Concomitant polymorphs of methoxyflavone (5-methyl-7-methoxyflavone)

Gong, Ningbo; Hu, Kun; Jin, Guimin; Du, Guanhua; Lü, Yang

doi:10.1039/c6ra05995c

Cited by 5 publications

(4 citation statements)

References 25 publications

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“…If the different nuclei are allowed to grow, different crystal forms are obtained [20,21]. Solvatomorphism formation also depends on the properties of the surrounding environment, such as temperature, humidity and the rate of generation of supersaturation, but the solvent has the most important impact [22].…”

Section: Sxrdmentioning

confidence: 99%

New crystal forms and amorphous phase of sophoricoside: X-ray structures and characterization

et al. 2019

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Sophoricoside, which is an isoflavone glycoside found in many plant species, has recently attracted attention because of its anti-fertility activity. One solvent-free form, two solvatomorphs and an amorphous phase of sophoricoside are reported for the first time. X-ray diffractometry, differential scanning calorimetry, thermal gravimetric analysis and Fourier-transform infrared spectroscopy were used to characterize the different forms. The results show that factors such as crystal symmetry, intermolecular arrangement, conformational flexibility, hydrogen-bonding interactions and solvent incorporation lead to different solid-state forms. An investigation of the transformations of the four forms showed that they can interconvert with each other under certain conditions. Amorphous phase and solvatomorphism were unstable but can improve the solubility of sophoricoside in water.

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Section: Sxrdmentioning

confidence: 99%

New crystal forms and amorphous phase of sophoricoside: X-ray structures and characterization

et al. 2019

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“…Concomitant polymorphs are seen in a variety of molecules. Gong et al found concomitant polymorphs for methoxyflavone, a non-steroidal anabolic isoflavone [20]. Jones and co-workers found Crystals 2024, 14, 99 2 of 16 two concomitant polymorphs of a polyamide molecules, which differ in their hydrogenbonding patterns in the crystal [21].…”

Section: Introductionmentioning

confidence: 99%

Synthesis and Crystal Structure Analysis of Some Aromatic Imines of Syringaldehyde

Hamaker,

Germann

2024

Crystals

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A series of syringaldehyde imines with para-substituted anilines have been synthesized in a good yield, and their crystal structures have been analyzed. The orientation of the syringaldehyde hydroxyl group plays in important role in the intermolecular hydrogen-bonding pattern of the molecules. The O–H…N hydrogen bonding interactions primarily determine the three-dimensional packing of the molecules, even though they make up a relatively small percentage of intermolecular interactions in the molecules. The three structures with the p-hydroxy group cis to the imine group give hydrogen-bonded zigzag chains in the monoclinic crystals, while the structure with a trans hydroxy group crystallize in a hexagonal space group (R3¯) and form hydrogen-bonded hexamers. The hexagonal structure also displays Br…Br interactions, forming additional hexameric clusters. The analysis of published p-hydroxyphenyl imine crystal structures from the Cambridge Crystallographic Database revealed patterns in the length of the hydrogen bonding interactions based on steric congestion around the hydroxyl group.

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“…In this study, we explored the use of crystallization in the presence of additives for minimizing concomitant crystallization that is often observed for pharmaceuticals − by studying isonicotinamide (INA) as the model substance. INA is widely used as a common conformer for the cocrystallization of pharmaceuticals − and has the potential for pharmacological effects. , INA is reported to crystallize in six polymorphs − (corresponding to Cambridge Structural Database (CSD) entries EHOWIH01-06), two monohydrates, and few solvates. − INA Form I contains amide homodimers arranged in isolated corrugated sheets .…”

Section: Introductionmentioning

confidence: 99%

Crystallization of Metastable Isonicotinamide Polymorphs and Prevention of Concomitant Crystallization by Additives

Semjonova,

Be̅rziṇš

2023

Crystal Growth & Design

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Concomitant crystallization of polymorphs is a major problem for the pharmaceutical industry, and in general, a better understanding of this phenomenon is necessary to ensure the crystallization of just one desired polymorph. Isonicotinamide (INA) forms six polymorphs which often crystallize concomitantly. Here, we studied whether the use of crystallization additives can facilitate the formation of INA metastable forms and prevent concomitant crystallization. Crystallization of INA was explored under different conditions by performing cooling and evaporative crystallization from different pure solvents and in the presence of crystallization additives. Some additives, such as naphthalene-1,5-diol, 4-carboxybenzeneboronic acid, and 2-picolinic acid, provided achieving crystallization control. Theoretical calculations allowed us to gain partial insight into the factors responsible for the polymorphic outcome of INA crystallization. The crystal structures of INA polymorphs II, IV, and VI, which often crystallize concomitantly, are almost identical. Therefore, it is possible that the energy barriers of nucleation and crystal growth rates for these polymorphs are highly similar, whereas, in the presence of additives, the crystallization of structurally more different Forms III or I could be achieved by altering these energy barriers.

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Concomitant polymorphs of methoxyflavone (5-methyl-7-methoxyflavone)

Abstract: A novel metastable polymorph and an unstable amorphous phase of methoxyflavone were discovered after a decade since the first report of the X-ray crystal structure of this bioactive compound.

Cited by 5 publications

References 25 publications

New crystal forms and amorphous phase of sophoricoside: X-ray structures and characterization

New crystal forms and amorphous phase of sophoricoside: X-ray structures and characterization

Synthesis and Crystal Structure Analysis of Some Aromatic Imines of Syringaldehyde

Crystallization of Metastable Isonicotinamide Polymorphs and Prevention of Concomitant Crystallization by Additives

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