Bis(4-acetoxy-N-ethyl-N-n-propyl-tryptammonium) fumarate-fumaric acid (1/1).

The solid-state structure of the title salt/adduct (systemic name: bis-{[2-(4-acet-yloxy-1H-indol-3-yl)eth-yl](eth-yl)propyl-aza-nium} but-2-enedioate-(E)-butenedioic acid (1/1)), 2C17H25N2O2 +·C4H2O4 2-·C4H4O4, was determined by single-crystal X-ray diffraction. The asymmetric unit consists of a singly protonated tryptammonium cation, one half of a fumarate dianion and one half of a fumaric acid mol-ecule. In the crystal, the ions and mol-ecules are linked together in infinite chains propagating along [001] through a series of N-H⋯O and O-H⋯O hydrogen bonds.

N-Cyclo-hexyl-tryptamine: freebase, bromide and fumarate.

The solid-state structures of N-cyclo-hexyl-tryptamine (I) {systematic name: N-[2-(1H-indol-3-yl)eth-yl]cyclo-hexa-namine}, C16H22N2, and two of its salts, N-cyclo-hexyl-tryptammonium bromide (II) {systematic name: N-[2-(1H-indol-3-yl)eth-yl]cyclo-hexa-naminium bromide}, C16H23N2 +·Br-, and N-cyclo-hexyl-tryptammonium fumarate (III) (systematic name: bis-{N-[2-(1H-indol-3-yl)eth-yl]cyclo-hexa-naminium} (2E)-but-2-enedioate), 2C16H23N2 +·C4H2O4 2-, were determined by single-crystal X-ray diffraction. The freebase compound forms infinite chains along [010] through N-H⋯N hydrogen bonds. The bromide salt is held together by N-H⋯Br inter-actions in two-dimensional sheets along (001). The fumarate salt is held together in infinite three-dimensional frameworks by N-H⋯O hydrogen bonds.

3,5-Lutidine penta-aqua sulfate complexes of first-row transition metals: [M(3,5-lutidine)(H2O)5]SO4, with M = Mn, Co, Ni, and Zn.

The reactions of MnSO4·H2O, CoSO4·7H2O, NiSO4·6H2O and ZnSO4·7H2O with 3,5-lutidine (3,5-di-methyl-pyridine) yield crystals of penta-aqua-(3,5-di-methyl-pyridine-κN)manganese(II) sulfate, [Mn(C7H9N)(H2O)5]SO4, (1), penta-aqua-(3,5-di-methyl-pyridine-κN)cobalt(II) sulfate, [Co(C7H9N)(H2O)5]SO4, (2), penta-aqua-(3,5-di-methyl-pyridine-κN)nickel(II) sulfate, [Ni(C7H9N)(H2O)5]SO4, (3), and penta-aqua-(3,5-di-methyl-pyridine-κN)zinc(II) sulfate, [Zn(C7H9N)(H2O)5]SO4, (4), which were characterized by single-crystal X-ray diffraction. The four crystals are isostructural, demonstrating near identical unit-cell parameters and atomic positions. The metal atoms are all octa-hedrally coordinated, with one lutidine ligand and five water ligands. The sulfate dianion hydrogen bonds with the coordinated water mol-ecules of the dicationic metal complex salts, generating infinite three-dimensional networks.

N-Methyl-serotonin hydrogen oxalate.

The solid-state structure of N-methyl-serotonin {systematic name: [2-(5-hy-droxy-1H-indol-3-yl)eth-yl](meth-yl)aza-nium hydrogen oxalate}, C11H15N2O+·C2HO4 -, is reported. The structure possesses a singly protonated N-methylserotonin cation and one hydrogen oxalate anion in the asymmetric unit. In the crystal, the mol-ecules are linked by N-H⋯O and O-H⋯O hydrogen bonds into a three-dimensional network.

Synthesis and structure of 4-hy-droxy-N-iso-propyl-tryptamine (4-HO-NiPT) and its precursors.

The title compound, 4-hy-droxy-N-iso-propyl-tryptamine (4) or 4-HO-NiPT (systematic name: 3-{2-[(propan-2-yl)amino]-eth-yl}-1H-indol-4-ol), C13H18N2O, was synthesized in three steps from 4-benzyl-oxyindole (1) (systematic name: 4-phen-oxy-1H-indole), C15H13NO. (1) was treated with oxalyl chloride and iso-propyl-amine to produce N-isopropyl-4-benz-yloxy-3-indole-glyoxyl-amide (2) {systematic name: 2-[4-(benz-yloxy)-1H-indol-3-yl]-2-oxo-N-(propan-2-yl)acet-amide}, C20H20N2O3. (2) was reduced to generate 4-benz-yloxy-N-iso-propyl-tryptamine (3) or 4-HO-NiPT, which was characterized as its chloride salt 4-benz-yloxy-N-iso-propyl-tryptammonium chloride (3a) (systematic name: {2-[4-(benz-yloxy)-1H-indol-3-yl]eth-yl}(propan-2-yl)aza-nium chloride), C20H25N2O·Cl. Finally the benzyl group of (3) was removed via hydrogenation to generate 4-HO-NiPT. The crystal structures of the title compound and all three synthetic precursors are presented.

Receptor Binding Profiles for Tryptamine Psychedelics and Effects of 4-Propionoxy-N,N-dimethyltryptamine in Mice.

Analogues of 4-phosphoryloxy-N,N-dimethyltryptamine (psilocybin) are being sold on recreational drug markets and developed as potential medications for psychedelic-assisted therapies. Many of these tryptamine-based psilocybin analogues produce psychedelic-like effects in rodents and humans primarily by agonist activity at serotonin 2A receptors (5-HT2A). However, the comprehensive pharmacological target profiles for these compounds compared to psilocybin and its active metabolite 4-hydroxy-N,N-dimethyltryptamine (psilocin) are unknown. The present study determined the receptor binding profiles of various tryptamine-based psychedelics structurally related to psilocybin across a broad range of potential targets. Specifically, we examined tryptamine psychedelics with different 4-position (hydroxy, acetoxy, propionoxy) and N,N-dialkyl (dimethyl, methyl-ethyl, diethyl, methyl-propyl, ethyl-propyl, diisopropyl, methyl-allyl, diallyl) substitutions. Further, the psilocybin analogue 4-propionoxy-N,N-dimethyltryptamine (4-PrO-DMT) was administered to mice in experiments measuring head twitch response (HTR), locomotor activity, and body temperature. Overall, the present pharmacological profile screening data show that the tryptamine psychedelics target multiple serotonin receptors, including serotonin 1A receptors (5-HT1A). 4-Acetoxy and 4-propionoxy analogues of 4-hydroxy compounds displayed somewhat weaker binding affinities but similar target profiles across 5-HT receptors and other identified targets. Additionally, differential binding screen profiles were observed with N,N-dialkyl position variations across several non-5-HT receptor targets (i.e., alpha receptors, dopamine receptors, histamine receptors, and serotonin transporters), which could impact in vivo pharmacological effects of the compounds. In mouse experiments, 4-PrO-DMT displayed dose-related psilocybin-like effects to produce 5-HT2A-mediated HTR (0.3-3 mg/kg s.c.) as well as 5-HT1A-mediated hypothermia and hypolocomotion (3-30 mg/kg s.c.). Lastly, our data support a growing body of evidence that the 5-HT2A-mediated HTR induced by tryptamine psychedelics is attenuated by 5-HT1A receptor agonist activity at high doses in mice.

Bis(oxotremorine) fumarate bis-(fumaric acid).

The title compound, bis-(oxotremorine) fumarate bis-(fumaric acid) {systematic name: 1-[4-(2-oxopyrrolidin-1-yl)but-2-yn-yl]pyrrolidinium (2E)-but-2-ene-di-o-ate bis-[(2E)-but-2-enedioic acid]}, 2C12H19N2O+·C4H2O4 2-·2C4H4O4, has a single oxotremorine monocation protonated at the pyrrolidine nitro-gen, one fumaric acid mol-ecule and half of a fumarate dianion in the asymmetric unit. The ions and fumaric acid mol-ecules are held together by N-H⋯O and O-H-⋯O hydrogen bonds in 40-membered rings with graph-set notation R 6 6(40). The fumarate ions join these rings into infinite chains along [001].

Structure-Activity Relationships for Psilocybin, Baeocystin, Aeruginascin, and Related Analogues to Produce Pharmacological Effects in Mice.

4-Phosphoryloxy-N,N-dimethyltryptamine (psilocybin) is a naturally occurring tertiary amine found in many mushroom species. Psilocybin is a prodrug for 4-hydroxy-N,N-dimethyltryptamine (psilocin), which induces psychedelic effects via agonist activity at the serotonin (5-HT) 2A receptor (5-HT2A). Several other 4-position ring-substituted tryptamines are present in psilocybin-containing mushrooms, including the secondary amine 4-phosphoryloxy-N-methyltryptamine (baeocystin) and the quaternary ammonium 4-phosphoryloxy-N,N,N-trimethyltryptamine (aeruginascin), but these compounds are not well studied. Here, we investigated the structure-activity relationships for psilocybin, baeocystin, and aeruginascin, as compared to their 4-acetoxy and 4-hydroxy analogues, using in vitro and in vivo methods. Broad receptor screening using radioligand binding assays in transfected cells revealed that secondary and tertiary tryptamines with either 4-acetoxy or 4-hydroxy substitutions display nanomolar affinity for most human 5-HT receptor subtypes tested, including the 5-HT2A and the serotonin 1A receptor (5-HT1A). The same compounds displayed affinity for 5-HT2A and 5-HT1A in mouse brain tissue in vitro and exhibited agonist efficacy in assays examining 5-HT2A-mediated calcium mobilization and ß-arrestin 2 recruitment. In mouse experiments, only the tertiary amines psilocin, psilocybin, and 4-acetoxy-N,N-dimethyltryptamine (psilacetin) induced head twitch responses (ED50 0.11-0.29 mg/kg) indicative of psychedelic-like activity. Head twitches were blocked by 5-HT2A antagonist pretreatment, supporting 5-HT2A involvement. Both secondary and tertiary amines decreased body temperature and locomotor activity at higher doses, the effects of which were blocked by 5-HT1A antagonist pretreatment. Across all assays, the pharmacological effects of 4-acetoxy and 4-hydroxy compounds were similar, and these compounds were more potent than their 4-phosphoryloxy counterparts. Importantly, psilacetin appears to be a prodrug for psilocin that displays substantial serotonin receptor activities of its own.

The methanol and ethanol solvates of 4-glutarato-N,N-diiso-propyl-tryptamine.

The solid-state structures of two solvated forms of 4-glutarato-N,N-diiso-propyl-tryptamine were determined by single-crystal X-ray diffraction, namely, 5-[(3-{2-[bis(propan-2-yl)azaniumyl]ethyl}-1H-indol-4-yl)oxy]-5-oxopentanoate meth-anol monosolvate, C21H30N2O4·CH3OH, and the analogous ethanol monosolvate, C21H30N2O4·C2H6O. In both compounds, the 4-glutarato-N,N-di-iso--pro-pyl-tryptamine exists as a zwitterion with a protonated tertiary ammonium and a deprotonated glutarato carboxyl-ate. The tryptamine zwitterions and alcohol solvates in both structures combine to produce near identical hydrogen-bonding networks, with N-H⋯O and O-H⋯O hydrogen bonds joining the mol-ecules together in two-dimensional networks parallel to the (100) plane.

The crystal structure of baeocystin.

The title compound, baeocystin or 4-phosphor-yloxy-N-methyl-tryptamine {systematic name: 3-[2-(methylazaniumyl)ethyl]-1H-indol-4-yl hydrogen phosphate}, C11H15N2O4P, has a single zwitterionic mol-ecule in the asymmetric unit. The mol-ecule has an intra-molecular N-H⋯O hydrogen bond between the ammonium cation and the hydro-phosphate anion. In the crystal, the mol-ecules are linked by N-H⋯O and O-H⋯O hydrogen bonds into a three-dimensional network.

Synthesis, Structural Characterization, and Pharmacological Activity of Novel Quaternary Salts of 4-Substituted Tryptamines.

Aeruginascin (4-phosphoryloxy-N,N,N-trimethyltryptammonium) is an analogue of psilocybin (4-phosphoryloxy-N,N-dimethyltryptamine) that has been identified in several species of psilocybin-containing mushrooms. Our team previously reported the synthesis, structural characterization, and biological activity of the putative metabolite of aeruginascin (4-hydroxy-N,N,N-trimethyltryptammonium; 4-HO-TMT) and its potential prodrug (4-acetoxy-N,N,N-trimethyltryptammonium; 4-AcO-TMT). Here, we report the synthesis, structural characterization, and pharmacological activity of several quaternary tryptammonium analogues of 4-HO-TMT and 4-AcO-TMT, namely, 4-hydroxy-N,N-dimethyl-N-ethyltryptammonium (4-HO-DMET), 4-hydroxy-N,N-dimethyl-N-n-propyltryptammonium (4-HO-DMPT), and 4-hydroxy-N,N-dimethyl-N-isopropyltryptammonium (4-HO-DMiPT), as well as their hypothesized prodrugs 4-acetoxy-N,N-dimethyl-N-ethyltryptammonium (4-AcO-DMET), 4-acetoxy-N,N-dimethyl-N-n-propyltryptammonium (4-AcO-DMPT), and 4-acetoxy-N,N-dimethyl-N-isopropyltryptammonium (4-AcO-DMiPT). Compounds were synthesized using established methods, and structures were characterized by single-crystal X-ray diffraction. Test compounds were screened for in vitro pharmacological activity at a variety of receptors and transporters to determine potential targets of action. None of the compounds exhibited measurable affinity for the serotonin 2A receptor (5-HT2A), but several analogues had low micromolar affinity (K i) for the serotonin 1D receptor (5-HT1D) and serotonin 2B receptor (5-HT2B), where they appeared to be weak partial agonists with low micromolar potencies. Importantly, 4-HO-DMET, 4-HO-DMPT, and 4-HO-DMiPT displayed sub-micromolar affinity for the serotonin transporter (SERT; 370-890 nM). The same 4-hydroxy analogues had low to sub-micromolar potencies (IC50) for inhibition of 5-HT uptake at SERT in transfected cells (3.3-12.3 µM) and rat brain tissue (0.31-3.5 µM). Overall, our results show that quaternary tryptammonium analogues do not target 5-HT2A sites, suggesting the compounds lack psychedelic-like subjective effects. However, certain 4-hydroxy quaternary tryptammonium analogues may provide novel templates for exploring structure-activity relationships for selective actions at SERT.

Crystal structure of serotonin.

The title compound, serotonin or 5-hy-droxy-tryptamine (5-HT) [systematic name: 3-(2-amino-eth-yl)-1H-indol-5-ol], C10H12N2O, has one mol-ecule in the asymmetric unit. The conformation of the ethyl-amino side chain is gauche-gauche [Ca-Ca-Cm-Cm and Ca-Cm-Cm-N (a = aromatic, m = methyl-ene) torsion angles = -64.2 (3) and -61.9 (2)°, respectively]. In the crystal, the mol-ecules are linked into a three-dimensional network by N-H⋯O and O-H⋯N hydrogen bonds.

Erratum: A cuboidal [Co4(SO4)4] structure supported by ß-picoline ligands. Corrigendum.

[This corrects the article DOI: 10.1107/S2056989022000780.].

Complete inhibition of a polyol nucleation by a micromolar biopolymer additive.

Preventing spontaneous crystallization of supersaturated solutions by additives is of critical interest to successful process design and implementation, with numerous applications in chemical, pharmaceutical, medical, pigment, and food industries, but challenges remain in laboratory and industry settings and fundamental understanding is lacking. When copresented with antifreeze proteins (AFPs), otherwise spontaneously crystallizing osmolytes are maintained at high supersaturations for months in over-wintering organisms. Thus, we here explore the inhibition phenomenon by AFPs, using persistent crystallization of a common sugar alcohol, D-mannitol, as a case study. We report experimentally that DAFP1, an insect AFP, completely inhibits D-mannitol nucleation. Computer simulations reveal a new mechanism for crystallization inhibition where the population of the crystal-forming conformers are selectively bound and randomized in solution by hydrogen bonding to the protein surface. These results highlight the advantages of using natural polymers to address crystallization inhibition challenges and suggest new strategies in controlling the nucleation processes.

A cuboidal [Cu4(SO4)4] structure supported by ß-picoline ligands.

The solid-state structure of the cobalt-ß-picoline-sulfate complex tetra-µ3-sulfato-tetra-kis-[bis-(3-methyl-pyridine)-cobalt(II)], [Co4(SO4)4(C6H7N)8], is reported. The tetra-meric cobalt cluster contains a cuboidal core comprised of four cobalt(II) cations and four sulfate anions at alternate cube vertices. The cobalt corners are each capped with two ß-picoline ligands. The sulfate anions adopt a rare [3.2110] bridging motif, and the cuboidal cluster is unprecedented in coordination chemistry.

The crystalline forms of nine hydrochloride salts of substituted tryptamines.

The crystal structures of the hydrochloride salts of nine substituted tryptamines, namely, 1-methyltryptammonium chloride, C11H15N2+·Cl-, (1), 2-methyl-1-phenyltryptammonium chloride, C17H19N2+·Cl-, (2), 5-methoxytryptammonium chloride, C11H15N2O+·Cl-, (3), 5-bromotryptammonium chloride, C10H12BrN2+·Cl-, (4), 5-chlorotryptammonium chloride, C10H12ClN2+·Cl-, (5), 5-fluorotryptammonium chloride, C10H12FN2+·Cl-, (6), 5-methyltryptammonium chloride, C11H15N2+·Cl-, (7), 6-fluorotryptammonium chloride, C10H12FN2+·Cl-, (8), and 7-methyltryptammonium chloride, C11H15N2+·Cl-, (9), are reported. The seven tryptamines with N-H indoles, (3)-(9), show very similar structures, with N-H...Cl hydrogen-bonding networks forming two-dimensional sheets in the crystals. These sheets are combinations of R42(8) and R42(18) rings, and C21(4) and C21(9) chains. Substitution at the indole N atom reduces the dimensionality of the hydrogen-bonding network, with compounds (1) and (2) demonstrating one-dimensional chains that are a combination of different rings and parallel chains.

'Foxtrot' fumarate: a water-soluble salt of N,N-di-allyl-5-methoxytryptamine (5-MeO-DALT).

The title compound, bis-(N,N-diallyl-5-meth-oxy-tryptammonium) (5-MeO-DALT) fumarate (systematic name: bis-{N-[2-(5-meth-oxy-1H-indol-3-yl)eth-yl]- N-(prop-2-en-1-yl)prop-2-en-1-aminium} (E)-but-2-enedioate), 2C17H23N2O+·C4H2O4 2-, has a single tryptammonium cation and half of a fumarate dianion in the asymmetric unit. The tryptammonium and fumarate ions are held together in one-dimensional chains by a series of N-H⋯O hydrogen bonds. These chains are combinations of R 4 4(22) rings, and C 2 2(14) and C 4 4(28) parallel chains along [111].

5-Meth-oxy-N,N-di-n-propyl-tryptamine (5-MeO-DPT): freebase and fumarate.

The solid-state structures of the synthetic psychedelic 5-meth-oxy-N,N-di-n-propyl-tryptamine (5-MeO-DPT) {systematic name: N-[2-(5-meth-oxy-1H-indol-3-yl)eth-yl]-N-propyl-propan-1-amine}, C17H25N2O, and its fumarate salt, bis-(5-meth-oxy-N,N-di-n-propyl-tryptammonium) fumarate (systematic name: bis-{N-[2-(5-meth-oxy-1H-indol-3-yl)eth-yl]-N-propyl-propan-1-aminium} but-2-ene-dio-ate), 2C17H25N2O+·C4H2O4 2-, are reported. The freebase has a single tryptamine mol-ecule in the asymmetric unit. The mol-ecules are linked together by N-H⋯N hydrogen bonds in zigzag chains along the [010] direction. The fumarate salt has a single tryptammonium cation and half of a fumarate dianion in the asymmetric unit. The tryptammonium and fumarate ions are held together in one-dimensional chains by a series of N-H⋯O hydrogen bonds. These chains are combinations of R 4 4(22) rings, and C 2 2(14) and C 4 4(28) parallel chains along [001].

Design and synthesis of C-aryl angular luotonins via a one-pot aza-Nazarov-Friedlander sequence and their Topo-I inhibition studies along with C-aryl vasicinones and luotonins.

A facile one-pot synthesis of C-ring substituted angular luotonins has been realized via a methanesulfonic acid mediated aza-Nazarov-Friedlander condensation sequence on quinazolinonyl enones. Topoisomerase I (topo-I) inhibition studies revealed that the angular luotonin library (7a-7l) and their regioisomeric analogs (linear luotonins, 8a-8l) are weak negative modulators, compared to camptothecin. These results would fare well for the design of topo-I-inert luotonins for non-oncological applications such as anti-fungal and insecticide lead developments. Surprisingly, the tricyclic vasicinones (9h, 9i, and 9j) showed better topo-I inhibition compared to pentacyclic C-aryl luotonins providing a novel pharmacophore for further explorations.

Psilacetin derivatives: fumarate salts of the meth-yl-ethyl, meth-yl-allyl and diallyl variants of the psilocin prodrug.

The solid-state structures of the salts of three psilacetin derivatives, namely, 4-acet-oxy-N-eth-yl-N-methyl-tryptammonium (4-AcO-MET) hydro-fumarate {sys-tematic name: [2-(4-acet-yloxy-1H-indol-3-yl)eth-yl](meth-yl)ethyl-aza-nium 3-carb-oxy-prop-2-enoate}, C15H21N2O2 +·C4H3O4 -, 4-acet-oxy-N-allyl-N-methyl-tryptammonium (4-AcO-MALT) hydro-fumarate {systematic name: [2-(4-acet-yl-oxy-1H-indol-3-yl)eth-yl](meth-yl)prop-2-enyl-aza-nium 3-carb-oxy-prop-2-eno-ate}, C16H21N2O2 +·C4H3O4 -, and 4-acet-oxy-N,N-di-allyl-tryptammonium (4-AcO-DALT) fumarate-fumaric acid (1/1) (systematic name: bis-{[2-(4-acet-yloxy-1H-indol-3-yl)eth-yl]diprop-2-enyl-aza-nium} but-2-enedioate-(E)-butenedioic acid (1/1)), 2C18H23N2O2 +·C4H2O4 2-·C4H4O4, are reported. All three salts possess a protonated tryptammonium cation. The 4-AcO-MET and 4-AcO-MALT compounds are charge-balanced by 3-carb-oxy-acrylate (hydro-fumarate) anions. The 4-AcO-DALT complex crystallizes as a two-to-one tryptammonium-to-fumarate salt, which co-crystallizes with a fumaric acid mol-ecule. Each structure is consolidated by N-H⋯O and O-H⋯O hydrogen bonds.