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Las enzimas proteolíticas vegetales desempeñan un papel decisivo en muchos procesos, tanto biológicos, como fisiológicos a lo largo del ciclo de vida de la planta. Una de las especies rica en este tipo de enzimas es Ananas comosus, proporcionándole numerosas propiedades a la especie botánica que favorecen su uso a nivel culinario, medicinal y en la industria farmacéutica. Estas enzimas se encuentran en un extracto acuoso presente en el tallo y/o fruto de la piña conocido como Bromelina y concretamente el extracto acuoso extraído del tallo presenta propiedades muy interesantes para el ámbito farmacéutico, donde destacamos su aplicación tópica en quemaduras, donde ejerce un papel como desbridante, eliminando el tejido dañado o necrótico. La aprobación en 2014 por la AEMPS de un medicamento huérfano llamado NexoBrid®, basado en un concentrado de enzimas proteolíticas enriquecido en Bromelina, demuestra el potencial clínico de Bromelina en quemaduras, ya que actualmente se está empezando a emplear como posible alternativa al desbridamiento quirúrgico en el tratamiento de ciertas quemaduras. El objetivo general de este trabajo es investigar el uso tópico de Bromelina en quemaduras, analizando su eficacia y seguridad como agente desbridante, así como las ventajas e inconvenientes frente a otros tratamientos similares, y de manera más específica, recopilar y analizar la información existente, sobre la utilidad clínica y la seguridad de NexoBrid®. Para ello, se ha llevado a cabo una búsqueda bibliográfica en las principales bases de datos biomédicas sobre los estudios más destacados que evaluasen la efectividad y seguridad de NexoBrid® en quemaduras, acotando dicha búsqueda a los últimos 5 años. Tras introducir las palabras clave en las bases de datos y aplicar los criterios de inclusión y de exclusión, se seleccionaron finalmente 10 artículos para su estudio. Según los artículos revisados, se concluye que NexoBrid® ha demostrado ser un medicamento seguro y eficaz en quemad

Sixteen compounds incluiding four benzofurans (1–4), three benzoic acid derivatives (6–8), one eremophilane (9), four diterpenes (10–13) and four pyrrolizidine alkaloids (14–17) were isolated from Senecio subcandidus, S. klugii and S. ayapatensis from Perú. Compounds 1–4 and 6–9 have not been previously reported as natural products. Their molecular structures were determined by NMR spectroscopic analysis, comparison with published NMR data and chemical transformations. The X-ray analysis of acetylated derivative 5 and compound 7 were also performed. Their insecticidal and antifungal activities were tested.

Twenty-four compounds including eleven eremophilanolides (1–11), one eremophilane (13), five shikimic acid derivatives (14–18), six flavonoids (19–24), and the macrocyclic unsaturated pyrrolizidine alkaloid integerrimine (25) were isolated from Senecio kingii, an endemic species from the Magallanes Region (Chile). Compounds 3, 5, 6, 8–11 and 13–18 have not been previously reported as natural products. Their molecular structures were determined by NMR spectroscopic analysis and comparison with published NMR data. An X-ray-analysis of compound 3 has been performed. Their insecticidal and antifungal activities were tested, being compound 3 the strongest insect antifeedant. Compounds 6, 9 and 18 were moderate antifungals.

Natural inspiration: Based on the biosynthesis of squalene‐derived polyethers, a total synthesis of teurilene is described. The carbocation formation in the Nicholas reaction serves to control the initiation of a polyepoxide ring‐opening cascade. The three furan rings present in teurilene were obtained in excellent yield in one step. Boc=tert‐butoxycarbonyl, TMS=trimethylsilyl.

In the title compound, C15H14N2O4, (I), the mol­ecule lies on a twofold rotation axis which passes through the central C atom of the aliphatic chain, giving one half-mol­ecule per asymmetric unit. The structure is a monoclinic polymorph of the triclinic structure previously reported [Brito, Vallejos, Bolte & López-Rodríguez (2010). Acta Cryst. E66, o792], (II). The most obvious difference between them is the O/C/C/C—O/C/C/C torsion angle [58.2 (7)° in (I) and 173.4 (3)/70.2 (3)° in (II) for GG and TG conformations, respectively]. Another important difference is observed in the dihedral angle between the planes of the aromatic rings [86.49 (7)° for (I) and 76.4 (3)° for (II)]. The crystal structure features a weak pi–pi inter­action [centroid–centroid distance = 4.1397 (10)Å]; this latter kind of inter­action is not evident in the triclinic polymorph.

The title compound, C15H14N2O4, has a trans–gauche [O/C/C/C–O/C/C/C] (TG) conformation. The angle between the planes of aromatic rings is 76.4 (3)°. The crystal structure is stabilized by van der Waals inter­actions and C—H ... O hydrogen bonds. The crystal used was a non-merohedral twin with a fractional contribution of the minor component of 0.443 (5).

The title compound. C15H14N2O4, (I), has a gauche–gauche (O/C/C/C—O/C/C/C or GG) conformation and is a positional isomer of propane-1,3-diyl bis­(pyridine-3-carboxyl­ate), (II). The mol­ecule of (I) lies on a twofold rotation axis, which passes through the central C atom of the aliphatic chain, giving one half-mol­ecule per asymmetric unit. There is excellent agreement of the geometric parameters of (I) and (II). The most obvious differences between them are the O/C/C/C—O/C/C/C torsion angles [56.6 (2)° in (I) and 174.0 (3)/70.2 (3)° in (II) for GG and TG conformations, respectively] and the dihedral angle between the planes of the aromatic rings [80.3 (10)° in (I) and 76.5 (3)° in (II)]. The crystal structure is stabilized by weak C—H ... N and C—H ... O hydrogen bonding.

Herein we report the crystal structures of tubular self-assemblies of flexible macrooligolides. The assembly is driven by the propensity of the macrocycles to create nearly flat structures displaying a void space within them and the cooperativity of weak directional interactions such as dipole–dipole interactions and CH***Ohydrogen bonds and non-directional interactions such as van der Waals contacts. The significance of the stereochemistry and the size of the cavity in the formation of the nanotubes are also studied.

The title compound, C20H22O4S2, was synthesized by the reaction of 1,4-dibromo­butene with methyl thio­salicylate. The aliphatic segment of this ligand is in an all-trans conformation. The bridging chain, –S-(CH2)4-S–, is almost planar (r.m.s. deviation for all non-H atoms: 0.056 Å) and its mean plane forms dihedral angles of 16.60 (7) and 5.80 (2)° with the aromatic rings. In the crystal, the mol­ecules are linked by weak C—H ... O inter­actions into chains with graph-set notation C(14) along [0 0 1]. The crystal studied was a racemic twin, the ratio of the twin components being 0.27 (9):0.73 (9).

There are two independent mol­ecules in the asymmetric unit of the title compound, C19H24S2. In both mol­ecules, the aliphatic segment of the ligand is in an all-trans conformation: the –S–(CH2)5–S–bridging chain is almost planar (r.m.s. deviation for all non-H atoms = 0.0393 and 0.0796 Å in the two mol­ecules) and maximally extended. Their mean planes form dihedral angles of 4.08 (6)/20.47 (6) and 2.22 (6)/58.19 (6)° with the aromatic rings in the two mol­ecules. The crystal packing is purely governed by weak inter­molecular forces.

Sixteen new 7,7-dialkyl-5-hydroxymethyl-6-oxabicyclo[3.2.1]octane-1-carboxylic acid amide derivatives with the hydroxymethyl and the N-alkylamide functional groups in axial positions have been synthesized, and the solid-state structure of 10 of them has been determined. All of them crystallized as anhydrous compounds, and the conformation of the hydroxyl and N-alkylamide substituents was found to be correlated with the types of interactions in which they are involved, generating two- and three-dimensional hydrogen-bonding networks based on identical dimeric substructures in 8 of the 10 cases. This dimer can be considered as a supramolecular synthon for future crystal engineering studies.

Two highly oxygenated hetisine-type diterpenoid alkaloids, delphigraciline (1), 14-hydroxyhetisinone N-oxide (2), and the norditerpenoid alkaloid 8-methoxykarakoline (3), were isolated from a neutral extract of Delphinium gracile. Their structures were elucidated on the basis of spectroscopic data and by comparison with previously reported spectroscopic data of similar alkaloids. Their antiparasitic and insecticidal activities are also discussed.

The cis-2-alkyl-3-oxy-tetrahydropyran unit as a novel structure for the design and synthesis of a new type of ionophores with C2-symmetry is reported. The synthesis of seven different macrolides and a crown ether and their cation complexation properties were investigated. The X-ray crystal structure of some of the receptors provides valuable information on the preferred conformation of tetrahydropyrans in the solid state that can be related to the cation complexation properties in solution. The kinetic template effect has been proved to be a useful tool to improve the yield and selectivity in the synthesis of macrodiolide 3.

A new microwave-assisted rearrangement of 1,3-oxazolidines scaffolds is the basis for a new, metal-free, direct, and modular construction of tetrasubstituted pyrroles from terminal-conjugated alkynes, aldehydes, and primary amines. This new reaction manifold entails two linked domino processes in a one-pot manner with both atom- and bond-efficiency and under very simple and environment-friendly experimental conditions.