Antenna 9,10-dimethyl

Fig. 4 Gas chromatographic traces of extracts from females of the pale brown chafer Phyl-lopertha diversa monitored by a conventional detector, flame-ionization detector (FID), and a biosensor, electroantennographic detector (EAD), using a male antenna as the sensing element. Although the peak of the sex pheromone (arrow) is hardly seen in the FID trace, its pheromonal activity was initially indicated by the strong EAD peak. Structural elucidation, followed by synthesis and behavioral studies lead to the identification of an unusual sex pheromone, l,3-dimethyl-2,4-(lff,3ff)-quinazolinedione [124]. It is unlikely that this minor compound would be fished out by a bioassay-oriented isolation procedure...

The Bostrychid Dinoderus bifoveolatus is a serious pest on cassava, the dried roots of manioc. Again, this species shows male specific volatiles, two of which were found to produce intense signals in the antennae of conspecific males and females. The minor component proved to be (3R,5S,6R)-3,5-dimethyl-6-hy-droxyoctan-2-one 116, while the major one was shown to be its homologue, (4R,6S,7R)-4,6-dimethyl-7-hydroxy-nonan-3-one 117 [235]. 

The male-produced volatiles eficiting responses from male and female antennae of the sap beetle, Colopterus truncatus Randall (Coleoptera Nitidulidae), were identified as (2A ,4A ,6A )-3,5-dimethyl-2,4,6-octa-triene, 2E, AE, 6T )-4,6-dimethyl-2,4,6-nonatriene and 2E, AE,6E,SE) 3,5,7-trimethyl-2,4,6,8-decatetraene. A fourth male-specific compound... 

Simultaneous GC-EAD analyses of the extracts of the sex pheromone gland of the female bronzed cutworm, Nephelodes minians, indicated two compounds which eficited strong EAD responses from conspecific male antennae, (2 )-ll-hexadecenal and (2 )-ll-hexadecenyl acetate. Double bond positions were confirmed by the dimethyl disulfide derivatives of the pheromone component. In a field test, a 5 1 blend of aldehyde and ester attracted male N. minians. ... 

A unique pheromone structure is represented by the alkaloid l,3-dimethyl-2,4-(17/,3 /)-quinazolinedione (Ar56), which is the sex pheromone of the pale-brown chafer Phyllopertha diversa260 Its degradation with special enzymes on the antennae leading to signal inactivation has been described 261... 

Covalent attachment of electronically active groups such as N,W-dimethyl-aminophenyl (8) [12] or ferrocene (9) [10] as a second electron donor further improves the systems performance (Fig. 7). After photoirradiation of the Donor-Por-Ceo system, a charge-separated state Donor" -Por-Cgo is generated with high quantum efficiency and moderate charge stabihzation. In the BDP-Por-Ceo complex, the boron dipyrrin unit acts as an antenna unit in that it transfers its excited state energy to the porphyrin, which is followed by electron transfer to the fuUerene to give the complex BDP-Por" -Ceo", reminiscent of the combined antenna-reaction center events in natural photosynthesis. 

Photosystem II (PSIl) membranes which are reasonably pure and stable can be isolated from chloroplasts and cyanobacteria (2,3). These PSIl membranes contain the antenna pigments, reaction centre chlorophylls, O2 evolution complex and the two polypeptides D2 and Di, which bind the primary quinone acceptors Qa and Qb respectively. They are, therefore, capable of light-induced O2 evolution in the presence of artificial PSIl acceptors such as dimethyl benzoquinone (DMBQ) or dichlorobenzoquinone (DCBQ). The PSIl membranes can be deposited on TI02 without appreciable loss of photosynthetic activity. 

Chlorophyll (chi a ) in thylakoid membrane takes several forms with different absorption maxima (chi forms) and act as a lightharvesting antenna or a primary electron donor in the photochemical reaction center. We have reported (la,b) the chi a forms specifically formed in the solution of poly(vinyl alcohol), poly(vinyl pyrrolidone), and bovine serum albumin (BSA). A new type of chi form was also suggested in the case of dimethyl sulfoxide (DMSO) (lc,d). Now we succeeded in preparing a novel chi a form (A-685) in aqueous tetrahydrofuran (THF) only in a narrow range of its concentration. Present study aimed to analyze detailed patterns of absorption and resonance Raman spectra of the chi a species and incorporate them into BSA or apocatalase (AC) as a model of the chi -protein complex. 

Knall et al. have tested a series of europium complexes with antenna chromo-phores in different polymer matrices in terms of sensitivity, response time, and dynamic range for the sensing of water vapor. A copolymer containing a Eu " chelate that can be spin-cast as thin film on glass slides was developed [110]. Scheme 6 shows the chemical structure of the polymerizable precursor 29. This complex can be copolymerized with norbomene-2,3-dicarboxylic acid dimethyl ester by means of ring opening metathesis polymerization. The sensor spots respond to water vapor by reversible luminescence quenching, which can be analyzed by means of phase sensitive measurements of luminescence lifetime [110]. 

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