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Hydroperoxide and hydroxy fatty-acid metabolites are one H short (lipoxygenase charge imbalance) #1042

Description

@edkerk

Split out from #348 (the redundant 1:1 duplicate reactions were removed in #1040; this tracks the remaining formula/balance correction).

The problem

The simple hydroperoxide fatty-acid metabolites are one H short. For example 12-peroxy-eicosatetraenoate (MAM00335) is C20H30O4 at charge −1, but the correct 12(S)-HPETE anion is C20H31O4 (arachidonate C20H31O2 + O2 → 12-HPETE C20H31O4 balances exactly). The corresponding hydroxy products (HETE/HDHA) are also one H short, which is why the reduction/consumption reactions balance with the current formulas while the fatty acid + O2 → hydroperoxide dioxygenations do not.

Scope

Correcting the formulas cascades to roughly 23 hydroperoxide + hydroxy metabolites and ~105 reactions, and the residual imbalances are non-uniform, so this needs a careful, individually verified pass rather than a blanket formula patch.

Hydroperoxide metabolites that are one H short (CnH30O4CnH31O4):
MAM00302 (11-peroxy-ETE), MAM00335 (12-peroxy-ETE), MAM01214 (8-peroxy-ETE), MAM01246 (9-peroxy-ETE), MAM00275 (10-peroxy-DHA), MAM00303 (11-peroxy-DHA), MAM00372 (14-peroxy-DHA), MAM00404 (16-peroxy-DHA), MAM00418 (17-peroxy-DHA), MAM01198 (7-peroxy-DHA), MAM01215 (8-peroxy-DHA). The hydroxy (HETE/HDHA) products they reduce to are short one H as well and must be corrected together.

Reactions currently charge-imbalanced (all mass-balanced), which would be rewritten to the clean parent + O2 → hydroperoxide form once the formulas are fixed:

  • DHA production (non-duplicate): MAR01410, MAR01411, MAR01412, MAR01413, MAR01414, MAR01416, MAR01417 (net charge +1)
  • DHA hydroperoxide consumption: MAR01403, MAR01404, MAR01406, MAR01407, MAR01408, MAR01409 (net charge −2)
  • MAR01363 (9,11-cycloperoxy-15-hydroperoxy endoperoxide, net +4) — a separate cyclooxygenase-type sub-case

Several of these reactions also use superoxide (O2-, MAM02631) where molecular O₂ (MAM02630) is the actual lipoxygenase co-substrate and should be used instead.

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