Table 1.

Overview of known isolated sesquiterpene lactones (SLs) from I. helenium root extracts to date.

Group	No.	Identified Compound(s)	Reference(s)
Eud-	1	Alantolactone	[94,95,96,97,98]
	2	Isoalantolactone	[99,100,101]
	3	Dihydroalantolactone	[102,103,104,105]
	4	Dihydroisoalantolactone	[102,103,104,105]
	5	Tetrahydroalantolactone	[106]
	6	Alloalantolactone (= 1-Deoxyivangustin, = (+)-Diplophyllin)	[107]
	7	Bialantolactone	[108]
	8	Trinoralantolactone	[108]
	9	5α-Epoxyalantolactone	[107]
	10	4-Noralantolactone (= 4-oxo-5(6),11-eudesmadiene-8,12-olide)	[109]
	11	4-Norisoalantolactone (= 4-oxo-11-eudesmene-8,12-olide)	[109]
	12	1α-Hydroxy-11,13-dihydroisoalantolactone	[110]
	13	3α-Hydroxy-11,13-dihydroalantolactone	[110]
	14	Macrophyllilactone E	[110]
	14	4α,15α-Epoxyisoalantolactone	[108]
	15	4,5-seco-Eudesm-11(13)-en-4,5-dioxo-8β,12-olide (=Umbellifolide)	[108]
	16	11α-Hydroxyeudesm-5-en-8β,12-olide	[108]
	17	3α-Hydroxyeudesma-4,11-dien-8β,12-olide	[108]
	18	Telekin	[108]
	19	3-Oxo-eudesma-4(5),11-dien-8,12-olide (= 3-Oxoalloalantolactone)	[111]
	20	11α,13-Dihydro-α-cyclocostunolide	[112]
	21	11α,13-Dihydro-β-cyclocostunolide	[112]
	22	15-Hydroxy-11βH-eudesm-4-en-8β,12-olide	[112]
	23	3α-Hydroxy-11βH-eudesm-5-en-8β,12-olide	[112]
	24	2β,11α-Dihydroxy-eudesm-5-en-8β,12-olide	[112]
	25	Isoheleproline	[113]
	26	11β-Hydroxy-13-chloro-eudesm-5-en-8β,12-olide	[7]
	27	5-epi-telekin	[7]
	28	Racemosalactone A	[7]
	29	Macrophyllilactone F	[74]
El-	30	Igala (= 1,3,11(13)-Elematrien-8β,12-olide)	[105]
Er-	31	Dugesialactone	[114]
Gua-	32	Dehydrocostus lactone	[112]
	33	4α-Hydroxy-1β-guaia-11(13),10(14)-dien-12,8α-olide	[111]
Ger-	34	Germacrene-D-lactone (= Germacra-1(10),4(15),5(6),11(13)-tetraen-8,12-olide)	[107]
	35	4β,5α-Epoxygermacra-1(10),11(13)-dien-12,8α-olide	[105]
	36	Isocostunolide	[79]
	37	(1(10)E)-5β-Hydroxygermacra-1(10),4(15),11(13)-trien-12,8α-olide	[109]
	38	14-Hydroxy-11β,13-dihydrocostunolide/ 11β, 13-Dihydro-14-hydrocostunolide	[8,112]
	39	Costunolide	[112]
	40	5β-Hydroxygermacra-1(10),4(15),11(13)-trien-12,8β-olide	[108]
	41	4α,5α-Epoxygermacra-1(10),11(13)-dien-12,8β-olide	[108]

Eud-: Eudesmanolides; El-: Elemanolides; Er-: Eremophilanolides; Gua-: Guaianolides; Ger-: Germacranolides.