472 Tuy^n tip H(>i nghi KHOA HQC T O A N Q U O C Vg SINH HQC BI^N VA P H A T TRifeN B £ N VCTNG
NGHIEN Ctru ANH HlTdNG THUY SINH CUA THUOC BAO VE THlTC VAT PYRETHROID CO TAI VIET NAM QUA CONG Cy
QSAR
Ngo Kim Chi, Pham Ngoc Khanh, Pham Quoc Long
Vien Hod hpc cdc Hpp chdt thien nhien, Vien Khoa hpc vd Cong nghe Vi^t nam
I. MO DAU
Pyrethroid la ho hoa chat trir sau va bao ve thyc vat (BVTV), ca diet mu6i hien dang diing tai Viet Nam. Ben canh boat chat pyrethrum co ngu6n g6c chiet tach tir san pham ty nhien hoa ciic loai chrysanthemum thi hien nay cd khoang tren 1000 loai pyrethroid tdng hgp hoa hpc vdi dgc lye cao bao gom: Alletbrin stereoisomers, Bifenthrin, Beta-Cyfluthrin, Cyfluthrin, Cypermethrin, Cypbenothrin, Deltamethrin, Esfenvalerate, Fenpropathrin, Tau-Fluvalinate, Lambda-Cyhalothrin, Gamma Cyhalothrin, Imiprothrin, IRS cis-Permethrin, Permethrin, Prallethrin, Resmethrin, Sumithrin (d-phenothrin), Tefluthrin, Teframethrin, Tralomethrin, and Zeta-Cypermethrin. Trong s6 cac pyrethroid do. Hifn tai cd 9 san pham thu6c trir sau chiing pyrethroid dugc dimg tai Viet Nam la: bifenthrin, cyfluthrin, lamda cyhalothrin, cypermethrin, alpha cypermethrin, deltamethrin, fenpropathrin, pyrethrin.
Hif n frang, gia tang sir dyng cac pyrethroid t6ng hgp cac nam gan day vdi sy cd mat ciia cac pyrethroid co bun co va co phot pho ke fren anh hudng den mdi trudng thuy sinh dac biet la ca va tao va cac thuy sinh thyc vat. Da phan cae san pham ke fren dugc hap thy rat nhanh vao co chat hihi ca do dac thii hoa ly ciia ho pyrethoid co tinh kj nude cao va khi da hap thy vao co chit hiru co khien cho CO chat kem phan buy sinh hge, tang thdi gian ban phan buy cac hgp chit do co thi din 13.5 tuan (vi du vdi fenpropathrin) va dac biet dgc vdi ea, mgt s6 loai thuy sinh thyc vat, pyrethroid tich luy lau frong ca gay dgc tryc tiep cho he than kinh. Pyrethroid anh hudng din eac thuy sinh d tAng nude mat, cac nhiem the, cac dgng vat phii du, cac loai giap sat, cua, tdm ca va cac sinh vat phii du. Cac nghien curu cung cho thay ca thieu he enzyme de phan buy cac pyrethroid t6ng hgp nay (Smith and Sfratton
1986; Moore and Wanng 2001; Polat et al. 2002).
Pyrethroid va dac biet la cypermethrin dgc vdi ca nen 1989, US EPA da cho ban chi sir dung eac san pham thu6c BVTV chua cypermethrin va liet ke chiing la hoa chat dgc hai cao loai II d6i vdi ca. Dgc lye vdi ca ciia pyrethroid thudng cao hon gap nhilu lan dgc lye doi vdi fren dgng vat can hoac cac loai chim (Edwards, 1986; Bradbury 1989). Vi vay, tieu chuin m6i trudng cua My da ban chi n6ng do t6i da frong m6i tirrdng nude la 0,001 pg/I vdi boa chat BVTV loai cypermethrin nay (US Environment Agency 1997). Nhimg nghien cuu danh gia nii ro cho mdi trudng thuy sinh do cac loai hoa chat BVTV thudng rat t6n kem, lien quan din kinh phi thir nghiem fren dgng- thyc vat, ca, thuy sinh m6i tiirdng nude, kh6ng khi va bim l4ng dgng va thudng ton nhilu e6ng sure, thdi gian.
Nen frong nhimg cac nam gan day, dac biet tii nam 2003, Uy ban Chau Au da cho phat friln cac phuang phap n^ien cim tuong quan boat chat - ciu true (QSAR) frong nghien cuu danh gia va dy bao cac dgc chat cho m6i tiirdng dl danh gia sang lgc nhanh cac boa chat hien cd, dy bao va phat hien cac chat co tiem nang gay nii ro cho moi trudng sinh thai vdi cac tai li?u Hudng din ky thuat ve danh gia nii ro [11 ]. Vdi yeu cau cung cip cac thong tin dgc tinh nhanh ch6ng, tilt kiem va franh cac thi nghiem fren dgng vat nhieu nhat co thi, Uy ban Chau Au da cho phep su dung phuong phap tinh toan bang phan mem may tinh m6i hrong quan boat tinh - ciu fruc djnh lugng QSAR (Quantitative
Tieu ban: CONG NGH!E SINH HOC BIEN VA MO! TR^'OMG 473
Structure - Activity Relationship) de nghien ciru dgc tinh hoa chat (Elton Zvinavashe, 2008 va Technical Document EUR20418).
QSAR con dugc sir dung de nghien ciru hoai tinh sinh hgc ciia hoa chat mdi, chua thu nghiem lien quan tdi cau triic phan tir cua chat do hoac tuong quan vdi tinh chat ciia cac phan tir da dugc khao sat ky boat tinh. Do vay QSAR sir dung cau tnic hoa hgc, cac thong s6 ly hoa, cau true va phan img lien quan ciia hgp chat nghien ciru lam th6ng s6 dau de tinh toan va dy doan dpc tinh chat nghien ciru. Cac gia trj doc tinh thu dugc nhd thyc nghiem va bang QSAR (in silico) se giup dy bao tiep cac dgc to ciia cac chat chua dugc biet ky ludng. Ngudi ta da tinh dirge trj sd log Ko„. dy doan do dgc ciia dan xuat mononitrobenzenes den 5 loai hgp chat frong jdioang K^,^^, dac trung. Dya tren trj so log Kow in silico va s6 li$u thyc nghiem in vitro, dimg cong cu QSAR de dy doan in vivo dgc tinh eua eac alkanes co nhom the Clo d6i vdi ca frong moi trudng thiiy sinh. Hieu theo mgt each khac thi dgc tinh ciia mgt chat co vai fro trong ca dgng doc hgc (toxikinetic) va nhiet dgc hgc (toxidynamic) co the dugc coi la t6ng sd giira kha nang tham thau cua chat d6 qua mgt mang sinh hgc va kha nang tuong tac cua chat do:
log (doc tinh) = a. (log (do tham thau)) + b.(Iog (tuong tac)); a, b: he sd phan ung Thiet lap m6 hinh QSAR bao g6m cac budc sau ca ban sau:
Chpn diem dich
Chgn chat thif mo hinh (training set)
Chpn chat kiem tra 1^1 mo hinh (neu c6)
Chpn dgi lugng mo ta va phuang ph^p thdng kS
Phat trien mo hinh QSAR (ca kiem tra tin c^y mfl hinh)
Djnh nghTa tieu chuan chpn, gidi han mS hinh QSAR cho loai ho^ chat chpn u-ng dyng MH
Chpn chit hgp vdi lo^i ho^ chat chpn Li-ng dyng MH
Chap nh|n
Danh gia ngogi suy cua mo hinh QSAR
t
Sd dyng de dy do^n diem dich cac chat da chpn
' ' Chap nhgn
Hinh 1a. S c dd c c ban theo hydng d i n cua OEDC cho phat trien cac md hinh QSAR [11]
4 7 4 Tuyln t§p H$i nghi KHOA HOC T O A N Q U O C Vg SINH HQC BlfeN v A P H A T TRifeN B^N V&NG
Xac djnh diem dich: dilm dich la dgc lyc hay boat tinh ciia cae chat va la phan quan frgng de thu thap s6 lifu, tiep theo la nhan dien nhom hda chat can tinh toan. Neu s6 lugng boa chat tinh toan dii Idn, chimg se dugc phan ra thanh 2 nhdm: Nhdm thyc nghifm va nhom kiem fra. Nhom thyc nghi?m (training set chemicals) la cac hda chat dimg frong suot qua trinh phat triln m6 hinh, edn nhom kiem fra (test set chemicals) la cac chat dimg de hi^u chuan, danh gia md hinh. D^i lugng m6 ta cd the la cac th6ng s6 hda ly, cau true cua phan tir (vi dy dg ky nude LogP), moment dien tich (vi dy moment ludng eye, nang lugng chiem giir orbital phan tu thap nhat (Ehomo) ho^c nang lugng kh6ng chiem giir orbital phan tu cao nhat (Elumo) hoac kh6ng gian (the tich phan tii, frgng lugng phan tir...). So lifu thyc nghiem fren HPLC, NMR (thdi gian luu, gia frj pho proton hoac carbon) ciing dugc dua va nhu so li|u md ta dac tinh cau tnic neu cd san.
Dai lugng hda ly hay sir dyng nhat la bf sd phan bd Octanol-nudc logP hay log Kow, mo ta boat tinh cua chat hiru co phan bo thy dgng va tich liiy frong sinh vat. Tam quan frgng ciia d^i lugng nay da dugc thao luan ky frong eac bao cao ve dgc td hgc. Khi ma mgt minh dai lugng log Kow khdng dii de tinh toan dgc tinh cua chat thi can phai sir dyng them mgt s6 dai lugng khac nhu dg dan di?n hay nang lugng ciia cac orbital phan tu, hoac cac tb6ng so cau tnic khac.
Bang l a . Cac dfii iu'g'ng md ti cd t h i tinh toan du'g'c vd Ccic d | c tinh lien quan D?i Iu'p'ng tinh toan Dgc tinh lien quan
H$ so phan bo nude - Octanol log Kow tinh ky nude / tinh ua dau Hang so phan ly pKa sy ion hoa
Ehomo The ion hoa, s y de oxy hda, phan ung & nhUn Elumo The ion hda, s y de khd, phan irng d\ dj^n \ii Gia trj thyc nghiem/tinh pho NMR, HPLC Lien quan den c i u true va cau hinh phan tif Trpng lupng phan tu-, the tich phan t u , dipn lien quan tdi receptor
tich be mat phSn tip
Tinh khue x? phan tu- kich thudc, dp phan eye cua manh phan tir Nhiet tao thSnh Elthalpies hoat hda
Moment ludng eye dipn tich trong mpt phan tu-
QSAR con dy doan dgc tinh ciia hda chit len iu triing nude daphnids. Vi du QSAR da dy doan dugc dgc tinh cua ciia cac thuoc Bao vf thyc vat bg organothiophosphate len tinng nude daphnids, ca ya thuy sinh. Md hinh QSAR cho mononifrobenzenes, alkanes co Clo va organothiophosphate da chiem khoang 0.7% trong s6 100196 h6a chat hifn dang luu th6ng. 54%
boa chat dang luu th6ng dugc ly thuylt boa nhdm thanh cac ldp dac thu va la doi frrgng nghien cim cua QSAR. Cac djch chilt tii thyc vat dl img dyng trong thyc pham, BVTV chilm khoang 3% cung dugc coi la ddi tugng nghien curu cua QSAR, nang tong s6 cac chit ed thi nghien cihi bang QSAR len tdi 57% so vdi ting cac hoa chit hi?n co vdi muc tieu: (i) QSAR thyc nghi?m in vifro va tinh toan (in silico) cd tbi giam hoac thay thi thi nghifm tren dgng vat. (ii) QSAR co thi dimg de tinh toan den 57% hda chit hi?n dang luu th6ng EINECS, (Elton Zvinavashe, 2008).
_ Bai bao nay tap hgp cac nghien cuu phdng thi nghiem vl thu nghiem dgc to cua cac san pham pyrethroid cua nude ngoai, xac djnh moi frrong quan boat tinh ciu tine cua hf hgp chat fren, su dung de dy bao dgc to LC50 vdi ca sau 96h va dua ra cac khuyen nghj vl anh hudng cua cac hgp chat co dgc lyc cao vdi m6i trudng nude cua cac pyrethroid hi^n co tai Vift Nam. Ben canh do nhan manh c6ng cy QSAR trong vi|e danh gia nii ro m6i trudng cung nhu viec can thiet phat tnen phuang phap danh gia riii ro vdi su frg giiip ciia cac c6ng cy tinh toan trong nghien cuu dQc hgc va danh gia nii ro m6i tirrdng.
Tieu ban: CONG NGHE SINH HOC BI^N VA MOI TRLfONG 475
II. DOI TI/QfNG VA PHtTONG PHAP
i) 9 loai thuoc trir sau, bao ve thyc vat him co clo hg pyrethroid (bang 1) hien dang dugc chap nhan sir dung va sir dung rgng rai tai Viet Nam theo quylt dinh so 49 /2008/QD-BNN ngay 27 thdng 3 nam 2008 ciia Bo NN va PTNT dugc dua vao nghien ciiru, bang 2.
ii) Th6ng so boa ly cua cac hgp chat: he s6 phan b6 frong h? octanol/nudc dugc tinh bang CLogP version 4.0 (Biobyte, Claremont, CA) hoac tra cim cae nghien cuu thyc nghiem. Thong tin cau fruc ciia phan tir dugc m6 ta bing so hieu CAS va code ma hoa ciu tnic SMILES-CAS database (Syracuse Research, Syracuse, NY). Do tan frong nude cua hgp chat dugc fra cim tir tai lieu tham khao hoac tinh theo mo hinh ACD/Laboratories version 8.14 for Solaris (Advanced Chemistry Development,Toronto, ON, Canada).
ii) Dgc lye thi nghiem dugc trich dan tir eac ngu6n tai lifu tham khao chuyen m6n [1-5,10].
N6ng do lieu chet fren ea LC50 sau 96h dugc tinh toan bang phuang frinh tuong quan nhan dugc tir nghien eihi, kiem tra lai bang phan mem tinh toan tuong quan cau tnic-dgc ti'nh vdi m6i trudng ECOSAR cua Cue Bao ve m6i truong My (US EPA) va so sanh lai vdi gia frj thyc nghiem neu cd. S6 lieu thir nghiem ve Lieu chet LD50 tren dgng vat (chugt) tra cuu tai tai lifu nghien ciru hif n cd.
Kieu dgc tinh 1 cua pyrethroid co tai Vift Nam: bifenthrin, perethrin
Kieu dgc tinh II cua pyrethroid co tai Viet Nam: cyfluthrin, cyhalothrin, cypermethrin, a- cypermethrin, deltamethrin, fevalerate, fenpropathrin, permethrin [10]. Qua trinh t6ng hgp pyrethroid dugc tien hanh qua cac Pyrethrins. Pyrethrin la eac esters cua chrysanthemic hoac axit pyrethric, t6ng hgp de bien d6i thanh cac hgp chat pyrethroid cd cau tnic lap the phuc tap khac nhau vdi dang 1 va 2 lift ke fren cua cac pyrethroid
B^ng 1. C l u true Vcl b i l u hif n dpc tinh qua c i u hinh cCia cdc pyrethroid
V 2 C X - ^
Mi8rtitM»J»»>*i-P-gwwrikWiii^
°\?^. ^^^^^
Q j ^ ^
476 Tuyen tap Hgi nghj KHOA HOC T O A N Q U 6 C Vfe SINH HOC BifeN VA P H A T T R I ^ N B ^ N VQNG
Dac tinh hoa ly cua cac pyrethroid la nhiet do s6i thip fr-ong khoang 34 C-100°C, dp hoa tan frong nude thip, do kj nude cao, co hf so tan frong hf dung m6i octanol/nudc cao (tir 4.6- 7.7). San phim cd dgc tinh cao vdi ca thi hifn qua ndng dg phoi nhiem thap nhat khong thi quan sat dugc ban Lowest NOECjo/NOLC50 tren ca dao dgng tir 0.01-1 pg/L [10].
Bang 2. Thdng sd hoa ly, ndng do l i i u chdt LDSO tren dgng v?t thyc nghlf m va tinh to^n k i l m tra
T6n thu6c trCr sSu Deltametrin cypermethrin a-cypermethrin A-cyhalothrin Bifenthrin Fenpropathrin Esfenvalarate Permethrin Cyfluthrin
CAS
5291863-5 52315-07-8 67375-30-8 91465-08-6 82657-04-3 39515-41-8 66230-04-4 52645-53-1 68359-37-5
Mw
505.21 416.31 416.31 449.86 422.8 349.43
419.9 319.9 434.3
N.d6.4i
"C 100 80.5 79.5 49.2 69 47 60 34 60
H#s6 tan octanol/n
LP<>c tinh 4.6-6.6
6.6 6.94 6.85 6 5.7 6.76 7.43 5.6-6.15
H^ sd tan octanol/n
u-^cthl nghiem 6.2 6.6 6.94
7 6 5.7 6.76 6.5-7.7
5.62
D^hod tan trong
nu^c mg/L 0.002 0.004 0.01 0.0008
0.1 0.33 0.002 0.006
LDsochuOt txp
mg/kg 9.36 57.5 79 56 54.5
18 87 383
?
LOsMu 9ttt
mg/kg
258 57
Bang 3. Lilu c h i t LDSO tren dgng vata va ndng dp LCSOb tren ca sau 96h.
1 2 3 4 5 6 7 8 9 a)
Thudc tn> sau, BVTV
Deltametrin cypermethrin a-cypermethrin A-cyhalottirin Bifenthrin Fenpropathrin Esfenvalarate Permethrin Cyfluthrin
S6 l i f u lay t i r c d d
LDso tren chupt t h d
n g h i e m ' mg/kg
9.36 57.5 79 56 54.5
18 87 383
? a lieu Chem
LDso tren c h u p t thip
nghipm m g / k g , tinh toan{pt-1)''
258 57 D p l u s . b ) S 6
Ndng d p " d 6 l v d i ca 96h- LCso mg/kg
0.017 0.077 0.006 0.031 0.012 0.091 0.018 0.14 0.025 ieu L N O E C s tij
Ndng d p ddc d6l v d i c d : 96h-LCso m g / k g , tinh toan°
theo (pt-2)
0.018 0.033
0.04 r ( 1 0 ) , c) T i n h tir
Nong dp dpc ddi v d i ck 96h- LC50 mg/kg, d y
bao theo ECOSAR
0.007 0.013
0.004 : p t - l ) va (pt-2)
Bang 4. DIP bao dgc tinh cac pyrethroid dgc n h i t bdng cdng ci^ ECOSAR.
Thuy d^c tinh d y bSo
theo EcoSAR (mg/L) a-cypermethrin Cyflumethrin
cyhalothrin Bifenthrin Esfenvalarate Deltamethrin CS (96h LC50) 0.004 0.01300 0.000158 0.000116 0.00173 0.007 Daphid (48li LC50) 0.004 0.01300 0.000158 0.000116 0.00173 0.007 0.007 Alga (96h EC50) 0.004 0.01300 0.000158 0.000116 0.00173
CS (giS trj thu-erng CliV) 0.000369 0.00136 0.000158 0.0000113 0.000173 Daphid (ChV) 0.000369 0.00136 0.000158 0.000113 0.000173 Alga (ChV) 0.000369 0.00136 0.000158 0.0000113 0.000173
0.000661 0.000661 0.000661
Tieu ban: CONG NGHg SINH HOC BI^N VA MOI TRLTONG 477
III. KET QUA VA THAO LUAN
Dgc tinh ciia pyrethroid tren ca cao gap hang nghin lin so vdi dgc tinh tren dgng vat. Dgc tinh tren dgng vat the hifn qua LD50 co xu hudng giam theo chieu tang ciia hf so phan b6 trong hf octanol/nudc LogP. Phat hifn thay tuong quan co y nghia thong ke giira LogP va Log (LD50):
Log (LDso) = 0.4008 x LogP - 0.8725 (pt-1), (n=7, R ' = 0.8816).
Oi th! l>liu dlin tit tinh LCGO trin chutt vi h< »i phin bi
LogP PhVi tliuf c dAc tinh vb'l c i vi h« s6 phan b6
1.500
• 1.000
0.500
0.000
y = 0.4008X . 0.8725 FF = 0.8816
LogP
Do thj 1 : H^ SO phan bd trong h^
octanol/nu'dc
LogP va Log (LC50) ddng v | t cua cac pyrethroid
Dd thj 2: H? sd phan bd trong hf octanol/nu'dc LogP va - Log (96h LC50)
tren c^ ciia pyrethroid
Bang 2, 3,4 cho thay, a-cypermethrin cd hf s6 kj nude cao nhat cho dgc tinh cao nhat doi vdi ca va thuy sinh, bifenthrin, X-cyhalothrin, cyflumethrin, esfenvalarate va deltamethrin vdi nong dg du bao LC50 vdi ea va Agas, cac au triing nude frong khoang 0.116-13pg/L.
Dgc t6 ciia nhom pyrethroid d6i vdi ca co xu hudng phu thugc theo chieu tang cua do ki nude cua cac pyrethroid, mgt each khac sy hap thu t6t cua cac hgp chat nay vao m6i trudng dich long hihi CO ciia CO the ca la mgt frong cae yeu to gia tang boat luc eua eac dgc t6 pyrethroid d6i vdi ca.
Log (LD5o) = 2.7772 X LogP-17.202 (pt-2), (n=5, R ' = 0.8685)
Cau true lap the quanh vong eyclopropan co anh hudng quyet dinh den dgc t6. Ben canh dd, kieu dang cau triic, khung cau triic pyrethrin I va cau triic pyrethroid II quyet co y nghTa den dgc tinh ciia san pham. Nhimg nghien cim sau ban ve anh hudng cua cac yeu t6 lap the khac ciia cac pyrethroid dang dugc tiep tuc nghien ciru song song vdi vifc lam sang to co che gay dgc va nghien ciru each thirc phan huy dgc t6 eua cac pyrethroid th6ng qua enzyme thuy phan ester ciia 6ac pyrethric acid.
Nghien cuu da tap hgp 9 loai thu6c trir sau pyrethroid hifn co d Vift Nam de phan tich tuong quan va tim cac md ta co y nghTa th6ng ke cho hf pyrethroid nay. Vifc dy bao cac s6 lifu dgc t6 con thieu cho. cac nghien cuu danh gia riii ro mdi trudng do cae pyrethroid hoac cac nghien ciru cd lien quan khac fren co sd giam thieu cac nghien cuu tren dgng vat la mgt trong nhimg kha nang ap dung eiia nghien ciru nay.
Ben canh do, nghien cuu tucmg quan boat tinh cau tnic trpng dgc to m6i trudng se phat trien cac phuong phap luan danh gia nii ro m6i trudng tren co sd cho phep dy bao nhanh nhat dgc lyc cho thuy sinh thyc vat cua hoa chat nham tim kiem kjp thdi cac giai phap ngan ngira.
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4 7 8 Tuyln t$p Hgi nghj KHOA HOC T O A N Q U 6 C V £ SINH HQC BI^N VA P H A T T R | £ N B £ N VtJWft
Ldi cam on: Nhom tac gia xin bay to cam on 6ng Des Clarsy, co vin tiTrdng Ho frg ky thuat TA 4903-VlE "Chuang trinh myc tieu qu6c gia bao vf ngu6n nude" cho vifc chuan bj de cuong du an "Phat friln cac phuong phap danh gia nii ro cho mdi trudng nude tai Vift Nam"
TV. TAI LEU THAM KHAO ^ 1. Akerblom, N. et al. 2007. Deltamethrin toxicity to the midge Chironomus riparius - Effects of .J
exposure scenario and sediment quality. Ecotoxicology and Environ. Safety. 70: 53-60. -'%
2. Moore, A. and Waring, C. P. 2001. The effects of a synthetic pyrethroid pesticide on some aspects of reproduction in Atiantic Salmon (Salmo salar L.). Aquat. Toxicol., 52: 1-12.
3. Smith, T. M., Stratton, G.W. (1986). Effects of synthetic pyrethroid insecticides on nontarget • organisms. Res. Rev. 97: 93-119.
4. Edwards, R., Millbum, P. and Hutson, D. H. 1986. Comparative toxicity of cis-cypermethrin in rainbow frout, frog, mouse and quail. Toxicol. Appl.Pharmacol., 84: 512-522.
5. Bradbury, S. P. and Coats, J. R. 1989. Comparative toxicology of phyrethroid insecticides. Rev'.
Environ. Contam. Toxicol., 108: 133-177.
6. US EPA. ECOSAR Software program. Center for Exposure Assessment Modeling (CE\M) Distribution Center.
7. Elton Zvinavashe, The potential of computer-based quantitative structure activity approaches for predicting acute toxicity of chemicals. Doctoral thesis. University, Wageningen, Netherlands, 2008.
8. Elton Zvinavashe. QSAR Models for Predicting in Vivo Aquatic Toxicity of Chlorinated
Alkanes to Fish, Chem. Res. Toxicol. 2008, 21, 739-745. i?
9. Trohalaki, S., Pachter, R., Geiss, K. T., and Frazier, J. M. (2004) Halogenated aliphatic toxicity * QSARs employing metabolite descriptors. J. Chem. Inf Comput. Sci. 44, 1186-1192.
10. Michael Dobbs va cgng sy. Environmental Fate and Aquatic toxicology of systhesis pyrethroids, 2007, Pyrethroid working group.
11. EC, Technical Guidance Document on Risk Assessment, Commission Directive 93/67/EEC on Risk Assessment for new notified substances Commission Regulation (EC) No 1488/94 on Risk Assessment for existing substances Directive 98/8/EC of the European Parliament and Council concerning the placing of biocidal products on the market. Part II, EUR 20418 EN/2. . ^
STUDY AQUATIC TOXICOLOGY OF PYRETHROID COMPOUNDS EXISTING IN VIET NAM USING QSAR TOOLS
Ngo Kim Chi, Pham Ngoc Khanh, Pham Quoc Long SUMMARY
Quantitative Structure - Activity Relationship has been carried out for 9 pyrethroid compounds existing in Vietiiam: bifenthrin, cyfluthrin, ^.-cyhalothrin, cypermethrin, a- cypermethrin, cyfluthrin, deltamethrin, fenpropathrin, esfenvalerate, pyrethrin. The results showed the statistical relationship with partition coefficient LogP octanol/water and Log LD50 of 7/9 pyrethroid compounds as well as with Log (96h-EC5o) vdi ea of 5/7 compounds. Using these correlations to predict missing data on toxicology with believable results. The prediction of aquatic toxicology of a-cypermethrin, cypermethrin, bifenthrin, ?i-cyhalothrin, cyflumethrin, esfenvalarate and deltamethrin to aquatic environment: fish, larva, aquatic invertebrates, green agars between ranges of 0.116-13pg/L.
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