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Selection pressure exerted by insects and microorganisms shapes the diversity of plant secondary metabolites. We identified a metabolic pathway for glucosinolates, known insect deterrents, that differs from the pathway activated by chewing insects. This pathway is active in living plant cells, may contribute to glucosinolate turnover, and has been recruited for broad-spectrum antifungal defense responses. The Arabidopsis CYP81F2 gene encodes a P450 monooxygenase that is essential for the pathogen-induced accumulation of 4-methoxyindol-3-ylmethylglucosinolate, which in turn is activated by the atypical PEN2 myrosinase (a type of [beta]-thioglucoside glucohydrolase) for antifungal defense. We propose that reiterated enzymatic cycles, controlling the generation of toxic molecules and their detoxification, enable the recruitment of glucosinolates in defense responses.

A ready-to-spot disposable DNA chip for specific and sensitive detection of DNA was developed. Plastic copolymeric substrate chemistry was optimized to selectively couple the target DNA with the active chip surface. At the same time, the developed substrate limits the unspecific adsorption of probe DNA molecules or additional polar contaminants in the test samples to the chip surface. The combination of glycidyl and n-butyl methacrylates was found to best fit the requirements of the assay. The fabricated DNA microarrays have mechanical properties similar to those of the glass or silicon substrates and, at the same time, provide chemically reactive surfaces that do not require lengthy chemical modification. An additional advantage of the plastic microchip is its compatibility with different analytical readout techniques, such as mass spectrometry (MALDI-TOF/MS), optical detection (fluorescence and enzyme-induced metal deposition), and imaging techniques (atomic force microscopy). These multiple readout techniques have given us the ability to compare the sensitivity, selectivity, and robustness of current state-of-the-art bioanalytical methods on the same platform exemplified by successful DNA-based detection of human cytomegalovirus. The obtained sensitivity for enzymatically enhanced silver deposition ([10.sup.-15] M) surpasses that of conventional fluorescence readouts. In addition, the assay's dynamic range ([10.sup.-6]-[10.sup.-15] M), reproducibility, and reliability of the DNA probe detection speaks for the silver deposition method. At compromised sensitivity ([10.sup.-9] M), the length of the DNA probes could be checked and, alternatively, DNA single point polymorphisms could be analyzed.

Vapor-phase infrared spectra allow the determination of the stereochemistry of carbon-carbon double bonds conjugated with a vinyl group. Cis and trans isomers of unsubstituted 1,3-alkadienes can be differentiated on the basis of the differences observed in the 900-1000 [cm.sup.-1] region (spectra of cis isomers show two bands at 993 and 906 [cm.sup.-1], while those of trans compounds show three absorptions at 998, 949, and 902 [cm.sup.-1]) and the 1590-1650 [cm.sup.-1] region (the C=C stretch bands are observed at 1595 and 1642 [cm.sup.-1] for cis compounds and at 1604 and 1650 [cm.sup.-1] for trans compounds). Compounds bearing [CH.sub.2]=CHC([CH.sub.3])=CH[CH.sub.2-] and [CH.sub.2]=CHC(=[CH.sub.2])-[CH.sub.2]- structural moieties, referred to as [Alpha]- and [Beta]-type compounds, are frequently encountered as natural products. For compounds bearing [Alpha]-type groups, the cis/trans configuration of the trisubstituted double bond can be determined unambiguously. An absorption at 3095-3091 [cm.sup.-1], for the =[CH.sub.2] stretch vibration, is common to both of these groups; however, due to the presence of two =[CH.sub.2] groups, the relative intensity of the band is much higher for [Beta]-type compounds. For [Alpha]-type compounds, a cis configuration at the C-3 carbon atom is characterized by a =[CH.sub.2] wag absorption at 907-906 [cm.sup.-1]. For [Beta]-type compounds and 3E-[Alpha]-type compounds, this band appears at 899-897 [cm.sup.-1]. In addition, a wavy 'fingerprint' pattern with two minima at 1632 (low intensity) and 1595-1594 [cm.sup.-1] (high intensity) is characteristic for [Beta]-type compounds. Our generalizations are based on spectra of cis and trans ocimene, myrcene, and dehydration products of many 3-methyl-1-alken-3-ols. Six isomers of farnesene can be characterized by GC/FT-IR. Furthermore, gas-phase IR allows the determination of the configuration of the trisubstituted double bond at C-3 in [Alpha]-type farnesene congeners. For example, the homo- and bishomofarnesene isomers from Myrmica ants were shown to include a 3Z bond.

Gas-phase Fourier transform infrared spectroscopy allows the determination of the geometric configuration of disubstituted carbon-carbon double bonds present in linear polyunsaturated compounds on the basis of the characteristic absorptions observed in the 3036-3011 and 982-947 [cm.sup.-1] regions. Although the 3036-3011 [cm.sup.-1] band, attributable to a =CH stretch vibration, is conventionally considered to be unreliable for cis/trans determinations, data obtained from a large number of mono- and polyunsaturated acetates show that many useful deductions can be based on this absorption. Double bonds of the RCH=CHR[prime] type separated by at least two methylene groups, present in polyunsaturated compounds, give rise to an absorption at 3013-3011 [cm.sup.-1] if the double bonds are not proximal to a functional group or a terminal methyl group. Cis dienes whose double bonds are separated by only a single methylene group show the cis =CH stretch band at 3017 [cm.sup.-1]. For methylene-interrupted polyenes, this band shows a gradual hypsochromic shift as the unsaturation increases. Furthermore, a band at 1391 [cm.sup.-1] was recognized to represent the deformation vibration of the C[H.sub.2] groups located between the double bonds. The intensity of this band is proportional to the number of skipped methylene groups. None of the isolated or methylene-interrupted dienes bearing only trans double bonds showed any significant absorptions above 3000 [cm.sup.-1]. However, spectra of trans-trans conjugated compounds show a =CH stretch band at 3016-3012 [cm.sup.-1] as a well-defined shoulder on the high-frequency side of the C[H.sub.2] asymmetric stretch band, in addition to the wag absorption observed at 984-982 [cm.sup.-1], which is highly characteristic for trans-trans conjugated compounds. The spectra of cis-trans or trans-cis conjugated compounds are virtually identical and show a characteristic 'fingerprint' consisting of two bands of similar intensity at 978-976 and 949-946 [cm.sup.-1], in addition to the =C-H stretch band observed at 3021-3017 [cm.sup.-1]. Interestingly, not only are the spectra of conjugated cis-cis compounds devoid of any significant absorption in the 982-947 [cm.sup.-1] region, but also the =CH stretch band is broad and appears as a poorly defined shoulder on the high-frequency edge of the [CH.sup.2] asymmetric stretch band.

Gas-phase Fourier-transform infrared spectra allow unambiguous determination of the configuration of the double bonds of long-chain unsaturated compounds bearing RCH=CHR prime type bonds. Although the infrared absorption at 970-967 cm to the -1 has been used previously for the identification of trans bonds, the absorption at 3028-3011 cm to the -1 is conventionally considered to be incapable of distinguishing cis and trans isomers. In this paper, we present a large number of gas-phase spectra of monounsaturated long-chain acetates which demonstrate that an absorption, highly characteristic for the cis configuration, occurs at 3013-3011 cm to the -1, while trans compounds fail to show any bands in this region. However, if a double bond is present at the C-2 or C-3 carbon atoms, this cis=CH stretch absorption shows a hypsochromic shift to 3029-3028 and 3018-3017 cm to the -1, respectively. Similarly, if a cis double bond is present at the penultimate carbon atom, this band appears at 3022-3021 cm to the -1. All the spectra of trans alkenyl acetates showed the expected C-H wag absorption at 968-964 cm to the -1. In addition, the spectra of (E)-2-alkenyl acetates show a unique three-peak 'finger-print' pattern which allows the identification of the position and configuration of this bond. Furthermore, by synthesizing and obtaining spectra of appropriate deuteriated compounds, we have proved that the 3013-3011 cm to the -1 band is representative of the C-H stretching vibration of cis compounds of RCH=CHR prime type.

The peroxidase activities of two coprophilous and litter-decomposing species of the genus Coprinus, namely Coprinus radians and Coprinus verticallatus are studied. The results show that the haloperoxidase secreted by Coprinus radians is used to catalyze the aromatic peroxygenation reaction.

The stereoselectivity of the reaction of furan with maleic anhydride and maleimide was studied experimentally and theoretically. The low thermodynamic stability of furan [4+2] adducts open retro-Diels-Alder reaction channels and overrules the very small kinetic preference of initial formation for endo stereoisomers.