Chapter Two - Naturally Occurring Cyclotryptophans and Cyclotryptamines

A chemical investigation of the endolichenic fungus Aspergillus versicolor (125a), which was found in the lichen Lobaria quercizans, resulted in the isolation of four novel diphenyl ethers, named diorcinols F-H (1-3, resp.) and 3-methoxyviolaceol-II (4), eight new bisabolane sesquiterpenoids, named (-)-(R)-cyclo-hydroxysydonic acid (5), (-)-(7S,8R)-8-hydroxysydowic acid (6), (-)-(7R,10S)-10-hydroxysydowic acid (7), (-)-(7R,10R)-iso-10-hydroxysydowic acid (8), (-)-12-acetoxy-1-deoxysydonic acid (9), (-)-12-acetoxysydonic acid (10), (-)-12-hydroxysydonic acid (11), and (-)-(R)-11-dehydrosydonic acid (12), two new tris(pyrogallol ethers), named sydowiols D (13) and E (14), and fifteen known compounds, 15-29. All of the structures were determined by spectroscopic analyses, and a number of them were further identified through chemical transformations and electronic circular dichroism (ECD) calculations. Preliminary bioassays of these isolates for the determination of their inhibitory activities against the fungus Candida albicans, and their cytotoxicities against the human cancer cell lines PC3, A549, A2780, MDA-MB-231, and HEPG2 were also evaluated.

Identification and Biological Evaluation of Secondary Metabolites from the Endolichenic Fungus Aspergillus versicolor

The degree of alkylation of the side chain nitrogen in tryptamines is one important factor that affects psychoactivity. The method of Speeter and Anthony is considered to be one of the most important synthetic preparative methods. The final step in this reaction is based on the reduction of a (substituted) indole-3-yl-glyoxalylamide to the desired tryptamine with metal hydride. Twelve symmetrically and 13 asymmetrically N,N-disubstituted glyoxalylamides and their corresponding tryptamine derivatives have been synthesised and characterised by gas chromatography EI-ion trap mass spectrometry, electrospray-triple quadrupole-tandem mass spectrometry and NMR spectroscopy. Mass spectral and NMR similarities and differences between the investigated compounds are discussed. A solvent dependency is observed that has to be taken into consideration for the unambiguous assignment of 1 H- and 13 C-NMR chemical shifts. The 1 HNMR study demonstrated that one can evaluate the rotamer populations of the asymmetrical glyoxalylamides. In a forensic or clinical scenario where single or multiple reaction monitoring approaches are contemplated, the appropriate ion transitions of choice may then focus on the two main fragmentations, namely b-cleavage ([M+H] + A CH2N + R 2 R 3 ) and/or a-cleavage ([M+H] + A [3-vinylindole] + ), respectively. The synthesis, NMR and MS analytical data presented provide the forensic analyst and clinical biochemist with a detailed and self-consistent body of information and mechanisms for the spectral identification of the more likely psychoactive tryptamines that may be met.

Analytical chemistry of synthetic routes to psychoactive tryptamines Part II.{ Characterisation of the Speeter and Anthony synthetic route to N,N-dialkylated tryptamines using GC-EI-ITMS, ESI-TQ-MS-MS and

The degree of alkylation of the side chain nitrogen in tryptamines is one important factor that affects psychoactivity. The method of Speeter and Anthony is considered to be one of the most important synthetic preparative methods. The final step in this reaction is based on the reduction of a (substituted) indole-3-yl-glyoxalylamide to the desired tryptamine with metal hydride. Twelve symmetrically and 13 asymmetrically N,N-disubstituted glyoxalylamides and their corresponding tryptamine derivatives have been synthesised and characterised by gas chromatography EI-ion trap mass spectrometry, electrospray-triple quadrupole-tandem mass spectrometry and NMR spectroscopy. Mass spectral and NMR similarities and differences between the investigated compounds are discussed. A solvent dependency is observed that has to be taken into consideration for the unambiguous assignment of (1)H- and (13)C-NMR chemical shifts. The (1)H-NMR study demonstrated that one can evaluate the rotamer populations of the asymmetrical glyoxalylamides. In a forensic or clinical scenario where single or multiple reaction monitoring approaches are contemplated, the appropriate ion transitions of choice may then focus on the two main fragmentations, namely beta-cleavage ([M+H](+)-->CH(2)N(+)R(2)R(3)) and/or alpha-cleavage ([M+H](+)-->[3-vinylindole](+)), respectively. The synthesis, NMR and MS analytical data presented provide the forensic analyst and clinical biochemist with a detailed and self-consistent body of information and mechanisms for the spectral identification of the more likely psychoactive tryptamines that may be met.

Analytical chemistry of synthetic routes to psychoactive tryptamines. Part II. Characterisation of the Speeter and Anthony synthetic route to N,N-dialkylated tryptamines using GC-EI-ITMS, ESI-TQ-MS-MS and NMR.

Isolation of three new naturally occurring compounds from the culture of Micromonospora sp. P1068

The chemical shifts of 298 naturally occurring and synthetic compounds containing the indole chromophoric group are listed. Substituent effects on 13C chemical shifts (SCS) induced by substitution on the heteroaromatic five-membered ring are discussed. The data provide a reference set for future 13C NMR investigations and highlight the need for unambiguous experimental evidence to resolve controversial assignments for differently substituted representative indole derivatives. Many original assignments have been changed, and values not considered to be unambiguously assinged are delineated. The 1J(CH) values for the parent indole were measured.

J. Espiñeira

Papers

13C NMR spectroscopy of indole derivatives