Mankhwala ophera tizilombo a pyrethroid ali ndi mawonekedwe amphamvu a chiral ndipo nthawi zambiri amakhala ndi ma enantiomers angapo.Ngakhale ma enantiomers ali ndi mawonekedwe ofanana ndendende akuthupi ndi makemikolo, amawonetsa zochitika zopha tizirombo komanso zachilengedwe mu vivo.Poizoni ndi zotsalira zachilengedwe.Monga Cypermethrin, Beta-Cypermethrin, Alpha-cypermethrin;beta-cypermetrin, cyhalothrin;Beta Cyfluthrin, Cyfluthrin, etc.

Cypermetrin
Cypermethrin ndi mankhwala omwe amagwiritsidwa ntchito kwambiri pa pyrethroid.Mapangidwe ake a mamolekyulu ali ndi malo atatu a chiral ndi ma enantiomers 8.Ma enantiomers osiyanasiyana amawonetsa kusiyana kwakukulu pazachilengedwe komanso kawopsedwe.
Ma 8 optical isomers a Cypermethrin amapanga 4 mapeyala a racemates.Pali kusiyana koonekeratu pakupha komanso kuthamanga kwa photolysis kwa ma isomer osiyanasiyana a Cypermethrin pa tizilombo.Ntchito yawo yopha tizilombo kuyambira yamphamvu mpaka yofooka ndi cis, trans Formula, cis-trans cypermethrin.
Pakati pa ma isomers asanu ndi atatu a Cypermethrin, awiri mwa ma trans isomers anayi ndi ma cis isomers anayi ndiabwino kwambiri.
Komabe, ngati isomer imodzi yokha ya Cypermethrin ikugwiritsidwa ntchito ngati mankhwala ophera tizilombo, sikuti ntchito yake yophera tizilombo ingasinthidwe kwambiri, komanso poizoni kwa zamoyo zomwe sizili zolinga komanso zotsatira zake zoipa pa chilengedwe zimatha kuchepetsedwa.Chifukwa chake Beta-Cypermetrin ndi Alpha-cypermetrin adakhalapo:

Alpha-cypermetrin
Alpha-cypermethrin imalekanitsa mitundu iwiri yochepetsetsa kapena yosagwira ntchito kuchokera ku chisakanizo chokhala ndi ma cis-isomers anayi, ndipo imapeza chisakanizo cha 1: 1 chokhala ndi ma cis-isomers awiri okha.
Alpha-cypermethrin imakhala ndi zochita zowononga za Cypermethrin kawiri.

Beta-Cypermetrin
Beta-Cypermethrin, dzina la Chingerezi: Beta-Cypermethrin
Beta-Cypermethrin imatchedwanso high-efficiency cis-trans cypermethrin.Imatembenuza mawonekedwe osagwira ntchito a cypermethrin yaukadaulo yomwe ili ndi 8 isomers kukhala mawonekedwe apamwamba kwambiri kudzera mu catalytic isomerization, motero imapeza ma cis isomers apamwamba kwambiri komanso cypermethrin yogwira ntchito kwambiri.Chisakanizo cha awiriawiri a racemates a trans isomer ali ndi 4 isomers, ndipo chiŵerengero cha cis ndi trans ndi pafupifupi 40:60 kapena 2:3.
Beta-Cypermethrin ali ndi mankhwala ophera tizilombo omwewo monga Cypermethrin, koma mphamvu yake yophera tizilombo ndi pafupifupi 1 nthawi yoposa ya Cypermethrin.
Beta-Cypermethrin ndi yochepa kwambiri poizoni kwa anthu ndi nyama, ndipo kawopsedwe ake kwa tizirombo aukhondo ndi wofanana kapena wamkulu kuposa Alpha-cypermethrin, kotero ili ndi ubwino wake popewa ndi kulamulira tizilombo taukhondo.

Fotokozerani mwachidule
Popeza ntchito yachilengedwe ya mawonekedwe a cis-high-efficiency nthawi zambiri imakhala yapamwamba kuposa mawonekedwe a trans-high-efficiency, dongosolo la mankhwala ophera tizilombo a abale atatu a cypermethrin ayenera kukhala: Alpha-cypermethrin≥Beta-Cypermethrin>Cypermethrin.
Komabe, Beta-Cypermethrin ili ndi mphamvu yowononga tizirombo kuposa zinthu ziwirizi.