*3.1. General Experimental Procedures*

Chiroptical measurements ([α]D) were obtained on a JASCO P-1010 polarimeter in a 100 × 2 mm cell at 25 ◦C. Nuclear magnetic resonance (NMR) spectra were acquired on a Bruker Avance 600 MHz spectrometer with either a 5 mm PASEL 1H/D-13C Z-Gradient probe or 5 mm CPTCI 1H/19F-13C/15N/DZ-Gradient cryoprobe. The spectra were acquired at 25 ◦C in DMSO-*d*<sup>6</sup> and referenced to residual signals (δ<sup>H</sup> 2.50 and δ<sup>C</sup> 39.5 ppm)

in deuterated solvents. High-resolution ESIMS measurements were obtained on a Bruker micrOTOF mass spectrometer by direct infusion in MeCN at 3 μL/min using sodium formate clusters as an internal calibrant. UPLC-QTOF analysis was performed on a UPLC-QTOF instrument comprising an Agilent 1290 Infinity II UPLC (Agilent Zorbax C8 RRHD 1.8 μm, 2.1 × 250 mm column, eluting at 0.417 mL/min with a 2.50 min gradient elution from 90% H2O/MeCN to 100% MeCN with a constant 0.1% formic acid modifier) coupled to an Agilent 6545 QTOF mass detector (Agilent, Mulgrave, Australia). Liquid chromatography-diode array-mass spectrometry (HPLC-DAD-MS) data were acquired on an Agilent 1260 series separation module equipped with an Agilent G6125B series single quad mass detector and diode array detector (Agilent Poroshell 120 SB-C8 2.7 μm, 3.0 × 150 mm column, eluting at 0.8 mL/min with a 6.25 min gradient elution from 90% H2O/MeCN to 100% MeCN with a constant 0.05% formic acid modifier). Ultra-high performance liquid chromatograms (UPLCs) were obtained on an Agilent 1290 infinity UPLC system composed of a 1290 infinity binary pump, thermostat, autosampler, and diode array detector (Agilent, Mulgrave, AustraliaPreparative and semi-preparative HPLC were performed using an Agilent 1100 Series diode array and/or multiple wavelength detectors and an Agilent 1100 Series fraction collector (Agilent, Mulgrave, Australia). *N*α-(2,4-dinitro-5-fluorophenyl)-L-alaninamide (L-FDAA, synonym 1-fluoro-2-4-dinitrophenyl-5-L-alanine amide) and *N*α-(2,4-dinitro-5-fluorophenyl)-D-alaninamide (D-FDAA, synonym 1-fluoro-2- 4-dinitrophenyl-5-D-alanine amide) were purchased from Merck (Darmstadt, Germany). Amino acids and standards were purchased from BAChem (Torrance, CA, USA) or Merck (Darmstadt, Germany). Analytical-grade solvents were used for solvent extractions. Chromatography solvents were of HPLC grade supplied by Labscan (Bangkok, Thailand) or Merck (Darmstadt, Germany) and filtered/degassed through 0.45 μm polytetrafluoroethylene (PTFE) membrane prior to use. Deuterated solvents were purchased from Cambridge Isotopes (Tewksbury, MA, USA). Microorganisms were manipulated under sterile conditions using a Laftech class II biological safety cabinet and incubated in either MMM Friocell incubators (Lomb Scientific, Taren Point, NSW, Australia) or an Innova 42R incubator shaker (John Morris, Chatswood, NSW, Australia).
