Confirmation of okadaic acid, dinophysistoxin-1 and dinophysistoxin-2 in shellfish as their anthrylmethyl derivatives using UV radiation

A rapid and simple method for confirmation of the diarrhetic shellfish poisons (DSP): okadaic acid (OA), dinophysistoxin-1 (DTX-1) and dinophysistoxin-2 (DTX-2) using fluorescence detection following derivatization with 9-chloromethylanthracene, has been established as an alternate to LC/MS. Exposure of the anthrylmethyl derivatives of OA, DTX-1 and DTX-2 to near UV light (300-400 nm) resulted in the loss of these compounds to below detection limits within 30 min, with a concurrent appearance of two additional compounds. Based on the mass spectral evidence, we propose that these newly formed compounds are the decarboxylation products of the derivatized diarrhetic shellfish poisons. UV radiation is, therefore, proposed as a rapid and simple confirmation technique for these DSP in mussel samples.     

Notiz zum mikrobiologischen Abbau des Nicotins

Zusammenfassung Zwei von A. Wenusch bei der Einwirkung von Tabaksamen bzw. Tabakwurzeln und Wurzeln einer Lapsana-Species auf Nicotin erhaltene Pikrate sind wahrscheinlich miteinander dimorph. Die ihnen zugrundeliegende Base ist identisch mit der von Wada und Yamasaki beim mikrobiologischen Abbau des Nicotins gewonnenen und als 3-Nicotinoylpropionsäure identifizierten Verbindung.Herrn Prof. Dr.L. Schmid zum 60. Geburtstag gewidmet.     

On the Complexity of Partial Order Properties

The recognition complexity of ordered set properties is considered in terms of how many questions must be put to an adversary to decide if an unknown partial order has the prescribed property. We prove a lower bound of order n ² for properties that are characterized by forbidden substructures of fixed size. For the properties being connected, and having exactly k comparable pairs, k n ² / 4 we show that the recognition complexity is (n\choose 2). The complexity of interval orders is exactly (n\choose 2) - 1. We further establish bounds for being a lattice, being of height k and having width k.     

PIGMENT ORGANIZATION IN THE LIGHT-HARVESTING CHLOROPHYLL-a/b PROTEIN COMPLEX OF LETTUCE CHLOROPLASTS. EVIDENCE OBTAINED FROM PROTECTION OF THE CHLOROPHYLLS AGAINST PROTON ATTACK and FROM EXCITATION ENERGY TRANSFER

Abstract— The light-harvesting Chl-a/b protein complex (LHC) of Lactuca sativa L. was examined for pigment content, excitation energy transfer and behavior under acidic conditions:
(1) Lettuce LHC contains Chl-a, Chl-b and xanthophylls (lutein, neoxanthin, lactucaxanthin, viola-xanthin) at a molar ratio of 6:4:3; their contribution to the absorbance of the LHC between 390 and 530 nm is estimated to be about 31% (Chl-a), 26% (Chl-h) and 43% (xanthophylls).
(2) Energy transfer from xanthophylls and Chl-fe to Chl-a takes place at 100% transfer efficiency.
(3) LHC exhibits an unusual acid stability: in contrast to complexes of photosystem I or II, LHC-bound chlorophylls are not converted to phaeophytin and LHC apoprotein is not denatured at pH 1.5; also, energy transfer is maintained.
(4) Pronase or trypsin treatment do not affect acid stability and energy transfer.
(5) Treatments that break down acid stability (heat, urea or TritonX–100) also inhibit energy transfer.
The coincidental breakdown of energy transfer and acid stability points at one underlying process, namely, the breakdown of a structure that enables protection of chlorophylls from proton attack and close contiguity of xanthophylls and chlorophylls as required for energy transfer. Dense packing of xanthophylls and chlorophylls within lipophilic crevices of the LHC is suggested.     

BACTERIORHODOPSIN AND THE SENSORY PIGMENT OF THE PHOTOSYSTEM 565 IN HALOBACTERIUM HALOBIUM

Abstract Blocking in vivo synthesis of retinal by addition of nicotine to the culture medium leads to the loss of photobehavior in Halobacterium halobium. Addition of rrans -retinol or frans-retinol₂ (3,4-dehy-droretinol) restores the responses to light decreases in the green-yellow spectral range. Action spectra of the reconstituted retinal- and retinal₂-photosystem show maximal sensitivity at 565 and 580 nm, respectively. Addition of retinol or retinol₂ also restores the formation of bacteriorhodopsin (BR) or bacteriorhodopsin₂ (BR₂= 3,4-dehydroretinal-bacterio-opsin complex). The absorption spectra of BR and BR₂, measured in isolated membranes, as well as in living bacteria, show maxima at 568 nm (BR) and at about 600 nm (BR₂), respectively. Comparison of the action spectrum of the retinal2-containing sensory photosystem with the absorption spectrum of BR₂ suggests that a retinal pigment different from BR is responsible for the photosensory behavior to green-yellow light.     

Trennung Isomerer Alkohole Mittels der Gas-Flüssig-Chromatographie, 2. Mitt.:

Zusammenfassung 15 isomere Alkohole C₈H₁₈O, unter welchen sich normale und verzweigte, primäre, sekundäre und tertiäre befanden, und deren Siedepunkte um etwa 50° auseinanderliegen, wurden mit drei verschiedenen stationären Phasen untersucht. Gute Trennbarkeit der Isomeren hängt nicht nur von ihrer Siedepunktsdifferenz ab. In Gemischen liegen dieR _z -Werte nicht immer genau dort, wo die der Einzelkomponenten gefunden wurden. Während in günstigen Fällen noch 6 Isomere als 6 Zacken (Schultern) nebeneinander nachgewiesen werden konnten, gaben komplexere Mischungen, z. B. aller 15 untersuchten Alkohole, maximal 10 Zakken bzw. Schultern.Mit 3 Abbildungen     

Nondestructive analysis of single rapeseeds by means of Raman spectroscopy

The value of different vegetable oils can be correlated with the content of polyunsaturated fatty acids, especially omega‐3‐fatty acids such as linolenic acid, because of their contribution to healthy nutrition. One expression for the degree of unsaturation is the iodine value normally measured with gas chromatography. The use of Raman spectroscopy allows a rapid calculation of the iodine value and, in addition, only in a minimal sample volume. Therefore, this method can be used in single rapeseeds in order to predict the iodine value before harvesting. Additionally, the method can also be used for breeding investigations. Here, the lipid content and composition of a plant can be predicted by measuring the seedling without destruction. Copyright © 2006 John Wiley & Sons, Ltd.