Giuseppe Savona

Abietane diterpenoids from the root of Salvia phlomoides

Abstract From the root of Salvia phlomoides three new abietane diterpenoids, demethylcryptojaponol, 14-deoxycoleon U and salviphlomone, have been isolated, besides the previously known diterpenes 8,13-abietadiene, 8,11,13-abietatriene, royleanone, 7α-acetoxyroyleanone, taxodione, taxodone, cryptojaponol and sugiol. The structures of demethylcryptojaponol (11,12-dihydroxy-8,11,13-abietatrien-7-one), 14-deoxycoleon U (6,11,12-trihydroxy-5,8,11,13-abietatetraen-7-one) and salviphlomone (6α,7β-dihydroxy-8,13-abietadiene-11,12-dione) were established by chemical and spectroscopic means.

A chlorine-containing and two 17β-neo-clerodane diterpenoids from teucrium polium subsp. Vincentinum

Abstract From the aerial parts of Teucrium polium subsp. vincentinum three new neo-clerodane diterpenoids, teuvincentins A, B and C, have been isolated besides four already known diterpenes (19-acetylgnaphalin, eriocephalin, isoeriocephalin and 3-deacetyl-20- epi -teulanigin) and the flavones cirsiliol and apigenin. The structures of teuvincentin A [(12 S , 20 S )-20- O -acetyl-19-acetoxy-18-chloro-15,16-epoxy-4α,7-dihydroxy-6-oxo- neo -clerodane-7,13(16),14-triene-20,12-hemiacetal], B [12 S ,20 S )-20- O -acetyl-4α,18;15,16-diepoxy-6α-hydroxy-17β- neo -clerodane-13(16),14-diene-7α,19; 20,12-dihemiacetal] and C [12 S ,20 S )-20- O -acetyl-6α,19-diacetoxy-4α,18; 15,16-diepoxy-7-oxo-17β- neo -clerodane-13(16), 14-diene-20,12-hemiacetal] were established by chemical and spectroscopic means and, in the case of teuvincentins A and B, also confirmed by X-ray diffraction analyses of their acetyl derivatives.

Neo-clerodane diterpenoids from Scutellaria columnae

Abstract Three new neo-clerodane diterpenoids, scutecolumnins AC, have been isolated from the acetone extract of the aerial parts of Scutellaria columnae subsp. columnae . The structures of these substances were established by spectroscopic means and by comparison with closely related compounds.

Neo-clerodane diterpenoids from Scutellaria alpina subsp. javalambrensis

Abstract Three new neo-clerodane derivatives, scutalpins B–D, were isolated from the acetone extract of the aerial parts of Scutellaria alpina subsp. javalambrensis . The structures of these compounds were established mainly by spectroscopic means as (11 S )-11,19-diacetoxy-4α,18-epoxy-8β-hydroxy-6α-tigloyloxy-13-neo-cleroden-15,16-olide (scutalpin B), (11 S )-19-acetoxy-4α,18-epoxy-8β,11-dihydroxy-6α-tigloyloxy-13-neo-cleroden-l5,16-olide (scutalpin C) and (13 S )-11β,19-diacetoxy-4α,18;8β,13-diepoxy-6α-tigloyloxy-neo-clerodan-15,16-olide (scutalpin D).

Neo-clerodane diterpenoids from Teucrium lanigerum

Abstract From the aerial part of Teucrium lanigerum , six new neo-clerodane diterpenoids, 7,8-dehydroeriocephalin, teulanigeral, teulanigin, 20-epi-teulanigin, teulanigerin and teulanigeridin, have been isolated. The first of these, 7,8-dehydroeriocephalin, is a natural substance, whereas the other compounds were isolated as their acetyl derivatives after acetylation of an inseparable mixture of natural diterpenoids. The structures of these substances were established mainly by spectroscopic means and, in the case of 7,8-dehydroeriocephalin, by partial synthesis from eriocephalin.

Isoeriocephalin and 20-deacetyleriocephalin, Neoclerodane Diterpenoids from Teucrium lanigerum

Abstract From the aerial part of Teucrium lanigerum two new neo-clerodane diterpenoids, 20-deacetyleriocephalin and isoeriocephalin, have been isolated, together with the previously known diterpene eriocephalin. The structures of 20-deacetyleriocephalin [19-acetoxy 4α,18:15,16-diepoxy-7α-hydroxy-6-keto-neo-cleroda-13(16),14-diene-20 S ,12 S -hemiacetal] and isoeriocephalin [19-acetoxy-4α,18:15,16-diepoxy-6α-hydroxy-7-keto-neo-cleroda-13(16),14-diene (20-acetyl)-20 S ,12 S -hemiacetal] were established by chemical and spectroscopic means and by correlation with known compounds.

Neo-clerodane diterpenoids from Teucrium polium subsp. capitatum

Abstract From the aerial part of Teucrium polium subsp. capitatum three new neo-clerodane diterpenoids, 7-deacetylcapitatin, picropolinol and 20-epi-isoeriocephalin, have been isolated, together with the previously known diterpenes picropolin, picropolinone, 19-acetylgnaphalin and teucjaponin B. The structures of 7-deacetylcapitatin [19-acetoxy-4α,18:15,16-diepoxy-7α-hydroxy-6-keto-neo-cleroda-13(16),14-dien-20,12S-olide], picropolinol [18,19-diacetoxy-15,16-epoxy-4α,6α-dihydroxy-7-keto-neo-cleroda-13(16),14-dien-20,12S-olide] and 20-epi-isoeriocephalin [19-acetoxy-4α,18:15,16-diepoxy-6α-hydroxy-7-keto-neo-cleroda-13(16),14-diene-(20-O-acetyl)-20R,12S-hemiacetal] were established by chemical and spectroscopic means and, in the case of 7-deacetylcapitatin and picropolinol, by correlation with known compounds.

Teuscorodin, teuscorodonin and 2-hydroxyteuscorolide, neo-clerodane diterpenoids from teucrium scorodonia

Abstract From the aerial part of Teucrium scorodonia (Labiatae) three new neo-clerodane diterpenoids have been isolated. Their structures, (12 S )-15,16-epoxy-2α-hydroxy-19-nor-neo-clerodane-4,6,13(16),14-tetraene-18,6:20,12-diolide (2-hydroxyteuscorolide), (12 S ,18 R )-15,16-epoxy-6-keto-neo-clerodane-13(16),14-dien-20,12-olide-18,19-hemiacetal (teuscorodin) and (12 S )-15,16-epoxy-19-hydroxy-neo-clerodane-3,13(16),14-triene-18,6β:20,12-diolide (teuscorodonin), have been established by chemical and spectroscopic means and by correlation with known products.

Two C-10 oxygenated neo-clerodane diterpenoids from Teucrium pestalozzae

Abstract From the aerial parts of Teucrium pestalozzae two new neo -clerodane diterpenoids, teupestalins A and B, have been isolated. The structures of teupestalin A (4α,18;15,16-diepoxy-6β,10β-dihydroxy- neo -cleroda-13(16),14-dien-20, 12 S -olide-3α,19-hemiacetal) and teupestalin B (19-acetoxy-4α,18;15,16-diepoxy-6-oxo- neo -cleroda-13(16),14-dien-20, 12 S -olide-3β,10⊝hemiacetal) were established by spectroscopic means and, in the case of teupestalin A, also by an X-ray diffraction analysis. Teupestalins A and B are the first C-10 oxygenated neo -clerodane derivatives found in plants belonging to the genus Teucrium .

The correct structure of salvifaricin a cis neo-clerodane diterpenoid from Salvia farinacea

Abstract The structure and absolute configuration of salvifaricin, a neo-clerodane diterpenoid isolated from Salvia farinacea , have been firmly established by extensive NOE experiments and by chemical correlation with salvifarin, another diterpenoid isolated from the same source. These results slightly modify the structure previously assigned to the compound.