Chemical components bioactivity

In research of the chemical components of Chinese medicines, the structures and bioactivities of more than a thousand new natural product compounds have been studied, published, and reviewed [2-5]. A notorious example is the study of antimalarial artemisinin (qinghaosu) and its derivatives [6,7],... 

More complex is the choice of excipients designed to act as lyopro-tectants of chemically labile bioactive components. Earlier discussions have demonstrated that biopharmaceuticals, in particular, proteins, can rarely be induced to crystallise during freezing. They thus remain in the amorphous, supersaturated freeze-concentrate, where they become... 

Zheng CJ, Qin LP (2007) Chemical components of Centella asiatica and their bioactivities. J Chin Integr Med 5 348-351... 

In this research, we systematically studied the chemical components of the seeds of Allium tuberosum, A total of 39 compounds were isolated. Twenty-three of them are new compounds (marked in ). The structures of the isolated compounds were eludidated by spectral methods which include APCI-MS, H-NMR, C-NMR, H- H COSY, TOCSY, ROESY, HMQC, and HMBC. In addition, 12 of them have been tested for the inhibition of the HL-60 cell line. One new spirostanol saponin (1) showed veiy strong inhibition with an IC50 values of 6.8 xg/mL. Further investigations on the prevention of disease and improvement of human health by the seeds of Allium tuberosum and/or its bioactive components are required. 

Ultrasonically assisted extraction is also widely used for the isolation of effective medical components and bioactive principles from plant material [195]. The most common application of low-intensity ultrasound is as an analytical technique for providing information about the physico-chemical properties of foods, such as in the analysis of edible fats and oils (oil composition, oil content, droplet size of emulsions, and solid fat content) [171,218]. Ultrasonic techniques are also used for fluids characterisation [219]. 

In this review, we use the terms, biologically active or bioactive for any substance which elicits some biological response in another organism. Early investigations on bioactive marine isonitriles focussed on compounds that might serve as chemical defense agents (cf. Sect. 5.1). As chemists began to resolve mixtures into individual components, other tests related to antiviral, antimicrobial, or antiparasitic activity, were reported. Often, bioassays were performed... 

An important number of these substances have an industrial origin. Some of them, like the pesticides, arrive intentionally in the environment and their use and release should be theoretically controlled. However, many of them have not been purposely produced as bioactive substances but more as components or additives of certain materials. Their significant growth in the chemical industry has not only been produced as a consequence of the discovery of new active principles in the pharmaceutical or pesticide area, but also because of the expansion of new technologies (electronics, containers, textiles, plastics, resins, foams, etc.), that require the development of new materials and substances with particular features. Most of these substances enter or are discharged to water and air sources without regulated controls. Wastewater treatment plants (WWTPs) are often not yet adapted to completely remove them, and therefore these new compounds can be found to some extent in wastewater effluents as well as in soil and sludge. 

The NIH has set up a consortium called the Molecular Libraries Screening Center Network (MLSCN), which performs HTS on assays provided by the research community. It currently has more than 100,000 chemically diverse compounds. This is an initiative of the Molecular Libraries Roadmap, which also has another two components Cheminformatics and Technology Development. The aim is to generate a comprehensive database of chemical compounds and their bioactivities to enhance the capability for the development of new drug entities. 

Many polymer-polymer complexes can be obtained by template polymerization. Applications of polyelectrolyte complexes are in membranes, battery separators, biomedical materials, etc. It can be predicted that the potential application of template polymerization products is in obtaining membranes with a better ordered structure than it is possible to obtain by mixing the components. The examples of such membranes from crosslinked polyCethylene glycol) and polyCacrylic acid) were described by Nishi and Kotaka. The membranes can be used as so-called chemical valves for medical applications. The membranes are permeable or impermeable for bioactive substances, depending on pH. 

To ensure lot-to-lot consistency, standardization of extracts often relies on constituents as biomarkers for plant identity and potency. SJW Hypericum perforatum), a perennial shrub traditionally used as a mood enhancer and mild antidepressant, has been tested in dozens of clinical trials, with mixed results for efficacy. Some of its purported bioactive constituents include naphthodianthrones, including hypericin flavonoids phloroglucinols, including hyperforin and essential oils. For many years, hypericin was presumed to be the active component. As a result most extracts were standardized based on hypericin concentration. Recent data, however, support other components such as hyperforin and the flavanoids, that may also contribute to the therapeutic efficacy of the SJW extracts (33-35). Because these secondary components were previously unaccounted for in the standardization of the former clinical test articles, and because these constituents are chemically unrelated to and their content within the plant varies independently of hypericin, it has been argued that the potency of these constituents in any particular batch was unlikely to be similar to that of other batches. This variability between batches could explain the observed differences in the clinical trial results (36). 

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