Design,Synthesis And Action Of 3-substituted Indole Derivatives As LSD1 Inhibitors

Histone methylation modification is one of the important ways of histone modification,and histone lysine-specific demethylase 1(LSD1)is a flavin adenine dinucleotide dependent amine oxidase,can specifically demethylate mono-,di-methylated H3K4 and H3K9.Through the combined action of histone methyltransferase and histone demethylation,the methylation level of histone is dynamically regulated,and the activation of gene transcription,inhibition and activity of p53 are controlled.The high expression of LSDl is positively related to the occurrence and development of a variety of malignant tumors.Downregulate the LSD1 expression,can inhibit the cancer progression in a certain extent.In this study,we found the indole compound zcx-7t which had a certain inhibitory activity against LSD1.The compound zcx-7t showed a strong inhibitory effect on LSD1.The IC50 of inhibiting LSD1 reached 2.224 ± 0.347?M.The IC50 of the compound zcx-7t inhibiting MGC-803,EC-109 and MCF-7 were 1.948 ± 0.245?M,14.588 ± 1.944 and 9.722 ± 1.488?M,respectively,in vitro and in vivo.Further,by computer simulation,it was found that zcx-7t could act on the active pocket of LSD1.In this paper,zcx-7t was used as the lead compound to keep the P2 site unchanged,and the P1 of indole was modified properly.1.Synthesis and activity determination of 3-acyl-5-chloroindole derivatives (Series I,Series ?)The compounds of series ? were prepared by affinity substitution and Friedel-Crafts acylation with 5-chloroindole as raw materials.21 compounds were synthesized and their antitumor cell proliferative activity,LSD1 inhibitory activity were evaluated.The compounds of series ? were prepared by Friedel-Crafts acylation,affinity substitution and aldol condensation reaction.5 compounds were synthesized and their antitumor cell proliferative activity,LSD1 inhibitory activity were evaluated.The results showed that the IC50 for tumor cells of the two series of compounds was greater than 50?M and the inhibition rate against LSD1 at 30?M was 0.This shows that the hydroxyl groups on the carbon atoms of the indole 3-position are strongly affected the activity.So we have designed and synthesized a new series of 3-hydroxymethyl-5-chloroindole derivatives.2.Synthesis and activity determination of 3-Hydroxymethyl-5-Chlorindole derivatives(Series ?)The compounds of series ??,the carbonyl group at the 3-position of indole,are reduced to hydroxyl group.Other compounds were synthesized by affinity addition at the 3-position of indole and affinity substitution at the 1-position nitrogen atom.21 compounds were synthesized and their antitumor cell proliferative activity,LSD1 inhibitory activity were evaluated.The results showed that the anti-tumor cell proliferation activity of this series of compounds was significantly higher than that of the series ? and ?,IC50 was generally 25 ~ 50?M;The inhibition rate of 9a,9c,12 c,12e against LSD1 were respectively 38.5%,47.4%,28.0%,28.7%.However,this series of compounds did not show a certain concentration-dependent effect on tumor cells,The inhibition rate of most compounds at 50 ?M is over 90%.When the concentration is diluted to 12.5,the inhibition rate drops rapidly to 0.After analysis,it is possible that the stability of the compound is poor and the stability is worse after dilution.A series of ? compounds(3-oxime-5-Chlorindole derivatives)were designed for this purpose.When the hydroxyl group is retained,the carbon nitrogen double bond is introduced,and the carbon nitrogen double bond and the double bond on the pyrrole ring form conjugate to increase the structural stability.At the same time,we synthesized a series of I? compounds to further investigate the effect of hydroxyl groups on the carbon atoms of indole 3 site on activity.3.Synthesis and activity determination of 5-chloro-1-tosyl-indole derivatives(Series I?)This series includes two 3-acyl-5-chloroindole compounds and the corresponding 3-hydroxymethyl-5-chloroindole compounds.The synthesis methods are similar to the synthesis of series ? and I? compounds,4 compounds are obtained in this series,and their antitumor cell proliferation activity and LSD1 inhibitory activity are evaluated.The results showed that the antitumor activity and LSD1 inhibitory activity of two 3-hydroxymethyl-5-indole compounds in this series was significantly higher than that of two 3-acyl-5-chloride compounds.IC50 differs little from the corresponding compounds in series ?I.It is further explained that the hydroxyl groups of indole 3-position are important for activity.4.Synthesis and activity determination of 3-Oxime-5-Chlorindole derivatives(Series ?)In series ?,some compounds and hydroxylamine hydrochloride were subjected to affinity addition reaction to produce 3-Oxime-5-Chlorindole derivatives.11 compounds were obtained,and their antitumor cell proliferative activity and LSD1 inhibitory activity were evaluated.The results showed that the series of ? compounds had a slightly higher proliferative activity compared with the series of I? compounds,and the IC50 was generally 10~25?M.Although the activity of this series has increased,but the concentration dependence is still very weak.The inhibition rate of most compounds at 25 ?M is over 80%.When the concentration is diluted to 12.5,the inhibition rate drops rapidly to 0.The inhibition rate of 14 c against LSD1 at 30?M was 42%?The effect of the compound on tumor cells did not show significant concentration dependence,and may be related to the effect of the drug on the target protein as a noncompetitive inhibitory effect.The specific reason is still under study.In this paper,the compound zcx-7t is used as a lead compound,based on this,the structure optimization of lead compound was studied.To investigate the effect of indole 3-position modification on the activity of compounds,and lay a good foundation for further study.