Сhiral and Racemic Fields Concept for Understanding of the Homochirality Origin, Asymmetric Catalysis, Chiral Superstructure Formation from Achiral Molecules, and B-Z DNA Conformational Transition

Valerii A Pavlov,Yaroslav V Shushenachev,Sergey G Zlotin

doi:10.3390/sym11050649

Valerii A Pavlov, Yaroslav V Shushenachev + Show 1 more

Open Access

https://doi.org/10.3390/sym11050649

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Abstract

The four most important and well-studied phenomena of mirror symmetry breaking of molecules were analyzed for the first time in terms of available common features and regularities. Mirror symmetry breaking of the primary origin of biological homochirality requires the involvement of an external chiral inductor (environmental chirality). All reviewed mirror symmetry breaking phenomena were considered from that standpoint. A concept of chiral and racemic fields was highly helpful in this analysis. A chiral gravitational field in combination with a static magnetic field (Earth’s environmental conditions) may be regarded as a hypothetical long-term chiral inductor. Experimental evidences suggest a possible effect of the environmental chiral inductor as a chiral trigger on the mirror symmetry breaking effect. Also, this effect explains a conformational transition of the right-handed double DNA helix to the left-handed double DNA helix (B-Z DNA transition) as possible DNA damage.

Highlights

Curie [1] was convinced that “without asymmetric physical impact no asymmetric chemical effect arises”
Modern experimental data support this criterion: asymmetric induction in asymmetric catalysis is only implemented through the asymmetric (C1 symmetry axis) key intermediate [2]
Noticeable distinctions between enantioselectivities of identical catalysts with ligands having a sSiymmimlaetrryst2r0u19c,t1u1r,e64b9ut different symmetry (C2-21,26,27 and C1-28) were observed in reactions (141)9aonf d56 (15) [138,139,140,141] (Scheme 8) where aromatic prochiral compounds were used as substrates

Summary

Introduction

Curie [1] was convinced that “without asymmetric physical impact no asymmetric chemical effect arises”. If a substrate has two or three functional groups which can be coordinated in that intermediate, chiral C2-symmetric catalyst loses C2 symmetry in the substrate coordination stage Nature has chosen such substrates (amino acids and sugars) as components of important macromolecules. PPPooossssssiiibbbllleee sssccceeennnaaarrriiiooosss ooofff hhhooommmoooccchhhiiirrraaallliiitttyyy ooorrriiigggiiinnn iiinnncccllluuudddeee EEEaaarrrttthhh aaannnddd eeexxxooottteeerrrrrreeessstttrrriiiaaalll ooorrriiigggiiinnnsss,,, mmmiiirrrrrrooorrr---sssyyymmmmmmeeetttrrriiicccaaalllaaannndddnnnooonnn---mmmiiirrrrrrooorrrsssyyymmmmmmeeetttrrriiicccaaalllfffooorrrccceeesss,,,dddiiiffffffeeerrreeennntttaaammmppplllllliiififfiicccaaatttiiiooonnnmmmeeeccchhhaaannniiisssmmmsssllleeeaaadddiiinnnggg tttoooLLL---ooorrrDDD---aaammmiiinnnoooaaaccciiidddsssaaannndddsssuuugggaaarrrsss,,,aaannndddLLL---aaammmiiinnnoooaaaccciiidddssseeexxxccceeessssssddduuurrriininngggmmmeeettteeeooorrriititeteeiimimmpppaaaccctt.t. WWWeeebbbeeellliiieeevvveee[[[333,,4,44]]]ttthhhaaatttaaapppooossssssiiibbbllleeebbbaaasssiiisssfffooorrrsssuuuccchhhaaarrraaatttiiioooooofffcccooonnnfiffiiggguuurrraaatttiiiooonnnsssiiisssttthhheeerrriiiggghhhttt---hhhaaannndddeeedddhhheeellliiixxx (((PPP)))cccooonnnfffooorrrmmmaattiioonn ooff iiimmmpppoorrttaanntt bbiioommaaccrroommoolleeccuuullleeesss ffoorrrmmmeeeddd fffrrroommm aammiiinnnooo aacciidddsss aannddd mmoonnoosssaaacccccchhhaaarrriiidddeeesss... It is not by chance that nature has chosen the double helix structure to stabilize the right-handed conformation of DNA. In this case, the configuration error reducing factor is important [27]. We continue the search for traces of the external chiral inductor, such as the chiral gravitational field, in the most studied reactions with mirror symmetry breaking

Gravity as a Chirality Inductor

Gravitational Field Impact on Chemical Reactions

HH33CC

OH O CH3

Results

Conclusions