring. The protein crystallizes in various forms with foreign ions. In solution, insulin normally forms aggregates of 2n molecules. The hormone can be regenerated from the separated polypeptide chains, and its total synthesis has been achieved in a similar manner from synthesized peptide chains. In the biosynthesis of insulin, the two chains are evidently built up separately and subsequently linked together. Insulin promotes the synthesis of glycogen, fat, and protein in the organism; insulin deficiency leads to an increase in the blood-sugar level. At the molecular level, the mechanism of action of the hormone is still unknown. Current hypotheses are discussed. No specific active center has so far been detected in the insulin molecule, which contains several antigenic regions.     

Novel Product Chemistry from Mechanistic Analysis of ent‐Copalyl Diphosphate Synthases from Plant Hormone Biosynthesis

An active‐site water molecule coordinated by conserved histidine and asparagine residues seems to serve as the catalytic base in all ent‐copalyl diphosphate synthases (CPSs). When these residues are substituted by alanine, the mutant CPSs produce stereochemically novel ent‐8‐hydroxy‐CPP. Given the requisite presence of CPSs in all land plants for gibberellin phytohormone biosynthesis, such plasticity presumably underlies the observed extensive diversification of the resulting labdane‐related diterpenoids.     

Chemistry,Biosynthesis and Pharmacology of Sarsasapogenin: A Potential Natural Steroid Molecule for New Drug Design,Development and Therapy

Sarsasapogenin is a natural steroidal sapogenin molecule obtained mainly from Anemarrhena asphodeloides Bunge. Among the various phytosteroids present, sarsasapogenin has emerged as a promising molecule due to the fact of its diverse pharmacological activities. In this review, the chemistry, biosynthesis and pharmacological potentials of sarsasapogenin are summarised. Between 1996 and the present, the relevant literature regarding sarsasapogenin was obtained from scientific databases including PubMed, ScienceDirect, Scopus, and Google Scholar. Overall, sarsasapogenin is a potent molecule with anti-inflammatory, anticancer, antidiabetic, anti-osteoclastogenic and neuroprotective activities. It is also a potential molecule in the treatment for precocious puberty. This review also discusses the metabolism, pharmacokinetics and possible structural modifications as well as obstacles and opportunities for sarsasapogenin to become a drug molecule in the near future. More comprehensive preclinical studies, clinical trials, drug delivery, formulations of effective doses in pharmacokinetics studies, evaluation of adverse effects and potential synergistic effects with other drugs need to be thoroughly investigated to make sarsasapogenin a potential molecule for future drug development.     

Factors Inhibiting the Alkyl-Branch Plasticization of Polyoxymethylene

The ability of an alkyl branch to depress the melting temperature in a polyoxymethylene chain is measurably less than that in a polyethylene chain. The factors that inhibit the alkyl-branch plasticization of polyoxymethylene are considered by computational assessment of a series of model compounds at various levels of theory: DFT B3LYP 6-31+G*, DFT B3LYP 6-311++G**, MP2 cc-pVTZ, T1, and G3(MP2). Intramolecular interactions—characterized as acetal CH···O hydrogen bonds—are surprisingly strong and likely encourage conformational regularity in the vicinity of the alkyl branches, allowing maintenance of the intermolecular chain-chain interactions. The acetal CH···O hydrogen bonds in dimethylene glycol average to 2.65 kcal/mol while the non-acetal CH···O interactions in 1,3-propanediol are much weaker with an average of 0.34 kcal/mol (G3(MP2)). The related, classical OH···O hydrogen bond in ethylene glycol is found to be worth 2.12 kcal/mol. To describe this energetic ordering, an additional stabilizing anomeric effect is invoked for dimethylene glycol, a model for polyoxymethylene.     

Synthesis and Biological Evaluation of a Cyclo-β-tetrapeptide as a Somatostatin Analogue

Short β -peptides can mimic natural peptide hormones , as has been shown with a cyclo-β-tetrapeptide ( 1 ) that displays micromolar affinity to human somatostatin receptors. β-Peptides are thus a promising new class of peptidomimetics with potential high bioavailability due to their excellent resistance against proteases.