THE DESIGN AND ANALYSIS OF EXPERIMENTS. By Oscar Kempthorne. New York, John Wiley and Sons, Inc., 1952. 631 pp. $8.50. This book by a teacher of statistics (as well as a consultant for \"experimenters\") is a comprehensive study of the philosophical background for the statistical design of experiment. It is necessary to have some facility with algebraic notation and manipulation to be able to use the volume intelligently. The problems are presented from the theoretical point of view, without such practical examples as would be helpful for those not acquainted with mathematics. The mathematical justification for the techniques is given. As a somewhat advanced treatment of the design and analysis of experiments, this volume will be interesting and helpful for many who approach statistics theoretically as well as practically. With emphasis on the \"why,\" and with description given broadly, the author relates the subject matter to the general theory of statistics and to the general problem of experimental inference. MARGARET J. ROBERTSON

The Design and Analysis of Experiments

Production of plant secondary metabolites: a historical perspective

Quality control of herbal medicines

Alkaloids represent a highly diverse group of compounds that are related only by the occurrence of a nitrogen atom in a heterocyclic ring. Plants are estimated to produce approximately 12,000 different alkaloids, which can be organized into groups according to their carbon skeletal structures. Alkaloid biosynthesis in plants involves many catalytic steps, catalyzed by enzymes that belong to a wide range of protein families. The characterization of novel alkaloid biosynthetic enzymes in terms of structural biochemistry, molecular and cell biology, and biotechnological applications has been the focus of research over the past several years. The application of genomics to the alkaloid field has accelerated the discovery of cDNAs encoding previously elusive biosynthetic enzymes. Other technologies, such as large-scale gene expression analyses and metabolic engineering approaches with transgenic plants, have provided new insights into the regulatory architecture of alkaloid metabolism.

Alkaloid Biosynthesis: Metabolism and Trafficking

Plant cell cultivations are being considered as an alternative to agricultural processes for producing valuable phytochemicals. Since many of these products (secondary metabolites) are obtained by direct extraction from plants grown in natural habitat, several factors can alter their yield. The use of plant cell cultures has overcome several inconveniences for the production of these secondary metabolites. Organized cultures, and especially root cultures, can make a significant contribution in the production of secondary metabolites. Most of the research efforts that use differentiated cultures instead of cell suspension cultures have focused on transformed (hairy) roots. Agrobacterium rhizogenes causes hairy root disease in plants. The neoplastic (cancerous) roots produced by A. rhizogenes infection are characterized by high growth rate, genetic stability and growth in hormone free media. These genetically transformed root cultures can produce levels of secondary metabolites comparable to that of intact plants. Hairy root cultures offer promise for high production and productivity of valuable secondary metabolites (used as pharmaceuticals, pigments and flavors) in many plants. The main constraint for commercial exploitation of hairy root cultivations is the development and scaling up of appropriate reactor vessels (bioreactors) that permit the growth of interconnected tissues normally unevenly distributed throughout the vessel. Emphasis has focused on designing appropriate bioreactors suitable to culture the delicate and sensitive plant hairy roots. Recent reactors used for mass production of hairy roots can roughly be divided as liquid-phase, gas-phase, or hybrid reactors. The present review highlights the nature, applications, perspectives and scale up of hairy root cultures for the production of valuable secondary metabolites.

Hairy Root Culture for Mass-Production of High-Value Secondary Metabolites

Vegetable sources and agro-industrial residues represent an important source of phenolic compounds that are useful in a wide range of applications, especially those with biological activities. Conventional techniques of phytochemical extraction have been associated with a high consumption of organic solvents that limits the application of bioactive extracts, leading to the implementation of novel extraction technologies using mechanisms such as Ultrasound Assisted Extraction (UAE). In the present review, an analysis of the involved variables in the extraction yield of phenolic compounds through UAE is presented, highlighting the advantages of this technology based on the results obtained in various optimized studies. A comparison with other technologies and a proposal of its possible application for agro industrial residues as raw material of phenolic compounds is also indicated. Finally, it is concluded that UAE is a technology that is placed within the area of Sustainable Chemistry since it promotes the use of renewable raw materials through the extraction of phenolic compounds, implementing the substitution of organic solvents with solvents that do not present toxic effects, lowering the energy consumption when compared to conventional methods and minimizing process times and temperatures, which is useful for the extraction of thermo-labile compounds.

Ultrasound assisted extraction for the recovery of phenolic compounds from vegetable sources

The aim of this paper was the screening of the variability of growth patterns, biomass and tropane alkaloid production of 500 hairy root lines ofDatura stramonium. Data on the long term stability in alkaloid production of these lines for more than 5 years are also provided. In an effort to obtain high alkaloid-producing root clones, it is demonstrated that systematic selection is necessary. Comparisons are made, mainly concerning alkaloid production and its stability, with normal root cultures initiated from the same mother plants when necessary. Hairy root cultures were found to have a hyoscyamine and scopolamine bioproductivity of 2 orders of magnitude higher than mother plants.

Establishment of hairy root cultures of Datura stramonium . Characterization and stability of tropane alkaloid production during long periods of subculturing

Catharanthus roseus (L.) G. Don hairy roots harboring hamster 3-hydroxy-3-methylglutaryl-CoA reductase (HMGR) (EC 1.1.1.88) cDNA without membrane-binding domain were evaluated by quantifying the levels of sterols and some indol-alkaloids. Clone 236, with the highest hybridization signal, had the lowest soluble and microsomal HMGR activity and produced more ajmalicine and catharanthine than the control but had reduced campesterol concentration. Clone 19, with low hybridization signal, had high soluble HMGR activity and produced high levels of campesterol and five to seven times more serpentine than the control but a low level of ajmalicine and no accumulation of catharanthine. These results suggest a possible role for HMGR in indole alkaloid biosynthesis and a possible cosuppression of both the endogenous and foreign HMGR genes in clone 236.

Overexpression in Catharanthus roseus hairy roots of a truncated hamster 3-hydroxy-3-methylglutaryl-CoA reductase gene.

Sensitive and rapid thin layer chromatographic-densitometric methods have been developed for the quantification of the indole alkaloids, ajmalicine and serpentine, and of the tropane alkaloids, hyosycamine and scopolamine. The concentration ranges in which accurate and reproducible results can be obtained are 1-8 μg for the tropane alkaloids, 1-10 μg for ajmalicine and 200–1400 ng for serpentine. The limit of detection for serpentine is 20 ng and 500 ng for the other alkaloids. The methods have been successfully employed for the determination of alkaloids in tumours and calli of Catharanthus roseus, in root tissues of Datura stramonium and also in the respective liquid culture media.

Quantitative analysis of serpentine and ajmalicine in plant tissues of Catharanthus roseus and hyoscyamine and scopolamine in root tissues of Datura stramonium by thin layer chromatography-densitometry

Teresa Ayora-Talavera

Papers

Ultrasound assisted extraction for the recovery of phenolic compounds from vegetable sources

Establishment of hairy root cultures of Datura stramonium . Characterization and stability of tropane alkaloid production during long periods of subculturing

Overexpression in Catharanthus roseus hairy roots of a truncated hamster 3-hydroxy-3-methylglutaryl-CoA reductase gene.

Quantitative analysis of serpentine and ajmalicine in plant tissues of Catharanthus roseus and hyoscyamine and scopolamine in root tissues of Datura stramonium by thin layer chromatography-densitometry

Effect of bio-chemical chitosan and gallic acid into rheology and physicochemical properties of ternary edible films.