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X-ray investigations of perchlorotriphenylene, a polycyclic aromatic chlorocarbon synthesized from tetrachlorophthalic anhydride, indicate a C2 conformation for this compound. It is stable under normal conditions, despite a distortion from planarity. Even in gas phase, the C2 conformation is favored, as is evident from MO and semiempirical calculations. This suggests the ability of the compound to undergo enantiomerization and its flexible nature.

We report a facile, microwave-accelerated, one-pot tandem synthesis of unsymmetrical ureas via a Curtius rearrangement. In this method, one-pot microwave irradiation of commercially available (hetero)aromatic acids and amines in the presence of diphenylphosphoryl azide enabled extremely rapid (1-5 min) construction of an array of unsymmetrical ureas in good to excellent yields. We demonstrate the utility of our method in the efficient, gram-scale synthesis of key biologically active compounds targeting the cannabinoid 1 and α7 nicotinic acetylcholine receptors. [ABSTRACT FROM AUTHOR]

Undesirable side effects associated with orthosteric agonists/antagonists of cannabinoid 1 receptor (CB1R), a tractable target for treating several pathologies affecting humans, have greatly limited their translational potential. Recent discovery of CB1R negative allosteric modulators (NAMs) has renewed interest in CB1R by offering a potentially safer therapeutic avenue. To elucidate the CB1R allosteric binding motif and thereby facilitate rational drug discovery, we report the synthesis and biochemical characterization of first covalent ligands designed to bind irreversibly to the CB1R allosteric site. Either an electrophilic or a photoactivatable group was introduced at key positions of two classical CB1R NAMs: Org27569 (1) and PSNCBAM-1 (2). Among these, 20 (GAT100) emerged as the most potent NAM in functional assays, did not exhibit inverse agonism, and behaved as a robust positive allosteric modulator of binding of orthosteric agonist CP55,940. This novel covalent probe can serve as a useful tool for characterizing CB1R allosteric ligand-binding motifs. [ABSTRACT FROM AUTHOR]

Roasting of solid tetrachlorophythalic anhydride yields compounds of general formula (C6H4)n such as perchlorotriphenylene, which is separated using thin layer chromatography. 8 mg of 80% pure perchlorotriphenylene is obtained from 1 gm of anhydride. X-ray analysis reveals the high distortion from planarity. The compound exhibits C2 symmetry and is stable under normal conditions.

Anexpeditious microwave-assisted synthesis of 4BP-TQS, its enantiomericseparation, and their functional evaluation is reported. Electrophysiologicalcharacterization in Xenopusoocytesrevealed that activity exclusively resided in the (+)-enantiomer 1b(GAT107) and (−)-enantiomer 1adidnot affect its activity when coapplied. X-ray crystallography studiesrevealed the absolute stereochemistry of 1bto be 3aR,4S,9bS. 1brepresents the most potent ago-PAM of α7 nAChRs availableto date and is considered for further in vivo evaluation. [ABSTRACT FROM AUTHOR]

One of the most abundant G-protein coupled receptors (GPCRs) in brain, the cannabinoid 1 receptor (CB1R), is a tractable therapeutic target for treating diverse psychobehavioral and somatic disorders. Adverse on-target effects associated with small-molecule CB1R orthosteric agonists and inverse agonists/antagonists have plagued their translational potential. Allosteric CB1R modulators offer a potentially safer modality through which CB1R signaling may be directed for therapeutic benefit. Rational design of candidate, druglike CB1R allosteric modulators requires greater understanding of the architecture of the CB1R allosteric endodomain(s) and the capacity of CB1R allosteric ligands to tune the receptor's information output. We have recently reported the synthesis of a focused library of rationally designed, covalent analogues of Org27569 and PSNCBAM-1, two prototypic CB1R negative allosteric modulators (NAMs). Among the novel, pharmacologically active CB1R NAMs reported, the isothiocyanate GAT100 emerged as the lead by virtue of its exceptional potency in the [(35)S]GTPγS and β-arrestin signaling assays and its ability to label CB1R as a covalent allosteric probe with significantly reduced inverse agonism in the [(35)S]GTPγS assay as compared to Org27569. We report here a comprehensive functional profiling of GAT100 across an array of important downstream cell-signaling pathways and analysis of its potential orthosteric probe-dependence and signaling bias. The results demonstrate that GAT100 is a NAM of the orthosteric CB1R agonist CP55,940 and the endocannabinoids 2-arachidonoylglycerol and anandamide for β-arrestin1 recruitment, PLCβ3 and ERK1/2 phosphorylation, cAMP accumulation, and CB1R internalization in HEK293A cells overexpressing CB1R and in Neuro2a and STHdh(Q7/Q7) cells endogenously expressing CB1R. Distinctively, GAT100 was a more potent and efficacious CB1R NAM than Org27569 and PSNCBAM-1 in all signaling assays and did not exhibit the inverse agonism associated with Org27569 and PSNCBAM-1. Computational docking studies implicate C7.38(382) as a key feature of GAT100 ligand-binding motif. These data help inform the engineering of newer-generation, druggable CB1R allosteric modulators and demonstrate the utility of GAT100 as a covalent probe for mapping structure-function correlates characteristic of the druggable CB1R allosteric space.