Paraherquamide E

In the title compound, C28H35N3O4, also known as 14-de­oxy­paraherquamide A,the two pyrrolidine rings adopt envelope conformations. The piperazine ring of the diaza­bicyclo­[2.2.2]octan-3-one unit adopts a boat conformation whereas the two piperidine rings are in distorted boat conformations. Intra­molecular C—H⋯O hydrogen bonds are observed. In the crystal, the mol­ecules are linked into chains along the b axis by inter­molecular N—H⋯O hydrogen bonds

IDENTIFICATION OF 24-ETHYLCHOLESTANES AS MOLECULAR INDICATORS OF VASCULAR PLANTS SOURCE INPUTS IN COASTAL SEDIMENTS FROM NIGER DELTA, NIGERIA

ABSTRACT The identification of ααα-24-ethylcholestane, 2α-methyl-24-ethylcholestane and 3β-Methyl-5α-stigmastane in extracts of sediments from the coastal areas of the Niger Delta of Nigeria was achieved by gas chromatography-mass spectrometry (GC-MS) technique. The concentrations of the 24-ethylcholestanes varied between 0.05 and 1.40 mgkg-1 in the entire study area. The distributions of the 24-ethylcholestanes, which are known to be diagenetic products of plant sterols (phytosterols) in our samples, suggest possible source inputs from vascular plants around the coastal vegetation of the Niger Delta environment