Roger A. Laine

Synthesis of homodinuclear macrocyclic complexes of lanthanides and phenolic schiff bases

Abstract Successful syntheses of the first examples of homodinuclear macrocyclic lanthanide complexes are reported. The complexes were obtained as compounds of the 2:2 Schiff base formed by condensing 2,6-diformyl-p-cresol and triethylenetetramine (L7) by a template procedure using lanthanide nitrates and perchlorates. When reactant methanolic solutions were concentrated the complexes were deposited as yellow or orange microcrystalline precipitates, Ln2L7(NO3)4sigma; nH2O or Ln2L7(NO3)4tau; x(OH)x, x = 1 or 2, whereas solutions diluted three times deposited complexes as flaky off-white crystalline precipitates of light lanthanides. The orange Ln2L7(NO3)2(OH)2 complexes can be converted in quantitative yield to the off-white flaky form of Ln2L7(NO3)4sigma; nH2O by refluxing them in methanolic solution containing triethylenetetramine and a three-fold excess of Ln(NO3)3. The complexes were characterized by elemental analysis, fast atom bombardment mass spectrometry, UV-Vis and infrared spectroscopy and thermogravimetry. Interesting and mostly new polyatomic oxo clusters, e.g. Ln2O3+, Ln3O4+, Ln4O6+, Ln5O7+, were dominant in the mass spectra but are treated in detail elsewhere.

Evaluation of Vetiver Oil and Seven Insect-Active Essential Oils Against the Formosan Subterranean Termite

Repellency and toxicity of 8 essential oils (vetiver grass, cassia leaf, clove bud, cedarwood, Eucalyptus globules,Eucalyptus citrodora, lemongrass and geranium) were evaluated against the Formosan subterranean termite, Coptotermes formosanus Shiraki. Vetiver oil proved the most effective repellent because of its long-lasting activity. Clove bud was the most toxic, killing 100% of termites in 2 days at 50 μg/cm2. The tunneling response of termites to vetiver oil also was examined. Vetiver oil decreased termite tunneling activity at concentrations as low as 5 μg/g sand. Tunneling and paper consumption were not observed when vetiver oil concentrations were higher than 25 μg/g sand. Bioactivity of the 8 oils against termites and chemical volatility were inversely associated. Listed in decreasing order of volatility, the major constituents of the 8 oils were: eucalyptol, citronellal, citral, citronellol, cinnamaldehyde, eugenol, thujopsene, and both α- and β- vetivone. Vetiver oil is a promising novel termiticide with reduced environmental impact for use against subterranean termites.

Structures of the asparagine-linked sugar chains of laminin

This investigation describes the isolation and characterization of oligosaccharides of the basement membrane glycoprotein, laminin. Pronase-released glycopeptides of isolated laminin, from a mouse Engelbreth-Holm-Swarm tumor, were fractionated using a combination of gel permeation chromatography and Con A-Sepharose affinity chromatography. The glycopeptides were analyzed for sugar linkage patterns by methylation analysis. Glycopeptides and hydrazine-released oligosaccharides were further analyzed using endo-beta-galactosidase, endo-beta-N-acetylglucosaminidase H and specific exoglycosidases in conjunction with calibrated gel permeation chromatography. Based on these experiments, murine tumor laminin was shown to contain asparagine-linked oligosaccharides with the following structures: bi-, tri- and tetraantennary complex-type oligosaccharides; polylactosaminyl side chains containing Gal(beta 1----4)GlcNAc(beta 1----3) repeating units attached to the trimannose core portion of the bi-, tri- and tetraantennary complex-type oligosaccharides; unusual complex-type oligosaccharides terminated at the nonreducing end with sialic acid, alpha-galactose, beta-galactose and beta-N-acetylglucosamine; alpha-galactosyl residues linked to N-acetyllactosamine sequences; high-mannose-type oligosaccharides. These results, in conjunction with analytical data, indicate that most of the carbohydrate of this laminin is N-linked to asparagine and that there are about 43 such N-linked oligosaccharides per laminin molecule.

Termites fumigate their nests with naphthalene

Termite nests provide a controlled environment and physical defence for the colonies of insects they house. Another important factor involved in colony defence may be volatile chemicals present in the nest: we have found the hydrocarbon naphthalene in extracts of the nest material produced by Formosan subterranean termites. This is the first time naphthalene has been found naturally associated with any insect species.

In vitro cytocidal effect of novel lytic peptides on Plasmodium falciparum and Trypanosoma cruzi.

Plasmodium falciparum and Trypanosoma cruzi were killed by two novel lytic peptides (SB‐37 and Shiva‐1) in vitro. Human erythrocytes infected with P. falciparum, and Vero cells infected with T. cruzi, were exposed to these peptides. The result, in both cases, was a significant decrease in the level of parasite infection. Furthermore, the peptides had a marked cytocidal effect on trypomastigote stages of T cruzi in media, whereas host eukaryotic cells were unaffected by the treatments. In view of the worldwide prevalence of these protozoan diseases and the lack of completely suitable treatments, lytic peptides may provide new and unique chemother‐apeutic agents for the treatment of these infections.—Jaynes, J. M.; Burton, C. A.; Barr, S. B.; Jeffers, G. W.; Julian, G. R.; White, K. L.; Enright, F. M.; Klei, T. R.; Laine, R. A. In vitro cytocidal effect of novel lytic peptides on Plasmodium falciparum and Trypanosoma cruzi. FASEB J. 2: 2878‐2883; 1988.

Nootkatone is a repellent for Formosan subterranean termite (Coptotermes formosanus).

We examined the behavior of Formosan subterranean termites toward one of the components of vetiver grass oil, the roots of which manufacture insect repellents. We found nootkatone, a sesquiterpene ketone, isolated from vetiver oil is a strong repellent and toxicant to Formosan subterranean termites. The lowest effective concentration tested was 10 μg/g substrate. This is the first report of nootkatone being a repellent to insects.

Formosan Subterranean Termite (Isoptera: Rhinotermitidae) Soldiers Regulate Juvenile Hormone Levels and Caste Differentiation in Workers

Abstract A caste structure is maintained in termite societies and juvenile hormone (JH) is generally regarded as the most important regulator in these termite colonies. Here, we demonstrate that the soldier caste regulates JH in workers of Coptotermes formosanus Shiraki. Worker termites (80–100 individuals) were placed in petri dishes with 0, 5, 10, or 20% soldiers. JH III titers of groups of these workers were monitored at 14, 28, 42, and 56 d. Any changes in soldier caste proportions also were noted at each sample date. On the first sample date, the JH levels in workers were similar among treatments with different initial soldier proportions, and no new soldiers were formed. Over the next three sample dates, the worker JH levels were higher for low initial soldier proportion treatments and vice versa. Concurrently, soldier formation increased with lower initial soldier proportions. JH titers in workers showed a positive and statistically significant relationship to soldier numbers until a certain soldier proportion was reached. These results provide evidence that soldier caste proportions regulate JH levels and thereby caste differentiation in workers. The means by which this regulatory mechanism may proceed is discussed.

Efficacy of vetiver oil and nootkatone as soil barriers against Formosan subterranean termite (Isoptera: Rhinotermitidae).

Abstract Vetiver oil and its components nootkatone and cedrene were assessed as sand treatments for their efficacy to disrupt food recruitment by Coptotermes formosanus Shiraki. Termites were required to tunnel through sand treated with vetiver oil, nootkatone, cedrene, or untreated sand to reach a food source. Results showed that sand treated with vetiver oil or nootkatone disrupted termite tunneling behavior. As a consequence, after 21 d, wood consumption and termite survival were significantly lower compared with cedrene-treated or untreated sand treatments. Sand treated with vetiver oil or nootkatone at 100 μg/g substrate were effective barriers to termites.

[13] Inositol-containing sphingolipids

Publisher Summary Glycophosphosphingolipids (GPSs) are membrane glycolipids containing a phosphodiester linkage between inositol and ceramide. The structure, “inositol (1-O)-phosphoryl-(O-1)ceramide” constitutes a common core. This chapter discusses some known glycophosphophingolipids. There is also a discussion of the procedure of isolation of a glycophosphosphingolipid fraction from plants. There is a description of the production of a carboxyl-reduced oligosaccharide mixture from the glycophosphoceramide concentrate. To isolate major fractions of the oligosaccharides, gel permeation chromatography on Bio-Rad P gels is used, effectively separating oligo saccharide fractions up to 10 sugars in length. Several methods in high-performance liquid chromatography (HPLC) can be utilized for further purification of the oligosaccharides, including reversed-phase separation of the acetylated derivatives and amino-derivatized normal-phase chromatography on silica gel. Detection methods include (1) benzoylation of the amino group on the glucosamine, (2) use of fluorescamine or o-phthaldehyde to synthesize a fluorophore on the glucosamine in glucosamine-containing GPSs for fluorescence detection of the molecules, and (3) use of tritiated acetic anhydride for radiolabeling of the aminosugar. High-performance thin-layer chromatography can complement these methods. There is also some discussion in the chapter about the new methods of sequence determination using fast atom bombardment mass spectrometry.

Seasonal Variation of Juvenile Hormone Titers of the Formosan Subterranean Termite, Coptotermes formosanus (Rhinotermitidae)

Abstract In lower termites, the soldier is the only sterile caste. Through hormonal control, soldiers seem to promote caste differentiation of workers to the reproductive caste. However, little data exist on how hormonal levels change in soldiers and workers in the field and how this may tie into the seasonal reproductive formation. Our objective was to collect baseline data on hormonal changes in colonies of subterranean termites in the field. Over a 1-yr period, the seasonal variation of juvenile hormone III (JH) titers was determined for Coptotermes formosanus Shiraki soldiers and workers collected monthly from field colonies infesting isolated cypress trees (Taxodium distichum L. Rich.). A total of five colonies were evaluated. Soldier JH titers leveled from February through May, with peak values in June and July. JH titers in workers followed a similar trend. Both soldier and worker JH titers remained at low levels in the fall and winter. This is the first effort to correlate physiological and hormonal aspects with soldier production in the field. Seasonal changes in JH titers as an intrinsic mechanism for reproductive caste differentiation is also discussed.