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Based on a previously prepared lead compound, a new series of hybrid compounds was prepared and tested against six human tumour cell lines. These new triazole linked tetrahydropyran–oxazole hybrids were prepared evaluating the impact of the LogP for the proposed modifications. The compounds exhibited good antiproliferative results when compared with standards cisplatin and 5-fluorouracil. A series of triazole linked tetrahydropyran–oxazole hybrids was synthesized based on a previously reported lead compound with selective antiproliferative activity against human tumour cell lines. The series was prepared to evaluate the impact of LogP and different modifications in the activity, and the new compounds were assayed against A549, HBL-100, HeLa, SW1573, T-47D, and WiDr cell lines. Also, the potentiality to be P-gp substrate was tested. The compounds exhibited good antiproliferative results when compared with the standards cisplatin and 5-fluorouracil. In silico studies to evaluate pharmacokinetic properties using pkCSM software were also carried out.

A one pot borylation/Suzuki-Miyaura reaction of the 4-bromochromanone lactones 21 and 23, respectively, followed by cleavage of the methyl ether moieties gave the homodimeric chromanone lactones 10 and 11. Reaction of a 1:1 mixture of 21 and 23 under otherwise identical conditions gave a 1:1:2-mixture of the two homodimers 10 and 11 and the heterodimer 12. This is the first example of the preparation of a heterodimeric chromanone lactone. For the enantioselective synthesis of the starting material, phenol 17 was transformed into the chromane 18 using a Wacker-type cyclisation with 99 % ee and 80 % yield.

This work reports on the enantioselective total synthesis of the two dimeric natural chromanone lactones phomopsis-H76 A (5) and blennolide H (6). Both syntheses could be achieved from chromane 11, which was obtained by an enantioselective Wacker-type cyclization with >99 % ee. The dimerization of the corresponding monomers was performed using a palladium-catalyzed Suzuki reaction. Moreover, within this work it was possible to revise the absolute configuration of phomopsis-H76 A and determine the relative as well as absolute configuration of blennolide H.

An enantioselective total synthesis of blennolide D and the enantiomers of blennolide E and F is described using an enantioselective Wacker-type oxidation followed by the formation of the lactone moiety. For the introduction of the hydroxyl group in the γ-lactone, a TEMPO-mediated α-oxygenation was used which was followed by a benzylic oxidation and deprotection to give the desired compounds. In addition, an unknown diastereomer was synthesized.

Inspired by diverse marine bioactive compounds, the principle of molecular hybridization was applied to produce a series of new compounds combining diverse heterocyclic systems (oxa/thiazoles and tetrahydropyrans) via a triazole ring, attempting to increase the activity of individual building blocks. These new compounds exhibit a highly interesting antiproliferative activity against different human tumour cells and good selectivity when compared to normal cells. The formation of reactive oxygen species and the interaction with P-gp were also evaluated for the lead compounds., This research was supported by CSIC Grupos No. 654 and No. 983, PEDECIBA Química and the Spanish MINECO. Co-financed by the European Regional Development Fund (ERDF) (CTQ2014-56362-C2-1-P). G. V. would like to thank ANII (Agencia Nacional de Investigación e Innovación) for the award of a doctoral fellowship.

Lambert-Eaton myasthenic syndrome (LEMS) is an autoimmune disorder caused by antibodies directed against the voltage-gated calcium channels that provide the calcium ion flux that triggers acetylcholine release at the neuromuscular junction. To study the pathophysiology of LEMS and test candidate therapeutic strategies, a passive-transfer animal model has been developed in mice, which can be created by daily intraperitoneal injections of LEMS patient serum or IgG into mice for 2-4 weeks. Results from studies of the mouse neuromuscular junction have revealed that each synapse has hundreds of transmitter release sites but that the probability for release at each one is likely to be low. LEMS further reduces this low probability such that transmission is no longer effective at triggering a muscle contraction. The LEMS-mediated attack reduces the number of presynaptic calcium channels, disorganizes transmitter release sites, and results in the homeostatic upregulation of other calcium channel types. Symptomatic treatment is focused on increasing the probability of release from dysfunctional release sites. Current treatment uses the potassium channel blocker 3,4-diaminopyridine (DAP) to broaden the presynaptic action potential, providing more time for calcium channels to open. Current research is focused on testing new calcium channel gating modifiers that work synergistically with DAP.

The first enantioselective total synthesis of natural dicerandrol C (1 c) as its enantiomer containing a dimeric tetrahydroxanthenone skeleton is described starting from the enantiopure chromane 6 which was obtained through a Wacker-type cyclization with >99 % ee. For the formation of the dimeric skeleton a palladium-catalyzed Suzuki reaction was used. The synthesis allowed the confirmation of the absolute configuration of the dicerandrols.

Lambert-Eaton myasthenic syndrome (LEMS) is an autoimmune disorder in which a significant fraction of the presynaptic P/Q-type Ca(2+) channels critical to the triggering of neurotransmitter release at the neuromuscular junction (NMJ) are thought to be removed. There is no cure for LEMS, and the current most commonly used symptomatic treatment option is a potassium channel blocker [3,4-diaminopyridine (3,4-DAP)] that does not completely reverse symptoms and can have dose-limiting side-effects. We previously reported the development of a novel Ca(2+) channel agonist, GV-58, as a possible alternative treatment strategy for LEMS. In this study, we tested the hypothesis that the combination of GV-58 and 3,4-DAP will elicit a supra-additive increase in neurotransmitter release at LEMS model NMJs. First, we tested GV-58 in a cell survival assay to assess potential effects on cyclin-dependent kinases (Cdks) and showed that GV-58 did not affect cell survival at the relevant concentrations for Ca(2+) channel effects. Then, we examined the voltage dependence of GV-58 effects on Ca(2+) channels using patch clamp techniques; this showed the effects of GV-58 to be dependent upon Ca(2+) channel opening. Based on this mechanism, we predicted an interaction between 3,4-DAP and GV-58. We tested this hypothesis using a mouse passive transfer model of LEMS. Using intracellular electrophysiological ex vivo recordings, we demonstrated that a combined application of 3,4-DAP plus GV-58 had a supra-additive effect that completely reversed the deficit in neurotransmitter release magnitude at LEMS model NMJs. This reversal contrasts with the less significant improvement observed with either compound alone. Our data indicate that a combination of 3,4-DAP and GV-58 represents a promising treatment option for LEMS and potentially for other disorders of the NMJ.

The Cu(I)-catalyzed Huisgen [3+2] cycloaddition is the basis of click chemistry to synthesize triazole derivatives by coupling azides with ethynyl blocks. In the development of new compounds inspired by bioactive natural products, the synthesis of new oxazole building blocks containing azide moiety and coupling them with aromatic alkynes via triazole linker is described. These oxazole building blocks are synthesized using amino acids as chiral and inexpensive starting materials. Using this approach, 16 new triazole-oxazole hybrids were synthesized., This research was supported by CSIC Grupos Nº 654, PEDECIBA Química, co-financed by the EU Research Potential (FP7-­REGPOT-2012-CT2012-31637-IMBRAIN), the European Regional Development Fund (FEDER), the Spanish Instituto de Salud Carlos III (PI11/00840), and the Spanish MINECO (CTQ2011-28417-C02-01/BQU). G.V. would like to thank ANII (Agencia Nacional de Investigación e Innovación) for the award of a doctoral fellowship under the grant BE_POS_2010_1_2422.

Lambert-Eaton myasthenic syndrome (LEMS) causes neuromuscular weakness as a result of an autoimmune attack on the calcium channels that normally regulate chemical transmitter release at the neuromuscular junction. Currently there are limited treatment options for patients with this and other forms of neuromuscular weakness. A novel, first-in-class calcium channel agonist that is selective for the types of voltage-gated calcium channels that regulate transmitter release at neuromuscular synapses has recently been developed. This compound (GV-58) slows deactivation (closing) of the channel, resulting in a large increase in total calcium entry during motor nerve action potential activity. This new calcium channel agonist is currently being evaluated for the treatment of neuromuscular weakness. Potential applications include development as single therapeutics, or for combination treatments.

The Cu(I)-catalyzed Huisgen [3+2] cycloaddition is the basis of click chemistry to synthesize triazole derivatives by coupling azides with ethynyl blocks. In the development of new compounds inspired by bioactive natural products, the synthesis of new oxazole building blocks containing azide moiety and coupling them with aromatic alkynes via triazole linker is described. These oxazole building blocks are synthesized using amino acids as chiral and inexpensive starting materials. Using this approach, 16 new triazole-oxazole hybrids were synthesized.

Lambert-Eaton myasthenic syndrome (LEMS) is an autoimmune disorder in which a significant fraction of the presynaptic P/Q-type Ca(2+) channels critical to the triggering of neurotransmitter release at the neuromuscular junction (NMJ) are thought to be removed. There is no cure for LEMS, and the current most commonly used symptomatic treatment option is a potassium channel blocker [3,4-diaminopyridine (3,4-DAP)] that does not completely reverse symptoms and can have dose-limiting side-effects. We previously reported the development of a novel Ca(2+) channel agonist, GV-58, as a possible alternative treatment strategy for LEMS. In this study, we tested the hypothesis that the combination of GV-58 and 3,4-DAP will elicit a supra-additive increase in neurotransmitter release at LEMS model NMJs. First, we tested GV-58 in a cell survival assay to assess potential effects on cyclin-dependent kinases (Cdks) and showed that GV-58 did not affect cell survival at the relevant concentrations for Ca(2+) channel effects. Then, we examined the voltage dependence of GV-58 effects on Ca(2+) channels using patch clamp techniques; this showed the effects of GV-58 to be dependent upon Ca(2+) channel opening. Based on this mechanism, we predicted an interaction between 3,4-DAP and GV-58. We tested this hypothesis using a mouse passive transfer model of LEMS. Using intracellular electrophysiological ex vivo recordings, we demonstrated that a combined application of 3,4-DAP plus GV-58 had a supra-additive effect that completely reversed the deficit in neurotransmitter release magnitude at LEMS model NMJs. This reversal contrasts with the less significant improvement observed with either compound alone. Our data indicate that a combination of 3,4-DAP and GV-58 represents a promising treatment option for LEMS and potentially for other disorders of the NMJ.

Inspired by diferent natural compounds with cytotoxic activity, we synthesised new modular compounds by Click Chemistry, using two kinds of building blocks which can be easily coupled. The Cu(I) catalyzed version of the Huisgen reaction, was the tool selected for the coupling of the building blocks. These compounds have been tested to determine their antiproliferative activity against five human solid tumor cell lines.

In this work, a collection of hybrid compounds of type 1 (Scheme 1) were synthesized by a convergent route as potential anthelmintic drugs. One fragment of the hybrids is an oxazole or thiazole prepared from a serine dipeptide. 1 The other domain, are a dihydropyran obtained by Prins’s cyclization, functionally with ethynyl moiety by Corey-Fusch reaction. 2 Both heterocycles were coupled using the Huisgen s reaction by a triazol. 3

We developed a novel calcium (Ca(2+)) channel agonist that is selective for N- and P/Q-type Ca(2+) channels, which are the Ca(2+) channels that regulate transmitter release at most synapses. We have shown that this new molecule (GV-58) slows the deactivation of channels, resulting in a large increase in presynaptic Ca(2+) entry during activity. GV-58 was developed as a modification of (R)-roscovitine, which was previously shown to be a Ca(2+) channel agonist, in addition to its known cyclin-dependent kinase activity. In comparison with the parent molecule, (R)-roscovitine, GV-58 has a ∼20-fold less potent cyclin-dependent kinase antagonist effect, a ∼3- to 4-fold more potent Ca(2+) channel agonist effect, and ∼4-fold higher efficacy as a Ca(2+) channel agonist. We have further evaluated GV-58 in a passive transfer mouse model of Lambert-Eaton myasthenic syndrome and have shown that weakened Lambert-Eaton myasthenic syndrome-model neuromuscular synapses are significantly strengthened following exposure to GV-58. This new Ca(2+) channel agonist has potential as a lead compound in the development of new therapeutic approaches to a variety of disorders that result in neuromuscular weakness.

Lambert-Eaton myasthenic syndrome (LEMS) causes neuromuscular weakness as a result of an autoimmune attack on the calcium channels that normally regulate chemical transmitter release at the neuromuscular junction. Currently there are limited treatment options for patients with this and other forms of neuromuscular weakness. A novel, first-in-class calcium channel agonist that is selective for the types of voltage-gated calcium channels that regulate transmitter release at neuromuscular synapses has recently been developed. This compound (GV-58) slows deactivation (closing) of the channel, resulting in a large increase in total calcium entry during motor nerve action potential activity. This new calcium channel agonist is currently being evaluated for the treatment of neuromuscular weakness. Potential applications include development as single therapeutics, or for combination treatments.

The acute effect of the potent cyclin-dependent kinase (cdk) inhibitor (R)-roscovitine on Ca(2+) channels inspired the development of structural analogues as a potential treatment for motor nerve terminal dysfunction. On the basis of a versatile chlorinated purine scaffold, we have synthesized ca. 20 derivatives and characterized their N-type Ca(2+) channel agonist action. Agents that showed strong agonist effects were also characterized in a kinase panel for their off-target effects. Among several novel compounds with diminished cdk activity, we identified a new lead structure with a 4-fold improved N-type Ca(2+) channel agonist effect and a 22-fold decreased cdk2 activity as compared to (R)-roscovitine. This compound was selective for agonist activity on N- and P/Q-type over L-type calcium channels.

The nature and influence of the N-sulfonyl group in aza-Prins cyclization and the reactivity of the six-membered aza-cycle generated has been studied. The aza-Prins cyclization of γ,δ-unsaturated amines with a tosyl group at the nitrogen atom produces 2-alkyl-4-halo-1-tosyl-1,2,5,6-tetrahydropyridines with a halovinyl function, extraordinarily stable to further derivatization and detosylation conditions. To modulate the reactivity of such aza-cycles, a general study of the aza-Prins cyclization reaction was performed with several sulfonamides. Ring formation occurs satisfactorily with both N-nosyl and N-mesylamines providing optimal conditions for further synthetic transformations. To exemplify the scope of this methodology, a short synthesis of the alkaloid coniine was successfully carried out.