Table 2.

Lysergic acid-linked substituents of natural ergopeptines ^a.

Ergopeptine	AA1	R1	AA2	R2	AA3	R3
Ergotamine (ERA)	Ala	Me	Phe	CH2Ph	Pro	prolyl (CH2)3
Ergovaline (ERV)	Ala	Me	Val	i-Pr	Pro	prolyl (CH2)3
Ergosine	Ala	Me	Leu	i-Bu	Pro	prolyl (CH2)3
Dihydroergosine b	Ala	Me	Leu	i-Bu	Pro	prolyl (CH2)3
β-Ergosine	Ala	Me	Ile	sec-Bu	Pro	prolyl (CH2)3
Ergosedmine	Ile	sec-Bu	Leu	i-Bu	Pro	Prolyl (CH2)3
Ergobine	Ala	Me	ABA	Et	Pro	prolyl (CH2)3
Ergocristine	Val	i-Pr	Phe	CH2Ph	Pro	prolyl (CH2)3
Ergocornine	Val	i-Pr	Val	i-Pr	Pro	prolyl (CH2)3
Ergocryptine c,d (ERK)	Val	i-Pr	Leu	i-Bu	Pro	prolyl (CH2)3
β-Ergocryptine d	Val	i-Pr	Ile	sec-Bu	Pro	prolyl (CH2)3
γ-Ergocryptinine c,e	Val	i-Pr	norLeu	n-Bu	Pro	prolyl (CH2)3
Ergobutyrine	Val	i-Pr	ABA	Et	Pro	prolyl (CH2)3
Ergoladinine e	Val	i-Pr	Met	EtSCH3	Pro	prolyl (CH2)3
Ergogaline	Val	i-Pr	homoIle	2-Me- n-Bu	Pro	prolyl (CH2)3
Ergostine	ABA	Et	Phe	CH2Ph	Pro	prolyl (CH2)3
Ergonine	ABA	Et	Val	i-Pr	Pro	prolyl (CH2)3
Ergoptine c	ABA	Et	Leu	i-Bu	Pro	prolyl (CH2)3
β-ergoptine	ABA	Et	Ile	sec-Bu	Pro	prolyl (CH2)3
Ergobutine	ABA	Et	ABA	Et	Pro	prolyl (CH2)3
Ergobalansine (ERB)	Ala	Me	Leu	i-Bu	Ala	Me
Unnamed, from Dicyma sp.	Ala	Me	Leu	i-Bu	Phe	CH2Ph

^a Abbreviations: AA= amino acid position; ABA = 2-aminobutyric acid, norLeu = l-norleucine; homoIle = l-homoisoleucine. Other l-amino acids and R-groups are abbreviated as standard; ^b Dihydroergosine has a saturated D-ring, whereas others listed here have a 9-10 double bond; ^c Synonyms: ergosine = α-ergosine, ergocryptine = α-ergocryptine, ergoptine = α-ergoptine; ^d Synonyms: α-, β-, or γ-ergocryptine = α-, β-, or γ-ergokryptine, respectively; ^e Only the 8(R) (=isolysergyl) isomers—namely, ergoladinine and γ-ergocryptinine—have been reported to date.