▁the ▁conversion ▁and ▁re arr ang ement ▁of ▁the ▁al de hy de ▁created ▁in ▁the ▁previous ▁step ▁into ▁ 9 - cis -- ap o - 1 0 ▁and ▁subsequently ▁producing ▁car la ct one . ▁ ▁It ▁is ▁still ▁not ▁clear ▁how ▁exactly ▁car la ct one ▁is ▁transformed ▁into ▁the ▁different ▁str ig ol act ones ▁identified ▁so ▁far , ▁but ▁several ▁studies ▁have ▁proved ▁that ▁car la ct one ▁is ▁definitely ▁the ▁prec ursor ▁of ▁str ig ol act ones . ▁This ▁last ▁step ▁of ▁the ▁b ios yn thesis ▁should ▁involve ▁the ▁addition ▁of ▁at ▁least ▁two ▁o xygen ▁mole cules ▁to ▁convert ▁the ▁car la ct one ▁in ▁ 5 - de ox y str ig ol , ▁a ▁simple ▁str ig ol act one , ▁and ▁more ▁ox id ation ▁should ▁be ▁required ▁to ▁produce ▁other ▁more ▁complex ▁str ig ol act one . ▁The ▁protein ▁MAX 1 ▁has ▁been ▁proposed ▁to ▁catal y ze ▁the ▁last ▁step ▁of ▁the ▁b ios yn thesis ▁of ▁str ig ol act ones ▁due ▁its ▁role ▁in ▁ox id ative ▁met abol ism ▁in ▁plants . ▁ ▁Ro le ▁of ▁A BA ▁in ▁b ios yn thesis ▁ ▁Both , ▁ab sc is ic ▁acid ▁( AB A ) ▁and ▁str ig ol act ones ▁have ▁a ▁common ▁group ▁of ▁en zym es ▁that ▁carried ▁out ▁the ▁synth esis ▁of ▁the ▁two ▁comp ounds , ▁previously ▁it ▁had ▁been ▁demonstrated ▁the ▁existence ▁of ▁a ▁correlation ▁of ▁the ▁two ▁b