Dietary supplement for energy and reduced appetite containing the β-agonist isopropyloctopamine leads to heart problems and hospitalisations

Figures & data

Table 1. MS/MS parameters for N-isopropyloctopamine.

Q1 mass	Q3 mass	DP (V)	CE (V)
196.1	91.1	41	39
196.1	41	41	67
196.1	39	41	89

Note: Quantification was performed by external standard calibration.

Figure 1. (colour online) Principal and schematic presentation of the multiplex bead-based β-agonist assay.

Table 2. Results of initial targeted chemical analysis by LC-MS/MS for plant toxins and selected stimulants.

Compound (mg kg^–1)	Sample 1	Sample 2	Sample 3
Ajmalicine	2.1	4	35
Caffeine	Present	Present	Present
Reserpine	0.11	0.19	0.86
Rescinnamine	0.056	0.091	1.2
Yohimbine	n.a.	81	970
Corynanthine/rauwolscine	400	350	990
Synephrine	1900	4400	9000
DMAA	n.a.	0.16	Trace

Note: n.a., Not analysed; caffeine was present at high levels but not quantified.

Figure 2. Controls and the three batches of the supplement as tested in the competitive radioligand β2-adrenergic receptor binding assay.

Table 3. Results of controls and the three batches of the supplement as tested in the clenbuterol and salbutamol ELISAs.

Sample	Clenbuterol ELISA			Salbutamol ELISA
	Mean OD at 450 nm	SD	%CV	Mean OD at 450 nm	SD	%CV
Blank	1.33	0.12	9.4	0.58	0.01	1.7
Blank + 0.25 µg kg^–1 clenbuterol	0.63	0.01	1.1	0.36	0.03	7.8
Blank + 0.25 µg kg^–1 salbutamol	1.12	0.01	1.3	0.43	0.01	3.3
Batch 1	0.04	0.01	21.3	0.06	0.01	11.4
Batch 2	0.05	0.01	17.1	0.05	0.01	19.8
Batch 3	0.06	0.01	11.0	0.08	0.01	7.4
Batch 1 diluted 10×	0.02	0	23.0	0.01	0.01	55.3
Batch 2 diluted 10×	0.03	0	5.4	0.01	0.01	67.6
Batch 3 diluted 10×	0.03	0	13.3	0.01	0.01	17.7
Batch 1 diluted 100×	0.14	0	0.5	0.04	0	0.0
Batch 2 diluted 100×	0.14	0.01	4.4	0.03	0	0.0
Batch 3 diluted 100×	0.15	0.01	6.2	0.04	0.01	7.9

Figure 3. Results (% B/B0) of a β-agonist mixture (1–4), a chemical blank (5) and sample extracts of three batches of the supplement causing hart problems (6–8) tested in a newly developed multiplex bead-based β-agonist assay.

Figure 4. Experimental (top) and simulated (bottom) profile mass spectrum of C₁₁H₁₇NO₂ + H+ (resolving power 50 000 full width at half maximum). The zoomed-in detail on the right shows the ¹⁵N¹³C isotope cluster (¹⁵N being the shoulder on the left-hand side of the mass peak). Relative abundance of the isotopes are indicated in the boxes.

Figure 5. Controls, IPO standards (Deterenol) and the three batches of the supplement as tested in the competitive radioligand β2-adrenergic receptor binding assay.

Figure 6. Response of standard series of clenbuterol (clen) in the ‘clenbuterol’ ELISA (left y-axis) and of salbutamol (salb) and IPO in the ‘salbutamol’ ELISA (right y-axis).

Figure 7. Results (% B/B0) of N-isopropyloctopamine (IPO) tested in a newly developed multiplex bead-based β-agonist assay for screening feed and food samples.