The Diterpenoids of the Genus Marrubium (Lamiaceae)

The occurrence and chemical structures of labdane diterpenoids from the genus Marrubium are reviewed and the published 13C NMR spectroscopic data for these compounds is presented. The pharmacological activities and biogenesis of these diterpenoids are also reported.

Volatile constituents of Calamintha origanifolia boiss. Growing wild in Lebanon

The essential oil of aerial parts of Calamintha origanifolia Boiss. (Lamiaceae), growing wild in Lebanon, was obtained by hydrodistillation and was analysed by GC and GC-MS. 49 compounds, representing 92.2% of the oil, were identified. The major components, belonging to the class of oxygenated monoterpenes, were pulegone (22.5%), isomenthone (12.2%) and piperitenone (9.6%). The oil showed a slight antimicrobial activity against three bacterial strains.

Photoinduced functionalization of diterpenes: transformation of the C-20 methyl of atractyligenin into a carbomethoxymethyl or carbamoylmethyl group

Abstract Irradiation of the nor-diterpene atractyligenin 1a and of its methyl ester 1b at λ=254 nm in methanol or in methanol in the presence of nitrogen nucleophiles such as ammonia or methylamine gave, besides the decarboxylation product 2, the ester 3a or the amides 3b, 3c, respectively, providing the transformation of the C-20 angular methyl into a carbomethoxymethyl or carbamoylmethyl group. A photochemical pathway involves formation of C-19/C-20 bond in the excited state, followed by a collapse into a ketene intermediate which will capture the nucleophilic reagent.

Advances on the chemistry of furano-diterpenoids from Teucrium genus

This paper updates the previous reviews, reporting the results published in the last six years on the chemistry of these diterpenoids.

Phytochemical composition, anti-inflammatory and antitumour activities of four Teucrium essential oils from Greece

Abstract The essential oils of four Teucrium species were studied and 150 components, in all, were identified. All oils were rich in sesquiterpenes (50.1–55.8%). Spathulenol and δ-cadinene were the main compounds of Teucrium brevifolium oil; caryophyllene and 4-vinyl guaiacol predominated in Teucrium flavum . Carvacrol and caryophyllene oxide predominated in Teucrium montbretii ssp. heliotropiifolium , while carvacrol and caryophyllene were the most abundant components in Teucrium polium ssp. capitatum . The oil which most effectively inhibited LPS-induced NO production in macrophage cell line RAW 264.7 was that from T. brevifolium (IC 50  = 7.1 μg/ml), followed by T. montbretii ssp. heliot…

Characterisation of the essential oil of Nepeta glomerata Montbret et Aucher ex Bentham from Lebanon and its biological activities.

The essential oil of Nepeta glomerata from Lebanon was studied by means of GC and GC/MS analysis; 70 compounds were identified. The oil was constituted mainly by monoterpenes and the most abundant components were α-pinene, spathulenol and carvacrol. Nepeta glomerata oil showed antibacterial activity, particularly towards Gram-positive bacteria, and also inhibited LPS-induced NO production in macrophage cell line RAW 264.7, with an IC(50) value of 78.1 µg mL(-1). Furthermore, an in vitro cytotoxic assay showed that the oil was more active on a renal adenocarcinoma cell line (48% of inhibition of proliferation at 100 µg mL(-1)) in comparison to an amelanotic melanoma.

ChemInform Abstract: Further Furoclerodanes from Teucrium “maghrebinum”

Two more pairs of C-12 epimeric neoclerodanes were isolated from the aerial parts of Teucrium “maghrebinum” (Teucriumpolium subspecies still unidentified). They are the known teukotschyn 1, the new 12-epi-teukotschyn 2, the new teughrebin 3 and the new 12-epi-teughrebin 4. The structures of the new products were elucidated mainly by spectroscopic methods.

Neoclerodanes from Teucrium orientale

Abstract Two new neoclerodane diterpenoids, 6-deacetyl-teucrolivin A (5) and 8beta-hydroxy-teucrolivin B (6), were isolated from the aerial parts of Teucrium orientale, along with four already known neoclerodane diterpenoids, teucrolivin A (1), teucrolivin B (2), teucrolivin C (3) and teucrolivin H (4), previously isolated from Teucrium oliverianum. Their structures were elucidated on the basis of spectroscopic evidence and chemical transformations. Compounds 1-3 were assayed for antifeedant activity against Spodoptera littoralis, S. frugiperda and Heliocoverpa armigera. Teucrolivin A was the most potent of the three compounds tested.

Neoclerodane Diterpenoids from Teucrium maghrebinum

Eight neoclerodane diterpenoids were identified in the extract of the aerial parts of Teucrium maghrebinum. Three of these, 12-epi-teucjaponin A (1), 12-epi-montanin D (2), and 12-epi-montanin B (3), are new natural products, whereas five, teucjaponin A, montanin D, 19-deacetylteuscorodol, teusalvin C (4), and montanin B, are already known. These eight compounds form four pairs of epimers at carbon C-12.

Volatile compounds of flowers and leaves of Sideritis italica (Miller)Greuter et Burdet (Lamiaceae), a plant used as mountain tea

Sideritis italica (Miller) Greuter et Burdet (Lamiaceae), widely used in ethnopharmacological medicine, occurs in Southern Italy and Sicily. The phytochemical composition of the essential oils of S. italica flowers and leaves, harvested in Piano Battaglia (Sicily), was analysed by GC and GC-MS. Of the 51 compounds, 43 in the oil from flowers and 29 in the oil from leaves were identified. Kaur-15-ene (20.0%) was recognised as the main constituent of the oil from flowers, together with beta-cubebene (12.1%), beta-pinene (8.5%), (Z)-nuciferol (6.5%), tricyclene (4.5%) and alpha-bisabolol (4.0%). In the oil from leaves, p-methoxyacetophenone (26.0%) prevailed, as did hexadecanoic acid (21.3%), …

Comparative chemical composition, free radical-scavenging and cytotoxic properties of essential oils of six Stachys species from different regions of the Mediterranean Area

Abstract The chemical composition of essential oils of six Stachys species, S. cretica L. ssp. vacillans Rech. fil., S. germanica L., S. hydrophila Boiss., S. nivea Labill., S. palustris L. and S. spinosa L., obtained by hydrodistillation, was studied by GC and GC–MS. All the oils have in common a great percentage of fatty acids and esters (24.2–58.5%) and a high amount of sesquiterpenes (16–35.9%), with the exception of the oil from S. palustris , which consisted mainly of carbonylic compounds (25.4%). The antioxidant activity by DPPH test and the antiproliferative activity on a series of human cancer cell lines (C32, amelanotic melanoma and ACHN, renal cell adenocarcinoma) were investigat…

ChemInform Abstract: Photoinduced Functionalization of the C-20 Methyl Group of the Nor-diterpene Atractyligenin.

Abstract Irradiation of the nor-diterpene atractyligenin at λ =254 nm in methanol gave, on one hand, the decarboxylation product, and provided, on the other hand, the transformation of the C-20 angular methyl into a methylene-carbomethoxy group. A photochemical pathway involving formation of C-19/C-20 bond is suggested.

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…

Labdane Diterpenoids from Marrubium globosum ssp. libanoticum

From the aerial parts of Marrubium globosum ssp. libanoticum, seven labdane diterpenoids were isolated. Three of them are new natural products [(13R)-9alpha,13alpha-epoxylabda-6beta(19),16(15)-diol dilactone (2), deacetylvitexilactone (7), marrulanic acid (8)], whereas the other four, namely, (13S)-9alpha,13alpha-epoxylabda-6beta(19),16(15)-diol dilactone (1), cyllenin A (3), 15-epi-cyllenin A (4), and marrulibanoside, are previously known compounds. The structures of 2, 7, and 8 were determined by spectroscopic and chemical methods.

Occurrence of (+)-6-desoxyandalusol in Stachys ionica and Stachys distans

Comparison of the volatile oils ofHypericum scabrum L. andHypericum perforatum L. from Turkey

The composition of the volatile oils obtained from the aerial parts of Hypericum scabrum L. and H. perforatum L. was analysed by GC and GC‐MS. While the oil of H. scabrum L. contained a-pinene (71.6%), b-caryophyllene (4.8%), myrcene (3.8%), cadalene (3.4%) and b-pinene (2.9%), the oil of H. perforatum L. contained a-pinene (61.7%), 3-carene (7.5%), b-caryophyllene (5.5%), myrcene (3.6%), cadalene (3.2%) and other components. Twenty-nine and 27 terpenoid compounds have been identified in the volatile oils of H. scabrum L. and H. perforatum L., respectively. #1997 by John Wiley & Sons, Ltd.

Minor diterpenoids from Scutellaria polyodon.

Four minor neoclerodane diterpene constituents were isolated from the aerial parts of Scutellaria polyodon. These compounds were characterized as the new scupolins J (1) and K (2) and the previously known scutalpin O (3) and scutalsin.

Antimicrobial and antioxidant properties of the essential oil of Salvia lanigera from Cyprus

The essential oil of aerial parts of Salvia lanigera Poir. (Lamiaceae) growing wild in Cyprus was obtained by hydrodistillation and was analysed by GC and GC-MS. A total of 67 compounds, representing 93.6% of the oil, were identified, and the major components were showed to be thymol (12.1%), hexadecanoic acid (6.0%), carvacrol and α-thujone (5.7%). The essential oil was assayed for its antioxidant and antimicrobial activities. Antimicrobial activity of the oil, evaluated using the broth dilution method, resulted higher against Gram-positive bacteria than the other referenced strains tested. Antioxidant activity of the oil was evaluated by using DPPH and FRAP methods together with three ant…

Essential oils of Salvia bracteata and Salvia rubifolia from Lebanon: Chemical composition, antimicrobial activity and inhibitory effect on human melanoma cells

Aim of the study: Salvia bracteata Banks et Sol. and Salvia rubifolia Boiss. are known in folk medicine of Lebanon for the treatment of microbial infections, cancer, urinary and pulmonary problems. In the present study the chemical composition and antimicrobial activity of essential oils from aerial parts of Salvia bracteata and Salvia rubifolia collected in Lebanon were evaluated. The oils were also tested for their potential antiproliferative effects against M14 human melanoma cells. Material and methods: The oils were studied by GC and GC-MS and their antibacterial activity (MIC and MBC) was tested against ten bacteria species using the broth dilution method. The inhibitory effect on hum…

Antifeedant activity of neo-clerodane diterpenoids from Teucrium fruticans and derivatives of fruticolone

The antifeedant activity of three neo-clerodane diterpenoids, fruticolone, isofruticolone and fruticolide from Teucrium fruticans was assessed using larvae of Spodoptera littoralis. Isofruticolone was one of the most potent of the Teucrium derived neo-clerodanes. Chemical modification of functional groups on fruticolone showed that its activity could be enhanced.

The Diterpenoids from the Genus Hyptis (Lamiaceae)

The genus Hyptis (family Lamiaceae) is known mainly for the essential oils isolated from the aerial parts of several species. Less known are the diterpenoids, extracted from a limited number of species. In consideration of the interest for the structures of this class of compounds, largely occurring in the whole Lamiaceae family, the present paper means to review and update their chemistry. Also the use of many species of Hyptis in folk-medicine is reported.

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 …

Addition reactions of heterocycles—IV

Abstract The reactivity of indole derivatives towards nitrilimines has been studied. Substituents at positions 1, 2 and 3 of the indole ring greatly affect the course of the reaction. 1,3-Dipolar cycloaddition products (3a,8a,dihydropyrazole-[3,4-b]-indole derivatives) and non-cyclic addition products (3-indolyl derivatives) were obtained depending on these substituents. The structures reported were assigned on the basis of satisfactory analytical, spectroscopic and chemical data.

The crystal and molecular structure of the epoxybromo derivative of atractyligenin.

Abstract The complete configuration of atractyligenin has been obtained by a three-dimensional single-crystal X-ray difiraction study. Previous structural work has been confirmed, in particular the configuration of the epoxy group. The space group is C2, with four molecules in the cell, a = 19·005, b = 7·165, c = 14·450 A, β = 108° 31′, and the final R is 0·125 for 1320 observed reflections. The stress in the molecule (as indicated by the torsional angles) and the molecular packing are discussed.

Flavonoids from Teucrium fruticans L.

From aerial parts of <em>Teucrium fncticans</em> L. three flavonoids were isolated and identified as 5-hydroxy-6, 7, 3', 4'-tetramethoxyflavone, 5, 4'-dihydroxy-6, 7, 3'-trimethoxyflavone (cirsilineol) and 5, 4'-dihydroxy-6, 7-dimethoxyflavone (cirsimaritin). The former compound was found to be a predominant flavone aglycone constituent of the plant material. This is the first report on the isolation of flavonoids from the plant.

Volatile constituents of Stachys palaestina L. (Palestine woundwort) growing in Lebanon

The hydrodistillation of the aerial parts of Stachys palaestina L. collected in Lebanon in the Kadisha Valley, yielded 0.1% (w/w) of essential oil. GC and GC-MS analyses enabled the identification of 87 compounds representing 90.8% of the total oil. Hexadecanoic acid (10%), hexahydrofarnesyl acetone (6.9%), eugenol (4.3%) and (E)-caryophyllene (4.3%) were the main components. On the whole, the oil was constituted mainly of sesquiterpenes (37.7%), among which sesquiterpene hydrocarbons (20.7%) slightly prevailed over oxygenated sesquiterpenes (17.0%). This is the first report on the chemical composition of S. palaestina essential oil.

Pterocarpol and triterpenes from Daemonorops draco

Analysis of Essential Oils from Scutellaria orientalis ssp. alpina and S. utriculata by GC and GC-MS

The chemical composition of the essential oils obtained from aerial parts of Scutellaria orientalis L. ssp. alpina (Boiss.) O. Schwarz and S. utriculata Labill. growing wild in Lebanon, were analyzed by GC and GC-MS. In S. orientalis ssp. alpina, strongly characterized by sesquiterpenes (41.2%) and particularly sesquiterpene hydrocarbons (31.7%), hexahydrofarnesylacetone (11.7%) was recognized as the main constituent, together with hexadecanoic acid (7.6%), caryophyllene (7.4%), caryophyllene oxide (6.8%), 4-vinylguaiacol (5.4%) and germacrene D (5.4%). S. utriculata oil was instead constituted above all by monoterpenes (42.2%), particularly oxygen containing monoterpenes (39.9%), and in t…

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).

Further Furoclerodanes fromTeucrium “maghrebinum”

Two more pairs of C-12 epimeric neoclerodanes were isolated from the aerial parts of Teucrium “maghrebinum” (Teucriumpolium subspecies still unidentified). They are the known teukotschyn 1, the new 12-epi-teukotschyn 2, the new teughrebin 3 and the new 12-epi-teughrebin 4. The structures of the new products were elucidated mainly by spectroscopic methods.

Analysis of the Essential Oil of the So-called“Mentha mirennae”Bruno by GC and GC/MS

ABSTRACT The essential oil of “Mentha mirennae” Bruno was analyzed by a combination of GC, GC/MS and 13C-NMR. It was found to contain more than 50 components of which about 40 (96%) were identified. The major compounds were linalool (70%), linalyl acetate (9.8%) and limonene (1.5%). From a comparison with the main constituents found in different Mentha oils, we presume that “M. mirennae” must be the hybrid M. citrata Ehrl. However, according to botanical and chemical data the possibility that “M. mirennae” is, in fact, M. spicata L. cannot be excluded.

Chemical composition of the essential oil of Salvia multicaulis Vahl. var. simplicifolia Boiss. growing wild in Lebanon

The essential oil of aerial parts of Salvia multicaulis Vahl. var. simplicifolia Boiss. (Lamiaceae) growing wild in Lebanon was obtained by hydrodistillation and was analysed by GC and GC-MS. 67 compounds constituting 95.2% of the oil were identified, the major components being alpha-copaene (8.0%), alpha-pinene (6.6%), myrtenol (5.7%), trans-sabinyl acetate (5.3%).

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.

Isomotiol, a new triterpene from strychnos potatorum

Isomotiol (fern-8-en-3β-ol) was isolated from the leaves of Strychnos potatorum; it was not known previously as a natural product, but it has been obtained by acidic isomerization of compounds with a fern-7-ene or a fern-9(11)-ene skeleton. From the leaves and the bark mixtures of sitosterol, stigmasterol and campesterol were also isolated.

Composition of the Essential Oil ofNepeta curvifloraBoiss. (Lamiaceae) from Lebanon

Abstract The essential oil of Nepeta curviflora Boiss. (Lamiaceae) grown in Lebanon, obtained by hydrodistillation of aerial parts, was analyzed by GC and GC/MS. Thirty-five compounds were identified constituting 93.2% of the oil, the major components being β-caryophyllene (50.2%), caryophyllene oxide (6.4%) and (E)-β-farnesene (5.3%).

Phenolic compounds of Marrubium globosum ssp.libanoticum from Lebanon

Phytotoxic effects of essential oils of Nepeta curviflora Boiss and Nepeta nuda L.subsp. albiflora growing wild in Lebanon

The chemical composition of the essential oils of two Nepeta species collected in Lebanon was studied by means of GC and GC-MS analysis. The essential oil from N. curviflora Boiss. contained high amounts of β-caryophyllene (41.6%), caryophyllene oxide (9.5%), (E)-β-farnesene (6.2%) and (Z)-β-farnesene (4.8%); in the oil from N. nuda L. subsp. albiflora (Boiss.) Gams. collected in Laklouk the main compounds were β-bisabolene (11.8%), pulegone (10.8%), (E,Z)-nepetalactone (8.0%), (E)-β-farnesene (7.1%) and caryophyllene oxide (6.9%), while N. nuda L. subsp. albiflora collected in Tannourine Cedar Forest contained high percentages of hexadecanoic acid (10.1%), β-bisabolene (7.8%), caryophyllen…

Triterpenes from amaracus dictamnus

Abstract From the aerial parts of Amaracus dictamnus several triterpenes were isolated: oleanolic and ursolic acids, uvaol, the rare 21α-hydroxyoleanolic acid and a new 21α-hydroxyursolic acid.

The diterpenoids from the genus Sideritis

ABSTRACT: The genus Sideritis consists of 100-150 or more species, growing mainly in the countries around the Mediterranean area. The genus is particularly rich in diterpenoids, occurring in almost all the species, and shows many different carbon skeleta. Several species are still used in traditional medicine. Recent studies indicated the occurrence of interesting biological activities, like anti-inflammatory, antibacterial, antimicrobial, anti-HIV replication, antifeedant, antiulcerogenic, analgesic, and antihypoglycaemic.

8 β-hydroxyfruticolone, a diterpenoid from Teucrium fruticans

ChemInform Abstract: Natural and Hemisynthetic Neoclerodane Diterpenoids from Scutellaria and Their Antifeedant Activity

Covering: Up to June 2001. Previous review: on the clerodanes, Nat. Prod. Rep., 1992, 9, 243.

Structure and Biological Activity of the Furan-Diterpenoids from the Genera Leonotis and Leonurus

The present review, covering the literature up to 2006, reports the chemistry and the biological activities of the diterpenoids occurring in the aerial parts of species belonging to the genera Leonotis and Leonurus, family Lamiaceae.

Volatile flavour components of ocimum basilicum var. hispidum (lam.) Chiov.

The volatile components obtained by steam-distillation ofOcimum basilicum var. hispidum (Lam.) Chiov. (Labiatae) were analysed by gas chromatography (GC) and gas chromatography—mass spectrometry (GC-MS). A total of 21 compounds, representing ca 90% of the total oil, were identified. The identity of the main component (82%), dihydrotagetone, was confirmed by 1H- and 13C-NMR spectroscopy. This is the first report of this compound in the genus Ocimum.

A minor diterpene from Amaracus akhdarensis

Abstract A new isopimarane diterpenoid, isoakhdartriol, was isolated in very small amount from the aerial part of Amaracus akhdarensis. Its structure, isopimar-15-en-3β,8β,19-triol, was established by spectroscopic means.

Photoinduced functionalization of diterpenes: photochemical behaviour of grandifloric acid in methanol and acetonitrile

Abstract Irradiation of grandiflorolic acid (11) at λ=254 nm in acetonitrile gave the two epimers 13 and 14 through a photodecarboxylation reaction of the carboxylic group on C-4. Irradiation of compound 11 in methanol at λ=254 nm provided the transformation of the C-20 angular methyl into a carbomethoxymethyl group. In this case, unlike compounds 13 and 14, only one of the two possible isomers (15) was obtained (equatorial methyl at C-4). A mechanistic approach of this reaction in discussed, and the role of mutual stereochemistry between C-20 methyl and C-19 carboxylic group in determining the course of the reaction is pointed out.

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…

Labdane Diterpenes from Stachys plumosa

Three new labdane diterpenoids were isolated from the aerial parts of Stachys plumosa. The first two (1, 2) were the dextrorotatory enantiomers of the known 6-deoxyandalusol and 13-epijabugodiol. Structures were determined using NMR and MS techniques. The absolute stereochemistry of the third compound (3) was not experimentally proved.

An ent-kaurane from Sideritis huber-morathii

WOS: A1996VW86500030

GC and GC/MS analysis of the essential oil of Salvia hierosolymitana boiss. Growing wild in Lebanon

The essential oil of the aerial parts of Salvia hierosolymitana Boiss. (Lamiaceae), growing wild in Lebanon, was obtained by hydrodistillation and analysed by GC and GC-MS. Ninety-two compounds, representing 92.7% of the oil, were identified. The major components were hexadecanoic acid (15.5%), phytol (5.4%), hexahydrofarnesyl acetone (4.6%), (Z,Z)-9,12-octadecadienoic acid (4.5%) and 4-vinylguaiacol (4.4%).

Hastifolins A-G, antefeedant neo-clerodane diterpenoids from Scutellaria hastifolia

From the aerial parts of Scutellaria hastifolia, family Lamiaceae (Labiatae), seven neo-clerodane diterpenoids (hastifolins A-G) were isolated. The products are similar to the known scuteparvin and are characterized by being trans-cinnamoyl derivatives. Structures and stereochemistry were determined by intensive NMR investigation. Six of the products form three pairs of epimers at C-13. Hastifolins A-C showed significant antifeedant activity.

The biotransformation of the Diterpenoid, Rosenonolactone by Mucor Plumbeus

The biotransformation of rosenonolactone by the fungus, Mucor plumbeus involves hydroxylation at C-2α C-6β C-12α and epoxidation of the Δ15-alkene.

Synthesis of β-methylfurolabdanes from (+)-sclareolide

An efficient synthesis of the methylfurolabdane 3 from (+)-sclareolide (6) via the hydroxyalkenes 12 is reported. Alternative modes of cyclization of 12 allowed the synthesis of methyldihydrofuran derivatives 4 and 5 and methyltetrahydrofuran derivatives 15. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2002)

Photoinduced functionalization of the C-20 methyl group of the nor-diterpene atractyligenin

Abstract Irradiation of the nor-diterpene atractyligenin at λ =254 nm in methanol gave, on one hand, the decarboxylation product, and provided, on the other hand, the transformation of the C-20 angular methyl into a methylene-carbomethoxy group. A photochemical pathway involving formation of C-19/C-20 bond is suggested.

Analysis of Essential Oil from Teucrium maghrebinum Greuter et Burdet Growing Wild in Algeria

The chemical composition of the essential oil obtained from aerial parts of Teucrium maghrebinum growing wild in Algeria was analyzed by GC and GC-MS. Among the 66 identified compounds, δ-cadinene (12.7%), germacrene D (11.4%), γ-cadinene (9.5%) and 4-vinyl guaiacol (4.0%) were the most abundant. The oil is strongly characterized by the presence of sesquiterpenes (61.5%), particularly hydrocarbon sesquiterpenes (49.6%).

Phytochemical and pharmacological studies on the acetonic extract of Marrubium globosum ssp. libanoticum

A new natural labdane diterpene, marrulibanoside, was isolated from the acetonic extract of aerial parts of M. globosum Montbr. et Auch. ex Benth. ssp. libanoticum Boiss. (Lamiaceae). Its structure was determined by spectroscopic methods such as 1D and 2D NMR and mass spectrometry. Pharmacological studies have shown that the extract of M. globosum exerts anti-inflammatory effects in the rat paw oedema induced by carrageenin resulting in reduced paw swelling. This activity, which seems due to marrulibanoside, is a consequence of iNOS and COX-2 activities inhibition.

Occurrence of non-basic metabolites in Amaryllidaceae

Abstract Narciclasine and margetine, previously extracted from many species of the genus Narcissus , are also present in the genera Galanthus , Haemanthus , Leucojum , Pancratium , Sprekelia , Sternbergia and Vallota . In the genus Hymenocallis only margetine was detected, but not narciclasine. Both products are absent in the genera Amaryllis , Clivia , Crinum and Nerine .

Antifeedant activity of neo-clerodane diterpenoids from Teucrium arduini

Antifeedant activity of neoclerodane diterpenoids from two Sicilian species of Scutellaria

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.

Volatile components and antifeedant activity of the essential oil from Scutellaria hastifolia L.

Revised structure for siderin

Natural and hemisynthetic neoclerodane diterpenoids from Scutellaria and their antifeedant activityElectronic supplementary information (ESI) available: natural neoclerodanes from Scutellaria. See http://www.rsc.org/suppdata/np/b1/b111150g/

Covering: Up to June 2001. Previous review: on the clerodanes, Nat. Prod. Rep., 1992, 9, 243.

The structure and stereochemistry of atractyligenin

Abstract The structure of atractyligenin C19H28O4, the nor-diterpenoidic aglycone of atractyloside C30H44O16S2K2 has been substantiated as Ia. The absolute configuration shown in Ia proves it to be a derivative of (−)kaurene.

Extremely potent antifeedant neo-clerodane derivatives of scutecyprol A

Two known neo-clerodane diterpenoids, scutecyprol A (1) and scutalbin C (2), have been isolated from the acetone extract of the aerial parts of Scutellaria sieberi. The antifeedant activity of scutecyprol A (1), of its 15-oxo derivative (3), and of several halohydrins (4-9), synthesized starting from compounds 1 and 3, against Spodoptera littoralis have been determined and structure-antifeedant relationships are discussed.

New furanoid diterpenes from l'her.

Scuteparvin, a new neoclerodane diterpenoid from Scutellaria parvula

Abstract The diterpenoid fraction occurring in the acetone extract of the aerial parts of Scutellaria parvula has been investigated. Only one neoclerodane diterpenoid, scuteparvin, was isolated and its structure elucidated as 4α,18-epoxy-6α- trans -cinnamoyloxy- neo clerod-13-en-15,16-olide, a new natural product. Scuteparvin is quite similar to the already known ajugarin V from Ajuga remota , the only difference being the occurrence of a trans -cinnamoyl ester system instead of an acetate on the 6α-OH group. This finding confirms that the genera Scutellaria and Ajuga are closely related taxonomically.

Assigning the C-15 configuration of 15-hydroxy-, 15-methoxy-, 15-ethoxy-hexahydrofurofuran neoclerodane diterpenoids

Abstract Examination of 1 H and 13 C NMR spectra allows the establishment of rules for assigning the correct configuration at C-15 of 15-hydroxy-, 15-methoxy-, 15-ethoxy-hexahydrofurofuran neoclerodane diterpenoids. The structure of several diterpenoids has been assigned or ammended.

Phenylethanoid glycosides from Prostanthera melissifolia

Abstract Six phenylethanoid glycosides were isolated from aerial parts of Prostanthera melissifolia, together with apigenin and ursolic acid. The glycosides were characterized by spectral methods as martynoside, isomartynoside, verbascoside, isoverbascoside, betonyoside F and isobetonyoside F, the latter being a new natural product.

GC and GC–MS analysis of the essential oil of Nepeta cilicica Boiss. ex Benth. from Lebanon

The hydrodistillation of the aerial parts of Nepeta cilicica Boiss. ex Benth., collected in Lebanon in the Horsh Ehden reserve, yielded 0.13% (w/w) of essential oil. Gas chromatography (GC) and GC-mass spectroscopy analysis enabled the identification of 75 compounds representing 96.8% of the total oil. The most abundant compounds were spathulenol (15.1%), hexadecanoic acid (14%), δ-cadinene (5.5%) and α-copaene (4.5%). On the whole, the oil was constituted mainly by sesquiterpenes (45.9%), among which sesquiterpene hydrocarbons (27.6%) slightly prevailed over oxygenated sesquiterpenes (18.3%).

Neo-clerodane diterpenoids from Scutellaria lateriflora

Abstract Three new diterpenoids, scutelaterins A-C, have been isolated from Scutellaria lateriflora and their structures established as (11S,13S,16S)-2β,6α,19-triacetoxy-4α,18;11,16;15,16-triepoxy-neo-clerod-14-ene (scutelaterin A), (11S,13S,16S)-6α,19-diacetoxy-2β-(2′-methyl)butyryloxy-4α,18;11,16;15,16-triepoxy-neo-clerod-14-ene (scutelaterin B) and (11S,13S,15R and S)-6α,19-diacetoxy-2β-(2′-methyl)butyryloxy-4α,18;11,16;15,16-triepoxy-neo-clerodan-15-ol (scutelaterin C) by chemical and spectroscopic means. In addition, the already known neo-clerodanes ajugapitin and scutecyprol A were also found in the same source.

Kauranoid dieterpenes in Espeletia grandiflora

Abstract The resin of Espeletia grandiflora contains (-)-kaur-16-en-19-ol, (-)-kaur-16-en-19-al (not previously isolated from natural sources), (-)-kaur-16-ene and (-)-kaur-16-en-19-oic acid.