Biological activities molluscicidal

Effects of Sesquiterpene Lactones on Seed Germination. Sesquiterpene lactones are common constituents of the Asteraceae but are also found in other angiosperm families and in certain liverworts (31,32). These highly bitter substances exhibit a wide spectrum of biological activities (J 3) which include cytotoxicity, anti-tumor, anti-microbial, insecticidal (34) and molluscicidal (35) properties. Furthermore, they are known causes for livestock poisoning and contact dermatitis in humans (33). Structure-activity relationship studies on sesquiterpene lactones have demonstrated that biological activity frequently depend on the presence of the cr... 

The diverse biological activity (e.g. insect antifeeding, plant growth regulation, molluscicidal) of a number of drimane sesquiterpenoids has stimulated considerable interest in their synthesis and the year under review has seen many new developments and improvements. Much of the synthetic work has centred around the key bicyclic diester (54) derived from 1-vinyl-2,6,6-trimethylcyclohexene and dimethyl acetylenedicarboxylate. In contrast to earlier results,34 Ley et al.8S... 

Kubo and Fukuhara [217] found that the methanolic extract of the root bark of Elaeodendron bunchananii exhibited various biological activities, such as insecticidal, molluscicidal, antimicrobial, and cytotoxic. This extract showed cytotoxic activity (ED50 100 against L-1210... 

This survey has also demonstrated that compounds isolated from a number of plants of this family possess a broad spectrum of biological activities such as cytotoxic, anti-fungal, anti-bacterial, anti-malarial, anthelmintic, anti-hepatotoxic, anti-oxidative, anti-ulcer, anti-inflammatory and hypothermic, hypolipimenic, hypotensive and spasmolytic activities. Insecticidal, molluscicidal, nematocidal and larvicidal activities are also... 

These results show that the tributyltin and triphenyltin derivatives of sucrose are at least equal in biological activity to the commercially used tributyltin oxide and fluoride and are superior with regard to algicidal and fungicidal properties (9, 10). This is even more remarkable when we compare the tin contents, see Table VII. Except in the case of molluscicidal activity the tricyclohexyltin compounds are less effective and, in most tests, the less accessible compound with the sucrose residue in the R groups is inferior. Tests on the orgeinolead compotands so far have been confined to molluscicidal activity. 

Biological activity as molluscicide against Helisoma tenue, H. subcrenatum (105 -). (m) Use as bactericide,... 

The first exploitation of this relationship in a biological context was by Boyce and Milbarrow [28], who showed a relationship between the molluscicidal activity of some A -alkyltritylamines and their Rm values on TLC plates. Many publications have reported the application of TLC to determine the relative lipophilicity of compounds. The first chapter of the book Chromatographic Determination of Molecular Interactions Applications in Biochemistry, Chemistry, and Biology [29[ summarises the theory and presents the major application fields of the TLC method. The advantage of the method for the determination of lipophilicity is that the layers can be easily covered by octanol and by using an aqueous buffer the retention parameter would be directly proportional to the octanol-water partition coefficients. The drawbacks of this method are the limited reproducibility and precision. 

Additional studies investigating nicotine and its biological effects are numerous a few examples will be listed here. The damage induced increase in alkaloid production in Nicotiana, and its mechanism have been investigated [44,45], Nicotine biosynthesis continues to be studied [46,47] and has included the use of NMR [48]. A synthesis of 1 from 3,3 -dipyridyl was reported [49]. Nicotine showed potential as a molluscicide [50], it was a potent inhibitor of TAK-induced activation of polymorphonuclear leukocytes [51], and it caused reduction of herpes simplex virus type 1 production, as well as reduction of viral attachment to cell membranes [52]. Mechanisms involved in the behavioral and cognitive effects of nicotine have been investigated [53]. 

The proanthocyanidins are widely distributed in nature and often represent the active compounds of medicinal plants or plants showing human health beneficial effects. Reports of several in vitro assays demonstrate potentially significant antiviral, antibacterial, molluscicidal, enzyme-inhibiting, antioxidant, and radical-scavenging properties. " Their potential to interact with biological systems rests, at least in part, on the ability to form complexes with other biomolecules, thus emphasizing the necessity to accurately define... 

Pesticides are chemicals or biological substances used to kill or control pests. They fall into three major classes insecticides, fungicides, and herbicides. Others classes are rodenticides, nematicides, molluscicides, and acaricides. These chemicals can be natural compounds or synthetic ones. Pesticides may also be divided into contact and systemic pesticides. Pesticides that were earlier produced were of the contact type. They do not appreciably penetrate plant tissue, so they are susceptible to the effects of the weather and moreover new plant growth is not protected. Vice versa, most of the recently developed pesticides are systemically active. They move through the plant vascular system and thus they not only can protect a plant from attack but also inhibit or cure established infections. Systemic pesticides are not affected by weathering and also confer immunity to all new plant growth. In 1993, 57% of all the pesticides used in the United States were herbicides, while 23% and 12% were insecticides and fungicides, respectively [1]. 

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