Triclosan Computational Conformational Chemistry Analysis for Antimicrobial Properties in Polymers

Abstract

Triclosan is a diphenyl ether antimicrobial that has been analyzed by computational conformational chemistry for an understanding of Mechanomolecular Theory. Subsequent energy profile analysis combined with easily seen three-dimensional chemistry structure models for the nonpolar molecule Triclosan show how single bond rotations can alternate rapidly at a polar and nonpolar interface. Bond rotations for the center ether oxygen atom of the two aromatic rings then expose or hide nonbonding lone-pair electrons for the oxygen atom depending on the polar nature of the immediate local molecular environment. Rapid bond movements can subsequently produce fluctuations as vibration energy. Consequently, related mechanical molecular movements calculated as energy relationships by forces acting through different bond positions can help improve on current Mechanomolecular Theory. A previous controversy reported as a discrepancy in literature contends for a possible bacterial resistance from Triclosan antimicrobial. However, findings in clinical settings have not reported a single case for Triclosan bacterial resistance in over 40 years that has been documented carefully in government reports. As a result, Triclosan is recommended whenever there is a health benefit consistent with a number of approvals for use of Triclosan in healthcare devices. Since Triclosan is the most researched antimicrobial ever, literature meta analysis with computational chemistry can best describe new molecular conditions that were previously impossible by conventional chemistry methods. Triclosan vibrational energy can now explain the molecular disruption of bacterial membranes. Further, Triclosan mechanomolecular movements help illustrate use in polymer matrix composites as an antimicrobial with two new additive properties as a toughening agent to improve matrix fracture toughness from microcracking and a hydrophobic wetting agent to help incorporate strengthening fibers. Interrelated Mechanomolecular Theory by oxygen atom bond rotations or a nitrogen-type pyramidal inversion can be shown to produce energy at a polar and nonpolar boundary condition to better make clear membrane transport of other molecules, cell recognition/signaling/defense and enzyme molecular "mixing" action.

Keywords: Triclosan; antimicrobial; bonds; conformational chemistry; molecular entanglement; polar and nonpolar; rotation.

Figure 1

Two dimensional (2D) Triclosan molecular structure. In addition to being a diphenyl ether structure, Triclosan is trichlorinated and has one hydroxyl group in the ortho position.

Figure 2

Triclosan energy profile is charted with the oxygen ether bond rotations from 20° to 90° with an energy minimum of about 30°. Triclosan 50° ether oxygen bond rotation to the right.

Figure 3

Triclosan ether bond angle of approximately 30° corresponds to the energy minimum in Figure 2 and better concealment of lone-pair electrons for the ether oxygen atom.

Figure 4

Triclosan ether bond angle of 90° corresponds to the charted energy maximum in Figure 2 to better expose lone-pair electrons for the ether oxygen atom.

Figure 5

Flexural strengths by adding Triclosan at increasing concentrations to Bis-GMA vinyl ester resin and cured to a polymer.

Figure 6

Flexural strength after adding Triclosan to chemical-cured acrylic.

Figure 7

Representation of a crosslinked Bis-GMA polymer backbone chain with Triclosan for compatibilization bond rotation entanglements. Similar molecular functional groups for both molecules include the two aromatic rings with an ether oxygen atom and also a hydroxyl group located on a ring for Triclosan and nearby for Bis-GMA.

Figure 8

Condensing Index demonstrates increasing loss of paste consistency by adding Triclosan when compressive force is applied.

Figure 9

Triclosan ether oxygen atom bond rotations create Mechanomolecular energy to reduce resin viscosity through disruption of hydrogen secondary bonding between the Bis-GMA resin backbone chains that greatly increase the resin viscosity.

Figure 10

Representation of a mammalian or eukaryotic cell membrane.