**3. Materials and Methods**

#### *3.1. General Procedures*

Optical rotations were obtained on an Anton Paar MCP 200 polarimeter (Anton Paar Graz, Austria) in a 100 mm-long 350 μL cell using MeOH as the solvent at 20 ◦C. High resolution ESITOFMS

measurements were performed using a Waters ACQUITY UHPLC system coupled to a Waters Micromass LCT-Premier Time-of-Flight mass spectrometer equipped with electrospray interface (ESI) (Waters, Manchester, England). Nuclear magnetic resonance (NMR) data were recorded in CD3OD on Bruker 500 MHz and 600 MHz spectrometers equipped with a 1 mm inverse detection probe. Chemical shifts (*δ*) are reported in ppm based on the TMS signal, and coupling constant (*J*) is reported in Hertz (Bruker, Rheinstetten, Germany). Flash chromatography was performed on a Grace Reveleris system with UV and ELSD detectors using 120 g C18 or 80 g silica gel columns (Grace, Maryland, USA). HPLC analysis was conducted on a Gilson system equipped with a 322 pumping device, a GX-271 fraction collector, a 171 diode array detector, and a prepELSII detector electrospray nebulizer (Gilson Middelton, USA). Analytical analysis was conducted using Phenomenex Luna C18 (5 μm, 4.6 × 250 mm) and Phenomenex Kinetex C8 (5 μm, 4.6 × 250 mm) columns. A preparation analysis was conducted using Phenomenex Luna C18 (5 μm, 21.2 × 250 mm) and Kinetex C8 (5 μm, 21.2 × 250 mm) columns (Phenomenex, Le Pecq, France). All the chemicals were purchased from Sigma-Aldrich (Sigma-Aldrich chimie, Saint-Quentin-Fallavier, France).

#### *3.2. Collection and Identification of Pantoea sp. SNB-VECD14B*

An individual insect from the Diaspididae family that was infected by entomopathogenic microorganisms was collected in Montsinéry, French Guiana. The cuticle of the insect was scraped with a handle and transplanted onto a Petri dish containing a solid potato dextrose agar (PDA) medium and then stored at 28 ◦C. After one day, growing bacteria were removed and transferred onto another Petri dish. The strain SNB-VECD14B was stored in triplicate at −80 ◦C in a H2O–glycerol mixture (50:50). A sample was submitted for amplification of the nuclear ribosomal internal transcribed spacer region 16S, which allowed for identification after comparison to the NCBI sequence. The sequence was registered in the NCBI GenBank database with the accession number KX858894 and identified as *Pantoea* sp. A molecular analysis was performed externally by BACTUP, France.

#### *3.3. Culture, Extraction, and Isolation*

The bacteria strain was initially cultivated on a small scale using Petri dishes with Mueller Hinton (MH) solid medium and then on a large scale using 176 14 cm Petri dishes at 28 ◦C for 8 days. The culture medium containing the mycelium was cut into small pieces and macerated with ethyl acetate (EtOAc) at room temperature on a rotary shaker (70 rpm) for 48 h. The contents were extracted three times with 5 L of EtOAc using a separatory funnel. The combined organic layers were washed with water. The organic solvent was evaporated to dryness under reduced pressure to yield the crude extract (2.5 g). A portion of the crude extract (2.35 g) was fractionated by reversed-phase flash chromatography on a C18 column using a linear gradient of water—acetonitrile (*v*/*v*, 1:0 to 0:1 over 20 min, flow rate = 80 mL/min) followed by another gradient of acetonitrile—methylene chloride (v/v, 1:1 to 0:1 over 10 min, flow rate = 80 mL/min) to generate 8 fractions that were labeled A to H. The larvicidal and antimicrobial activities were concentrated in fractions E (60.5 mg), F (445.7 mg), G (898.7 mg) and H (108.4 mg).

Fraction E was fractionated by preparative HPLC using H2O–ACN (37:63 to 26:74 over 30 min, flow rate = 21 mL/min) to afford compound **1** (1.9 mg, tR = 20.40 min) and compound **2** (1.2 mg, tR = 24.10 min).

Fraction F was fractionated by preparative HPLC using H2O–ACN (33:67 to 17:83 over 30 min, flow rate = 21 mL/min) to afford compound **3** (10.3 mg, tR = 17.10 min).

Compound **1**: White powder; [*α*] 20 *<sup>D</sup>* + 29 (*c* 0.2, MeOH); 1H and 13C NMR spectroscopic data, see Table S1; HRESITOFMS *m/z* 392.2769 [M+H]+ (calculated for C23H38NO4 +, 392.2795). MSMS spectra were deposited at CCMSLIB00004684200.

Compound **2**: White powder; [*α*] 20 *<sup>D</sup>* +6(*c* 0.2, MeOH); 1H and 13C NMR spectroscopic data, see Table S2; HRESITOFMS *m/z* 418.2926 [M+H]+ (calculated for C25H40NO4 +, 418.2952). MSMS spectra were deposited at CCMSLIB00004684202.

Compound **3**: White powder; [*α*] 20 *<sup>D</sup>* + 12 (*c* 0.2, MeOH); 1H and 13C NMR spectroscopic data, see Table S3; HRESITOFMS *m/z* 402.3004 [M+H]+ (calculated for C25H40NO3 +, 402.3003). MSMS spectra were deposited at CCMSLIB00004684204.
