Furfuryl alcohol can be transformed in a simple way into the long‐awaited sulfur analog of porphyrin, the tetrathiaporphyrin dication 1, isolated as the perchlorate. The key to the synthesis is a remarkably straightforward sulfur/oxygen exchange in tetraoxaporphyrinogen. As would be expected from the relatively large van der Waals radius of sulfur, the transformation from the tetraoxaporphyrin dication to 1 is accompanied by loss of planarity in the ring system.

7] Crystallographic data for 2 . 3py (C,,H,,CI,LiN,, M = 328.16): Monoclinic, space group P2,ln, a=1271.3(1). b =1072.8(5), c =1273.1(1)pm, / 3 = 91.81(1Y. V=1735.5(8)x 10-30m3. 2 = 4. p ,, =1.256 Mgm-'. ~(CU,,) = 3.331 mm". Data collection on an Enraf-Nonius CAD4 diffractometer with graphite monochromated Cu,, -radiation. o scans. max. 12 s per reflection, T = 150(2) K. 2604 reflections were collected (4 < 0 i 55"). of which 2185 were unique (R,,, = 0.053). The structure was solved with direct methods (SHELXTL) and was refined on F2 with all reflections (SHELXL-93). non-hydrogen atoms anisotropic, hydrogen atoms (without Hl) on calculated positions with fixed isotropic temperature factors. The parameters of the weightingschemecalculated by the program were: 0.1150,2.3053, wR2(Rl for 1949 reflections with I > Zu(1)): 0.2051 (0.0740), Goof =1.033; 204 refined parameters. The data were corrected with the program DIFABS ( R values without the DIFABS correction: 0.2283.0.0834). Relatively high temperature factors for the atoms C9 and C10 and "too short" bond lengths C8-C9 and C9-C10 indicate disorder which has not been resolved [13]. All calculations have been performed on an Micro-VAX I1 and a Dec 3000-300X [8-121 [8] Siemens SHELXTL (VMS) Vers. 5.04, Siemens-Analytical-X-Ray-lnstru-

ZUSCHRIFTENAutoren, die e k e ,,Zuschrift" veroffentlichen wollen, soliten vor der Abfassung ihres Manuskripts unbedingt die ,,Hinweise f i r Autoren" lesen, die jeweils im Januarheft eines Jahrgangs nach dem Inhaltsverzeichnis gedruckt sind; auf Anforderung konnen sie auch von der Redaktion erhalten werden.

geometry of the copper complex (Fig. 3a).ii3f Moreover. the EPR spectrum is indicative of a type-I1 copper binding site in a similar ligdnd environment with g , , = 2.27 and A , , = 173 (cm-x lo4). Peisach and Blumberg analysis[141 is

Als Modellverbindung in der Thiaporphyrin‐Reihe empfiehlt sich aufgrund guter Löslichkeit das Dikation 1 (als Perchlorat). Schlüsselschritt der Synthese von 1 ist die säureinduzierte Kondensation (nicht biomimetisch!) von 3,4‐Diethyl‐2‐hydroxymethylthiophen, die außer dem Tetra‐ auch das Pentacyclokondensationsprodukt liefert. Letzteres eröffnet den Weg zum 22π‐Pentathiapentaphyrin‐Trikation 2, dem Schwefelanalogon von Pentaphyrin.

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The endothelium and the glycocalyx play a pivotal role in regulating microvascular function and perfusion in health and critical illness. It is unknown today, whether aerobic exercise immediately affects dimensions of the endothelial surface layer (ESL) in relation to microvascular perfusion as a physiologic adaption to increased nutritional demands. This monocentric observational study was designed to determine real-time ESL and perfusion measurements of the sublingual microcirculation using sidestream dark field imaging performed in 14 healthy subjects before and after completing a 10 km trial running distance. A novel image acquisition and analysis software automatically analysed the perfused boundary region (PBR), an inverse parameter for red blood cell (RBC) penetration of the ESL, in vessels between 5 and 25 µm diameter. Microvascular perfusion was assessed by calculating RBC filling percentage. There was no significant immediate effect of exercise on PBR and RBC filling percentage. Linear regression analysis revealed a distinct association between change of PBR and change of RBC filling percentage (regression coefficient β: − 0.026; 95% confidence interval − 0.043 to − 0.009; p = 0.006). A single aerobic exercise did not induce a change of PBR or RBC filling percentage. The endothelium of the microvasculature facilitates efficient perfusion in vessels reacting with an increased endothelial surface layer.

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