RESUMEN
Quercetin (QUE) is a widely studied nutraceutical with a number of potential therapeutic properties. Although QUE is abundant in the plant kingdom, its poor solubility (≤20 µg/mL) and poor oral bioavailability have impeded its potential utility and clinical development. In this context, cocrystallization has emerged as a useful method for improving the physicochemical properties of biologically active molecules. We herein report a novel cocrystal of the nutraceutical quercetin (QUE) with the coformer pentoxifylline (PTF) and a solvate of a previously reported structure between QUE and betaine (BET). We also report the outcomes of in vitro and in vivo studies of QUE release and absorption from a panel of QUE cocrystals: betaine (BET), theophylline (THP), l-proline (PRO), and novel QUEPTF. All cocrystals were found to exhibit an improvement in the dissolution rate of QUE. Further, the QUE plasma levels in Sprague-Dawley rats showed a 64-, 27-, 10- and 7-fold increase in oral bioavailability for QUEBET·MeOH, QUEPTF, QUEPRO, and QUETHP, respectively, compared to QUE anhydrate. We rationalize our in vivo and in vitro findings as the result of dissolution-supersaturation-precipitation behavior.
RESUMEN
Cocrystallization of two or more molecular compounds can dramatically change the physicochemical properties of a functional molecule without the need for chemical modification. For example, coformers can enhance the mechanical stability, processability, and solubility of pharmaceutical compounds to enable better medicines. Here, we demonstrate that amino acid cocrystals can enhance functional electromechanical properties in simple, sustainable materials as exemplified by glycine and sulfamic acid. These coformers crystallize independently in centrosymmetric space groups when they are grown as single-component crystals but form a noncentrosymmetric, electromechanically active ionic cocrystal when they are crystallized together. The piezoelectricity of the cocrystal is characterized using techniques tailored to overcome the challenges associated with measuring the electromechanical properties of soft (organic) crystals. The piezoelectric tensor of the cocrystal is mapped using density functional theory (DFT) computer models, and the predicted single-crystal longitudinal response of 2 pC/N is verified using second-harmonic generation (SHG) and piezoresponse force microscopy (PFM). The experimental measurements are facilitated by polycrystalline film growth that allows for macroscopic and nanoscale quantification of the longitudinal out-of-plane response, which is in the range exploited in piezoelectric technologies made from quartz, aluminum nitride, and zinc oxide. The large-area polycrystalline film retains a damped response of ≥0.2 pC/N, indicating the potential for application of such inexpensive and eco-friendly amino acid-based cocrystal coatings in, for example, autonomous ambient-powered devices in edge computing.
RESUMEN
The mol-ecular structure of the title compound, C10H12O4, contains an intra-molecular hydrogen bond between the phenol and acetyl substituents. In the crystal, C-Hâ¯π inter-actions act between the mol-ecules in a cyclic manner to stabilize stacks of mol-ecules along the b axis. Several C-Hâ¯O inter-actions are present between the stacks.
RESUMEN
The title mol-ecule, C20H23NO2S, adopts a twisted conformation in which the two aromatic rings connected to the central piperidine ring are orientated trans to each other. An intra-molecular C-Hâ¯S contact occurs. In the crystal, C-Hâ¯π and C-Hâ¯O inter-actions act to stabilize the structure in three dimensions.
RESUMEN
The title compound, C13H17NO3, adopts a conformation in which the aromatic ring and the mean plane of the piperidine ring are almost perpendicular to each other [dihedral angle = 79.25â (6)°]. The presence of the carbonyl group alters the conformation of the piperidine ring from a chair to a twisted half-chair conformation. In the crystal, pairs of strong O-Hâ¯O hydrogen bonds link the mol-ecules into inversion dimers. Weak C-Hâ¯O inter-actions extend the hydrogen-bonding network into three dimensions.
RESUMEN
The title compound, C21H24O9, crystallizes with two independent mol-ecules in the asymmetric unit which are almost centrosymmetrically related to each other. The ethano-ate group in one of the two mol-ecules is disordered over two positions with a site-occupation factor of 0.880â (7) for the major occupied site. In the crystal, the 1,3-diketone group exists in the keto-enol isomeric form due to the stabilizing effect of the intra-molecular O-Hâ¯O hydrogen bond present in this form. The compound packs as a layered structure in which C-Hâ¯π and C-Hâ¯O inter-actions are present within and between the layers.
RESUMEN
The title indole derivative, C(17)H(15)NO(3)S, crystallizes with two independent mol-ecules in the asymmetric unit. The benzene ring of the tosyl group is almost perpedicular to the indole ring in both mol-ecules, with inter-planar angles of 82.60â (5)° and 81.82â (6)°. The two mol-ecules are, as a consequence, able to form an almost centrosymmetric non-bonded dimer, in which the molecules are linked by pairs of C-Hâ¯π inter-actions. The crystal structure displays a three-dimensional network of C-Hâ¯O inter-actions. A π-π inter-action occurs between inversion-related indole rings with a centroid-centroid distance of 3.6774â (16)â Å and an inter-planar angle of 1.53â (15)°. This inter-action leads to a stacking of mol-ecules along the a axis.
RESUMEN
The title organic salt, 6C(3)H(10)N(+)·C(10)H(2)O(8) (4-)·C(10)H(4)O(8) (2-)·4H(2)O, contains seven independent entities in the asymmetric unit which comprises three propyl-ammonium cations, two water mol-ecules, half a 2,5-dicarb-oxy-benzene-1,4-carboxyl-ate dianion (H(2)btc(2-)) and half a benzene-1,2,4,5-tetra-carboxyl-ate tetra-anion (btc(4-)), the latter two anions being located about centres of inversion. One of the water mol-ecules is disordered over two positions in a 0.55â (2):0.45â (2) ratio. The combination of mol-ecular ions and water mol-ecules results in an extensive and complex three-dimensional network of hydrogen bonds, the network being made up of nine unique N-Hâ¯O inter-actions between the ammonium cations and the anions, as well as four unique O-Hâ¯O inter-actions between the water mol-ecules and the anions.
RESUMEN
In the title hydrated salt, C(8)H(18)N(+)·C(4)H(5)O(4) (-)·H(2)O, the cyclo-octyl- ring of the cation is disordered over two positions in a 0.833â (3):0.167â (3) ratio. The structure contains various O-H.·O and N-Hâ¯O inter-actions, forming a hydrogen-bonded layer of mol-ecules perpendicular to the c axis. In each layer, the ammonium cation hydrogen bonds to two hydrogen succinate anions and one water mol-ecule. Each hydrogen succinate anion hydrogen bonds to neighbouring anions, forming a chain of mol-ecules along the b axis. In addition, each hydrogen succinate anion hydrogen bonds to two water mol-ecules and the ammonium cation.
RESUMEN
In the mol-ecular structure of title compound, C(18)H(13)NO(2), the succinimide ring is orientated away from the plane of the anthracene moiety by 71.94â (4)°. The crystal structure features three different types of inter-molecular inter-actions, viz. C-Hâ¯O, C-Hâ¯π and π-π bonds. Mol-ecules along the b axis stack on each other as a result of π-π inter-actions which have a centroid-centroid distance of 3.6780â (15)â Å, while C-Hâ¯π inter-actions are present between neigbouring stacks. Also, acting between the stacks are the C-Hâ¯O inter-actions between the aromatic H atoms of the anthracene and the O atoms of the succinimide.
RESUMEN
In the title compound, C(13)H(9)NO(8)·CH(3)OH, the main mol-ecule possesses three carb-oxy-lic acid groups, which are asymmetrically distributed around the mol-ecule core. This results in hydrogen-bonding motifs ranging from a chain to various rings. The combination of the chain motif together with a carb-oxy-lic dimer R(2) (2)(8) ring motif creates a ribbon of mol-ecules propagating along the c-axis direction. A second ribbon results from the combination of the chain motif together with a methanol solvent mol-ecule and carboxyl-containing R(4) (4)(12) ring motif. These two ribbons combine alternately, forming a hydrogen-bonded layer of mol-ecules parallel to (2[Formula: see text]0).