The sesquiterpene lactones dunnianin (1), debenzoyldunnianin (2), 7-deoxy-7-oxodunnianin (3), and pseudoanisatin (4) were isolated from fruits of Illicium floridanum. On the basis of the molecular structure of 4, 1−3 had previously been assigned structures containing 11,14-ε-lactone rings (1a−3a). Due to inconsistencies in the 1H-NMR spectra of 1−3, when compared with the spectrum of 4, their structures were reinvestigated by NMR spectroscopic analyses, and the molecular structure of 1 was determined by single-crystal X-ray diffraction. Compounds 1−3 were found to contain an 11,3-δ-lactone ring instead of the previously reported 11,14-ε-lactone, which required revision of their structures from 1a−3a to 1b−3b, respectively.

1. Leukotriene (LT) B3 was prepared by total chemical synthesis and its identity was confirmed by nuclear magnetic resonance analysis and proton homonuclear plot of connectivities and chemical shift assignments. The effects of LTB3 on complement receptor enhancement, chemotaxis and lysozyme release in human neutrophils (PMN) were compared with those of LTB4 and LTB5. 2. LTB3 and LTB4 elicited a virtually identical dose- and time-dependent enhancement in complement receptors type 1 (CR1) and type 3 (CR3) and release of lysozyme. LTB5 was approximately 100 times less potent than LTB4 in enhancing CR1 and CR3, whereas it was 10,000 times less potent than LTB4 in releasing lysozyme from human PMN. 3. LTB3 and LTB5 were respectively 5- and 100-fold less potent than LTB4 in eliciting chemotaxis. 4. These findings indicate that the pro-inflammatory potential of LTB3 and LTB4 are similar, whereas LTB5 is substantially less potent as an inflammatory mediator. 5. The finding that LTB5 is a weak and partial agonist relative to LTB3 and LTB4 could be due to the rigidity of the C-17-C-18 double bond in LTB5. This may interfere with the active site specificity of LTB5 to a substantial extent. 6. One approach to the development of antagonists to the LTB4 receptor may be to establish a rigid structure in the C-17-C-18 region of the LTB4 molecule.

Thallium(I) tris(pyrazol-1-yl)methanesulfonate (TlTpms) has been prepared as a new versatile precursor for Tpms complexes. TlTpms readily reacts with the rhodium(I) complexes [Rh(LL)Cl] 2 [LL = (CO) 2 , cod, nbd] to give the corresponding TpmsRh(LL) complexes [LL = (CO) 2 (2a), cod (3), and nbd (4)]. In solution, 2a reversibly forms the binuclear complex TpmsRh(µ-CO) 3 RhTpms (2b). 3 and 4 react with CO to form 2a. TpmsRh(CO)(PR 3 ) complexes [PR 3 = PPh 3 (5a), PMe 3 (5b), PCy 3 (5d), P(Ph) 2 (PhSO 3 K) (5e)] have been obtained by reaction of 2a with the corresponding phosphanes. The solidstate structures of 2a, 3, 4, and 5a have been determined by X-ray analysis. 2a, 3, and 5a have square-planar geometries

In continuation of our phytochemical investigation of Illicium floridanum Ellis (American star anise, star bush), three new sesquiterpene lactones possessing the anisatin-type carbon skeleton (8,9-seco-prezizaane skeleton), 14-acetoxy-3-oxofloridanolide (1), 13-acetoxy-14-(n-butyryloxy)floridanolide (2), and 3beta-acetoxy-14-n-butyryloxy-10-deoxyfloridanolide (3), were isolated from fruits of this plant. Their structures were elucidated by 1D and 2D NMR measurements. The molecular structure of 1 was obtained by single crystal X-ray diffraction. The 11,3-delta-lactone structure of the compound previously described as debenzoyldunnianin in our previous communication, on grounds of NMR spectral evidence and X-ray crystallographic analysis is revised to a delta-lactone closed between C-11 and C-7 (compound 4). The neurotoxic sesquiterpene lactone anisatin (5) and its isomer 2alpha-hydroxyneoanisatin (3-deoxy-2alpha-hydroxyanisatin, 6) were also isolated and identified by spectroscopic means. The presence of the neurotoxin 5 in relatively high amounts in the fruits and leaves confirms and explains early reports on the toxicity of this plant.