RESUMO
An inverse linear relationship between the experimentally observed (195)Pt NMR signals and the overall sum of coordinated halido ligands' ionic radii was discovered in Pt(ii) and Pt(iv) complexes. The reduction of (195)Pt NMR frequencies parallels the increase of coordinated halido ligands' ionic radii sum. This suggests that each halido ligand may act as a conducting ring whose induced electric current shields the (195)Pt NMR signals proportionally to the ionic radius of the coordinated halido ligand.
RESUMO
As a continuation of our study on plants of the Sapindaceae, the chemical composition of the oil extracted from seeds of Allophylus natalensis (Sonder) De Winter and of A. dregeanus (Sonder) De Winter has been investigated. The oil from both species contained approximately equal amounts of TAG and type I cyanolipids (CL), 1-cyano-2-hydroxymethylprop-2-en-1-ol-diesters, with minor amounts of type III CL, 1-cyano-2-hydroxymethylprop-1-en-3-ol-diesters. Structural investigation of the oil components was accomplished by chemical, chromatographic (TLC, CC, GC, and GC-MS), and spectroscopic (IR, NMR) means. GC and GC-MS analysis showed that C20 FA were dominant in the CL components of the oil from the two species (44-80% vs. 21-26% in TAG), with cis-11-eicosenoic acid (36-46%) and cis 13-eicosenoic acid (paullinic acid, 23-37%) as the major esterified fatty acyl chains in A. natalensis and A. dregeanus, respectively. cis-Vaccenic acid was particularly abundant (11-31%) in the CL from A. dregeanus, whereas eicosanoic acid (10-22%) was also a major component of CL in both species.
