From Plant to Patient: Thapsigargin, a Tool for Understanding …
67
of either thapsanes or polyoxygenated guaianolides is dependent on the number of
chromosomes [41]. A new taxonomic investigation based on sequences of the nuclear
ribosomal internal transcribed spacer (nrITS) region led to a suggestion that the genus
Thapsia should be divided into 14 species: T. asclepium, T. garganica, T. gummifera,
T. gymnesica, T. laciniata, T. leucotricha, T. maxima, T. minor, T. scabra, T. smittii, T.
tenuifolia, T. thapsioides, T. transtagana, and T. villosa [42]. This taxonomic revision
of Thapsia is generally well accepted and supported. However, the full resolution of
this genus and its sister genera is still ongoing.
5 Phytochemistry of Thapsia garganica
5.1 Transtaganolides and Basiliolides from Species
Belonging to Thapsia
Besides thapsigargin (1), several SERCA-inhibitory transtaganolides have been
isolated from plants belonging to the genus Thapsia (Fig. 5, compounds 35a–35d,
36a, and 36b) [47, 48]. In the first report [47] compounds 35a and 35b isolated
from T. transtagana were named transtaganolides C and D, and compounds 36a and
36b transtaganolides A and B. In a second report [48], the compounds 35a–35d as
isolated from T. garganica were named basiliolides A1, A2, C, and D.
The basiliolides were claimed to be SERCA inhibitors because of their ability to
drain endoplasmic reticulum Ca
2+ from sea urchin eggs [48] and from Jurkat cells
[49]. These compounds, however, are, unlike thapsigargin (1) [50], unable to provoke
apoptosis after 18 h incubation with Jurkat cells [48], and they have never been tested
Fig. 5 Basiliolides 35a–35d
and transtaganolides 36a and
36b
O
O
O
O
O
35a R = CH 3 ,
C-8: α-CH 3 , β-vinyl (basiliolide A1)
35b R = CH 3 ,
C-8: α-vinyl, β-CH 3 (basiliolide A2)
35c R = COOCH 3 , C-8: α-CH 3 , β-vinyl (basiliolide B)
35d R = CH 2 OOAc, C-8: α-CH 3 , β-vinyl (basiliolide C)
O
O
O
O
O
O
36a C-8: α-CH 3 , β-vinyl (transtaganolide A)
36b C-8: β-CH 3 , α-vinyl (transtaganolide B)
8
R
67
of either thapsanes or polyoxygenated guaianolides is dependent on the number of
chromosomes [41]. A new taxonomic investigation based on sequences of the nuclear
ribosomal internal transcribed spacer (nrITS) region led to a suggestion that the genus
Thapsia should be divided into 14 species: T. asclepium, T. garganica, T. gummifera,
T. gymnesica, T. laciniata, T. leucotricha, T. maxima, T. minor, T. scabra, T. smittii, T.
tenuifolia, T. thapsioides, T. transtagana, and T. villosa [42]. This taxonomic revision
of Thapsia is generally well accepted and supported. However, the full resolution of
this genus and its sister genera is still ongoing.
5 Phytochemistry of Thapsia garganica
5.1 Transtaganolides and Basiliolides from Species
Belonging to Thapsia
Besides thapsigargin (1), several SERCA-inhibitory transtaganolides have been
isolated from plants belonging to the genus Thapsia (Fig. 5, compounds 35a–35d,
36a, and 36b) [47, 48]. In the first report [47] compounds 35a and 35b isolated
from T. transtagana were named transtaganolides C and D, and compounds 36a and
36b transtaganolides A and B. In a second report [48], the compounds 35a–35d as
isolated from T. garganica were named basiliolides A1, A2, C, and D.
The basiliolides were claimed to be SERCA inhibitors because of their ability to
drain endoplasmic reticulum Ca
2+ from sea urchin eggs [48] and from Jurkat cells
[49]. These compounds, however, are, unlike thapsigargin (1) [50], unable to provoke
apoptosis after 18 h incubation with Jurkat cells [48], and they have never been tested
Fig. 5 Basiliolides 35a–35d
and transtaganolides 36a and
36b
O
O
O
O
O
35a R = CH 3 ,
C-8: α-CH 3 , β-vinyl (basiliolide A1)
35b R = CH 3 ,
C-8: α-vinyl, β-CH 3 (basiliolide A2)
35c R = COOCH 3 , C-8: α-CH 3 , β-vinyl (basiliolide B)
35d R = CH 2 OOAc, C-8: α-CH 3 , β-vinyl (basiliolide C)
O
O
O
O
O
O
36a C-8: α-CH 3 , β-vinyl (transtaganolide A)
36b C-8: β-CH 3 , α-vinyl (transtaganolide B)
8
R