## 4 Discussion
In order to explain epi-cochlioquinone very easily it can be divided into two segments. The first one is catechol (1,2-dihydroxybenzene) and the second is oxadecalin, but _CM_ is only concerned with the synthesis of first segment. The main skeleton of cochlioquinone would be synthesized by the cycloaddition of these both segments described by [PERSON] et al. 2010 [55]. Catechol would be synthesis by stereoselective manner of treatment of aminophenol with quinone which is the product of shikimate pathway. The reaction for synthesis of catechol is presumed that, first the aminophenol should be oxidized to iminoquinone which further gives o-quinone by receiving acid hydrolysis which works as an oxidant for aminophenol to synthesize catechol and iminoquinone through autoredox catalysis. And also phenylalanine is the precursor of benzoic acid which is first hydroxylated to SA at the ortho-position and then converted to catechol, moreover it is predicted that SA is directly converted to catechol due to oxidative decarboxylation [56]. Supplementary Material (Supplementary Materials Figure S2) describes the role of _OsCM_ in the shikimate pathway and the correlation of the shikimate pathway with cq-9, which is also known as luteoleersin [51]. The scientific name of its underlying structure is 17-methoxyocchioquinone [57]. It is a highly complex compound, and its biosynthesis is also very complex. Cochlioquinone is composed of two basic units, one is a farnesyl group or also identical to oxadecalin, and the second unit is acetogenin derivative of aromatic compound and synthesise cq-9 by cycloaddition of both the segments [55]. The structure of cq-9 was compared with other structure of Cochlioquinone such as Cochlioquinone A, B and D. The difference between Cochlioquinone A and Cochlioquinone B is that -OH and -H are bonded to C-12 (R3), and -OCOCH3 and =O are bonded to C-4 (R4), respectively [58]. Cochlioquinone D is similar to B, but has a double bond of C-2 and C-3 [59]. The molecular structural of cq-9 is most similar to that of Cochlioquinone A, except that the methyl group is bonded to C-15 (R1) rather than C-14 (R2). The mixed biosynthesis of cq-9 occurs through the introduction of a farnesyl unit onto an aromatic precursor, whose secondary metal groups are provided by methionine, which is produced in the methionine biosynthesis pathway [52]. The first unit of cq-9 is famesyl pyrophosphate, which is synthesized from Tyr in the shikimate pathway. Tyr is the ultimate source of acetyl-CoA synthesis, produced by a series of reactions, like oxidative decarboxylation of pyruvate and Tyr, and the catabolism of other amino acids (Phe, Trp and lysine). Furthermore, acetyl-CoA undergoes a series of reactions in the isopenoid pathway (mevalonate kinase pathway) and gelites isopentenyl pyrophosphate, which further pairs with other isopentenyl pyrophosphate molecules and produces geranyl pyrophosphate. This geranyl pyrophosphate is the accepter of another isoprene molecule and, as a result, produces farnesyl pyrophosphate, which is the precursor of all types of sesquiterpenes [52]. Tyr and Phe synthesis is highly regulated by the _OsCM_. The prenylation of the acetogenin aromatic-derived nucleus, leading to an intermediate complex and the decarboxylation-hydroxylation reaction, converts it into another intermediate, which is further converted to cq-9 by the cyclisation of the farnesyl chain [52]. This prenyl accepter is primarily produced by polykeptides, but it can also be derived from Tyr, which is evidence of the involvement of _OsCM_ in cochlioquinone synthesis. Moreover, quinone is the basic moiety of this compound, which is also a product of the shikimate pathway. _OsCM_ is not concerned with the synthesis of the second unit of the compound, but it is necessary to describe its synthesis briefly. It has been reported that oxadecalin is the derivative of glycosyl cyanide by cycloaddition reaction with ketone and reductive alkylation with cyclopropylketone.