Diastereoselective metabolism of a novel cis ...

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mm, Daicel Chiral Technologies Co., Ltd., Tokyo, Japan). The isocratic elution was conducted with HPLC pure ethanol (Tedia Company Inc., Cincinnati, Ohio, ...
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Diastereoselective metabolism of a novel cis-nitromethylene neonicotinoid paichongding in aerobic soils

Qiuguo Fu,† Jianbo Zhang,† Xiaoyong Xu,§ Haiyan Wang,† Wei Wang,† Qingfu Ye,†,* Zhong Li§,* † Institute of Nuclear Agricultural Sciences, Zhejiang University, Hangzhou, 310029, China § School of Pharmacy, East China University of Science and Technology, Shanghai, 200237, China

*

Corresponding to: Qingfu Ye Institute of Nuclear Agricultural Sciences, Zhejiang University, Kaixuan Road No. 268, Hangzhou, 310029, Zhejiang Province, China. Tel: +86 571 86971423; Fax: +86 571 86971423 E-mail: [email protected] Zhong Li School of Pharmacy, East China University of Science and Technology, 130 Meilong Road, Shanghai 200237, China Tel: +86-21-64253540; Fax: +86-21-64252603 E-mail: [email protected] S1

Text S1 Separation of the four stereoisomers of paichongding Preparative High Performance Liquid Chromatography (HPLC) condition: HPLC K-Prep LAB100S with a Daicel Chiralpak IC column (5-μm, 250 mm × 30 mm, Daicel Chiral Technologies Co., Ltd., Tokyo, Japan). The isocratic elution was conducted with HPLC pure ethanol (Tedia Company Inc., Cincinnati, Ohio, USA) at a flow rate of 20 mL/min and a column temperature of 35 ± 1 °C, with detection at a wavelength of 325 nm. This method was used to manually collect fractions of the pure stereoisomers.

Text S2 The enantiomeric purity, chemical purity, radiochemical purity and specific activity analysis of individual stereoisomer The enantiomeric purity of each

14

C-stereoisomer was analyzed by chiral HPLC

analysis using Shimadzu LC-20AT (Tokyo, Japan) equipped with two LC-20AT solvent delivery modules, a DGU-20A3 online degasser, a CBM-20Alite system controller, a UV detector SPD-20A,and a Daicel Chiralpak IC column (5-μm, 0.46 cm × 15 cm, Daicel Chiral Technologies Co., Ltd., Tokyo, Japan). An advanced laser polarimeter (ALP) on-line optical rotation detector (PDR Chemical Inc., Colquitt, GA, USA) was connected to the UV detector to identify the elution order of

14

C-IPP

stereoisomers. HPLC pure ethanol (Tedia Company Inc., Cincinnati, Ohio, USA) was used for elution. The elution program was isocratic, and the flow rate was set at 0.8mL/min. The concentration of each stereoisomer was 10 ppm. The injection

S2

volume was 5 µL and the column temperature was maintained to 35 ± 1 ° C. Chromatographic data were acquired and processed with the computer-based LC-solution software (Shimadzu, Tokyo, Japan). The absolute configuration of the four individual 14C-stereoisomers was determined by comparing the optical rotations with the corresponding non-labeled stereoisomer standards. The chemical purity, radiochemical purity, and specific activity of individual 14

C-stereoisomers analysis was achieved on a Waters HPLC system equipped with a

Waters 2695 multi-solvent delivery unit, a Waters 2998 photodiode array (PDA) detector (Waters corp, MA, USA) at 254 nm and 325 nm, a Diamonsil C18 column (5-μm, 250×4.6 mm, Dikma Technologies Inc., CA, USA) and a C18 guard column (5-μm, 30×4.6 mm, Dikma Technologies Inc., CA, USA). The column temperature was maintained at 30 ± 1 °C. The elution was conducted using an isocratic program with mobile phase acetonitrile/water (65/35, v/v) at a flow rate of 1.0 mL min-1. The Chromatographic data were acquired and processed with Empower 5 (Waters Corp., MA, USA) to determine the chemical purity. The post-column eluent was collected in aliquots of 1.0-ml intervals into 20-ml glass scintillation vials with a Waters Faction Collector II (Waters Corp., MA, USA). The radioactivity of the eluent was measured using a Liquid Scintillation Counter (LSC) (Wallac WinSpectral-1414, PerkinElmer Inc., Turku, Finland) to determine the radiochemical purity and specific activity. Text S3 The description of the recovery of the extraction method Six replicates of soil samples (10.0 g, dry weight equivalently) were added 100-μl stock solution (0.2% acetonitrile in distilled water) contained a total radioactivity of S3

21900±39 Bq 14C-paichongding and malaxation as described in the section Incubation Experiment and immediately the soil samples were consecutively extracted three times from 50 ml 0.01 M CaCl2 to acetonitrile/water (9:1, v/v), methanol, and finally dichloromethane as described in the section Soil Sampling, Extraction and Pretreatment. At the same time, six replicates of soil samples (10.0 g, dry weight equivalently) were added 100-μl stock solution (0.2% acetonitrile in distilled water) contained no paichongding as the control. The extraction process was described above. 1-ml of each extraction phase was added into 10-ml scintillation cocktail A and measured the radioactivity. The recoveries were calculated as followed. Radioactivity of each phase was calculated as followed: Radioactivity = [radioactivity of 1-ml solution (dpm)] x [extraction volume (ml)] Recovery (%) = [the sum of the radioactivity of four extraction phases (dpm)] / [the total applied radioactivity (dpm)] x 100% Text S4 The degradation of the parent compound of paichongding (IPP) was fitted to modified bi-exponential model: M  M 1 e k1 t  M 2 e k 2 t M = Total amount of chemical present at time t M1 = Amount of chemical degraded in initial rapid phase of degradation M2 = Amount of chemical degraded in followed slower phase of degradation k1 = Rate constant in rapid phase k2 = Rate constant in slow phase

The DT50 and other degradation parameters was showed in Table S1

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Table S1 the parameters of the fitting curve of the parent compound in different soils

Soil type

Isomer type

R-Square

DT50

SSE

RMSE

RR

0.9965

15.9228

29.28

2.42

SS

0.9879

12.0584

98.44

4.437

SR

0.9997

1.3327

2.121

0.6513

RS

0.9995

1.4187

3.46

0.8318

RR

0.9999

1.0992

0.153

0.1749

SS

0.9998

1.2650

1.271

0.5042

SR

0.9999

0.7354

0.01853

0.06088

RS

0.9999

0.8457

0.06117

0.1106

RR

0.9923

12.6280

42.55

2.917

Coastal saline

SS

0.9835

12.2008

95.49

4.37

soil

SR

0.9998

0.8712

1.657

0.5757

RS

0.9998

0.8812

1.399

0.529

Fluvio-marine yellow loamy soil

Red clay soil

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Take M4 for example, the cleavage of M4 and the daughter ions of m/z 351 was proposed in Figure S1

Figure S1 Deduction of intermediate M4

S6