• Nghien ciJu - Ky thuat
M6 hinh 3D-pharmacophore cua chat ij-c che kenh ion liali hERG
Thai Khic Minh\ Bui Thuy Vi', Doan Cao Som^
' Bo mon Hoa Du^rc, Khoa Duac, Dgi Hoc YDuac TP. Ho Chi Minh
^ Vien Kiem nghidm Thuoc Trung uang
D#t vin de
Cdc phdn dng cd hgi do thulc (ADR) Id mOt tnang nhung nguyen nhdn hang dau cua benh tgt va t d vong trong cham sde sue khde. Hipn tpi cd mpt so Idn myc tidu tdc dpng sinh hpe trong c a the khdng ndn bj hoat hda, bl cam dng hay de e h l bdi mOt thule. Terfenadin, mdt thuoe khdng histamin Hi khdng gdy an than, v i n dT d u ^ e ehung minh rd rang la an todn trong cdc nghien euu lam sang v d chl ed r i t ft tde dgng phg nhp.
Tuy nhidn, sau khi dua vao sd dgng rdng rdi trong tri lidu, terfenadin dua tdi logn nhjp tim vd x o l n iSnh nguy hiem d i n tinh mgng vi khd ndng u c e h l manh kenh ion kali hERG {human ether-a-go-go- related gene). Binh thudng, terfenadin dupe ehuyln hda bdi enzym cytoehrom P450 ed trong CO* t h i v d khfing do dupc n i n g dp trong huyet tuong eung nhu khdng thay tac dung phu trdn tim.
S d dgng mOt c h i t de e h l dong phan cytoehrom 3A4 eua enzym nay cd the ngan can qud trJnh ehuyln hda terfenadin va Idm tang nong dO terfenadin trong huylt tucng, gdy ra s y de che kdnh ion kali hERG, keo dai khoang QT trdn didn tdm dl'^ ^'. Hipn nay, terfenadin da dupc thay the bdi fexofenadin, mOt chat chuyen hda cd hoat tfnh cCia terfenadin vd khdng cd khd nang d c c h l kdnh ion kali hERG. Nhu vgy, terfenadin bj rtt khdi thj trudng do hai nguydn nhdn chinh, do la dde tfnh trdn tim vd tuong tdc thulc-thuoc vdi cac c h i t de e h l manh enzym cytoehrom P450''l T d vf dg trdn, kdnh ion kali hERG va enzym cytoehrom P450 3A4 Id nhung muc tieu tac dOng sinh hpc d n d u p ^ xem xdt kT ludng tnang qud trinh phat triin thulc. N h i t id trong tinh hinh cdc phan dng ed hgi, ehO y l u do tuong tac thuoc-thuoc, Idm tidu t i n g i n 1391! dd la hdng ndm d l\/ly va con s l thidt hgi Idn hon nhilu trdn todn the gidi'^l Do dd, h i l u bilt v l tuong tde phdn t d giua ede mgc tidu tdc dOng sinh hpe ndu tren vdi cdc thulc hode cdc hyp c h i t mdi dang nghidn edu Id d i l u c i n thilt.
Trong nghien edu ndy, md hinh 3D- pharmacophore cua cdc c h i t ed hogt tinh d c che kdnh ion kali hERG duoe xay dyng va k i t qua cua nghien cdu nay ed t h i dng dung vao viec d y dodn khd nang tuong tae thulc-thule khi phdi hpp trong dieu trj va lam c o s d cho t h i l t ke thudc mdi hpp ly, trdnh kha nang gan k i t cua hpp chat len kdnh ion kali hERG.
P h u ' a n g p h a p n g h i e n C I P U C o s d d d lieu
Tap hop 69 hpp c h i t da dupe xde djnh gid trj iCsothye nghidm ve hogt tinh d c che kenh Ion kali hERG'^' ^^ dupc thu th§p vd s d dgng trong xdy dyng md hinh 3D-phamiacophore. Trong so nay ed 42 e h i t cd hogt tfnh d c c h l kenh hERG manh vdi plC5o> 6 (IC50 < 1 pM), 13 c h i t khdng cd hogt tinh de e h l kdnh hERG vdi pICso < 5 (ICgo > 10 pM), edn Igl la cac c h i t ed hogt tfnh d c che kenh hERG tmng binh vdi IC50 nam trong khoang 1-10 pM. Gid trj IC50 (pM) dwac chuyen doi thanh gid tri plC50 = -lg(IC5o) de s d dgng. C l u tnjc 3 chieu cua cdc chat dwac xdy dyng bdng p h i n mem Sybyl - Tripos http://tripos.com. Sau khi xdy dyng cau true 2D, ede eau taie se dupe t i i thieu hda ndng lupng (EM) vd dpng lye hpe phan t d (MD) d l xac dinh cau dang cd mdc ndng lupng toi thieu todn phan.
Xdy d y n g m o h i n h 3D-pharmacophore S d dgng p h i n m i m MOB de xdy dyng v d tmy van 3D-pharmacophore (Chemical Computing Group Inc., Canada, ww.chemcomp.
com). Cae thdng so xac djnh bao gom: (i) Chpn nhap cau dgng (Confonnation Import); (ii) Chpn dO chong phu hogt tfnh (Active Coverage) n la 0,9 (toi t h i l u truy v i n phannaeophore phai lien quan t d i 90% trong t i n g s l phan t d d u a vdo, day eung la gia tn mgc djnh); (iii) Gidi hgn s l y l u t l phannaeophore = 5; (iv) Phdn cum truy v i n (Query Cluster) = 1,25 (gid trj mgc djnh cua chuong trinh) dgc tm-ng cho mpt gid tri nnsd
TAP C f i nirmr-Hfir"-. ii/-»nii /GA^^OMZ M52) 13
• Nghien CLPU - Ky thuat (don vj A) su dung d l phdn cum cac truy van uu tien theo dilm chdng phu vd diem xip loai.
Tim cac hap chat thoa man mo hinh 30- pharmacophore
Mo hinh pharmacophore xdy dyng td cdc ehit cd hogt tfnh mgnh se duoc tiln hdnh tim
kiem cdc cac hyp chit thda man md hinh ndy trong tdp hop cdc chit khdng ed hogt tfnh vd trong ede tdp hp'p du li^u khong dung trong xdy dyng md hinh bdng chuong trinh Tim kilm pharmacophore (Phannaeophore Search) d phan mem MOE nhu hinh 1.
Hinh 1: Tim cie h<?p chit co ciu dang thoa man mo hinh 3D-pharmacophore bing tim kiim pharmacophore (Pharmacophore Search) Ket qua va ban lufln
Md hinh 3D-pharmacophore cua chat dc che kdnh ion kali hERG
Md hlnh 3D-phannacophore cua ehit de chl kdnh ion kali hERG dupc xay dyng dya tren tgp hpp 42 cac chat dc che kenh ion kali hERG mgnh vdi gid trj hERG ICso ^ 1 pM hay plC5o> 6. Kit qua
md hinh xdy dyng dupc cd 39/42 ehat thda man md hinh, DO chong phu =24,04; Tinh chfnh xac = 0,93; So lupng ede ylu to trong md hinh bdng 4 vdi 1 vdng thom/vdng lien hpp n (Aro|PiR), 2 nhdm ky nude (Hyd) va 1 nhdm nhdn lidn kit hydro (Ace). Md hinh pharmacophore xdy dyng duoc trinh bay d hinh 2.
F3:Hyd
(A)
F2:Hyd
Fl:Aro|PiR
Hinh 2: (A) Mo hinh 3D-pharmacophore cua ehit we ehi kenh ion kali hERG. F1:Aro\PiR la trung tam vdng tham/vdng liin hgp < F2:Hyd vi F3:Hyd la cic tmng tam ky nw&c;
vi F4:Ace la trung tam nhan lien kit hydro. Khoang cich giira cic diim chinh giQa eOa cic trung tam (cie yeu to) trong mo hinh ddpc xac djnh bing A.
(B) Sw chong phi^ cua 39/42 dan chat wc ehe hERG m^nh trin mo hinh pharmacophore
TAP CHI njTar Hor -11 /ini t a^ A^Q TsiiM= ^
I Nghien ciru - Ky thuat
Bdn lu$n
Trong nhdm 13 chit khdng cd hogt tfnh de chl kdnh hERG cDa tdp hpp dd lidu 1, cd 7 chit thda man md hinh phannaeophore hERG gom ed diltiazem (pICso = 4,76). chlorpheniramin (pICso = 4,68), fexofenadin (pICso = 4,67), diphenhydramin (pICso = 4,57), cetirizin (pICso = 4,52), pearlstein-5 (pICso = 4,12), disopyramid (pICso = 4,04). So sdnh elu tnte cdc chat ndy vdi cac ehat de chl kdnh d l thiy kit qua ndy Id phCi hpp vdi ydu cau v l tfnh thdn diu cua mOt chat d l cd thi gan kit trong khoang tnjng tdm kenh hERG. Vi dy:
Sertidol vd pear1stein-5 (din ehat sertindol) ed clu tnic tuong ty nhau, nhung nhdm fluorobenzen d sertindol thay bang nhdm benzoat ttidn nudc hon d pear1stein-5 (Hinh 3) din tdi hogt tfnh de ehl kdnh hERG cua peadstein-5 thlp hon nhieu so vdi sertindol.
Sertindol(pICM = 8,52) Pearlstein-S (pIC„ = 4,12)
Hlnh 3: Ciu trdc hda hge cda sertindol vi din chit cda sertindol (pearistein-5)
Terfenadin vd fexofenadin cd clu tnJc tuong ty nhau, nhung nhdm tert-butylbenzen ky nude d terfenadin thay bing nhdm 2-methyl-2- phenylpropanoat thdn nude hon d fexofenadin din tdi hogt tfnh dc chl kdnh hERG eua fexofenadin thlp hon nhilu so vdi terfenadin (Hlnh 4). Bdn thdn nhdm cartxixylat ndy cQng Idm cdn trd sy gin kit kdnh gidn tiep qua sy can trd xdm nhdp mdng t l bdo trudc-khi tdi dilm gan kit, ndn md hlnh docking van dy dodn fexofenadin gin kit kdnh hERG trong khi chat nay la chat khdng cd hogt tfnh dc ehl kdnh hERG. Oilu nay cung phil hyp vdi nhilu nghien edu trdn ede chat dc chl kdnh hERG. Cdc cmt cd sy thay dli nhd d d u trdc din din sy thay dli rat Idn d khd ndng de chl vd sy hi$n didn cOa nhdm cartuxylat lam gidm sy dc chl trdn kenh hERG.
Te[&nadm(pICM = 7,25) FesoJcaadm^CM=4,67)
Hlnh 4: Ciu tnic hda hgc cua terfenadin va fexofenadin
T^ CHi DirgtC HQC - 11/2012 ( S 6 439 N A M 52)
Nhdm ky nudc gan vao nguyen td N* ei)a disopyramid qud ngan ndn khdng dO d l tgo tuong tac ky nudc vdi Phe656, trong khi nhdm ky nudc gdn vao nguydn td N* cua cetirizin ddi hon, cd t h i tao tuong tde vdi ky nude vdi Phe656, nen ed gia tri pICso cao hon (IC50 nhd hon) disopyramid (hlnh 5).
Disopytaiiiid Cetirizin (pICs, = 4.04) (pIC„ = 4,52)
Hlnh 5: Ciu trdc hda hgc cda disopyramid vi cetirizin
Tuong ty nhu disopyramid, elu true cQa ede hpp c^at diltiazem, chlorpheniramin, diphenhydmmln cung khdng thda man dieu kipn cd mOt tgp hpp cac nhdm the xung quanh trung tdm nito base ndy du ky nudc de gin kit chgt vdi myc tidu tdc dfing ndn cdc chat nay khdng cd hogt tfnh dc chl kdnh hERG.
Truy van pharmacophore trdn co" sd dd li^u khac
Md hinh pharmacophore hERG dupe sd dyng d l tim cdc hpp chat ed clu dgng thda mdn md hinh nay td tdp hpp dd lidu 2 - tdp hpp ndy khfing diing d l xdy dyng mfi hinh, kit qud eho thiy 9 chat (trdn ting so 27 chit) thda man md hinh 3D-pharmacophore eOa ehit dc che kdnh hERG dupc trinh bay trong bdng 1.
Bang 1: Cie hgp chat cd ciu dang thda man md hinh pharmacophore hERG trong tip hgp dw ligu 2 Idiong dung de xiy dwng mo hinh
Hgp chit
pICso 12 3 4 5 6 7 8 9
Ketoconazol Itraconazol Indinavir Nelflnavir Amlodaron Tamoxifen Lansoprazol
Omeprazol Trimethoprim NT: Ctiira xSc djnh (non
5,72 NT NT 4,94 6,00 6,00 NT NT 3,62 -test)
Amiodaron va tamoxifen (hinh 6) thda man
mfi hinh pharmacophore eda ehit de ehl kdnh
• Nghien CLFU - Ky thuat
hERG, phil hpp vdi d d lieu t h y c nghiem, ddy la 2 chat cd hogt tinh d c chd kenh hERG manh (pICso hERG = 6,0). Chl ed nelflnavir tuy khdng phai la chat dc e h l kenh hERG (pICso MERG = 4,94) nhung van thda man mo hinh pharmacophore cua ehdt d c c h l kenh hERG.
Cd t h i gidi thieh d i l u trdn do hpp chdt nay cd cdc nhdm t h i hydroxyl gan tren eac phan ky nude/thom lam giam tinh than ddu can cho s y gan k i t vdi kdnh hERG (hinh 6).
Amiodaron Tamoxifen Tnmethopnm (pICso = 6,0) (pICso = 6,0) (pICjo = 3,62)
r^x^"'
Nelflnavir (pIC5o = 4,94)
Hlnh 6: Md hinh pharmacophore hERG trong cau dang mdt so hg'p chit
T d md hinh pharmacophore cua chat d c che kenh hERG eho thdy cdc y l u t l phan t u quyet djnh cua mot chat de gan k i t vdi kenh nay va giai thich cae t u o n g tac giua phdn t d hpp chat vdi mgc tieu tae dfing. Khi phan t u hpp e h i t gan k i t vdi kenh hERG, nguyen t d N* (phan F4:Acc, k h i i e l u mau xanh duong) se t u o n g tde cation- n vdi Tyr652 hoac cac eac acid amin phan eye vung ipc ehpn Ipe. Phan F1:Aro|PiR (vdng thom/vdng lidn hpp n. khdi edu mau cam) chu y l u tgo cae t u o n g tdc xdp chfing TT hogc ky n u d c vdi Phe656, trong khi F2:Hyd vd F3;Hyd
(nhdm ky n u d c , ede khoi eau mdu xanh Id) tgo t u o n g tac x i p chfing n hogc ky n u d e vdi Tyr652, trdn F2 hogc F3 g i n thdm cac nhdm the (methanesulfonamid hoac halogen tich didn am) CO t h i t u o n g tac tTnh dien vdi Thr623, Ser624 hode ca hai. F2 va F3 eung cd the la vdng thom, Md hinh xdy d y n g dup'c phti hop vdi mdc dd quan trpng cCia tfnh than ddu (ky n u d c ) cua cdc c h i t ed kha ndng de c h l kenh hERG. Mfi hlnh cd ede trung tam ky n u d c d l cd the phu hpp vdi khoang g i n k i t cd be mat ky n u d c Idn nhu tnj'dng h o p cua hERG. Giua ede chat de ehe hERG, cytoehrom P450 va P-glycoproteln cd sy t u o n g tde eheo do s y hidn hien cua nhieu nhom the ky n u d e . Mfi hinh 3D-pharmacophore cua chat de e h l kenh hERG dat trong md hinh trgng thdi m d eua kenh hERG duo'c trinh bay d hinh 7 '^' ^'. Khi dgt md hinh nay d trgng thai ddng cua kenh hERG (phdn t u h o p chat cd c l u dgng uon cong) thi cae t u o n g tae vdi md hinh pharmacophore khd hinh dung ra. Tuy nhidn, t h i tieh khoang trung tam thu hpp hon nen cdc phan eua phan t d gdn v d i cac acid amin d dilm gan k i t hon.
Hlnh 7: Sw chiem chd cua mo hinh 3D- pharmacophore cua chit wc che kenh hERG d trong kinh hERG trang thai ma
Ket luan
Md hinh 3D-pharmaeophore cua chat dc ch^
kenh ion kali hERG gom cd 1 trung tdm nh§n lien ket hydro, 2 trung tdm ky n u d c vd 1 tmng tdm vdng thom/vdng lien h o p it ndm xung quanh vdi dO ddng 9 3 % d u y c xdy dyng. MOt dgc d i l m can luu y la eau trdc kenh ion kail hERG, enzym cytoehrom v d b o m ngupc P- glycoprotein cd vj trf gan k i t vdi ligand r i t linh
TAP CHI DirOC H Q C - 11/2012 (SO 439 NAM 52)
I Nghien C I J U - Ky thuat dOng vd khd ndng gin kit ding thdi nhilu phdn td hyp ehit. Do dd, md hinh pharmacophore cin kit hop cung vdi md hinh QSAR va mfi hinh md td phan td docking tren kdnh hERG (kdnh ddng va md) se gidp fch cho qud trinh phat triin thule mdi nhim logi th>
cdc chit cd khd ndng dc ehl kenh kali hERG vd trdnh kha ndng tuong tdc cheo vdi cytoehrom P450. Nghien cdu gidp fch eho qud trinh thilt ke vd toi uu eac hop chit bang cdeh logi bd ede tfnh chit phan td cd thi lam tang sy gin kit gay dc ehl kdnh hERG, tang tfnh bin chuyen hda, gidm kha nang dc che cytoehrom P450 md hgu qud Id tuong tac thulc-thule khi phii hpp trong dilu tn. Td dd mang Igi Ipi feh v l chi phf va vd thdi gian cho qud trinh phat triin thule mdi.
Summary
A 3D-pharmaeophore model of high affinity hERG blockers was developed from a dataset of 42 compounds with hERG IC50 £ IpM (plCso >
6). The 4-polnt pharmacophore consisting of a hydrogen-bond acceptor (Ace), an aromatic ring (Aro\PiR) and two hydrophobe features (Hyd) was resulted in an accuracy scoring of 93%
(39/42 compound) for actives and overiapped
the scoring of 24.04. The obtained results could be useful for designing new novels with or without hERG blockade.
Tdi li^u tham khao
1. Vaz R. J., Klabunde T. (2008), "Antitargets:Prediction and Prevention of Drug Side Effects", Methods and Principles in Medicinal Chemistry, 38.
103-108.
2. Thai K. M., Ecker G. F. (2007), "Predictive Models for hERG Channel Blockers: Ugand-Based and Stmcture-Based Approaches", Current Medicinal Chemistry. 14. 3003-3026.
3. Choe H. et al. (2006), "A novel hypothesis or the binding mode of HERG channel blockers", Biochem Biophys. Res. Commun., 344, 72-78
4. Thai K M., Ecker G. F. (2008), "Classificatian Models for hERG Inhibitors by Counter-Propagation Neural Nehworks", Chem. Biol. Drug Des., 72, 279- 289.
5. Thai K. M., Windisch A , Stork D., Weinzinger A , Schiesaro A , Guy R. H., Timin E. N., Hering S., Ecker G. F. (2010), "The hERG Potassium Channel and Drug Trapping: Insight from Docking Studies with Propafenone Derivatives", Chem. Med. Chem., 5, 436-442.
6. Stansfeld P. et al. (2007), "Drug Block of the hERG Potassium Channel: Insight From Modeling", Proteins, 68, 568-580.
Xac dinh ham lirong mot so flavonoid trong thw! pham chirc nang bang phvong phap HPLC
Nguyin Tttdng Vy\ Cao Cfing Khanh^
'Tru&ng dgi HQC Dugrc Hd Ndi
^Vi§n Kiem nghiem An todn Vesinh Thuc phdm Qudc Gia
B^t van de
Flavonoid Id mOt nhdm hpp chit ggp nhilu trong dup'c lidu vd hidn nay do nhilu cfing dgng eOa ede flavonoid'^^ md ede dup'c lipu nay dupc dua vdo d l sdn xuit thyc pham chdc nang. Khi nilm tin cua con ngudi vdo thyc phim chdc ndng ngdy edng cao thi ed mOt vin d l dgt ra, dd Id ehit lup'ng cCia cdc sdn pham ndy trdn thj trudng. Do dd, chtfng tdi tiln hdnh nghien edu ndy nhim xdy dyng mOt phuong phdp d l xac
djnh ham lupng cdc flavonoid trong thyc pham chdc nang.
Nguyen l i f u, phuxyng phdp nghien
CIPUHda chat, thilt bi Hoa chit
- Cdc chat ehuln: Daldzein (>98%, Sigma- Aldrich), luteolin (>98%, Sigma-Aldrich), kaempferol (a 90%, Sigma-Aldrich), mtin hydrat
TAP CHi Dirac HOC -11/2012 rsA 439 N \ M 52)
