Activities from various plant

Table II ALS Activities from Various Plant Sources...

Juvabione is a terpene-derived ketoester that has been isolated from various plant sources. There are two stereoisomers, both of which occur naturally with R-configuration at C(4) of the cyclohexene ring and are referred to as erythro- and f/trao-juvabione. The 7(.S )-cnan(iomcr is sometimes called epijuvabione. Juvabione exhibits juvenile hormone activity in insects that is, it can modify the process of metamorphosis.18... 

Sterols and Cholesterol. Natural sterols are crystalline C76 C1(1 steroid alcohols containing an aliphatic side chain at C17. Sterols were first isolated as lionsaponifiable fractions of lipids from various plant and animal sources and have been identified in almost all types of living organisms. By far, the most common sterol in vertebrates is cholesterol (8). Cholesterol serves two principal functions in mammals. First, cholesterol plays a role in the structure and function of biological membranes.. Secondly, cholesterol serves as a central intermediate in the biosynthesis of many biologically active steroids, including bile acids, corticosteroids, and sex hormones. 

Table 4 summarizes properties of various plant cells with photosynthetic ability, indicating the Chi contents, RubisCO activities, and apparent C02 fixation rates of photoautotrophic cells derived from various plants [34,38,40]. The callus of G. max possessed the Chi content of 1.4-1.9 x 103 mg (kg-FW)-1, the value of which was about 28-fold over that in the callus of N. tabacum (58 mg (kg-FW)1). The photoautotrophic hairy roots of pak-bung exhibited relatively high Chi content of 6.1 x 102 mg (kg-FW)-1 though the value was lower than that of G. max callus. On the other hand, as shown in Table 4, the levels of RubisCO activity and Chl-based C02 fixation rate of the pak-bung hairy roots were comparable to those of the photoautotrophic plant cells reported in the literatures. These values, therefore, can be used as indicators for the potentials of photoautotrophic growth of plant cells. 

Table 4. Chi contents, RubisCO activities and apparent C02 fixation rates of photo autotrophic cells derived from various plants... 

Compounds with different structures but with the same therapeutic activity isolated from different plant species act as active moieties for the treatment of particular diseases. Some of these compounds have been abandoned due to toxicity but these compounds apparently do not cause serious adverse effects. Some of these active principles originate from edible plants and their inclusion in the diet would undoubtedly be of some value because of their hypocholesterolemic potential. Several phytoconstituents including inulin, pectin, gugglu lipids, flavonoids, ginkoloids, saponins, tannins, and others obtained from various plant sources have proven hypolipidemic potentials as has been further explained in Tables I and II. The chemical structures of a few potential phytoconstituents with hypolipidemic activity are shown in Figure 2. It is hoped that as new additions are made to the list of these active compounds causing only minimum untoward side effects, these naturally... 

A biologically active additive from Jerusalem artichoke is described, made from various plant parts, which is claimed to have a beneficial effect on the skin. 

The isolation and identification of new eremophilane sesquiterpenoids from various plant species continues to be an active area of research. For the sake of simplicity new furanoeremophilanes are shown in Table 89 Other new eremophilane sesquiterpenoids include (518)—(532). A number of other eremophilanes have been isolated from various South African... 

Various commercial routes for the production of L-phenyalanine have been developed because of the utilization of this amino acid in the dipeptide sweetener Aspartame. One route that has been actively pursued is the synthesis of L-phenylalanine from trans-cinnamic acid using the enzyme phenylalanine ammonia lyase (105,106). This enzyme catalyzes the reversible, nonoxidative deamination of L-phenylalanine and can be isolated from various plant and microbial sources (107,108). 

The majority of resolutions that have been carried out depend upon the reaction of organic bases with organic acids to yield salts. Let us suppose, for example, that we have prepared the racemic acid, ( )-HA. Now, there are isolated from various plants very complicated bases called alkaloids (that is, alkali-like), among which are cocaine, morphine, strychnine, and quinine. Most alkaloids are produced by plants in only one of two possible enantiomeric forms, and hence they are optically active. Let us take one of these optically active bases, say a levorotatory one, ( )-B, and mix it with our racemic acid ( )-HA. The acid is present in two configurations, but the base is present in only one configuration there will result, therefore, crystals of two different salts, [(--) BH (- -)-A ] and [( )-BH+-(-)-A ]. 

There are literally thousands of published scientific papers from around the globe describing the antimicrobial activities of natural products [14-17], A search of the PubMed database (data from 1975 to 2005, available on the Internet) produced approximately 1360 reports in the scientific and medical literature that described the antimicrobial activities of various plant species and their chemical constituents. Furthermore, a search of the Napralert database, the world s largest natural products database housed within the University of Illinois at... 

Active medical research indicates that polyphenols from various plant foods hold the promise to favorably impact human health. For example, there is preliminary evidence that polyphenols act against these major threats ... 

The term opium alkaloids has been used rather loosely to cover all narcotic analgesics, whether they be synthetic compounds, partially synthetic, or extracted from plant material. To be precise, we should really only use the term for those natural compounds which have been extracted from opium—the sticky exudate obtained from the poppy (Papaver somniferum). The term alkaloid refers to a natural product which contains a nitrogen atom and is therefore basic in character. There are, in fact, several thousand alkaloids which have been extracted and identified from various plant sources and examples of some of the better known alkaloids are shown in Fig. 12.1. These compounds provide a vast library of biologically active compounds which can be used as lead compounds into many possible fields of medicinal chemistry. However, we are only interested at present in the alkaloids derived from opium. 

PZC/IEP of Activated Carbon Obtained from Various Plant Precursors... 

Since the discovery of brassinolide, ten years ago, research on brassinolide and related steroids has attained a remarkable degree of development. So far, twenty-three brassinosteroids [BS] have been isolated and identified from twenty-two plant species. Furthermore, many unknown brassinolide-like active substances have been detected, so that the number of identified ones is likely to increase in the future. The background to successful isolation of new BS from various plant sources is due to the use of a rice-lamina inclination test for screening that is sensitive and specific for brassinosteroids. 

Brassinosteroids are ubiquitous in nature. Brassinolide was first isolated from the pollen of rape (Brassica napus L.) plant and has plant-growth-promoting activity on various plants. Following the brassinolide discovery, other (about 20) brassinosteroids including brassinolide were found mostly from various higher plants. 

The focus of the work of many of the articles published in the last 10 years by researchers in the field of essential oil biological activity is on the activity to inhibit microorganisms. Over a third (out of 220) of the articles obtained from a recent literature search dealt with antimicrobial activity, either against bacteria or fungi or both. Essential oil activity for the inhibition of bacteria and/or fungi was determined, usually followed by an investigation of the activity of the individual components. Sometimes the activities associated with the essential oils from various plant varieties, with different amounts of constituents, were compared. 

The molecule(s) in litchi, longan, and dried longan responsible for induction of COX-2 expression in the macrophage are not known. Plant lectin may be one of candidates because of its water-soluble nature. Lectins from various plant sources have been shown to bind to macro-phage surface glycoproteins (63,64) and can result in activation of the macrophages (64). 

As long as mankind continues to cultivate and grow plants for food, feed, and fiber, crops will be threatened by various enemies and agents such as insects, fungi, and bacteria. Prevention and control of insect pests and plant diseases will remain an important objective of agrochemical research. In this study, the isolation and structure determination of several compounds showing insect antifeedant activity and antifungal activity from Peru plants are presented. 

Chalcone synthases (CHS) and stilbene synthase (STS) are closely related plant PKSs that catalyze the stepwise condensation between acyl CoA esters in the biosynthesis of flavonoids, stilbenes, and other related plant aromatic polyke-tides [70,72,75]. Sequences for munerous CHS as well as a few STS have been determined from various plants [72-76, 122-131]. They all possess a highly conserved cysteine (Cys) residue that is essential for PKS activity, although the sequences in this Cys motif have no apparent similarity to that of KS of bacterial and fungal PKSs [ 132]. The plant PKSs are essentially condensing enzymes,lack the ACP domain, and use the acyl CoA esters directly as substrate for the condensing reactions [72,75]. 

The biochemistry and enzymology of CHS and its closely related plant PKSs have been extensively studied [72, 75]. The native enzymes have been isolated from various plants [70,71,73,74,124,125,127,128], and the recombinant proteins have been produced in E. coli and purified [71,76,124,125,132-135,139]. The active site for the condensation reaction has been mapped to a single Cys residue [132]. The dimeric nature of CHS and STS has been established with each homodimer to constitute two active sites [76,127,133]. The subtle differences among the CHS and STS proteins have been compared, which seems to have a profoimd effect on substrate specificity and regiospedfidty for the condensation and cyclization reactions, respectively [74, 127, 128, 133, 134]. The interactions between CHS and other proteins, such as KR [133,136-139] and methylmalonyl CoA-specific condensing enzyme [76], have been examined to account for the biosynthesis of deoxychalcones and methylchalcones. 

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