YK- 1101, with its structure as S-（（E）-4-（（7S, 10S,Z）-4-ethylidene-7-isopropyl-2,5,8,12- tetraoxo -9-oxa- 16-thia-3,6,13,18-tetraazabicyclo[ 13.2.1 ]octadeca- 1 （17）, 15（ 18）-dien- 10-yl）but-3-en- 1 -y l） ...YK- 1101, with its structure as S-（（E）-4-（（7S, 10S,Z）-4-ethylidene-7-isopropyl-2,5,8,12- tetraoxo -9-oxa- 16-thia-3,6,13,18-tetraazabicyclo[ 13.2.1 ]octadeca- 1 （17）, 15（ 18）-dien- 10-yl）but-3-en- 1 -y l） ethanethioate, is synthesized as a potential histone deacetylase inhibitor. Its quality and stability under various stress conditions are not fully understood. In this study, a high performance liquid chromatographic （HPLC） method was established and validated for the analysis of YK-1101 bulk drug samples. The chromatographic separation was performed on a C18 column with acetonitrile and water as mobile phase in a gradient elution. Based on the established method, the stability studies of YK-1101 under various stress conditions were carried out. YK-1101 was shown to undergo degradation under basic and acidic stress conditions, while it was stable under oxidative, photolytic and thermal conditions. In addition~ a time of flight mass spectrometer （TOF/MS） was coupled to HPLC for the characterization of major degradation products produced under basic and acidic stress conditions. Their degradation pathways were also discussed.展开更多
The soliton solution and collapse arrest are investigated in the one-dimensional space-fractional Schrodinger equation with Kerr nonlinearity and optical lattice.The approximate analytical soliton solutions are obtain...The soliton solution and collapse arrest are investigated in the one-dimensional space-fractional Schrodinger equation with Kerr nonlinearity and optical lattice.The approximate analytical soliton solutions are obtained based on the variational approach,which provides reasonable accuracy.Linear-stability analysis shows that all the solitons are linearly stable.No collapses are found when the Levy index 1<α≤2.Forα=1,the collapse is arrested by the lattice potential when the amplitude of perturbations is small enough.It is numerically proved that the energy criterion of collapse suppression in the two-dimensional traditional Schrodinger equation still holds in the one-dimensional fractional Schr odinger equation.The physical mechanism for collapse prohibition is also given.展开更多
We theoretically study the existence and stability of optical solitons in saturable nonlinearity with a two-dimensional parity–time（PT） symmetric Bessel potential.Besides the fundamental solitons,a novel type of dr...We theoretically study the existence and stability of optical solitons in saturable nonlinearity with a two-dimensional parity–time（PT） symmetric Bessel potential.Besides the fundamental solitons,a novel type of dressed soliton,whose intensity looks like a ring dressed on an intensity hump,are presented.It is found that both the fundamental solitons and dressed solitons can exist when the propagation constant is beyond a certain critical value.The propagation stability is investigated with a linear stability analysis corroborated by a beam propagation method.All the fundamental solitons are stable,while dressed solitons are unstable for low values of saturable parameter.As the value of saturable parameter increases,the dressed solitons tend to be stable at high powers.展开更多
基金supported by the postgraduate innovation foundation of Simcere (No. CX11S-002XS)
文摘YK- 1101, with its structure as S-（（E）-4-（（7S, 10S,Z）-4-ethylidene-7-isopropyl-2,5,8,12- tetraoxo -9-oxa- 16-thia-3,6,13,18-tetraazabicyclo[ 13.2.1 ]octadeca- 1 （17）, 15（ 18）-dien- 10-yl）but-3-en- 1 -y l） ethanethioate, is synthesized as a potential histone deacetylase inhibitor. Its quality and stability under various stress conditions are not fully understood. In this study, a high performance liquid chromatographic （HPLC） method was established and validated for the analysis of YK-1101 bulk drug samples. The chromatographic separation was performed on a C18 column with acetonitrile and water as mobile phase in a gradient elution. Based on the established method, the stability studies of YK-1101 under various stress conditions were carried out. YK-1101 was shown to undergo degradation under basic and acidic stress conditions, while it was stable under oxidative, photolytic and thermal conditions. In addition~ a time of flight mass spectrometer （TOF/MS） was coupled to HPLC for the characterization of major degradation products produced under basic and acidic stress conditions. Their degradation pathways were also discussed.
基金supported by the National Natural Science Foundation of China(Grant No.11947122)the Guangdong Basic and Applied Basic Research Foundation(Grant No.2019A1515110935)+2 种基金the Research Start-up Foundation of Dongguan University of Technology,the Guangdong Science and Technology Planning Program(Grant No.2017A010102019)the Guangdong Province Natural Science Foundation of China(Grant Nos.2018A030307028 and 2019A1515010916)the Maoming Natural Science Foundation of Guangdong,China(Grant No.2019018001).
文摘The soliton solution and collapse arrest are investigated in the one-dimensional space-fractional Schrodinger equation with Kerr nonlinearity and optical lattice.The approximate analytical soliton solutions are obtained based on the variational approach,which provides reasonable accuracy.Linear-stability analysis shows that all the solitons are linearly stable.No collapses are found when the Levy index 1<α≤2.Forα=1,the collapse is arrested by the lattice potential when the amplitude of perturbations is small enough.It is numerically proved that the energy criterion of collapse suppression in the two-dimensional traditional Schrodinger equation still holds in the one-dimensional fractional Schr odinger equation.The physical mechanism for collapse prohibition is also given.
基金Project supported by the National Natural Science Foundation of China(Grant No.61308019)the Guangdong Provincial Natural Science Foundation,China(Grant Nos.2015A030313650 and 2014A030310262)the Guangdong Provincial Science and Technology Planning Program,China(Grant No.2017A010102019)
文摘We theoretically study the existence and stability of optical solitons in saturable nonlinearity with a two-dimensional parity–time（PT） symmetric Bessel potential.Besides the fundamental solitons,a novel type of dressed soliton,whose intensity looks like a ring dressed on an intensity hump,are presented.It is found that both the fundamental solitons and dressed solitons can exist when the propagation constant is beyond a certain critical value.The propagation stability is investigated with a linear stability analysis corroborated by a beam propagation method.All the fundamental solitons are stable,while dressed solitons are unstable for low values of saturable parameter.As the value of saturable parameter increases,the dressed solitons tend to be stable at high powers.
