Antibacterial Activity of Essential Oil and Extracts of <Emphasis Type="Italic">Cleistocalyx operculatus</Emphasis> Buds Against the Bacteria of <Emphasis Type="Italic">Xanthomonas</Emphasis> spp.

This study was undertaken to assess the antibacterial efficacy of the essential oil and extracts of Cleistocalyx operculatus buds against plant pathogenic bacteria of Xanthomonas spp. The diameter of inhibition zones of oil (1,000 μg/disc) and extracts (1,500 μg/disc) against the tested bacteria were found in the range of 7–23 mm. The MIC and MBC values of the oil and extracts against the tested Xanthomonas spp. ranged from 31.25–125 to 62.5–250 μg/ml and 125–500 and 250–1,000 μg/ml, respectively. The cell viability study demonstrated a potential detrimental effect of the oil (1,000 μg/ml) and hexane extract (250 μg/ml) on the tested Xanthomonas spp. Also the oil displayed significant antibacterial effects in vivo against Xoo KX019 and Xsp SK12 conducted on greenhouse-grown oriental melon plants (Cucumis melo L. var. makuwa). The results of this study suggest that C. operculatus-derived essential oil and extracts could be used as natural bactericides in the food and agriculture industries.     

Sequestration of Furostanol Saponins by <Emphasis Type="Italic">Monophadnus</Emphasis> Sawfly Larvae

Sawfly larvae of the tribe Phymatocerini (Hymenoptera: Tenthredinidae), which are specialized on toxic plants in the orders Liliales and Ranunculales, exude a droplet of deterrent hemolymph upon attack by a predator. We investigated whether secondary plant metabolites from Ranunculaceae leaves are sequestered by phymatocerine Monophadnus species, i.e., Monophadnus alpicola feeding upon Pulsatilla alpina and Monophadnus monticola feeding upon Ranunculus lanuginosus. Moreover, two undescribed Monophadnus species were studied: species A collected from Helleborus foetidus and species B collected from Helleborus viridis. Comparative high-performance liquid chromatographic–photodiode array detection–electrospray ionization–mass spectrometric analyses of plant leaf and insect hemolymph extracts revealed the presence of furostanol saponins in all samples. Larvae of species A and B actively sequestered (25R)-26-[(α-l-rhamnopyranosyl)oxy]-22α-methoxyfurost-5-en-3β-yl O-β-d-glucopyranosyl-(1→3)-O-[6-acetyl-β-d-glucopyranosyl-(1→3)]-O-β-d-glucopyranoside (compound 1). This compound occurred at a 65- to 200-fold higher concentration in the hemolymph of the two species (1.6 and 17.5 μmol/g FW, respectively) than in their host plant (0.008 and 0.268 μmol/g FW, respectively). In M. monticola, compound 1 was found at a concentration (1.2 μmol/g FW) similar to that in the host plant (1.36 μmol/g FW). The compound could not be detected consistently in M. alpicola larvae where, however, a related saponin may be present. Additional furostanol saponins were found in H. foetidus and H. viridis, but not in the two Monophadnus species feeding on them, indicating that sequestration of compound 1 is a highly specific process. In laboratory bioassays, crude hemolymph of three Monophadnus species showed a significant feeding deterrent activity against a potential predator, Myrmica rubra ant workers. Isolated furostanol saponins were also active against the ants, at a concentration range similar to that found in the hemolymph. Thus, these compounds seem to play a major role for chemical defense of Monophadnus larvae, although other plant secondary metabolites (glycosylated ecdysteroids) were also detected in their hemolymph. Physiological and ecological implications of the sequestered furostanol saponins are discussed. Dedicated to the memory of Professor Ivano Morelli (1940–2005)     

Cyanolipid-rich seed oils from <Emphasis Type="Italic">Allophylus natalensis</Emphasis> and <Emphasis Type="Italic">A. dregeanus</Emphasis>

As a continuation of our study on plants of the Sapindaceae, the chemical composition of the oil extracted from seeds of Allophylus natalensis (Sonder) De Winter and of A. dregeanus (Sonder) De Winter has been investigated. The oil from both species contained approximately equal amounts of TAG and type I cyanolipids (CL), 1-cyano-2-hydroxymethylprop-2-en-1-oldiesters, with minor amounts of type III CL, 1-cyano-2-hydroxymethylprop-1-en-3-ol-diesters. Structural investigation of the oil components was accomplished by chemical, chromatographic (TLC, CC, GC, and GC-MS), and spectroscopic (IR, NMR) means. GC and GC-MS analysis showed that C₂₀ FA were dominant in the CL components of the oil from the two species (44–80% vs. 21–26% in TAG), with cis-11-eicosenoic acid (36–46%) and cis 13-eicosenoic acid (paullinic acid, 23–37%) as the major esterified fatty acyl chains in A. natalensis and A. dregeanus, respectively. cis-Vaccenic acid was particularly abundant (11–31%) in the CL from A. dregeanus, whereas eicosanoic acid (10–22%) was also a major component of CL in both species.     

Natural estolides produced by <Emphasis Type="Italic">Pseudomonas</Emphasis> sp. 42A2 grown on oleic acid: Production and characterization

Estolides are a group of FA polyesters resulting from ester bond formation between a hydroxyl or olefinic group of one FA and the terminal carboxyl group of a second FA. These products are commonly found in trace amounts, forming tetraglycerides in several oil seed plants, and have been produced by acid clay and enzymatic catalysis in vitro. In this study, natural estolides produced by a bacterial culture are presented for the first time. Pseudomonas sp. 42A2 produced (E)-10-hydroxy-8-octadecenoic acid and (E)-7,10-dihydroxy-8-octadecenoic acid when grown on oleic acid. It is suggested that these FA were polymerized in culture by a lipase produced by the bacterial strain, resulting in a mixture of estolides. These compounds amounted to 3.8 g/L after 72 h of incubation. LC-MS analysis indicated that the types of estolides formed were dimers (m/z 560–610), trimers (m/z 845–906), tetramers (m/z 1122–1202), pentamers (m/z 1328–1424), and hexamers (m/z 1554–1788), with a relative abundance of 27.5, 19.4, 15, 9.7, and 11%, respectively. This is the first report in which hexamers were detected in a bacterial culture.     

<Emphasis Type="Italic">Santalum </Emphasis><Emphasis Type="Italic">insulare</Emphasis> Acetylenic Fatty Acid Seed Oils: Comparison within the <Emphasis Type="Italic">Santalum</Emphasis> Genus

The sandalwood kernels of Santalum insulare (Santalaceae) collected in French Polynesia give seed oils containing significant amounts of ximenynic acid, E-11-octadecen-9-oic acid (64–86%). Fatty acid (FA) identifications were performed by gas chromatography/mass spectrometry (GC/MS) of FA methyl esters. Among the other main eight identified fatty acids, oleic acid was found at a 7–28% level. The content in stearolic acid, octadec-9-ynoic acid, was low (0.7–3.0%). An inverse relationship was demonstrated between ximenynic acid and oleic acid using 20 seed oils. Results obtained have been compared to other previously published data on species belonging to the Santalum genus, using multivariate statistical analysis. The relative FA S. insulare composition, rich in ximenynic acid is in the same order of those given for S. album or S. obtusifolium. The other compared species (S. acuminatum, S. lanceolatum, S. spicatum and S. murrayanum) are richer in oleic acid (40–59%) with some little differences in linolenic content.     

Differential Attractiveness of Potato Tuber Volatiles to <Emphasis Type="Italic">Phthorimaea operculella</Emphasis> (Gelechiidae) and the Predator <Emphasis Type="Italic">Orius insidiosus</Emphasis> (Anthocoridae)

The behavioral responses of the potato tuberworm moth Phthorimaea operculella and the polyphagous predator Orius insidiosus to volatiles emanating from exposed tubers were studied by four-arm olfactometer bioassays. Mated females of P. operculella distinguished volatiles released by intact potato tubers from volatiles damaged mechanically or by conspecific larvae. Volatiles from intact potato tubers were attractive to them. On the other hand, unmated females of P. operculella did not respond to tuber volatiles. Adults of O. insidiosus were attracted to volatiles from tubers damaged by P. operculella larvae, but did not respond to intact or mechanically damaged tubers. Methyl jasmonate (MeJA) was the only compound identified from the headspace of potato tubers (GC-MS of direct headspace sampling). The amount varied with the type of induction, being 0.001 ± 0.0003 ng g⁻¹ in tissues of intact fresh tubers, 0.002 ± 0.0007 ng g⁻¹ in mechanically damaged tubers, and showing a six- to tenfold increase in P. operculella damaged tubers (0.090 ± 0.006 ng g⁻¹). Behavioral bioassays with synthetic MeJA confirmed that the response of the insects is dependent on MeJA concentration. Mated females of P. operculella showed the highest response at 0.001 ng g⁻¹ (concentration released by intact tubers), whereas O. insidiosus showed the highest response, between 0.01 and 0.05 ng g⁻¹, which is close to the concentration released by P. operculella damaged tubers. Based on these results, we postulate that P. operculella and O. insidiosus have adapted their responses to plant volatiles differently, enabling them to locate suitable hosts or prey.     

Isolation and Identification of Host Cues from Mango, <Emphasis Type="Italic">Mangifera indica</Emphasis>, That Attract Gravid Female Oriental Fruit fly, <Emphasis Type="Italic">Bactrocera dorsalis</Emphasis>

The oriental fruit fly, Bactrocera dorsalis, is an economically damaging, polyphagous pest of fruit crops in South-East Asia and Hawaii, and a quarantine pest in other parts of the world. The objective of our study was to identify new attractants for B. dorsalis from overripe mango fruits. Headspace samples of volatiles were collected from two cultivars of mango, ‘Alphonso’ and ‘Chausa’, and a strong positive behavioral response was observed when female B. dorsalis were exposed to these volatiles in olfactometer bioassays. Coupled GC-EAG with female B. dorsalis revealed 7 compounds from ‘Alphonso’ headspace and 15 compounds from ‘Chausa’ headspace that elicited an EAG response. The EAG-active compounds, from ‘Alphonso’, were identified, using GC-MS, as heptane, myrcene, (Z)-ocimene, (E)-ocimene, allo-ocimene, (Z)-myroxide, and γ-octalactone, with the two ocimene isomers being the dominant compounds. The EAG-active compounds from ‘Chausa’ were 3-hydroxy-2-butanone, 3-methyl-1-butanol, ethyl butanoate, ethyl methacrylate, ethyl crotonate, ethyl tiglate, 1-octen-3-ol, ethyl hexanoate, 3-carene, p-cymene, ethyl sorbate, α-terpinolene, phenyl ethyl alcohol, ethyl octanoate, and benzothiazole. Individual compounds were significantly attractive when a standard dose (1 μg on filter paper) was tested in the olfactometer. Furthermore, synthetic blends with the same concentration and ratio of compounds as in the natural headspace samples were highly attractive (P < 0.001), and in a choice test, fruit flies did not show any preference for the natural samples over the synthetic blends. Results are discussed in relation to developing a lure for female B. dorsalis to bait traps with.     

Umbelliferone aminoalkyl derivatives as inhibitors of oxidosqualene cyclases from <Emphasis Type="Italic">Saccharomyces cerevisiae,Tripanosoma cruzi</Emphasis>, and <Emphasis Type="Italic">Pneumocystis carinii</Emphasis>

A series of umbelliferone aminoalkyl derivatives, previously studied as inhibitors of squalene-hopene cyclase, were tested as inhibitors of yeast (Saccharomyces cerevisiae) oxidosqualene cyclase (OSC) and OSC from Trypanosoma cruzi and Pneumocystis carinii expressed in yeast. Enzymes from these pathogens were included in this study to provide a preliminary screening for antiparasitic activity. Tests were carried out both on cell homogenates incubated with radiolabeled oxidosqualene and on spheroplasts incubated with radiolabeled acetate. Derivatives bearing a methylallylamino group were the most effective on all of the three enzymes. The P. carinii enzyme was the most susceptible to the action of the inhibitors, with IC₅₀ values for almost all of them ranging from 0.1 to 1μM. The T. cruzi enzyme was appreciably inhibited (IC₅₀ 4–5 μM) only by derivatives bearing a methylallylaminoalkyl flexible chain. Results identify a particularly promising new family of OSC inhibitors, for the development of novel antiparasitic agents.     

Behavioral Responses of Adult <Emphasis Type="Italic">Sitophilus granarius</Emphasis> to Individual Cereal Volatiles

The antennae of Sitophilus granarius (L.) (Coleoptera: Curculionidae) adults detect a wide variety of compounds in the odor blend of various cereal grains (Germinara et al., Tec. Molit., 53:27–34, 2002). In the present study, we looked at the behavioral responses of the granary weevil to 20 of these individual volatiles (aliphatic alcohols, aldehydes, ketones, and aromatics) in a two-choice pitfall olfactometer, using the aggregation pheromone and propionic acid as the attractant and repellent controls, respectively. Five doses, ranging from 1 μg to 1 mg, of each compound were tested. At least one concentration of eight compounds attracted beetles but required doses 1,000- to 5,000-fold higher than the concentration of aggregation pheromone to elicit a response. Three compounds, while attractive at lower concentrations, acted as repellents at higher doses. Twelve compounds were repellent at concentrations similar to the quantity of propionic acid that significantly repelled beetles. The data show that granary weevil adults have the ability to respond behaviorally to a wide range of cereal volatiles and that responses may change as a function of concentration. The results suggest that host finding behavior of weevils will depend on the balance of positive and negative volatile stimuli from grain as the relative concentrations of volatiles may change during storage. An understanding of how the weevils respond to such changes could be useful for the development of effective integrated pest management strategies.     

Fractionation and characterization of proteins from <Emphasis Type="Italic">Gevuina avellana</Emphasis> and <Emphasis Type="Italic">Rosa rubiginosa</Emphasis> seeds

Gevuina avellana and Rosa rubiginosa proteins were evaluated for their potential food use. The proteins were sequentially separated into five fractions according to their solubilities in deionized water, 0.5 M NaCl, 70% (vol/vol) isopropyl alcohol, 50% (vol/vol) glacial acetic acid, and 0.1 M NaOH. The five fractionated protein groups were then characterized by SDS-PAGE and gel filtration chromatography to determine their M.W. profiles. Ninety-six percent of G. avellana total protein was solubilized in three extraction stages, and 88% of R. rubiginosa total protein was solubilized in one extraction stage. Albumins were the major protein fraction in G. avellana and glutelins-1 the most abundant in R. rubiginosa. The protein solubility profile determined over the pH range 1–12 showed minimal solubilities at pH 3–5 and pH 3–7 for G. avellana and R. rubiginosa, respectively. Electrophoretic studies revealed the existence of proteins composed of two major kinds of polypeptides linked together via disulfide bonds and with molecular masses ranging from 13 to 119 kDa. Gel filtration chromatography profiles of globulins and albumins were studied for both seeds. Isoelectric focusing showed an isoelectric point in the ranges of 4.5–6 and 3–6.5 for G. avellana and R. rubiginosa proteins, respectively.     

Effect of <Emphasis Type="Italic">trans</Emphasis>8, <Emphasis Type="Italic">cis</Emphasis>10+<Emphasis Type="Italic">cis</Emphasis>9, <Emphasis Type="Italic">trans</Emphasis>11 Conjugated Linoleic Acid Mixture on Lipid Metabolism in 3T3-L1 Cells

Evidence suggests that minor isomers of conjugated linoleic acid (CLA), such as trans8, cis10 CLA, can elicit unique biological effects of their own. In order to determine the effect of a mixture of t8, c10+c9, t11 CLA isomers on selected aspects of lipid metabolism, 3T3-L1 preadipocytes were differentiated for 8 days in the presence of 100 μM linoleic acid (LA); t8, c10+c9, t11 CLA; t10, c12+c9, t11 CLA or purified c9, t11 CLA. Whereas supplementation with c9, t11 and t10, c12+c9, t11 CLA resulted in cellular triglyceride (TG) concentrations of 3.4 ± 0.26 and 1.3 ± 0.11 μg TG/μg protein, respectively (P < 0.05), TG accumulation following treatment with CLA mixture t8, c10+c9, t11 was significantly intermediate (2.5 ± 0.22 μg TG/μg protein, P < 0.05) between the two other CLA treatments. However, these effects were not attributable to an alteration of the Δ⁹ desaturation index. Adiponectin content of adipocytes treated with t8, c10+c9, t11 mixture was similar to the individual isomer c9, t11 CLA, and both the t8, c10+c9, t11 and c9, t11 CLA groups were greater (P < 0.05) than in the t10, c12+c9, t11 CLA group. Overall, these results suggest that t8, c10+c9, t11 CLA mixture affects TG accumulation in 3T3-L1 cells differently from the c9, t11 and t10, c12 isomers. Furthermore, the reductions in TG accumulation occur without adversely affecting the adiponectin content of these cells.     

Regulation of Cell Division and Growth in Roots of <Emphasis Type="Italic">Lactuca sativa</Emphasis> L. Seedlings by the <Emphasis Type="Italic">Ent</Emphasis>-Kaurene Diterpenoid Rabdosin B

Rabdosin B, an ent-kaurene diterpenoid purified from the air-dried aerial parts of Isodon japonica (Burm.f) Hara var. galaucocalyx (maxin) Hara, showed a biphasic, dose-dependent effect on root growth and a strong inhibitory effect on root hair development in lettuce seedlings (Lactuca sativa L.). Lower concentrations of rabdosin B (20–80 μM) significantly promoted root growth, but its higher levels at 120–200 μM, by contrast, had inhibitory effects. Additionally, all tested concentrations (10–40 μM) inhibited root hair development of seedlings in a dose-dependent manner. Further investigations on the underlying mechanism revealed that the promotion effect of rabdosin B at the lower concentrations resulted from increasing the cell length in the mature region and enhancing the mitotic activity of meristematic cells in seedlings’ root tips. In contrast, rabdosin B at higher concentrations inhibited root growth by affecting both cell length in the mature region and division of meristematic cells. Comet assay and cell cycle analysis demonstrated that the decrease of mitotic activity of root meristematic cells was due to DNA damage induced cell cycle retardation of the G₂ phase and S phase at different times.     

Antifungal Activity of Leaf Essential Oil and Extracts of <Emphasis Type="Italic">Metasequoia glyptostroboides</Emphasis> Miki ex Hu

Plant diseases constitute an emerging threat to global food security. Many of the currently available antifungal agents for agriculture are highly toxic and nonbiodegradable and cause extensive environmental pollution. Moreover, an increasing number of phytopathogens are developing resistance to them. Therefore, the aim of this study was to assess the antifungal efficacy of the leaf essential oil and the leaf extracts of Metasequoia glyptostroboides against Fusarium oxysporum, Fusarium solani, Phytophthora capsici, Colletotrichum capsici, Sclerotinia sclerotiorum, Botrytis cinerea and Rhizoctonia solani. The oil (1,000 μg/disc) and the extracts (1,500 μg/disc) revealed a remarkable antifungal effect against the tested plant pathogenic fungi with a radial growth inhibition percentage of 41.3–66.3% and 13.4–54.4%, respectively along with their respective MIC values ranging from 62.5 to 1,000 μg/ml and 500–4,000 μg/ml. The oil had a strong detrimental effect on spore germination of all the tested plant pathogens along with the concentration as well as time-dependent kinetic inhibition of Botrytis cinerea. Also, the oil exhibited a potent in vivo antifungal effect against Phytophthora capsici on greenhouse grown pepper plants. The results of this study indicate that the oil and extracts of M. glyptostroboides leaves could become natural alternatives to synthetic fungicides to control certain important plant fungal diseases.     

Response of the Aphid Parasitoid <Emphasis Type="Italic">Aphidius funebris</Emphasis> to Volatiles from Undamaged and Aphid-infested <Emphasis Type="Italic">Centaurea nigra</Emphasis>

Two issues have hindered the understanding of the ecology and evolution of volatile-mediated tritrophic interactions: few studies have addressed noncrop systems; and few statistical techniques have been applied that are suitable for the analysis of complex volatile blends. In this paper, we addressed both of these issues by studying the noncrop system involving the plant Centaurea nigra, the specialist aphid Uroleucon jaceae, and the parasitoid Aphidius funebris. In a Y-tube olfactometer, A. funebris was attracted to the odor from undamaged C. nigra, but preferred the plant–host complex (PHC) after 3 d of feeding by 200 U. jaceae over the undamaged plant, but not after three or 5 d of feeding by 50 U. jaceae. When aphids were removed, the initial preference for the damaged plant remained, but the final preference was not greater than for the undamaged plant. No qualitative differences were detected between the headspaces of C. nigra and the C. nigra–U. jaceae PHC. For quantitative analysis, we used a compositional approach, which treats each compound produced as part of a blend, and not as a compound released in isolation, thus allowing analysis of the relative contribution of each compound to the blend as a whole. With this approach, subtle increases and decreases of some green leaf volatiles and monoterpenoids on the third day of aphid infestation were detected. Mechanically damaged C. nigra had a volatile profile that differed from undamaged C. nigra and the PHC. One and 10 ng of (Z)-3-hexenyl acetate, and 10 or 100 ng of 6-methyl-5-hepten-2-one were attractive to the parasitoid when placed in solution on filter paper. A. funebris appears to be using a combination of chemical cues to locate host-infested plants.     

Fatty acids of the seeds of <Emphasis Type="Italic">Origanum onites</Emphasis> L. and <Emphasis Type="Italic">O. vulgare</Emphasis> L.

Seed oils of Origanum onites L. from the Antalya and Mugla regions and O. vulgare L. from the Kirklareli region of Turkey were extracted with hexane in a Soxhlet apparatus. The oil yields were 14.1–20.0 and 18.5%, respectively. FA compositions of the seed oils were determined by GC and GC/MS. Twenty FA were identified in both O. onites and O. vulgare seeds. The major FA of both species were linolenic (56.3–57.0%; 61.8%), linoleic (21.5–21.7%; 18.8%), oleic (8.7–8.9%; 5.9%), palmitic (5.9–6.5%; 5.5%), stearic (2.1–2.4%; 2.1%), and (Z)-11-octadecenoic (0.6–0.8%; 0.5%), respectively.     

Antifungal Activity of Essential Oil and Extracts of <Emphasis Type="Italic">Piper chaba</Emphasis> Hunter Against Phytopathogenic Fungi

The efficacy of the essential oil and various leaf extracts of Piper chaba Hunter was evaluated for controlling the growth of some important phytopathogenic fungi. The hydrodistilled essential oil was analysed by GC–MS. Fifty-three compounds representing 95.1% of the total oil were identified, of which α-humulene (16.4%), caryophyllene oxide (12.2%), viridiflorol (8.1%), globulol (7.4%), β-selinene (7.1%), spathulenol (6.2%), (E)-nerolidol (5.1%), linalool (4.5%) and 3-pentanol (3.5%) were the major compounds. The oil (1,000 ppm) and organic extracts (1,500 ppm) of P. chaba Hunter displayed a great potential of antifungal activity as a growth inhibition against the tested phytopathogenic fungi, Fusarium oxysporum KACC 41083, Phytophthora capsici KACC 40157, Colletotrichum capsici KACC 410978, Fusarium solani KACC 41092 and Rhizoctonia solani KACC 40111 in the range of 55.1–70.3% and minimum inhibitory concentration ranging from 125 to 500 μg/ml. The oil had also a strong detrimental effect on spore germination of all the tested fungi along with concentration as well as time-dependent kinetic inhibition of P. capsici. The results obtained from this study may contribute to the development of new antifungal agents to protect crops from fungal diseases.     

Soluble polyimides based on a novel pyridine-containing diamine <Emphasis Type="Italic">m</Emphasis>,<Emphasis Type="Italic">p</Emphasis>-PAPP and various aromatic dianhydrides

A novel pyridine-containing aromatic diamine monomer, 4-phenyl-2,6-bis[3-(4-aminophenoxy)phenyl]pyridine (m,p-PAPP), was successfully synthesized by a modified Chichibabin reaction of benzaldehyde and a substituted acetophenone, 3-(4-nitrophenoxy)acetophenone (m,p-NPAP), followed by a reduction of the resulting dinitro compound 4-phenyl-2,6-bis[3-(4-nitrophenoxy)phenyl]pyridine (m,p-PNPP) with Pd/C and hydrazine monohydrate. The aromatic diamine was employed to synthesize a series of pyridine-containing polyimides (PIs) by polycondensation with various aromatic dianhydrides in N,N-dimethylformamide (DMF) via the conventional two-step method, and further thermal or chemical imidization forming PIs. The inherent viscosities of the resulting poly(amic acid)s and PIs were 0.59–0.73 and 0.56–0.68 dL/g; most of the PIs obtained by chemical imidization were readily soluble in common organic solvents such as DMF, N,N-dimethylacetamide (DMAc), N-methyl-2-pyrrolidone (NMP), tetrahydrofuran (THF), etc. Meanwhile, strong and flexible PI films were obtained, which had good thermal stability, with the glass transition temperature (T _g) of 204.5–237.4 °C and the temperature at 10% weight loss of 527.7–552.0 °C in nitrogen atmosphere, as well as outstanding mechanical properties with tensile strengths of 88.6–90.4 MPa, a tensile moduli of 1.04–1.56 GPa, and elongations at break of 7.2–8.7%. The PI films also were found to possess low water uptake of 0.89–0.98%.     

Antibacterial and xanthine oxidase inhibitory cerebrosides from <Emphasis Type="Italic">Fusarium</Emphasis> sp. IFB-121, and endophytic fungus in <Emphasis Type="Italic">Quercus variabilis</Emphasis>

Two antibacterial and xanthine oxidase inhibitory cerebrosides, one of which is chemically new, were characterized from the chloroform-methanol (1∶1) extract of Fusarium sp. IFB-121, an endophytic fungus in Quercus variabilis. By means of chemical and spectral methods [IR, electrospray ionization MS (ESI-MS), tandem ESI-MS, ¹H and ¹³C NMR, distortionless enhancement by polarization transfer, COSY, heteronuclear multiple-quantum coherence, heteronuclear multiple-bond correlation, and 2-D nuclear Overhauser effect correlation spectroscopy], the structure of the new metabolite named fusaruside was established as (2S,2′R,3R,3′E,4E,8E,10E)-1-O-β-d-glucopyranosyl-2-N-(2′-hydroxy-3′-octadecenoyl)-3-hydroxy-9-methyl-4,8,10-sphingatrienine, and the structure of the other was identified as (2S,2′R,3R,3′E,4E,8E)-1-O-β-d-glucopyranosyl-2-N-(2′-hydroxy-3′-octadecenoyl)-3-hydroxy-9-methyl-4,8-sphingadienine. Both new and known cerebrosides, although inactive to Trichophyton rubrum and Candida albicans, showed strong antibacterial activities against Bacillus subtilis, Escherichia coli, and Pseudomonas fluorescens, with their minimum inhibitory concentrations being 3.9, 3.9, and 1.9 μg/mL, and 7.8, 3.9, and 7.8 μg/mL, respectively. Furthermore, both metabolites were inhibitory to xanthine oxidase, with the IC₅₀ value of fusaruside being 43.8±3.6 μM and the known cerebroside being 55.5±1.8 μM.     

Male-Produced Aggregation Pheromones of the Cerambycid Beetles <Emphasis Type="Italic">Xylotrechus colonus</Emphasis> and <Emphasis Type="Italic">Sarosesthes fulminans</Emphasis>

Adults of both sexes of the cerambycid beetles Xylotrechus colonus (F.) and Sarosesthes fulminans (F.) were attracted to odors produced by male conspecifics in olfactometer bioassays. Analyses of headspace volatiles from adults revealed that male X. colonus produced a blend of (R)- and (S)-3-hydroxyhexan-2-one and (2 S,3 S)- and (2R,3R)-2,3-hexanediol, whereas male S. fulminans produced (R)-3-hydroxyhexan-2-one and (2 S,3R)-2,3-hexanediol. All of these compounds were absent in the headspace of females. Two field bioassays were conducted to confirm the biological activity of the synthesized pheromones: (1) enantiomerically enriched pheromone components were tested singly and in species-specific blends and (2) four-component mixture of racemic 3-hydroxyhexan-2-one plus racemic 2-hydroxyhexan-3-one and the four-component blend of the stereoisomers of 2,3-hexanediols were tested separately and as a combined eight-component blend. In these experiments, adult male and female X. colonus were captured in greatest numbers in traps baited with the reconstructed blend of components produced by males, although significant numbers were also captured in traps baited with (R)-3-hydroxyhexan-2-one alone or in blends with other compounds. Too few adult S. fulminans were captured for a statistical comparison among treatments, but all were caught in traps baited with lures containing (R)-3-hydroxyhexan-2-one. In addition to these two species, adults of two other species of cerambycid beetles, for which pheromones had previously been identified, were caught: Neoclytus a. acuminatus (F.) and its congener Neoclytus m. mucronatus (F.). Cross-attraction of beetles to pheromone blends of other species, and to individual pheromone components that are shared by two or more sympatric species, may facilitate location of larval hosts by species that compete for the same host species.     

Ferrocenyl Monomers and Polymers of <Emphasis Type="Italic">N</Emphasis>-Allyl and <Emphasis Type="Italic">N</Emphasis>-Acrylatenaphthalimides

A series of N-allyl, N-ethylmethacrylate and N-phenylmethacrylatenaphthalimide monomers have been prepared with –C=CFc, –C≡CFc and –C≡CSiMe₃ substituents at the 4-position of the naphthalimide ring. All have been characterised by elemental analysis and spectroscopy; the X-ray structure of N-allyl-4-ethenylferrocenylnapththalimide is also reported. Free-radical polymerisation of these monomers gave homopolymers, random co- and terpolymers with polydispersities ranging from 1.7 to 3.2. Incorporation into a polymer matrix has no effect on the spectroscopic and electrochemical properties of the naphthalimide or ferrocenyl components. The ferrocenyl polymers are electrochromic and when oxidised give naphthalimide charge-transfer bands in the NIR; this electrochromism was examined by OTTLE techniques.