Novel water-soluble unsaturated poly(ether amide)s (PEAs) were synthesized by low-temperature polycondensation of fumaryl chloride and amine-terminated poly(ethylene glycol) (Jeffamine(R)). The unsaturated copolymers were further chemically modified with thiols to provide reactive pendant functional groups. Hydrogels based on these copolymers were prepared by copolymerization of the PEA with N-vinyl pyrrolidone exposure to ultraviolet (UV) irradiation. The resulting hydrogels exhibited a high swelling ratio, and the magnitude of swelling depended on the molecular weight of Jeffamine(R). The swelling ratio and equilibrium water content tended to increase with increasing chain length of the Jeffamine(R) used in copolymer synthesis. (C) 1999 John Wiley & Sons, Inc.

Covalent linkage of poly(ethylene glycol) (PEG) to drug molecules results in water-soluble conjugates with altered bioavail-ability, pharmacokinetics, immunogenic properties, and biological activities. For drugs bearing one or more amino groups, reductive amination is a potentially useful method for conjugation to PEG. PEG acetaldehyde has been used for this purpose, but its ease of polymerization under certain conditions and its susceptibility to air oxidation have caused some problems in its application. A simple and reliable method for preparation and use in reductive amination of PEG acetaldehyde hydrate generated in situ by hydrolysis of PEG acetaldehyde diethylacetal is demonstrated. PEG acetaldehyde diethylacetal is prepared in high yield and purity by reaction of PEG with chlorodiethylacetal in dioxane in the presence of finely powdered sodium hydroxide under heterogeneous conditions. PEG acetaldehyde hydrate is generated in solution by hydrolysis in aqueous acids. Solutions of the hydrate may be used directly, in conjunction with sodium cyanoborohydride, to effect reductive amination. We demonstrate application of these methods in PEGylation of lysozyme and chitosan to form water-soluble methoxy poly(ethylene glycol) (mPEG) derivatives and PEG-chitosan hydrogels.

The effects of citrus limonoids, applied topically to potato (Solanum tuberosum L. var. ‘Katahdin’) foliage, on Colorado potato beetle (Leptinotarsa decemlineata (Say) (Chrysomelidae) larval development, growth, and survival were quantified in laboratory assays and a small‐plot field test. In laboratory assays, survival, development rate, and body weight decreased with increasing limonoid concentration, however these measures of larval response did not significantly differ among varying periods of limonoid exposure (three, six, or nine days). Significant limonoid application concentration and frequency effects on survival, development rate, and defoliation were observed in the field test. These results indicate the potential utility of lethal and non‐lethal effects of citrus limonoids for management of the Colorado potato beetle.

Oxidation of the 19-side-chain of betulin 3 beta,28-diacetate, a pentacyclic triterpene derived from the readily available birchbark triterpene, betulin, yielded compounds active as antifeedants against larvae of the agricultural insect pest Colorado potato beetle, Leptinotarsa decemlineata. Of the eight compounds investigated, the most active was 30-hydroxy-20-oxo-29-norlup-3 beta,28-diacetate (VI). Acetylation of VI significantly reduced antifeedant activity.

The effects of citrus limonoids, applied topically to potato foliage, on colonization and oviposition by Colorado potato beetle, Leptinotarsa decemlineata (Say), adults were quantified in no-choice laboratory assays, choice and no-choice greenhouse arena observations, and small-plot field tests. In laboratory assays the oviposition rate decreased with increasing limonoid dosage and exposure time. Oviposition suppression time also increased with increasing dosage. Over a 9-d observation period, ED 50 s (50% reduction in fecundity) were 7.2 mg/ml, 1.93 mg/ml, and 0.64 mg/ml for 3-, 6-, and 9-d exposures, respectively. Adult colonization and oviposition rates were significantly reduced by limonoid treatment in both greenhouse and field tests. The seasonal density of adults was significantly reduced with a low rate (3.6 kg/ha) application of limonoids, whereas a higher application rate (10.8 kg/ha) was needed to reduce significantly the seasonal egg mass density in the field. The total number of treatment applications (1, 2, or 3) made at 3-d intervals significantly lengthened the period during which colonization and oviposition were inhibited, but did not affect seasonal densities of either adults or egg masses. These results indicate that citrus limonoids have very good potential for use in pest management.

The effects of citrus limonoid antifeedants used alone and in sequence with a Bacillus thuringiensis var. san diego delta endotoxin product against the Colorado potato beetle, Leptinotarsa decemlineata (Say), were examined in laboratory and field tests. In the laboratory, prior exposure to citrus limonoid did not alter Colorado potato beetle mortality in response to the endotoxin. Larval development time was significantly slower among larvae treated with limonoid or endotoxin; the most delayed development occurred among larvae receiving endotoxin following limonoid treatment. In field tests, rates of Colorado potato beetle adult colonization and oviposition were significantly lower in plots treated with endotoxin following treatment with limonoid compared with plots treated with either compound alone. Bioassays and chemical analyses of residues indicate that limonoids persist on potato foliage for ≈6-8 d under field conditions. The tests indicate that citrus limonoid antifeedants may be effectively used in conjunction with B. thuringiensis var. san diego endotoxin in an integrated approach to Colorado potato beetle management.

From the rootbark of Turraea mombasana, two new limonoids, 1 and 2, of the prieurianin class have been isolated and their structures established by spectroscopic means.

A new limonoid, mzikonol {2}, in addition to the known limonoids mzikonone {1}, azadirone {3}, 1,2-dihydroazadirone {4}, and nimbolinin B {6}, was isolated from the root bark of Turraea robusta. In addition, a new tetranortriterpene lactone, turranolide {5}, and the known triterpene, butyrospermol {7}, both possible protolimonoids, were isolated. Compounds were identified by chemical and spectroscopic methods.

The antifeedant effects of three citrus limonoids (limonin, obacunone, and nomilin) which differ only in the structure of the A-ring were compared in feeding assays with fourth-instar Colorado potato beetles, Leptinotarsa decemlineata (Say). In contrast to studies with other insects, the results of choice assays showed no differences among the three limonoids in their ability to deter feeding. No-choice assays also indicated no differences among the limonoids and, along with incidental observations, suggested that all three limonoids acted as toxins. The changes in the A-ring represented by obacunone and nomilin may be important in enhancing deterrency against some insect species but have no effect in increasing the toxicity of limonoids against Colorado potato beetle larvae.

The uptake of limonin double salt through leaf petioles and transport in potato leaves were demonstrated by significant feeding and growth reductions in short-term and long-term feeding bioassays with fourth stadium Colorado potato beetle, Leptinotarsa decemlineata (Say). However, limonin double salt was not an effective antifeedant when applied to leaf surfaces. It was converted to limonin (an antifeedant) within potato leaves, where it evoked feeding and growth reductions. The loss of antifeedant activity of limonin double salt revealed that the integrity of the D-ring was important for antifeedant activity of limonin. Limonin double salt or its converted product at high doses (greater-than-or-equal-to 50-mu-g/cm2) was phytotoxic to potato leaves.

Colorado potato beetle, Leptinotarsa decemlineata (Say), neonate larvae and adults were bioassayed with the antifeedant epilimonol. Three-day exposure of neonate larvae resulted in increasing delays in development (appearance of 4th instars) corresponding to increasing dosages. At a dosage of 20-mu-g/cm2, development was delayed by about 40% without other detrimental effects. Mouthpart coating of adult beetles with epilimonol emulsion resulted in significant feeding reductions, while injection of epilimonol into the haemolymph of female adults did not elicit significant feeding reduction or oviposition suppression. The results indicated that epilimonol did not elicit significant internal toxicity, and feeding reductions were most likely exerted by action on chemoreceptors on mouthparts or in the preoral cavity.

Entomologia Experimentalis et ApplicataVolume 58, Issue 2 p. 191-194 A comparison of the effects of limonin on Colorado potato beetle, Leptinotarsa decemlineata, and fall armyworm, Spodoptera frugiperda, larval feeding M. J. Mendel, M. J. Mendel Department of Entomology, Deering Hall, University of Maine, Orono, ME 04469, USASearch for more papers by this authorA. R. Alford, Corresponding Author A. R. Alford Department of Entomology, Deering Hall, University of Maine, Orono, ME 04469, USADepartment of Entomology, Deering Hall, University of Maine, Orono, ME 04469, USASearch for more papers by this authorM. D. Bentley, M. D. Bentley Department of Chemistry, Aubert Hall, University of Maine, Orono, ME 04469, USASearch for more papers by this author M. J. Mendel, M. J. Mendel Department of Entomology, Deering Hall, University of Maine, Orono, ME 04469, USASearch for more papers by this authorA. R. Alford, Corresponding Author A. R. Alford Department of Entomology, Deering Hall, University of Maine, Orono, ME 04469, USADepartment of Entomology, Deering Hall, University of Maine, Orono, ME 04469, USASearch for more papers by this authorM. D. Bentley, M. D. Bentley Department of Chemistry, Aubert Hall, University of Maine, Orono, ME 04469, USASearch for more papers by this author First published: February 1991 https://doi.org/10.1111/j.1570-7458.1991.tb01467.xCitations: 12AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat Citing Literature Volume58, Issue2February 1991Pages 191-194 RelatedInformation

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTA Heliothis zea antifeedant from the abundant birchbark triterpene, betulinFulgentius N. Lugemwa, Fu Yung Huang, Michael D. Bentley, Michael J. Mendel, and A. Randall AlfordCite this: J. Agric. Food Chem. 1990, 38, 2, 493–496Publication Date (Print):February 1, 1990Publication History Published online1 May 2002Published inissue 1 February 1990https://pubs.acs.org/doi/10.1021/jf00092a035https://doi.org/10.1021/jf00092a035research-articleACS PublicationsRequest reuse permissionsArticle Views232Altmetric-Citations41LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InRedditEmail Other access optionsGet e-Alertsclose Get e-Alerts

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

AbstractEpilimonol, a limonin derivative, was tested in short and long term feeding bioassays against Colorado potato beetles, Leptinotarsa decemlineata (Say), for feeding reduction and ovipositional suppression. At dosages of 10 to 30 μg/cm2, epilimonol reduced feeding by 42% to 65% in short term no‐choice assays. However, beetles did not strongly select untreated potato leaf discs over epilimonol‐treated (10 μg/cm2) ones in short term choice assays. In long term tests, epilimonol at 10 μg/cm2 remained effective against feeding, caused mortality, and suppressed oviposition. Starvation (> 16 hours/day) also caused mortality and suppressed oviposition.RésuméEffets de l'épilimonol et du jeûne sur l'alimentation et la ponte de Leptinotarsa decemlineataLes effets de l'épilimonol, dérivé de la limonine, ont été observés sur l'alimentation et la ponte de L. decemlineata au cours d'expériences d'alimentation brèves ou prolongées. L'épilimonol à 10 à 30 μg/cm2 réduit de 42 à 65 % la prise de feuillage de Solanum tuberosum lors d'expériences sans choix. Au cours d'expériences prolongées, l'épilimonol à 10 μg/cm2 empêche la ponte et provoque la mort des adultes. Aucune accoutumance des adultes à l'épilimonol n'est apparue quant à l'alimentation et à la ponte. La ponte commence 3 à 5 jours après des traitements à l'épilimonol de 9 et 25 jours. Le jeûne supérieur à 16/jour provoque aussi la mortalité des adultes et supprime la ponte et peut être le mécanisme initial dû à l'épilimonol. Cependant, dans des expériences brèves de choix entre des rondelles de feuilles de pommes de terre traitées à 10 μg/cm2 et non traitées, L. decemlineata ne choisit pas particulièrement les rondelles non traités. On peut ainsi estimer que l'épilimonol n'a que des effets mineurs ou est sans effet sur la sélection de l'hôte par L. decemlineata. La régression de la prise de nourriture pourrait être due à l'action sur les sensilles gustatives de la bouche ou de de la cavité préorale qui sont moins impliquées dans le processus de sélection de l'hôte et plus responsables de la prise de nourriture.

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTVolatiles of wild blueberry, Vaccinium angustifolium: possible attractants for the blueberry maggot fruit fly, Rhagoletis mendaxFulgentius N. Lugemwa, Wilber Lwande, Michael D. Bentley, Michael J. Mendel, and A. Randall AlfordCite this: J. Agric. Food Chem. 1989, 37, 1, 232–233Publication Date (Print):January 1, 1989Publication History Published online1 May 2002Published inissue 1 January 1989https://pubs.acs.org/doi/10.1021/jf00085a053https://doi.org/10.1021/jf00085a053research-articleACS PublicationsRequest reuse permissionsArticle Views316Altmetric-Citations41LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InRedditEmail Other access optionsGet e-Alertsclose Get e-Alerts

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTTetranortriterpenes from Melia volkensiiMohamed S. Rajab and Michael D. BentleyCite this: J. Nat. Prod. 1988, 51, 5, 840–844Publication Date (Print):September 1, 1988Publication History Published online1 July 2004Published inissue 1 September 1988https://doi.org/10.1021/np50059a004RIGHTS & PERMISSIONSArticle Views184Altmetric-Citations24LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (260 KB) Get e-Alerts Get e-Alerts

A new tetranortriterpene, mzikonone (12α-acetoxy-1,2-dihydro-7-deacetylazadirone), has been isolated as the major limonoid from the root bark of Turraea robusta and its structure determined by spectroscopic and chemical methods. Its degree of oxidation is much lower than that of limonoids previously reported from two other Turraea species and this suggests that care must be taken in using the prieurianin and closely related limonoids as taxonomic markers for this genus.