Document K0bzDk3vzbOyzaDD6DBKop6N

. . .".j ..'myo.mn.e. one . -W ..r.d en.wher which depend.-* a:.vc.uidty ot active Na I. er,::i*ut:C!''. U..S SpCCmt m ef reports that the Na ...<w*S J j*"1 CO.-.- 19 J... :,.j. -Tt.'Ts .Ui / / vave:enmb c: dm snorter v.aveter.gt :.'.c res:;r.' ../in' ;/n in.tn:bo!i:e DDE \lJ-:iE`iloro- o components ".'.ay apply 2.2?bi\{p-ci:!n!cpiicnyi^rliyEnD c.r: be *o cxj.i.twic cincr tnir. tlic pf.orooxidiztd in mvihcnoi. E'r.oioiyric sodorts plan: neuron. Car data support /pc.ncrx'.ior. of free radie.th Eta: rr.ay ab dm hypothesis ;C; th..t dm sped..!./ stract hydrogen from solver'.:, read v irh anarecae r. >tms or tnc rcstinu "cmnt.ai oxygen, or absirae: hydrogen from an- -* / in different nerve and museie eedsAe- reacted s::bs:ra:t occurs. Eurther de sd; from meeirardsms. such as phe Na composition of short-lived intertttediates pump, tha: modify a predmtade ic.nie yields many compounds. Oxidation potential ccmmcr. :o aii exeimbie ends. products ittciude benzoic acids, aromatic M. F. M.\nv:o!t keton.es. and chlorinated phenols. Tire A. L. ?. CoxmaN DDE also undergoes photocyciization Laboratory of Seurophannacology. to give diclilorop.aorene derivatives. Division of Special Menial Health Rescetrcit, Sr. Elizabeths Hospital, Washington, D.C. 20032 . The isersir.cn: inseeddde DDT may be slowly degraded by ;a; action of .vi*;o.-o i: c cs un.1 No{a.* light and air. Photodcccmpoittion or DDT has been discussed widely (i). A. L. Konkin. I'Id.'. X.'v. 2j, 339 (iybir. ;w;-. Xdc. Ser. P Jiol. Sc:. 143, 1 (5*5$). 2. -- r.r.d H. K.v.z, 7. /7;;-r;o?. (Ltp/i.lon) OS. 37 .l^l. 3. A. L. IPwickln tr.u ?. HorD'.vHz, 143. 4. ?. TUXer. r.y.C H. C:d;'.,i:`45*, Anar. J. Physiol. 102, ?$S {1v. 2,; J, C. PldX-d'V'.nri. 8. L. Gini- oc::, C. Hr.A /. Phv.iio:. (LvnJo.-n 1G7. 374 J. Dc; C-Ai!:r>. W. C. ic Meilo. T. Vo::/...', y. f-r.ytio!. 42. 129 (1964): V. D. C:*rdsi:r.ov. ?. G. l<o.%;y.;k. V. A. Maibkii. Diop-hysic: \j, 33j H. Gruncres:. Fed. Proc. 23, 1513 (lAw >: G. A. rlcrky: ar.d H. V/. MeuTk, Cotr.p. Jiijc.::c:n, P.-.ysiol. CO. 4U FSCiZ): H. K'd:i>-rv.a. J. Phyiiui. ILondon) 55 (1903a . M. Vaughan William* 14.1. 411 (1959). 5. _>. G. Cc.:-"cn:er 2nd 8. O. Alvina J. Gen. PhyPo!. 52, 1 11963). 6. K. Gry.-i-.'.''!. ia K`.ecirochcmis:ry ;:s pidloyy i.-.;; 'F. Shsdiovsky, Ed. -.Wilzy. >-.'v ^'s'.rk. 1 55i. p. 141: II. Grami:cc, C:p. Physiol, liiochcm. 2. 1 (1906). 7. ... L. i:. Gor:r.:;r. and M. Miroli*. J. Exp. . -0.A.`.. \p. nros; M. Mirolli dnd A. I.. r. G.'dr/.rn, C.Jioihcm. Physiol. 25, 743 We now report investigations of the photoxidatioa c: DDT 'i,l,l-trichioro-2-2-bis(//-chio:ophenyi;c:haaei and DDE [!, l-dichioro-2.2-bis(;j-ch!orophenyltethylene]. 01 C! Cl C! 9. J. L-. Hobun.-ic::. 7. G.vf. C;dI. 23, 277 019520 13, .'3. ii. Col-rr.;.:,, y. Gc/:. Pi.yslo.. 27, 37 nets o: p i-.o to d eao r.. p o d: i a a ' n . : A0,\. <~ .e1.:....r ,i...-. ................ . .. and mass sycdzcre.r.ry, n : ... by other teehnian.s fbb.bie 2,. Tim tores of the products eaepor; ti.e m- quer.ee of reactions of tree .-...dead postulated by Mcder e: r.l. ii). The products formed in tue presume of c::ygcr. are complex and reed, r.ri- rrtariiy from the reaction of oxygen v. ith radical intermediates. A reae...:.n ee- quence (Eqs. 5-S) is postdated : or the formation of methyi-2.3-eidp-eid- ropher.yl) acetate, a photoo:;.:!..::.:.-. prcauc. o. evlss .n nr......a.. --r ...~ ygen (Side A). _ The re.-Ction scet.er.ce .'a:.;, a-- follows that suggcs.ed f.-r p.-:.._c'.;ir:.'- ethane p'.rotooxtd.tton i2j. A sin.d.m secuenee could give rise to y.p -d:h.:- robenzophenone (Eos. O-s'i;. See....: molcculis may be involved in tue re actions and add to the reactive ir.rcr- DSW 201625 CivA=N Ci 1:. H. II. Mi:.:.):-,. /. r.v/A 45, 611 (196s:. 12. ;:. H. C: -- >, I;. C. .'Hy.-v.-j, H. Hylvjva. /. 1 o!. iwl, .:05 i. H: '51>. :i. Gryddiy'r. C. /. H;.0, N;. AUa'r.i.r.r.o, J. Gen. Physiol. 2'>, 2,5 G. A. Ks.rkd: cr..l H. P. p'.-wi.eiii. ohrh, '.4. i'>7 H. Kv...:.r. .V-;.;/'*,- l -d. 5*6 . T202: l.. j. M .i'.'.'-is Ni. 11. Av, ..J,, 3. (7;';:. Physiol. 4:.. "C: . 3.r'; li. Pr.-c .*...4 S. l\. .s.:.v,, .a../,, -. ^;7. 13. P. 1;. 11..At. M. P. 1/1:.H. C. X<.> 3. M.i. v. H. S:ci:'.lir.:\.;. y. 459 c-a-.v,; {. m. P'.ur:r\,*.,i, lo. j.'.i J. C. .S-dHI. Pirn'll.it:. Pi- pay:.. Ac:.i 23, (I'l'--H G.-J. <^\^C0iCH3 c.d Cl C0;CHs I*?j. 1. Fo::hu!as oi procucis oC ;:!ic.u)OA.\ir.Hd.~.. JAAvAHY IvTv STLCOPCB4059692 1. I's.Tv.v..:.'. yu\.i* o: ;r:.V;.:.:;on ;':Ov:;y*> of DOT i;i i (i 3/::;cr;; X o /'-U.ii.Ci. Vicki (9o) C'.-'-ur > C: iCCl3 CilCIlC, CUCH.Cl a ic:^:h > SirJCllirc is .-x ur.E (;. *;..j / .:b!v IJ, . .o a `fi..-.. (.:y were uetect.u. -'e/-,...0.' piteucis. dlch:^.v>e.-./olc :.~V. : uOc un^crvoos rcuuciivc cj* ch;o:;-.i:ior. by : :Tor:;Jic:il nicciianisin. In oxygjr.. DDE also undergoes a ol:o;oeyeiizadon reaction. We have obtained a 10 pcrceii: yield o: 3.6-dici'.Ioroduorenone (3) by irradiation c: eoir.pose or reae: \a::li solvent. Seel; reactions orobabiv account icr the r'armation of chlorocer.zolc r.cid. methyl chiorobermoatc, chiorophcr.ols, r.r.d other rrci^rr. mien -.roducts. pW*&- p.pU'eUt ' Table 2. Photolysis products of DDT ar.e DDE'in 1r.iih.2noi: R is CiC.H,. Thi compounds h-ied ropr-uen: ih.e volatile components 0: li'.i photolyaate separated by ;is ch:o~a:oaraphy; m.. present in moderate amount; -r, detected; --, not detectable; ?h, phenyl. m/e 136 ICO 170 ISO 15-4:oa 21 -t "I"*-? 226 222 226 248 24S 250 260 266 2S0 232 254 2S4 294 3:4 316 31$ 3:4 33$ 352 *42 170 176 204 210 22$ 2S0 254 63 Structure DDT O3 N. Xeutra! fraction Pb.CO-.CH, RCHO RCOvCHj PhX = CH. RCH.CO.CHj (2) PhRC = CHa R; Ph.CHCO.CH3 PhRCHOCH, R.CH; R.C = CH. (3) R,CO PhRCHCOXH, R;CHOCH, (4) . R.C = CHCI PhRCHCHCl, (5) - R.CHCOXHj (6j - R..C = CCl. (DDE) R-.CHCH.CI3 ;DDD) R..C(OCH:jC03CH, (1) Unknown S3CHCCI3 (DDT) A A -1. -r -- -- -- *T -- -i" -- -- -r. m + -- -h m m -- -- m --. -- -p -- -- -- -T -- -- -- -r -- 4-- -- m "T -r -- -- -- -- J-- m *r -- -- -!- W ' 'V >* J Acidic and phenolic compounds (methylated) -- RCC.CHj -r ChC.HjOCH, Ci3C-.H3CO.CHj ' .A -j. Cl.CdTOCH, -r (7) -- (8) R..CHCOXH, *r -r DDE O3 N. -- -- m -- 'T -- -- -- .-- ~r --m -r ~r -- 4-- -r T - ra -- m -- -- -- -- -- -r -- m -r m -- j- -r -- -r -- ' -r -r -u -r -r 4- chlorine radicals. V. e v.beu a pr..reary a v/aier-cooiea via..."..! .a-.^.r. _ to (about 1 ^''Ii:c"). eumrnatcu. ::3: 0: i Corcx > 2iCJ A or Pyre:; > . rA.)- Oxygen or nil; egen was Imb through the solution in separate ex merits. Products were obtained by chroma tography of the methar.oltc solution niter it was concentrated irt a rotary evaporator. 3.6-Dichioroiluorar.one, which crystallized from the rcaciicn mixture, was removed by filtration, '.'he remaining syrup was dhsoh ed in elk.:. Acids and phenols were remove- ay extraction with sodium hydroxide. Vhc sodium hydroxide extract was aci-.ti.d. and the free acids and piteno.s vrare extracted into ether. Acids were then extracted from the ether with sodium bicarbonate solution. Portions of the free acids and phenols thus obtained were methylated with diazomeikana be fore being subjected to gas chroma tography. . The neutral extract was fractionated by chromatography or. a silica column. Infrared spectra of individual fraction.; were determined. Each -Tacit:r. v. _s examined by combined gas chroma tography and mass spectrometry We identified a numuer of prod.etc by cochromaiography and by comparison with authentic specimens 0; hnow.a physical properties. In many e..; e.s. structures could be postulated from mass spectral fragmentation p..:ierns. The compounds obtained by reductive loss of chlorine have fragmemaiiun patterns related to their preaurre r,, DDT and DDE. The fragmentation of DDT and DDE has be-cr. discu.sta (5). The number of chicrir.e -.or.; present in the molecular icr. of ,.r. known could be deduced from lire ative peak heights of lire rrc.-c_...r weigh: (M), the mciecuiar ve: At s- DSW 201626 STLCOPCB4059693 Hydrogen, abstruaiu:: e.chcci. - ci MCCk q- CH .OH------- MCHCKCi. - CH.OH _. n.;h: _. *Uv-.-C:.4.h ' H-CHCXCI -j- C. ------ wl-.V. * -- ______v'C. * x.c: :c:-:.ci - ch.Oh "ICO. O. /: presence of oxygen Mbh.dCl.li.) ' ... ::cc- dh.CHCChd -r 6; ..CKCCi.O----- R.CKCOC! ~ CI :.c;-.ccc: - ck.oh------r.chccoch, h :-:ci - c: - h.CCCi, - HCI T> ~ >~W.- "7- . r.co.cc;. / ic.co.cc:.- 2H.COCCL - Os R_s.OCC.: il.^O -- u.ck (R'= P-CI-C,H.) u; m) & .it (7) (3) (5) (1C) .in (12) - ; ; ' i ; i ' : j . \ i 2 (M -- 2), and so forth, as "'Cl and -TC1 occur in the ratio of 3:1. Many of the oxidation products arc known; therefore, mass spectra! rata chroma tographic comparisons could be made with authentic samples. Mass spectra! studies were extended to model com pounds, and tire photochemistry of p,.v'-dichiorober.2ophenone was aiso in vestigated to obtain information on the further breakdown of photoiytic prod ucts. Substitution of an oxygen atom at C-l of the ;, i -diphenylethar.c system affords' ahouadant fragments at m/e 135 (:;'CiC0K..CO) and n:/c 111 (-SC1C,,K.;). Molecular ions were obtained in the majority of cases, but difficulty was en countered with (i). An intense base peak at m/e 265 suggested the oxonium ion structure (1A). presumably formed by loss of a methoxycarbonyl residue from (1). The presence of this residue in the isolated material was confirmed by the infrared and nuclear magnetic resonance spectra of the isolated frac tion. The compound with n:/c 33S, which was present in signideaut quantity in the photooxidation products of DDT, could not be assigned a complete struc ture on the- available evidence. How ever, nuclear magnetic rcsonan.ee, in frared, and mass spectral data suggest that it contains a methyl dicitioro- fhtoronyl carboxylate moiety. Mass spectral data alone were used for assignment of structure where trace quantities were obtained and auilientic material was unavailable. 1 Most of the photolysis products could be examined with these tech niques. Compounds of higher molecu lar weight, such as those described by Fleck (i), are probably present in small quantity. The seqer.ee of reac tions of free radicals postulated by Mosier et al. (i) explains the photolytic pathway. There are many in stances of photoiytic tlssion of a C-Cl bona to form a radical which can sub sequently react with solvent by hydro gen abstraction (6;. 'Ve postulate that, in the presence of excess oxygen, photochemicaiiy generated free radicals from DDE and DDT add oxygen. Re arrangement and reaction of unstable intermediates account for the forma tion of the photcoxidation products which we have identified. Jack E. Eiummer. Utz I. Xlinceoizl. iMhvon E. Hummer Crops Research Division, Agricultural Research Service, Beltsviile, Meryland 20705 Ivy;cri.-Eccs ind Note* 1. F. J. C::::;he:, Ch-r,n. F.duc. 22. 23S (1945): F. E. Fleck. /. Ai;isr. C7::*:. i'er. 71, 1034 (1945); J. Return, C.'icm. iLur.Jon) 1555 (1903): A. Is.. .Vo.:::, V/. D. Cujfui, L. L. Mil!:.'. oofi'-Ttv io4. \ivC3). 2. C. V'r..';r.2t .'v: F-.Ucg!: in SoUuiox (Wiley, New York, 155?) -4'. 3. J. R. r.ii:ir.M;r Id. I. Cr.eni. Cotr.nsun. 4.,j ( . .Myj. 4. rvrkiH-- Z;i;;:v: C-C 170 ir.M.Ti.iidr.: ii:u;rT-4 ill o o;-'.n uio;::;.: citpIILry :Ir.i,ioo cih.-ov::: .`.SI .`jj;. CCf-i:-! wi;:i iii 50 C.ro:*.v.>or:> '.V :or;. 5. J. R. Ci. Sp.'uilcr. MonJisli. Chctn. v7, h'n.; iV'.h/i. 6. J. R. I'liiiitndf 15. j Imnr.'.cr, / A fir. rood Char.. 17, 251 ^Ivu5). 29 Anjiust !Sf.9 /OCd'.M' ;/< '.M.-".' J "J,*: . V.cc. 0:1;Jj p a.:......... up .In. :o f.drror vj \s . bj*. -.veov,-o; : U.i:n::;:cgicju:i:i hf ae::.:.i_. other for t.rar.m.or'.ooiii:.. sins produced i::.'.hu::i indicating that tj-v. ;/ ta.ueousty , e.et.sucst. /.t:.. both -;M and yO at.tibodie. A com-reheaslve ur.de :hi synthetic C4?aci:;23 c: 1. i?... 12. C w J:t j J --5....h ,v.. ... o ..iv,... wi:h which :he crchcicis o: . I: h.c may be collected and analyzed, dhtg..- ceil isolation procedures permit i,,eh. sampling, but the numbers of cells t.-..:t can be examined are reiat-vely few Fluorescent antibody techniques al-.o permit reasonable e.-.ferer.cee _cc..: intmunoglobuiln .-.thesis -.in:a t-te-y detect restutta: woe...ms m -or an `...e ceils of fixed tissue seeclme.'.s ;b.. Studies of single cei.s b> dee :^a;:.;.wn procedure showed that up to 15 per cent of immune ceils may produce tv ^ classes of immunoglobulins simult:...e.- ousiy (/), while with duo.-ejc.-r: anti body techniques instances of towil.e double producer ce.is i.ave crdinarilv averaged around i percent -.2'. '.V. now report a new repltea-yl.-ting proce dure which allows dupheme s_mp.ir of the proditets of single viable :nm...n ceils without necessitating holmlon o. single ceils. Adult female New Zeah.ml . - - rabbits were immunized in:::.-. _.tc -I with 10-mi portions of .brie.-. ..-...... :0 percent sheep -e.-ythrocyte. or 0, 5, IS, and 24. Suspend-ms :f Im mune ceils (5) were obtai/.e-w ' p:.:.- Cssing the whole spiee.ts of m m.als on days 5, o, ?, 3, ...:d _T. . !.; ceils were washed by cer.trif.. tic '. and those from two rabbi: spl.m^ pooled and suspended in 23 m. of e- - Hanks solution. Very :l.ln . - ^iteep erytiiroemev itt agar -eve pm- pared as follows. A rnixtttt'j eom, >e u o t . o t u.- o. _ - - - - - lied haotoagar ' ffl.c. m : v - 0.053/ tris-buii'-ered i.-l- f- minimum csscr.d.d e l., .a .......... M.VNU'AT'.Y tv-0 DSW 201627 STLCOPCB4059694 /...ij.i .`.2*.. .. a 2...; .j..-; ; 0 .'o;`.v r. I > I or 3 e.:;j ho prem.tod by the ionic T...ad .mother which depends .;'! mo oloctrogcnicity of active No ThN .og..ration n:,, meemi . -'-. ir. of reports that the Na ....o ' ,-.ot only atahos a general con- :rm..mm .o go:cu:h.h ho: may hove :::o:c <ycc.:.:c .'.mo..cuts such ..s :;ic mediation of :t..p:ic effects Ho). The r..:io P:- .ip gears :o vary v. !:.i ;em- ptnuture and provides another mecha nism by which the potential is regu lated. A similar division or the resting potential into components may apply :o excitable cells other than the And- setters ciun: neuron. Our data support tire hypothesis td; thuc the specini chcroc:eristics of tire resting potential in different nerve end r.vu>cic ceils re sult from mceh.mlsms. such ns the Na pump, that modify a predictable ionic potentinl common to nii excitable cells. hi. F. Maun:or A. L. F. Gorman Laboratory of .\Teuropharmacology, Division of Special Mental Health Research, St. Elizabeths Hospital. V/ashington, D.C. 20022 References uaJ Notes 1. A. L. Konkin. B:dI. Rev. 26. 339 (-961); Proc. Row Soc\ S^r. R Biol. Sci. 143. I (1 >53). 2. ---------- sr.J 3. Kaiz, A Physiol. (London) 3GS. 37 3. A. L. :!oc!::kir. ssti P. Korovvicz, ibid. 148, 127 t!v:5j. 4. ?. Helior. ;,.tg I-i. Gr;:r.2fest, Anar. J. Physiol. 235, C962); J. C. Mickmnn, 'd. L. Gir.s- oor.7, C. Xr.y. A Physio:. {Litr.dor.) 107. 374 u9o?r, J. Dei Ca.'iiiUa. \V. C. <ic Melio, T. Morales, A Gi"i. Physiol. 43, 129 (1904k V. D. Gor.yiirr.C'v, ?. G. Kcvy\:k. V. A. Maiskii. Biophysics 13, 300 (i9?5`,; \i. Grur.ilfeat, Fed. ?roc. 26. 1613 (1967';; G. A. Korku: s.r.il U. W. Meec:\ Comp. Biocncrn. Physiol. 20. 411 ".957): H. Kur;:-arr.a. A Physiol. (London) ICS. 15 (1963;: Z. M. Vaughan Williams* i.-icl. UC. 41 1 (1959). ' 5. D. O. Caipentcr aad B. O. Alvins, A Gen. Physiol. 52. i (193S). . 6. VI. Cr.-.nuJcNj, jp. Fivinrochemistry in Biology r.:.J .'wine, T. SheUlovsky, Ed. (Wiley. New York, 1955), p. 141: H. Grundfcst, Camp. Physiol. Bitxhem. 2. 1- (1966k 7. A. L. I*. Gorman and M. Mirolli. J. Exp. r in press; M. Mirolli and A. t.. F. (j.N'-ir.n, Comp. Biochcm. Physiol. 25. 743 Z. M. pc.'ior.a! ciinmuriication. 9. j. D. i<ob.rsc.n, J. Lx?- Liol. 20, 277 (1953). 10. D. Vi. Goi'Jr.tur., J. Go/:. Physiol. 27, 37 (1943). 11. K. 3. Morgan, ^ Lxp. Biol. 43, 611 (196X1. 12. 3. Cross, V;. C. Keyros, ?,. Kybova. J. PhyiSA. 131. v.65 (ly.'o): K. Gruncf^M. C. S. K.-.o, M. Asiarr.irr.no, A Gcri. Physiol. j$, 245 C. A. Kurkut anti A. P. Thomas. C/vn:^. Vioohen:. Physi.il. 14. * S7 (1 .'*5>: V. Kcmr.n. Suture l'?3, 936 (1902): L. J. NT..131::'s r.r.l Si. ?.. .`w-jJ, J. Gen. Physiol. 43. 701 r.9655; J*. Paoe and 5. II. Strom, ..'kV., p. 957. 13. I*. I'. Hr.kcr. M. i*. Dli.u.'ioin, U. C. Kcyuc^. J. M.mil. T. 1. Sl:r.-w, X. SuinUarai, i. PhyP.-A. 20i>, 459 I. M. Gi.nn. iP.r.rma.ol. i\ s .*. l(i. 3M (J. C. Skua, ilivchim. y*. A eta 23. 3;' 4 (1957); li.-j, ^ i 1, .' J iv>j,-. * 2n i'.V/ Abstract. if/:c pesticide DDT [1,1,1irichioro-2,2-bis\p-ci.iorop:iinyl', ethane] and its metabolite DDE \l,i-di;hloro2.2-!>b(p-cliloropl:ctty!)et!iy!er.e} can re phoiooxidiZid i:i methanol. Phololytic generation of free radicals that may ab stract hydrogen from solvent, react with oxygen, or abstract hydrogen from un reacted substrate occurs, i'urther decontpositiot: of short-lived intermediates yields many compounds. Oxidation products include benzoic acids, aromatic ketones, c.ttd chlorinated phenols. The DDE also undergoes photocyclization to give dichlorojiitorenc derivatives. The persistent insecticide DDT may be slowly degraded by the action, of light and air. Photodecomposition oi DDT has been discussed widely (i). We now report investigations oi the photoxidation of DDT [1,1,1-trichioro - 2- 2-bis(p - chloropheny!)e thane] and DDE [l,l-dichioro-2,2-bis(/;-cn!orophenyHethylene], oiver.:, :.r>u vmv,:: i- ...... \... .. . of of chlcri.te fre; ... . - s.tov.;u lac.c .. .u:.; .>.^.2 ...- ^;c.t:orc-2,2-c.. r-ct., ,rt. . _. . and j-ch::rc-2.2-i;i-.f;:-t'..:era; .... . mi.tes the .tutttre of a.c -reduc..-.; shorter wavelength., chlorine is placed from the aromatic ring. Prc-acts of ph0icciccor.t;.os:::c.n v.ure tuied oy rente.r.cu gr.s cr.r^r.... . ... ' and mass snectroittctry, ..s v. ..v .t other tccltr.lqucs \T.bolc 2,. Vac mr_cturcs oi the products st:p;mr: t.te se qucnco of -cue::;o:;s oj 1722 r.;.::2,,...> postulated by M osier e: rd. ill. The p roci L:cts ,formed in the pres-nce of oxyg.:n ?.re aempiex and result primariiy f;;cm :>.e r ji.ci'.cri Oi! ji;yjdR a ;;r. radical inicnr.cd intes. A reaction sequence (Eqs. 5-S) is postulated for the formation of me:hy:-2.2-b.isi>-cr io rophcnyl) acetate, a photooxldatter. product of DDT In methanol with ox ygen (2S00 A). The reaction sequence .'fits. i--~; follows that suggested f-r pentachlerocifcanc photooxiclaticn (2j. A sin.ih.r sequence could give rise to p.p'-diehie- robeezophenone (Eqs. 9-12). Sofv;:t; molecules may be involved in the re actions and add to the reactive inter- 2 JANUARY 197C DSW 201628 STLCOPCB4059695