Identification and quantification of cannabinol as a biomarker for local hemp retting in an ancient sedimentary record by HPTLC-ESI-MS.

Cannabis products have been used in various fields of everyday life for many centuries, and applications in folk medicine and textile production have been well-known for many centuries. For traditional textile production, hemp fibers were extracted from the stems by water retting in stagnant or slow-moving waters. During this procedure, parts of the plant material' among them phytocannabinoids' are released into the water. Cannabinol (CBN) is an important degradation product of the predominant phytocannabinoids found in Cannabis species. Thus, it is an excellent indicator for present as well as ancient hemp water retting. In this study, we developed and validated a simple and fast method for the determination of CBN in sediment samples using high-performance thin-layer chromatography (HPTLC) combined with electrospray ionization mass spectrometry (ESI-MS), thereby testing different extraction and cleanup procedures' as well as various sorbents and solvents for planar chromatography. This method shows a satisfactory overall analytical performance with an average recovery rate of 73%. Our protocol enabled qualitative and quantitative analyses of CBN in samples of a bottom sediment core' having been obtained from a small lake in Northern India, where intense local retting of hemp was suggested in the past. The analyses showed a maximum CBN content in pollen zone 4 covering a depth range of 262-209 cm, dating from approximately 480 BCE to 1050 CE. These findings correlate with existing records of Cannabis-type pollen. Thus, the method we propose is a helpful tool to track ancient hemp retting activities. Graphical Abstract.

Conversions at C-30 of glycyrrhetinic acid and their impact on antitumor activity.

The extracts of the roots of licorice have been used in traditional and folk medicine to treat a broad variety of maladies. The main ingredient of these extracts is glycyrrhicinic acid. Its aglycon, glycyrrhetinic acid, has many biological activities, among them a pronounced cytotoxicity against tumor cells. In this study we varied glycyrrhetinic acid at position C-30 to get "simple" derivatives, for example esters, amides and a nitrile. The influence of these changes on the cytotoxic activity is noteworthy and was determined by a colorimetric sulphorhodamine B test using 7 human tumor cell lines and mouse embryonic fibroblasts (NIH3T3) for comparison. A Trypan blue test as well as an acridine orange/ethidium bromide test was used to discover the ability of the compounds to induce apoptosis.

Synthesis of monomeric and dimeric acridine compounds as potential therapeutics in Alzheimer and prion diseases.

Starting from substituted 9-chloroacridines, a series of quinacrine and spacered dimeric acridine compounds was prepared. Their ability to interrupt the protein association of prion- and Alzheimer-specific proteins and Ab peptides was explored using a fast screening system based on FACS analysis. The bis-acridines displayed a higher activity than the corresponding monomers. Among these derivatives, best results were obtained with the 2,4-dimethoxy-6-nitro compound 7h for Abeta-peptides and the 2-methoxy-6-nitro compound 7f for PrP.

Synthesis of dimeric quinazolin-2-one, 1,4-benzodiazepin-2-one, and isoalloxazine compounds as inhibitors of amyloid peptides association.

The synthesis of dimeric compounds derived from quinazolin-2-one and 1,4-benzodiazepin-2-one possessing a piperazine or homopiperazine spacer was investigated. In addition, a piperazine spacered bis-isoalloxazine and a bis-riboflavin compound were prepared and their ability to interrupt the association of prion proteins and Alzheimer-specific Abeta peptides was investigated using a fast screening system based on flow cytometry. The bis-isoalloxazine 14 was identified as a new lead structure.