Md 2015

The identification and quantification of carotenoids were conducted according to the methods described by Ma et al. [11 ]. Pigments were extracted from the samples using a hexane:acetone:ethanol (2:1:1 [v/v]) solution containing 0.1 % (w/v) 2,6-di-tert-butyl-4-methylphenol and 10 % (w/v) magnesium carbonate basic. After the organic solvents had been completely evaporated, the extracts containing carotenoids esterified to fatty acids were saponified with 20 % (w/v) methanolic KOH. Water-soluble extracts were then removed by adding NaCl-saturated water. The pigments repartitioned into the diethylether phase were recovered and evaporated to dryness. Subsequently, the residue was redissolved in 5 mL of a TBME: methanol (1:1 [v/v]) solution. An aliquot (20 μL) was separated by a reverse-phase HPLC system (Jasco, Tokyo, Japan) fitted with a YMC Carotenoid S-5 column of 250- × 4.6-mm-i.d. (Waters, Milford, MA) at a flow rate of 1 mL min⁻¹. The eluent was monitored by a photodiode array detector (MD-2015, Jasco). The carotenoid concentration was estimated by the standard curves and expressed as milligrams per gram fresh weight [34 (link)]. Carotenoid quantification was performed in three replicates.

For synthetic protocols of β-galactosidase fluorescence probes, see the Supplementary Information. Preparative HPLC was performed on HPLC system composed of a pump (PU-2080, JASCO) and detector (MD-2015, JASCO), with an Inertsil ODS-4 (10.0 mm × 250 mm) column (GL Sciences, Inc.). NMR spectra were recorded on a JNM-LA300 instrument (JEOL) at 300 MHz for ¹H NMR and 75 MHz for ¹³C NMR. Mass spectra were measured with a JMS-T100LC AccuToF (JEOL).

NMR spectra were recorded on a JEOL JNM‐LA400 instrument at 400 MHz for ¹H NMR and at 100 MHz for ¹³C NMR. Mass spectra (MS) were measured with a JEOL JMS‐T100LC AccuToF (ESI). Preparative HPLC was performed on an Inertsil ODS‐3 (10.0 × 250 mm) column (GL Sciences Inc.) using an HPLC system composed of a pump (PU‐2080, JASCO) and a detector (MD‐2015 or FP‐2025, JASCO). LC‐MS analyses were performed on a Waters Acquity UPLC (H class)/QDa quadrupole MS analyzer or Acquity UPLC (H class)/Xevo TQD quadrupole MS/MS analyzer equipped with an Acquity UPLC BEH C18 column (Waters). Column chromatography using silica gel was performed on a MPLC system (Yamazen Smart Flash EPCLC AI‐5805 (Tokyo, Japan)). Reversed‐phase MPLC purification was performed on an Isolera One (Biotage) equipped with a SNAP Ultra C18 30 g (Biotage).