## 2 Materials and Methods
### Phytochemical Evaluation  
_L. flos-cuculi_ callus biomass (\(\sim\)100 mg) was pulverized using an MM 400 Mixer Mill (Retsch GmbH, Haan, Germany). Samples were prepared in Eppendorf tubes with 100% methanol and 100 mg/mL (Sigma-Aldrich, St. Louis, MO, USA) as an internal standard for UPLC-MS. After vortex mixing for 20 min and sonication for 15 min (Bandelin Sonorex, Bandelin Electronic GmbH and Co., Berlin, Germany), samples were centrifuged at 12,000 rpm for 10 min. The supernatant (\(\sim\)800 mL) was collected, vacuum-dried (Savant SC100 SpeedVac, Farmingdale, New York, NY, USA), and reconstituted in 1 mL of 0.1% formic acid in water solution. Following another 10 min sonication and 5 min centrifugation at 15,000 rpm, methanolic extraction of _L. flos-cuculi_ biomass was purified using Oasis HLB Cartridges (1 cc, 30 mg of solid phase, Waters Corp., Milford, MA, USA). Three biological replicates were analyzed.  
_E. planum_ and _K. elatine_ cell biomass were pulverized and then added to 0.1% Formononetin (Sigma-Aldrich, St. Louis, MO, USA) and 100% and 80% methanol, respectively. The mixtures were then vortexed for 15-20 min and sonicated at room temperature for 15 min. The samples were centrifuged at 15,000 rpm for 10 min, followed by filter-extraction using a Kinesis KX Syringe Filter PTFE 13 mm pore size 0.45 \(\upmu\)m (Kinesis Scientific Expert, [PERSON], St. Neots, UK). Three biological replicates were used in the analysis.  
Extracts were analyzed via Waters ACQUITY UPLC (Milford, CT, USA) coupled with a PDA detector and HRMS/MS (Qexactive, Thermo Fisher Scientific, Bremen, Germany). A 5 \(\upmu\)L of extract was separated on an Acquity BEH Shield column (2.1 \(\times\) 150 mm, 1.7 \(\upmu\)m, Waters, Milford, MA, USA) at 40 \({}^{\circ}\)C. A 0.1% of formic acid in water (A, LC-MS grade, Merck, Darmstadt, Germany) and acetonitrile (B, LC-MS grade, Merck) gradient was applied: 5-75% B (1-14 min), 75-99% B (14-16 min), 99% B isocratic (16-19 min), and 5% B re-equilibration (19-20 min) at a 400 \(\upmu\)L/minute flow rate. UV-Vis spectra were recorded at a wavelength of 250-550 nm and a scan rate of 20 Hz. The HESI-II operated at \(-\)3.5 kV in negative ion mode, with an ion transfer tube temperature of 350 \({}^{\circ}\)C. Nitrogen was used as a sheath, auxiliary, and sweep gas with flow rates of 35, 10, and 3 arbitrary units, respectively. An auxiliary gas temperature was set at 400 \({}^{\circ}\)C and an S-lens RF level of 50. Full MS scans (120-1800 \(m/z\)) were acquired at 70,000 FWHM with a 200 ms ion-trap time, while ddMS2 scans (TopN = 5) were collected at 17,500 FWHM with a 100 ms ion-trap time and 30% of normalized collision energy in the HCD cell.  
Putative annotation of selected peaks and the raw data from UPLC-HRMS/MS in negative ion mode were processed using MS-DIAL software (version 5.5) [31], with the following parameters. Data collection was performed with 0.01 Da and 0.025 Da tolerance for MS1 and MS2, respectively. Furthermore, the retention time was set from 2 to 17 min, MS1 ranging between 120 and 1800 Da, and a range of 50-2000 Da for MS/MS. Peak detection was applied with a minimum 10,000 amplitude and 0.1 Da mass slice width. Simple moving average level 5 and a minimum of 7 scans of peak width were set in the advanced settings. Deconvolution parameters were set with a value of 0.5 for the sigma window and an MS/MS abundance cutoff of 1 amplitude. Identification and annotation of the detected peaks were completed using ESI(-)-MS/MS from standards + bio + in silico and RIKEN PlaSMA bio-MS/MS from plant tissues from the MS-DIAL metabolomics MSP spectral kit. Alignment was performed with 0.2 min of retention tolerance and 0.015 Da of MS1 tolerance. Additionally, the 0.4 and 0.6 factors were set for retention time and MS1, respectively.