Neo-clerodane diterpenoids from Teucrium salviastrum

From the aerial parts of Teucrium salviastrum six new neo-clerodane diterpenoids, teusalvins A–F, have been isolated, together with the previously known diterpenes teucvidin teucroxide. The structures of teusalvins A [15,16-epoxy-2,6-diketo-neo- cleroda-13(16),14-dien-20,12S-olide-18R19-hemiacetal], B [15,16-epoxy-2β-hydroxy-6-keto-neo-cleroda-13(16),14-dien-20,12S-olide-18R,19-hemiacetal], C [15,16-epoxy-6β,18,19-trihydroxy-neo-cleroda- 3,13(16),14-trien-20,12R-olide], D [15,16-epoxy-2β,6β,18,19-tetrahydroxy-neo-cleroda-3,13(16),14-trien-20,12S-olide], E [15,16-epoxy-2β,6β,12S,18-tetrahydroxy-neo-cleroda-3,13(16),14-trien-20,19-olide] and F [15,16; 19,2α-diepoxy-6β,8-dihydroxy-neo-cleroda-3,13(16),14-trien-20,12S-olide] were established mainly by spectroscopic means and, in the case of teusalvin F, by X-ray diffraction.     

Teugin,a neo-clerodane diterpenoid from Teucrium fragile

From the aerial part of Teucrium fragile a new neo-clerodane diterpenoid, teugin, has been isolated. Its structure, 15,16-epoxy- 2β,6β-dihydroxy-neo-cleroda-3,13(16),14-triene-18,19:20,12S-diolide, was established mainly by spectroscopic means.     

Neo-clerodane diterpenoids from Teucrium chamaedrys: The identity of teucrin B with dihydroteugin

The previously proposed structure for teucrin B [15,16-epoxy -1,7-dihydroxy-cleroda-13(16),14-diene- 18,19:20,12-diolide] must be amended to 15,16-epoxy-2β,6β-dihydroxy-neo-cleroda-13(16), 14-diene-18,19:20,12S-diolide, which corresponds to the structure that has been established for dihydroteugin.     

Neo-clerodane-type diterpenoids from Salvia keerlii

From the aerial parts of Salvia keerlii two new neo-clerodane diterpenoids have been isolated. Their structures: 8,12(R)epoxyneo-cleroda-3,13(14)-diene-18,19:15,16-diolide, kerlin and 7-acetoxy-12(R)hydroxyneoclerodane-3,13(14)-diene-18,19:15,16-diolide, kerlinolide, have been established by spectroscopic means. X-ray diffraction analysis was performed for kerlin.     

Dihydroteugin,a neo-clerodane diterpenoid from Teucrium chamaedrys

From the aerial part of Teucrium chamaedrys a new neo-clerodane diterpenoid, dihydroteugin, has been isolated, besides the previously known diterpenoids teucrin A and teugin. The structure of dihydroteugin, (12S)-15,16-epoxy-2β,6β-dihydroxy-neo-cleroda-13(16), 14-diene-18,19:20,12-diolide, was established by chemical and spectroscopic means and by partial synthesis from teugin.     

A neo-clerodane glucoside and neo-clerodane diterpenoids from Teucrium flavum subsp. Glaucum

From the aerial part of Teucrium flavum subsp. glaucum a new neo-clerodane diterpenoid, teuflavin, and a new 19-nor-neo-clerodane glucoside, teuflavoside, have been isolated, besides the previously known diterpene teuflin. The structures of teuflavin (19-acetoxy-4α,18:15,16-diepoxy-6β-hydroxy-3-keto-neo-cleroda-13(16),14-diene-20,ξ,12S-hemiacetal) and teuflavoside (18-acetoxy-15,16-epoxy-19-nor-neo-cleroda-4,13(16),14-trien-20,12S-olid-6β-yl-2′-O-acetyl-β-d-glucopyranoside) were established by chemical and spectroscopic means and by correlation with known compounds. In addition, the previously known flavone salvigenin has also been obtained from the same source.     

Neo-clerodane diterpenoids from Teucrium massiliense

From the aerial part of Teucrium massiliense three new neo-clerodane diterpenoids, deacetylajugarin-II, teumassilin and 6,19-diacetylteumassilin, have been isolated, besides the previously known diterpenes montanin C and teucjaponin A. The structures of deacetylajugarin-II (4α,18-epoxy-6α,19-dihydroxy-neo-clerodan-13-en-15,16-olide), teumassilin (4α,18:15,16-diepoxy-6α,12S,19-trihydroxy-neo-cleroda-13(16),14-diene) and 6,19-diacetylteumassilin (6α,19-diacetoxy-4α,18:15,16-diepoxy-12S-hydroxy-neo-cleroda-13(16),14-diene) were established by chemical and spectroscopic means. In addition, the previously known flavones salvigenin and cirsimaritin have also been obtained from the same source.     

neo-Clerodane diterpenoids from Baccharis flabellata

Three diterpenoid derivatives were isolated from the acetone extract of Baccharis flabellata. Their structures were elucidated as 2,19;15,16-diepoxy-neo-clerodan-3,13(16),14-trien-18-oic acid, 15,16-epoxy-5,10-seco-clerodan-1(10),2,4,13(16),14-pentaen-18,19-olide and 15,16-epoxy-neo-clerodan-1,3,13(16),14-tetraen-18,19-olide through spectroscopic analyses.     

Humirianthenolides,new degraded diterpenoids from Humirianthera rupestris

The tuber of Humirianthera rupestris (Icacinaceae) contains the degraded diterpenoids 3β,20-epoxy-30α- hydroxy- 14-oxo-9β-podocarpan-19,6β-olide (humirianthenolide A), 3β,20-epoxy-3α,14α-dihydroxy-9β-podocarpan-19,6β- olide (humirianthenolide B), 3β,20; 16,14-diepoxy-3α-hydroxy-17-nor-15-oxo-9β-abiet-13-en-19,6β-olide (humirianthenolide C), 3β,20-epoxy-3α,14-dihydroxy-13-oxo-9β-podocarp-8(14)-en-19,6β-olide (humirianthenolide D), 3β,20-epoxy-3α-hidroxy-14-oxo-8α,9β-podocarpan-19,6β-olide (humirianthenolide E) and 3β,20-epoxy-3α,14β- dihydroxy-8α,9β-podocarpan-19,6β-olide (humirianthenolide F). ¹H NMR and ¹³C NMR spectroscopy were efrective for the determination of the humirianthenolide structures.     

Antibacterial clerodane diterpenes from Goldenrod (Solidago virgaurea)

Nine clerodane diterpenes, solidagoic acids C-I (1-7), cleroda-3,13(14)-dien-16,15:18,19-diolide (8) and cleroda-3,13(14)-dien-15,16:18,19-diolide (9) were isolated and characterised from the ethanol-ethyl acetate (1:1) extract of Solidago virgaurea. The structures were determined by NMR spectroscopic analysis. Several displayed moderate antibacterial activity against Staphylococcus aureus.     

Epoxysalviacoccina,neo-clerodane diterpenoid from Salvia plebeia

A new neo-clerodane derivative, epoxysalviacoccin, has been isolated from the aerial part of Salvia plebeia, together with the previously known diterpenoid salviacoccin. The structure of epoxysalviacoccin, 2β,3β; 15,16-diepoxy-10β-hydroxy-neo-cleroda-7,13(16),14-triene-17,12R; 18,19-diolide, has been established by spectroscopic means and by partial synthesis from salviacoccin.     

Neo-clerodane diterpenoids from Teucrium pyrenaicum and T. subspinosum

From the aerial parts of teucrium pyrenaicum two new neo-clerodane diterpenoids, teupyrins A and B, have been isolated. The structures of teupyrin A [3β,12S-diacetoxy-4α,18; 15,16-diepoxy-6-keto-neo-cleroda-13(16),14-diene-20R,19-hemiacetal] and teupyrin B [6α-acetoxy-4α,18; 15,16-diepoxy-3β,12ξ,19-trihydroxy-neo-cleroda-13(16),14-diene] were established mainly by spectroscopic means and, in the case of teupyrin A, by X-ray diffraction analysis. The acetone extract of the aerial parts of T. subspinosum yielded four previously known neo-clerodane diterpenoids: teucvin, teuflin, teucrin H2 and 6α-hydroxyteuscordin.     

Teumarin a neo-clerodane diterpenoid from Teucrium marum

A new neo-clerodane diterpenoid, teumarin, was isolated from the aerial part of Teucrium marum. Its structure, 19-acetoxy-4α,18:15,16-diepoxy-2β,6β-dihydroxy-neo-cleroda-13(16),14-dien-20,12S-olide, was established by chemical and spectroscopic means and by comparison with closely related compounds.     

New neutral diterpenes from southern pine tall oil

Five new diterpene natural products isolated from southern pine (Pinus spp.) tall oil were characterized as 8(14),15-pimaradiene-3β,18-diol, 19-hydroxy-15,16-dinorlabd-8(17)-en-13-one, 8,13β-epoxy-14-labden-6α-ol, 8,11, 13-abietatriene-15,18-diol and 9,10-secoabieta-8,11,13-trien-18,10-olide.     

2β-hydroxyteucvidin from teucrium webbianum

A new 19-nor-neo-clerodane diterpenoid, 2β-hydroxyteucvidin, has been isolated from the aerial parts of Teucrium webbianum, besides the previously known diterpenoids teuflidin and teucrin A. The structure of 2β- hydroxyteucvidin, (12S)-15,16-epoxy-2β-hydroxy-19-nor-10α-neo-clerodane-4,13(16),14-triene-18,6β;20,12-diolide, was established mainly by spectroscopic means.     

Isoeriocephalin and 20-deacetyleriocephalin,Neoclerodane Diterpenoids from Teucrium lanigerum

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-20S,12S-hemiacetal] and isoeriocephalin [19-acetoxy-4α,18:15,16-diepoxy-6α-hydroxy-7-keto-neo-cleroda-13(16),14-diene (20-acetyl)-20S,12S-hemiacetal] were established by chemical and spectroscopic means and by correlation with known compounds.     

2-Deoxychamaedroxide,a neo-clerodane diterpenoid from Teucrium divaricatum

A new neo-clerodane diterpenoid, 2-deoxychamaedroxide, has been isolated from the aerial parts of Teucrium divaricatum subsp. canescens. Also identified were the previously known diterpenoids teuflin, teucrin H₂, teuflidin, teucrins A, F and G, 6β-hydroxy-teuscordin, montanin D and dihydroteugin. The structure of 2-deoxychamaedroxide, (12S)-4β,6β; 15,16-diepoxy-neo-clerodane-13(16),14-diene-18,19; 20,12-diolide, was established mainly by spectroscopic means.     

Stereochemistry of strictic acid and related furano-diterpenes from conyza japonica and grangea maderaspatana

Extraction of Conyza japonica gave strictic acid, ent-2β-hydroxy-15,16-epoxy-3,13(16),14-clerodatrien-18-oic acid and 5,7-dihydroxy-3,8,4′-trimethoxyflavone. Extraction of Grangea maderaspatana gave (-)-hardwickiic acid, ent-15,16-epoxy-1,3,13(16),14-clerodatetraen-18-oic acid and 3-hydroxy-8-acetoxypentadeca-1,9,14-trien-4,6-diyne. The structure of ent-2β-hydroxy-15,16-epoxy-3,13(16),14-cleroclatrien-18-oic acid was deduced by spectroscopic methods and by partial synthesis from (-)-hardwickiic acid and the stereochemistries of strictic acid and (ent-15,16-epoxy-1,3,13(16),14-clerodatraen-18-oic acid were established by correlation with ent-2β-hydroxy-15,16-epoxy-3,13(16),14-clerodatrien-18-oic acid.     

2-keto-19-hydroxyteuscordin,a neo-clerodane diterpene from Teucrium scordium

From the aerial parts of Teucrium scordium a new neo-clerodane diterpenoid, 2-keto-19-hydroxyteuscordin, has been isolated, besides the previously known diterpenoids teucrin E and teucrin H4. The structure of 2-keto-19-hydroxyteuscordin, (12S)-15,16-epoxy-2-keto-19-hydroxy neo-clerodane-13(16),14-dien-18β,6β:20,12-diolide, was established by chemical and spectroscopic means.     

Glechomanolides and eudesmanolides from Smyrnium perfoliatum

In addition to five known sesquiterpenoids, six new compounds were isolated from Smyrnium perfoliatum. The new compounds were 1β-acetoxy-eudesma-3,7(11),8-trien-8,12-olide, 1β-acetoxyeudesma-4(15),7(11),8-trien-8,12-olide, 1β-10α;4α,5β-diepoxy-8β-isobutoxy-glechomanolide, 1β, 10α;4α,5β-diepoxy-8α-isobutoxy-glechomanolide, 1β,4α-dihydroxy-2α,3α-epoxy-eudesma-7(11),8-dien-8,12-olide, 1β,4α-dihydroxy-2α,3α-epoxy-8β-methoxy-eudesma-7(11)-en-8α,12-olide.