Effects of ajugarins and related neoclerodane diterpenoids on feeding behaviour of Leptinotarsa decemlineata and Spodoptera exigua larvae

Three naturally occurring ajugarins and seven semisynthetic derivatives of them, possessing different functionalities in the decalin part, together with two natural furoneoclerodane diterpenes, have been assessed as feeding behavior modifying agents of larvae of the generalist Spodoptera exigua and a specialist like Leptinotarsa decemlineata. Ajugarin I and some of its derivatives exhibited a significant antifeedant activity against larvae of S. exigua in both choice and no-choice assays. Conversely, the furoneoclerodane diterpenes only presented antifeedant activity against larvae of L. decemlineata. These results indicate that the biological action of the tested substances is strongly mod…

Neoclerodane Diterpenoids from Teucrium massiliense

A reinvestigation of the diterpene metabolites of Teucrium massiliense L. allowed the isolation of four new neoclerodane derivatives, teumassilenins A-D, together with all the diterpenoids previously reported as constituents of this plant. The structures of the new compounds (1-4) were established by chemical and spectroscopic means. A plausible biogenetic relationship between several of these substances is briefly discussed, and some unpublished physical and spectroscopic data of the previously known diterpenoid teumassin (5) are now reported.

ChemInform Abstract: Photochemical Transformations of Some Neoclerodane and Labdane Diterpene Ketones.

Some neoclerodane (2–4) and labdane (5 and 6) diterpene ketones having a β- or γ-hydroxy function, an α-epoxy group, or an α-olefinic double bond have been irradiated at λ = 313 nm in dry solvents (benzene or methanol). Fruticolone (2) yielded the naturally occurring 5,6-seco-neoclerodan-6,1α-olide derivative fruticolide (1), while hispanolone (5) gave the δ-lactone 8, both transformations involving a Norrish type I photoreaction. The α,β-unsaturated ketone derivative 4 was transformed into 7 by a stereoselective intramolecular [2+2] cycloaddition reaction involving its furanic 13(16)-double bond. Finally, the α-epoxy ketone 6 was rearranged to the 10(98)abeo-labda-7,9-dione derivative 10. …

Synthetic studies of neoclerodane diterpenoids from Salvia splendens and evaluation of opioid receptor affinity

Abstract Salvinorin A ( 1 ), a neoclerodane diterpene from the hallucinogenic mint Salvia divinorum , is the only known non-nitrogenous and specific κ-opioid agonist. Several structural congeners of 1 isolated from Salvia splendens ( 2 – 8 ) together with a series of semisynthetic derivatives ( 9 – 24 ), some of which possess a pyrazoline structural moiety ( 9 , 19 – 22 ), have been tested for affinity at human μ, δ, and κ opioid receptors. None of these compounds showed high affinity binding to these receptors. However, 10 showed modest affinity for κ receptors suggesting that other natural neoclerodanes from different Salvia species may possess opioid affinity.

Clerodane diterpenoids from Salvia splendens.

Four new clerodane diterpenoids, salvisplendins A-D (1-4), have been isolated from an acetone extract of the flowers of SalVia splendens, together with an artifact (5), arising from salvisplendin D (4) by addition of diazomethane, and the already known clerodane olearin (6). The structures of the new compounds (1-5) were established mainly by 1D and 2D NMR spectroscopic studies and, in the case of salvisplendin A (1), by chemical correlation with splenolide B (7). Complete 1H and 13C NMR assignments for olearin (6), not published hitherto, are also reported.

Synthesis of permethylnarciprimine and permclhy tisonarciprimine

The C-12 and C-20 configurations of some neo-clerodane diterpenoids isolated from Teucrium species

Abstract A convenient and conclusive method for determining the C-12 stereochemistry of neo-clerodan-20,12-olide derivatives, even when only one epimer is available, is by 1H NMR NOE measurements. The C-12 configuration of 26 neo-clerodane diterpenoids isolated from Teucrium species has been re-examined by using this type of experiment. The results indicated that all the previous assignments were correct, except for teupyreinin, where the previously assigned C-12(S) configuration must be amended to C-12(R). This was confirmed by chemical transformations and additional 1H and 13C NMR studies. Furthermore, the NOE experiments allowed the assignment of a C-20(S) configuration for teuflavin, th…

Synthetic studies on neoclerodane diterpenes from Salvia splendens: oxidative modifications of ring A.

Salvinorin A (1), a neoclerodane diterpene from the hallucinogenic mint Salvia divinorum, is the only known naturally occurring non-nitrogenous and specific κ-opioid agonist. Some oxidative modifications of the A ring in the congeners of 1 isolated from Salvia splendens salviarin, splenolide B, splendidin and in the non-natural 8-epi-salviarin gave new derivatives, some of which were tested as agonists at opioid receptors. However, none of these compounds were active. The presence of the C-18, C-19 lactone could be at the origin of the observed lack of binding affinity.

Dammarane triterpenes of Salvia hierosolymitana

Abstract Salvilymitone and salvilymitol, two new triterpenoids isolated from Salvia hierosolymitana , have been shown to be 7β,25-dihydroxy-(20 S ,24 R )-epoxydammaran-3-one and (20 S ,24 R )-epoxydammaran-3β,7α,25-triol, respectively. The absolute stereochemistry of these triterpenoids has been established by an X-ray diffraction analysis of a 25,26,27-trinor derivative obtained by degradation of both compounds. In addition, four previously known triterpenoids were isolated from the same source.

Rearranged abietane diterpenoids from the root of two Teucrium species

Abstract From the root of Teucrium fruticans , two new rearranged abietane diterpenoids, teuvincenones F and G, have been isolated together with the known diterpene teuvincenone E. The acetone extract of the root of T. polium subsp. expansum yielded three previously known compounds (ferruginol and teuvincenones A and B) and two new 17(15 → 16)- abeo -abietane derivatives (teuvincenones H and I). The structures of the new diterpenoids [12,16-epoxy-11,14-dihydroxy-17(15 → 16), 18(4 → 3)- diabeo -abieta-3,5,8,11,13,15-hexaene-2,7-dione (teuvincenone F), (16 S )-12,16-epoxy-11,14-dihydroxy-17(15 → 16)- abeo -abieta-8,11,13-triene-3,7-dione (teuvincenone G), 12,16-epoxy-6,11,14-trihydroxy-17(15 …

INVESTIGATION OF THE ACQUEOUS TRANSMETALATION OF pi-ALLYLPALLADIUM WITH INDIUM: SOME THEORETICAL AND EXPERIMENTAL EVIDENCES ABOUT THE NATURE OF ALLYLINDIUM INTERMEDIATES

Complete assignments of1H and13C NMR spectra of four hispanane diterpenoids

An NMR study of four hispanane diterpenoids is described. In addition to conventional 1D NMR methods, 2D shift-correlated experiments [1H,1H-COSY, 1H,1H-TOCSY, 1H,13C-HSQC-1J(C,H). 1H,13C-HMBC-nJ(C,H) (n = 2 and 3)] and 2D 1H,1H-NOESY were used for the complete and unambiguous 1H and 13C chemical shift assignments of these diterpenoids. Copyright © 2000 John Wiley & Sons, Ltd.

The synthesis of nareielasie aldehyde and related lsocarbostyrils

The synthesis of several isoearboslyrils is reported, including lorrnyl derivatives at (1-4, like nareiclasie aldehyde (I) and the homologous aldehyde (XV).

Rearranged abietane diterpenoids from the root of teucrium polium subsp. vincentinum

Abstract From the root of Teucrium polium subsp. vincentinum (Labiatae) four new rearranged abietane derivatives, teuvincenones A, B, C, and D (1-4, respectively), have been isolated. Two of these compounds, teuvincenones C (3) and D (4), possess a novel hydrocarbon skeleton which contains a cyclopropane ring constituted by the C-3, C-4, and C-18 carbons of the 17(15→16)-abeo-abietane framework. The structures of these diterpenoids were established mainly by spectroscopic means and, in the case of teuvincenones A (1) and C (3), also confirmed by X-ray diffraction analyses.

Derivati neoclerodanici semisintetici come potenziali leganti dei recettori oppioidi

Photochemical Transformations of Some Neoclerodane and Labdane Diterpene Ketones

Some neoclerodane (2–4) and labdane (5 and 6) diterpene ketones having a β- or γ-hydroxy function, an α-epoxy group, or an α-olefinic double bond have been irradiated at λ = 313 nm in dry solvents (benzene or methanol). Fruticolone (2) yielded the naturally occurring 5,6-seco-neoclerodan-6,1α-olide derivative fruticolide (1), while hispanolone (5) gave the δ-lactone 8, both transformations involving a Norrish type I photoreaction. The α,β-unsaturated ketone derivative 4 was transformed into 7 by a stereoselective intramolecular [2+2] cycloaddition reaction involving its furanic 13(16)-double bond. Finally, the α-epoxy ketone 6 was rearranged to the 10(98)abeo-labda-7,9-dione derivative 10. …

8 β-hydroxyfruticolone, a diterpenoid from Teucrium fruticans

Complete 1H and 13C NMR assignments of clerodane diterpenoids of Salvia splendens.

Unambiguous and complete assignments of 1H and 13C NMR chemical shifts for five clerodane diterpenes, four of them isolated from Salvia splendens (salviarin, splendidin and splenolides A and B) and one obtained by acetylation of splenolide A, are presented. The assignments are based on 2D shift-correlated [1H,1H–COSY, 1H,13C-gHSQC–1J(C,H) and 1H,13C-gHMBC-nJ(C,H) (n = 2 and 3)] and nuclear Overhauser effect (NOE) experiments. The conformation of the rings of these compounds is supported by the 3J(H,H) values and NOE results. Copyright © 2006 John Wiley & Sons, Ltd.

Neo-clerodane diterpenoids from Teucrium kotschyanum

Abstract From the aerial parts of Teucrium kotschyanum three new neo-clerodane diterpenoids have been isolated. Their structures, (12R)-15,16-epoxy-19-nor-10α-neo-cleroda-4,13(16),14-triene-18,6β; 20,12-diolide (12-epiteucvidin), (12R)-15,16-epoxy-19-nor-neo-cleroda-4,13(16),14-triene-18,6β; 20,12-diolide (12-epiteufiin) and (12S,18R)-15,16-epoxy-6β-hydroxy-neo-cleroda-13(16),14-dien-20,12-olide-l8,19-hemiacetal (teukotschyn), have been established by chemical and spectroscopic means. In addition, ursolic acid, the flavones cirsimaritin and cirsiliol, and six previously known neo-clerodane diterpenoids (teucvidin, teuflin, teuscorodin, teucrin H2, teuscorodonin and montanin D) were also fou…

Diterpeni neoclerodanici sa Salvia splendens

Ent-clerodane diterpenoids from six further species of Teucrium

Abstract Fifteen further species of the genus Teucrium have been investigated. Six of them contain known ent -clerodane diterpenoids; the others did not yield any diterpenoid. The chemotaxonomic significance of these results is discussed.

6-epiteucrin A, a neo-clerodane diterpenoid from Teucrium chamaedrys

Abstract From the aerial part of Teucrium chamaedrys a new 19-nor-neo-clerodane diterpenoid, 6-epiteucrin A, has been isolated, besides the previously known diterpenoids teuflin, teuflidin, teucrin E and teuchamaedryn B. The structure of 6-epiteucrin A, (12S)-15,16-epoxy-7α-hydroxy-19-nor-neo-cleroda-4,13(16),14-triene-18,6β: 20,12-diolide, was established by spectroscopic means and by correlation with teucrin A.

New furanoid diterpenes from l'her.

Investigation of the aqueous transmetalation of pi-allylpalladium with indium: some theoretical and experimental evidence about the nature of allylindium intermediates

In this paper we report some theoretical and experimental evidence concerning the nature of the allyl-In intermediate generated by umpolung of allyl-Pd complexes in the Pd(OAc)(2)/TPPTS catalysed allylation reaction of benzaldehyde. The allylic substrate reacts at the substituted terminus, because of the formation of an equilibrating mixture of eta(1)-allyl-In(I) specie with the gamma-substituted regioisomer being more reactive.