The New Structure Of The Hiv And Vegf Inhibitors

This dissertation has two parts of research as followed:Design,Synthesis of DCK Analogs and HIV Inhibitory Activity:Suksdorfin(1),a natural product isolated from the fruit of Lomatium Suksdorfii, has an angular pyranocoumarin skeleton with interesting biological properties, especially its anti-HIV activity(EC₅₀=2.6±2.1μM,TI=30.6±22.4,TI= therapeutic index IC₅₀/EC₅₀).Structural modification of 1 yielded DCK(2) and 4-methyl-DCK(11),which demonstrated extremely potent inhibitory activity against HIV-1 replication in H9 lymphocytic cells(EC₅₀=4×10^-4μM,TI=136719 and EC₅₀ =1.57×10^-7μM,TI＞10⁹,respectively).The recent mechanistic studies indicated that HIV-1 RT is possibly the target of DCK and DCK is a unique HIV-1 RT inhibitor that inhibits the DNA-dependent DNA polymerase activity.In contrast,DCK did not significantly affect the RNA-dependent DNA polymerase activity.Due to its unique mode of action,DCK and its derivatives with high activity and selectivity become an attactive new anti-HIV drug research field.Accordingly,selected modifications on DCK skeleton are highly desirable in order to identify the pharmacophores in this class of potent anti-HIV agents and explore the structural aspect of the target bio-molecule(s).To this end,a variety of novel DCK analogs containing N,N-,O,N-,N,O-,O,S-,S,O- or O,C- by displacing the O,O atoms in the DCK skeleton were synthesized previously in our group.The structural modifications of 4-methyl-DCK by replacing the ring oxygen atom of DCK with a sulfur or a nitrogen atom(22a,23a and 17a) demonstrated that these analogs also exhibited potent inhibitory effects on HIV-1 replication in H9 lymphocytes;some O,C- analogs(24b,25) which showed lower inhibitory effects implied that there probably was a electronic effect at 7-position with the target. On the basis of these results,we have expanded further structural modification aiming at the A ring of DCK.Keeping the S atom at the 1-position of compound(23a) and replacing the C to N atom at the 4-position,we designed,synthesized and bioactively explored 1,4-thiazine-2-one structure(26),or its isomer 1,4-thiazine-3-one structure(27) and the analog(28).All of these target compounds belong to novel structural heterocycle systems,their synthetic work has a certain chanllenge.This study has potent scientific significance by accumulating new knowledge and providing a synthetic method of such heterocycle system.According to the retro-synthetic analysis,we successfully synthesized the key three-ring precusors(36,39) of the target compounds,using 4-methoxyaniline as the starting material and through two routes respectively.Since the change of A-ring structure,the Sharpless AD reaction of 9,10-double bond in 36 and 39 did not occour successfully,therefor the preparation of corresponding 9,10-dicamphanoyl analogs did not complete.However,the single 10-hydroxyl intermediate was obtained via epoxidation followed by bromo-hydroxylation,and further camphanic esteration to get 10-camphanoyl ester analog(144),which is on biological testing.Structural modification of A ring of DCK such as replacingα-pyranone ring by ),-style(DCP 69,70) was recently reported to have potent inhibitory activity(EC₅₀= 0.00032μM,TI=116200).This result demonstrated the modification of A ring has potential foreground and merits further exploration.Combind the research results of DCP with the SAR knowledge of DCK accumulated throgh the former structural modification,in order to exploring the effection of intact A ring and C ring to the activiy,a series of new Seco-DCK analogs were designed and synthesized.The simplest effective skeleton moiety and necessary pharmacophores were in searching of by cleavaging different carbon bond of A ring or C ring.Four series of seco-DCK analogs were successfully synthesized.Seco-DCK analog is a new breakthrough in the research on anti-HIV drug DCKs which is a novel HIV inhibitor and has not been reported.Thereinto,compound 74 exhibits excellent anti-HIV activity(IC₅₀＞25μg/mL(58.4μM),EC₅₀＜0.025μg/mL (0.058μtM),TI＞1000),compound 71b has a potent extent of activity(IC₅₀＞25μg/mL(39.04μM),EC₅₀＜0.12μg/mL(0.19μM),TI＞208),compound 73 and 75 still has a little acitivy(IC₅₀＞25μg/mL(39.2μM),EC₅₀=16.2μg/mL(25.4μM), TI=1.7;IC₅₀=＞25μg/mL(56.5μM),EC₅₀=15.8μg/mL(35.7μM),TI=1.83), and compound 72 loses activity completedly.The accurate bioactive data of some other target prodcuts are still in testing.By comparison,some new information of the anti-HIV SAR of the seco-DCK analogs and the aspect of biological target molecule binding with them could be obtained as followed:(1) The C₂-C₃ seco-A ring DCK analog of 4-Me-DCK(71b) still maintained potent anti-HIV activity which indicated the integrality of A ring merited further study and the seco-A ring DCK analog was possessed of more modified room.Whether the interaction of A ring to receptor is related with hydrogen bond,electronic effection or room combination will be illustrated by further investigating the seco-A ring analog. Accordingly,it will provide new hints for design,synthesis and search of new structural type of anti-HIV drugs.(2) The compound 72 lost activity may be due to the pharmacophores of two bulky (S)-(-)-camphanoyl groups away from the original 9,10-binding district of DCK, which demonstrated the camphanoyl groups pharmacophores should be maintained at 8-position of coumarin ring.(3) Compound 73 and 75 have a little acitivy,that explored in the area of binding with receptor there only exist a narrow cavity on theα-side at 9,10-positoin of molecule.In binding site 10-camphanoyl group was must located theβ-side of molecule plane.The activity would decline dramatically while 10-α-H was changed to CH₃ or bigger group.This is consistent with the strict requirment for the 3'R,4'R-configurations of DCKs.(4) Compound 74 exhibited excellent activity demonstrated that the camphanoyl group at the 10-position in DCK was much more essential than 9-camphanoyl,and the integrity of C ring was also not necessary absolutely.The C ring seco-DCK has small molecular weight,and its character of logP value,solubility and biological availability might be better than 4-Me-DCK.At the same time,the metabolic caused by the two bulky camphanoyl groups in 4-Me-DCK could be avoided.Additionaly,the simplified structure,especially the lack of the chiral requirement was easy to be synthesized.All of these will be of advantage to develop a drug.These preliminary results provide us some useful hints and foundation for further research of new type HIV inhibitory agents.We designed and synthesized a series of analogs(110-117) using compound 74 as hit.And the detailed information will be offered when the results are returned.Additionally,compound 71b exhibited some extent of inhibitory activity of HCV, which proived us a new leading compound to enrich and develop our anti-viral research content.Some accidental reactions were discovered and studied in detail during synthesis. The structure of the accidental products were determined and the mechanism was discussed and explained,which offered some new knowledge for the synthetic methods and chemical properties of these compounds.Design,Synthesis of Benzothiazoline Analogs and HIV Inhibitory Activity:1.The synthesized N-methyl-2-arylbenzothiazolines(2),o-(N-aryloyl-N-methyl-amino) phenyl disulfides(3) and 2-arylthiazolium halide(4) were screened for VEGF inhibitory activity in the human breast cancer cell MDA-MB-231 in comparison with 2-ME.Three classes of novel compounds 2,3 and 4 exhibited potent inhibitory activities against VEGF with millimolar or sub-millimolar values of EC₅₀.Among them,some compounds showed potent VEGF inhibitory activities and selectivities as 2b(EC₅₀=0.07mM,SI=25);21(EC₅₀=0.115mM,SI＞32);3g(EC₅₀=0.03mM, SI＞32);4b(EC₅₀＜0.15mM,SI＞32),respectively,which were about 10 fold of those of 2-ME(EC₅₀=0.49mM,SI=3.37).The scaffolds of 2 were privileged and merited further investigation as VEGF inhibitors. 2.The solid N-methyl-2-monoarylbenzothiazolines(2) are stable and can be stored in atmosphere,whereas they present different behaviors in different solvents.They are relatively stable in alcohol and DMSO-H₂O.However,in other organic solvents such as acetone,CH₂Cl₂,CHC13 and EtOAc etc.,an oxidation-coupling reaction occurred spontaneously to give the corresponding disulfide dimmers(3).The substituents at 2-phenyl rings,reaction temperature and the acidities of the solutions exerted obvious impacts on the reaction rates and yields of 3.3.Duing expanding the applicability of pTS/vinyl ether as deprotecion reagents against thiazolins found by ourselves,we found that the benzothiazolines from arylaldehydes were easy to be destroyed,some 2-mono substituented benzothiazolines could be converted to benzothiazolium pTS salts.The deprotection method of THF/HCl system was suitable to 2,2-dialkyl substituted benzothiazolines;as to 2-mono substituented benzothiazolines,the method can not occur deprotection and held back their radical reaction to occur.Moreover,CH₃I/THF/H₂O system was also suitable for the deprotection of benzothizaolines.These different deprotection reagents and their selectivity in deprotection reaction gave us a clue to organic synthesis.Total of 180 compounds were synthesized in this research among them,90 compounds were new compounds.The structure of all new compounds were determined by spectra.