Pyrrolizidine alkaloids in Tussilago farfara from Bulgaria

Figures & data

Table 1. GC-MS data of established PAs.

Alkaloid	RRI	M^+ (%)	Characteristic ions (%)
Senecionine	2348	335(13)	246(20), 220(42),153(9), 136(100), 120(90), 109(27), 93(67), 80(32), 67(15), 53(21)
Seneciphylline	2369	333(5)	288(4), 246(11), 218(5), 167(4), 151(6), 136(67), 120(100), 108(17), 94(62), 80(30)
Integerrimine	2405	335(4)	291(14), 248(15), 220(19), 138(50), 136(86), 120(100), 93(89), 80(33), 67(22)
Senkirkine	2543	365(3)	294(32), 266(47), 250(36), 222(24), 168(75), 151(100), 140(25), 123(63), 110(94), 96(47), 82(65)

Figure 1. Structure of pyrolizidine alkaloids (PAs) in Tussilago farfara. Senkirkine (A), Senecionine (B), Integerrimine (C) and Seneciphylline (D).

Table 2. Microscopic differentiation of the leaves of coltsfood (Tussilago farfara) and Petasites spp.

Species	Tussilago farfara	Petasites spp.
	Monotypic	Petasites hybridus
		Petasites albus
		Petasites kablikianus
Leaf's vegetation	Rosette leaves, after flowering stems shooting	Rosette leaves, after flowering stems shooting
Petiole (leaf stem)	Hollow narrowly winged, half oval, adaxial side flat	Hollow; 2-furrowed above (1) solid; rounded above (2 and 3)
Leaf	Bifacial	Bifacial
Upper epidermis	Polygonal with straight walls	Irregularly shaped with sinous walls
Indumentum/upper leaf surface	Upper surface glabrate due to age	Upper surface ± glabrate due to age
Palisade layer	Broad, three or four rows of cells	One or two rows of very short cells
Leaf mesophyll	Aerenchyma with very large spaces between narrow rows of cells	Aerenchyma, spaces (cavities) not as large as those in Tussilago (Figure 4)
Stomata	Anomocytic stomata (35 µm) long	Anomocytic stomata (30 µm) long
Lower epidermis	Lower epidermis is densely tomentose	Lower epidermis is densely tomentose
Trichomes	Base of few small cells, followed by one larger spherical cell and one extremely long, twisted and slightly thick-walled terminal cell	Base of few small cells, followed by one extremely long, twisted and slightly thick-walled terminal cell

Figure 2. Leaf morphology of Tussilago farfara. Leaf margin with red-brown teeth (A); upper leaf surface (B); lower leaf surface with indumentum (C); leaf base with petiole upper surface (D); and leaf base with petiole lower surface (E).

Figure 3. Transverse section of dried leaf. Tussilago farfara (A); Petasites hybridus (B).

Figure 4. Transverse section of dried leaf. Tussilago farfara; aerenchyma cavities.