Leukotriene C(4) is a potent inflammatory mediator formed from arachidonic acid and glutathione. 5-Lipoxygenase (5-LO), 5-lipoxygenase activating protein (FLAP) and leukotriene C(4) synthase (LTC(4)S) participate in its biosynthesis. We report evidence that LTC(4)S interacts in vitro with both FLAP and 5-LO and that these interactions involve distinct parts of LTC(4)S. FLAP bound to the N-termi...

A 66-year-old man presented with a large squamous cell carcinoma of the right nasal vestibule. He underwent partial rhinectomy and medial maxillectomy followed by staged reconstruction. Reconstruction of a full-thickness nasal defect requires repair of three distinct layers: the skin-soft tissue envelope, subsurface framework and intranasal lining. We report the first use in the UK of an osteoc...

In the chiral title compound, C(14)H(17)ClO(7)S, an inter-mediate in the synthesis of the AIDS treatment drug zidovudine, the threose ring adopts an envelope configuration, with the O atom at the flap position.

The oxolan-2-one ring in the title compound, C(12)H(9)NO(4), has an envelope conformation with the atom linking the two five-membered rings being the flap atom.

In the title compound, C(16)H(14)ClN, the conformation of the five-membered ring approximates to an envelope with a C atom as the flap. The dihedral angle between the aromatic rings is 78.71 (9)°.

In the title compound, C(23)H(17)NO(3)S, the thio-phene and isoxazole rings each have an envelope conformation with the spiro C atom linking them forming the flap of the envelope in each case. The dihedral angle between the mean planes of the benzothio-phene ring and isoxazole rings is 81.35 (7)°. In the crystal, an inter-molecular C-H⋯O hydrogen bond links the mol-ecules into a chain running p...

The title compound, C(10)H(9)NO(3), is a chiral mol-ecule with one stereogenic carbon atom, but which crystallizes as a racemate in the centrosymmetric space group P2(1)/n. The central six-membered ring of the indolizine moiety adopts a definite envelope conformation, while the conformation of the oxopyrrolidine ring is close to that of a flat-envelope with a maximum deviation of 0.352 (1) Å fo...

In the title compound, C(37)H(34)N(2)O(4)S, the piperidine ring adopts a half-chair conformation. The thia-zole ring adopts a slightly twisted envelope conformation and the pyrrole ring adopts an envelope conformation; in each case, the C atom linking the rings is the flap atom. An intra-molecular C-H⋯O inter-action is noted. The crystal structure is stabilized by C-H⋯O and C-H⋯π inter-actions.

In the title compound, C22H23NO2S, the inner pyrrolidine ring (A) adopts an envelope conformation with the methine C atom opposite the fused C-N bond as the flap. The thio-pyran ring (C) has a half-chair conformation and its mean plane is inclined to the fused benzene ring by 1.74 (11)°, and by 60.52 (11)° to the mean plane of pyrrolidine ring A. In the outer pyrrolidine ring (B), the C atom op...

In the title compound, C38H32N4O3·H2O, the quinoxaline-indene and pyrrolizine systems are essentially planar, with maximum deviations from their mean planes of 0.162 and 0.563 Å, respectively. The pyrrolizine ring forms dihedral angles of 88.53 (5) and 89.95 (8)° with the quinoxaline-indene system and the indoline ring, respectively. The central pyrrolidine ring has an envelope conformation wit...