Methyl phenylacetate

Reactions and manipulations were carried out under dry nitrogen, using double manifold and glove‐box methods. Solvents were distilled off sodium‐potassium amalgam (Et₂O, hexane) immediately before use. Methyl propionate (99 %) and methyl phenylacetate (>99 %) were purchased from Sigma–Aldrich and stored over molecular sieve (4 Å). TMA (2.0 m in toluene) was purchased from Sigma–Aldrich and used as received. Elemental analysis was carried out on a PerkinElmer 240 Elemental Analyser. NMR data were collected on a Bruker Avance III HD 400 MHz Smart Probe FT NMR spectrometer (400.130 MHz for ¹H, 100.613 MHz for ¹³C, 104.261 for ²⁷Al). Spectra were obtained at 25 °C. For ¹H and ¹³C, chemical shifts are internally referenced to deuterated solvent and calculated relative to TMS. For ²⁷Al, an external reference was used (1 m AlCl₃(H₂O)₆ in D₂O). Chemical shifts are expressed in δ ppm. The following abbreviations are used: br=broad, m=multiplet, q=quartet, s=singlet, sh=shoulder, t=triplet.

Chemicals were obtained from the following suppliers: acetone (99.8%) from Acros Organics B.V.B.A., sodium carbonate (≥ 99%, water free), sulfuric acid (98%), d-glucose, malt extract, and sodium hydroxide (≥ 98%) from Carl Roth GmbH & Co. KG (Karlsruhe, Germany), d-fructose from Hamburger Zuckergesellschaft mbH (Hamburg, Germany), sucrose from Südzucker (Mannheim, Germany), and sodium hydrogen carbonate (≥ 99.7%) from Th. Geyer GmbH & Co. KG (Renningen, Germany).
Authentic standard compounds were purchased from commercial sources: geraniol (99%), malic acid (> 99%), 2-nonanone (99%), 1-octen-3-ol (98%), 2-phenylethanol (99%), and terpinen-4-ol (97%) from Acros Organics B.V.B.A (Fair Lawn, USA), phenylacetic acid (99%) from Alfa Aesar (Haverhill, USA), acetic acid (100%), citric acid (water free), and oxalic acid-dihydrate from AppliChem GmbH (Darmstadt, Germany), l-tartaric acid (≥ 99.5%), eugenol (pure) from Carl Roth GmbH, linalool (97%), methyl phenylacetate (> 99%), trans-nerolidol (analytical standard), 2-nonanol (99%), and lactic acid (≥ 85%) from Sigma Aldrich (St. Louis, USA), and 3,4-dimethylbenzaldehyde (95%) from TCI Chemicals (Tokyo, Japan).

E. coli total lipid extract (EPL) was purchased from Avanti Polar Lipids (Alabaster, AL, USA). Laurdan (6-dodecanoyl-2-dimethylamino) was purchased from Sigma-Aldrich (Munich, Germany).
2-PEtOH, phenylacetic acid, phenyllactic acid, Tyrosol, 1-hexanol, and methyl phenylacetate were all purchased from Sigma-Aldrich (Munich, Germany). All structures were drawn with the program ChemSketch V5 (Freeware from ACD/Labs, Toronto, Ontario, Canada). The partition coefficient (logP value) was calculated using Molinspiration v2016.10 (www.molinspiration.com, accessed on 21 June 2018.).
It can be expected that the effect of a given compound on a membrane correlates with its tendency to incorporate into the membrane, represented by the corresponding partitioning coefficient P. This type of correlation is probed as [28 (link)]
$\log \frac{1}{\mathrm{C}}=\mathrm{a}\times \mathrm{logP}+\mathrm{b}$
if only logP is considered as the predictor for the activity of the substance, with a and b being constants and C the concentration relevant for the effect to be tested, here: Minimal inhibitory concentration 50 (MIC50; see [28 (link)] for a recent discussion of the approach).