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Supporting Information� Copyright Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, 2011
New Insight into Marine Alkaloid Metabolic Pathways: Revisiting OroidinBiosynthesis
Gr�gory Genta-Jouve,[a] Nadja Cachet,[a] Serge Holderith,[b] FranÅois Oberh�nsli,[c] Jean-Louis Teyssi�,[c]
Ross Jeffree,[c] Ali Al Mourabit,*[d] and Olivier P. Thomas*[a]
cbic_201100449_sm_miscellaneous_information.pdf
S2
General Information for the isolation and characterization processes
Analytical and semi‐preparative HPLC purification were carried out on a Waters 600 system equipped with a Waters 996 Photodiode Array detector and a Waters 717 plus Autosampler. A fraction collector Foxy 200 (Roucaire) was used for automated collection after semi‐preparative HPLC. NMR experiments were performed on a Bruker Avance 500 MHz spectrometer. Chemical shifts (δ in ppm) are referenced to residual proton (δH 3.31) signals of CD3OD, the solvent.
Isolation and characterization of oroidin (1).
The dried sponge (9.97 g) was cut into pieces of about 1 cm3 and extracted with MeOH/CH2Cl2 1:1 at room temperature yielding 3.17 g of crude extract after solvent evaporation. The crude extract was fractionated by RP‐C18 Vacuum Liquid Chromatography (elution with a decreasing polarity gradient of H2O/MeOH from 1:0 to 0:1, then MeOH/CH2Cl2 from 1:0 to 0:1). The H2O/MeOH 1:3 (0.41 g) was then subjected to RP‐C18 semi‐preparative HPLC (Waters, Symmetry C18, 300 × 7.8 mm, 7 µm) with a gradient of H2O/MeOH/TFA (flow 3.0 mL.min‐1, 75:25:0.1 to 25:75:0.1) to yield pure oroidin (1) (tr: 25.5; 67.2 mg).
2.62.83.03.23.43.63.84.04.24.44.64.85.05.25.45.65.86.06.26.46.66.87.07.27.4f1 (ppm)
-500
0
500
1000
1500
2000
2500
3000
3500
4000
4500
5000
5500
6000
Oroidin
4.04
4.05
6.07
6.10
6.11
6.12
6.28
6.31
6.72
6.84
NH
O
NH
N
NHNH2
Br
Br
1H NMR (500 MHz, CD3OD) spectrum of oroidin (1).
S3
Quantification of oroidin (1).
The quantification of oroidin (1) was performed by HPLC‐MS using an Agilent 1200 series HPLC coupled with 3200 QTRAP® LC/MS/MS AB Sciex Instrument. Injections were made on a Zorbax C18 (150 mm x 2.1 mm, 3.5 µm) column at 40 °C with a gradient mobile phase of H2O/MeOH/FA (flow 0.4 mL.min‐1, from 85:15:0.1 to 30:70:0.1 in 20 min).
HPLC‐MS traces of oroidin (1) standard
150 200 250 300 350 400 450 500 550 600 650 700 750 800 850m/z, Da
0.0
2.0e6
4.0e6
6.0e6
8.0e6
1.0e7
1.2e7
1.4e7
1.6e7
1.8e7
2.0e7
2.2e7
2.4e7
Inte
nsity
, cps
390.1
392.0
165.2 373.3 412.0299.6
S4
0.0 0.1 0.2 0.3 0.4 0.5 0.6
0
50
100
150
200
250
Aera
(mA
U)
Qty (mg)
Equation y = a + b*xAdj. R-Square 0.99965
Value Standard ErrorAera Intercept 0 --Aera Slope 373.53565 2.63098
Oroidin (1) calibration curve.
S6
Kinetics of proline and arginine incorporation
L‐[U‐14C]proline (9.95 GBq.mmol‐1, Amersham)
L‐[U‐14C]arginine (12.8 GBq.mmol‐1, Perkin Elmer)
A sample of the seawater (2 mL) present in the closed beaker was counted in a liquid scintillation analyzer (Tri‐Carb 2900TR, Perkin Elmer).
Color Wet weight Amino acid Added radioactivity % incorporation after 12 h Red 6.1 g
L‐ [U‐14C]arginine 44 kBq 90
Blue 6.9 g 52 kBq 97 Green 6.0 g
L‐[U‐14C]proline 44 kBq 98
Pink 8.8 g 66 kBq 94
S7
Autoradiography parameters:
Semi‐automatic sample application for qualitative and quantitative analyses was performed with ATS 4 (CAMAG). Chromatogram development was performed with the automatic developing chamber ADC 2 (CAMAG). Beta‐radioactivity thin layer analysis was performed by RadioTLC with Rita Star (Raytest) and autoradiography was performed with beta‐imager (Biospace Lab). For thin layer chromatography we used HPTLC plates (Silica gel 60 RP‐18 F254, Glass plates 20 x 10 cm, Merck) for RadioTLC and TLC plates (Silica gel RP‐18W/UV254, aluminum sheets 20 x 20 cm, Merck) for autoradiography.
Limit of detection (LOD) and limit of quantification (LOQ) by autoradiography
Autoradiography counting of the radioactivity associated to spots of 36 mm2 deposited on a HPTLC plate was quantified on 85.25 mm2 squares with 65 h of counting. The mean value of the background for
85.25 mm2 squares was measured as 0.314 cpm with 0.028 cpm of noise σ. We used statistical theory of hypothesis testing to define both detection limit (LOD) and quantification limit (LOQ)1. LOD and LOQ were then defined as:
3.29 0.092
.
Beta autoradiography detection efficiency
3.7 Bq of pure L‐[U‐14C]proline was deposited on a 36 mm2 square and 14C counting was measured by autoradiography on a 85.25 mm2 square containing the radioactive spot.
Deposited activity (Bq)
dpm cpm Corrected cpm Efficiency (%)
L‐[U‐14C]proline 3.7 216 27.7 27.4 12.7
1 1. Currie, L. A. Detection and quantification limits: basic concepts, international harmonization, and outstanding (“low‐level”) issues. Applied Radiation and Isotopes. 2004, Vol. 61, 61, pp. 145‐149.
S8
LOQ for the incorporation rate and isotopic ratio of oroidin (1)
The incorporation rate into oroidin (1) is given by:
% 100 ..
100 with 1.2 0.2
0.0225 0.00375 0.314
ww: sponge wet weight in g ; m in mg and in the formula aexp is measured in cpm
The LOQ of incorporation rate is:
. %
The isotopic ratio of oroidin (1) for a sponge of 1 g (wet weight) is given by:
1.2 0.2
45.10.314
sa: specific activity of the amino acid precursor in Bq.mmol‐1 and in the formula aexp is measured in cpm
The LOQ of isotopic ratio for a sponge of 1 g (wet weight) is:
.
S9
Metabolisation of L-[U-14C]proline into oroidin (1) after 3, 13 and 38 days
Each sponge individual (approximately 5 g ww) of Axinella damicornis was freeze‐dried and extracted 3 times by 20 mL of CH2Cl2/MeOH 1:1 in an ultrasonic bath. After addition of 1 g of C18 phase to the organic extract the solvents were removed under reduced pressure. Desalting was performed by reverse phase SPE (Strata C18‐E, 2 g, phenomenex). Elution of the SPE cartridge with H2O/MeOH 1:3 (20 mL) led to the desalted P‐2‐AI secondary metabolites.
For qualitative analyses: semi‐automatic sample application of the desalted extract was performed with ATS 4 and chromatogram development was performed with the automatic developing chamber ADC 2 on RP‐C18 HPTLC plates with H2O/MeOH/Formic Acid 2:8:0.4 as the eluent. Beta‐radioactivity thin layer analysis was performed by RadioTLC with 3 h of counting time.
For quantitative analysis: automated fractionation (1 tube.min‐1) of the desalted extract was performed by RP‐C18 semi‐preparative HPLC (Waters, Symmetry C18, 300 × 7.8 mm, 7 µm) with a gradient of H2O/MeOH/TFA (flow 3.0 mL.min‐1, 75:25:0.1 to 25:75:0.1). Evaporation of the fractions was undertaken with Speedvac (Thermo Electron Corporation, SPD 111‐V). Oroidin (1) was collected pure in fraction 28 and dissolved in MeOH to a final concentration of 1 mg.mL‐1 as checked by HPLC‐MS (see before). Semi‐automatic sample application of oroidin (1) (100 µg in 6 mm × 6 mm squares) was performed with ATS 4 on C18 TLC plates. Beta autoradiography with beta imager was used for quantitative detection with 65 h of counting time on squares of 85.25 mm2 centered on the deposited spot.
S10
Measured activity
(cpm) Incorporation
rate (%) Isotopic ratio (g‐1)
O3 0.55 5.4E‐03 O13 1.43 2.5E‐02 O38 2.29 4.4E‐02 9.0E‐09
L‐[U‐14C]proline (9.95 GBq.mmol‐1, Amersham)
S11
Metabolisation of L-[U-14C]arginine, L‐[1‐14C]ornithine hydrochloride, L-[U-14C]lysine and L‐[U‐14C]histidine into oroidin (1) after 13 days.
The same quantitative analytical protocol as above was used with 13 days of metabolization time, changing the amino acid precursor.
Measured Activity
(cpm) Incorporation rate
(%) Arginine 0,48 3.8E‐03 Ornithine 0,47 3.6E‐03 Lysine 1,70 3.1E‐02 Histidine 0,34 6.7E‐04
L‐[U‐14C]lysine (9.25 GBq.mmol‐1, Hartmann analytic)
L‐[U‐14C]histidine (12.5 GBq.mmol‐1, Amersham)
L‐[U‐14C]arginine (12.8 GBq.mmol‐1, Perkin Elmer)
L‐[1‐14C]ornithine hydrochloride (1.92 GBq.mmol‐1, Hartmann analytic)