Table 1. Secreted beauverolides in the ex vivo culturing system.

[M+H]+	RT/min	n	AA2	AA3	AA4	beauverolide	fold change on brain	fold change on muscle
482.3261	13.99	3	Val	Lxx	Lxx	this study		L 4.6D ∞
488.2894	13.54	3	Ala	Phe	Lxx	this study	L 5.9
500.3652	13.62	3	Val	Met	Lxx	this study		L 4.4
510.3574	15.07	5	Val	Lxx	Lxx	this study		L 6.3
514.3808	13.93	3	Lxx	Met	Lxx	this study		L 6.2
516.3432	13.98	3	Val	Phe	Lxx	E		L 6.1
528.3965	14.5	5	Val	Met	Lxx	this study		L 6.2
530.3588	14.3	3	Lxx	Phe	Lxx	this study		L 6.2
532.3426	13.3	3	Val	Tyr	Lxx	this study	L 4.7
544.3745	15.01	5	Val	Phe	Lxx	B		L 7.7
558.3902	15.5	5	Lxx	Phe	Lxx	this study		L 8.8
560.3739	14	5	Val	Tyr	Lxx	this study
564.3872	14.24	3	Phe	Phe	Lxx	F
576.4405	14.74	5	Phe	Met	Lxx	this study
580.3866	13.54	3	Tyr	Phe	Lxx	this study		L 4.4
592.4073	15.4	5	Phe	Phe	Lxx	C		L 9.9
603.4239	14.02	3	Trp	Phe	Lxx	J		L 6.8
608.4067	14.28	5	Tyr	Phe	Lxx	this study
615.466	14.58	5	Trp	Met	Lxx	this study		L 8.2
631.444	14.99	5	Trp	Phe	Lxx	K		L 8.7

For each identified beauverolide the accurate mass of the protonated molecular ion, retention time, n, and the identities of the amino acids at positions 2–4 are given (Figure 4a). The ones discovered in other studies are indicated by the letter assigned to them. The fold changes on brain and muscle indicate the tissue specificity of beauverolides. All of them are heterogeneously secreted on live tissues (indicated by L), while one is uniquely secreted on dead muscle tissue as well (indicated by D). The beauverolides mentioned in gray were identified in our raw data set but were not of enough abundance to be used in the further data analysis.