Studies on the metabolism of mitragynine,the main alkaloid of the herbal drug Kratom,in rat and human urine using liquid chromatography‐linear ion trap mass spectrometry

Mitragynine (MG) is an indole alkaloid of the Thai medicinal plant Mitragyna speciosa (Kratom in Thai) and reported to have opioid agonistic properties. Because of its stimulant and euphoric effects, Kratom is used as a herbal drug of abuse. The aim of the presented study is to identify the phase I and II metabolites of MG in rat and human urine after solid‐phase extraction (SPE) using liquid chromatography‐linear ion trap mass spectrometry providing detailed structure information in the MSⁿ mode particularly with high resolution. The seven identified phase I metabolites indicated that MG was metabolized by hydrolysis of the methylester in position 16, O‐demethylation of the 9‐methoxy group and of the 17‐methoxy group, followed, via the intermediate aldehydes, by oxidation to carboxylic acids or reduction to alcohols and combinations of some steps. In rats, four metabolites were additionally conjugated to glucuronides and one to sulfate, but in humans, three metabolites to glucuronides and three to sulfates. Copyright © 2009 John Wiley & Sons, Ltd.     

Synthesis and Crystal Structures of NiPdTe and Ni2PdSe2

The metal‐rich chalcogenides NiPdTe and Ni₂PdSe₂ were synthesized by heating stoichiometric mixtures of the elements at 823–1323 K in silica ampoules under argon atmosphere. The structures were determined by single crystal X‐ray diffraction. NiPdTe (Pnma, a = 8.337(2), b = 3.758(1), c = 6.290(1) Å, Z = 4) is build up by a distorted cubic closed packing of Te atoms with Ni atoms in one half of the tetrahedral holes. The Ni atoms form zigzag‐chains with short Ni–Ni bonds. The Pd atoms are located in the octahedral holes and are fivefold coordinated by Te atoms due to a strong shift off the centers. The structure of NiPdTe is related to the TiNiSi type due to a similar nickel substructure and to the Cu₂Sb type with respect to the fcc packing of the anions. Ni₂PdSe₂ (I4/mmm, a = 10.446(1), c = 5.751(1) Å, Z = 8) forms a new structure type with strongly distorted edge‐ and corner‐sharing NiSe₄ tetrahedra. The Pd atoms are either planar coordinated by four Se or located in the centers of face‐sharing Ni₈ cubes. The structure of Ni₂PdSe₂ merges metallic building blocks with structural fragments typical for polar compounds.     

β‐Substituted Terthiophene [2]Rotaxanes

Towards polythiophene polyrotaxanes : The β‐substituted terthiophene [2]rotaxanes have been synthesized (see figure). Basic optical and electrochemical properties of the synthesized [2]rotaxanes are also reported.

     

Analogues of DIOP. Synthesis, reactivity, and NMR behaviour

The (4R,5R)-4,5-Bis(diphenylphosphinomethyl)-2-(-naphthoxy)-1,3,2-dioxaphospholane (1) and (4R,5R)-4,5-bis(diphenylphosphinomethyl)-2-dimethylamino-2-oxo-1,3,2-dioxaphospholane (2), analogues of the chiral bisphosphine ligand DIOP, have been synthesized. Both compounds have a second phosphorus functionality in the backbone of the chiral bisphosphine. That the reactivities of the various phosphorus atoms in 1 are different was shown for the reaction with BH₃. The complexation behaviour of 1 towards Rh^I was studied with the aid of ³¹P NMR spectroscope.