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Iridoids are a major group of biologically active molecules that are present in thousands of plant species, and one versatile iridoid, secologanin, is a precursor for the assembly of thousands of monoterpenoid indole alkaloids (MIAs) as well as a number of quinoline alkaloids. This study uses bioinformatics to screen large databases of annotated transcripts from various MIA-producing plant species to select candidate genes that may be involved in iridoid biosynthesis. Virus-induced gene silencing of the selected genes combined with metabolite analyses of silenced plants was then used to identify the 7-deoxyloganic acid 7-hydroxylase (CrDL7H) that is involved in the 3rd to last step in secologanin biosynthesis. Silencing of CrDL7H reduced secologanin levels by at least 70%, and increased the levels of 7-deoxyloganic acid to over 4 mg g(-1) fresh leaf weight compared to control plants in which this iridoid is not detected. Functional expression of this CrDL7H in yeast confirmed its biochemical activity, and substrate specificity studies showed its preference for 7-deoxyloganic acid over other closely related substrates. Together, these results suggest that hydroxylation precedes carboxy-O-methylation in the secologanin pathway in Catharanthus roseus.

An investigation to optimize the extraction yield and the radical scavenging activity from the agricultural by-product olive tree wood (Olea europaeaL., cultivar Picual) using six different extraction protocols was carried out. Four olive wood samples from different geographical origin, and harvesting time have been used for comparison purposes. Among the fifty olive wood extracts obtained in this study, the most active ones were those prepared with ethyl acetate, either through direct extraction or by successive liquid-liquid partitioning procedures, the main components being the secoiridoids oleuropein and ligustroside. An acid hydrolysis pretreatment of olive wood samples before extractions did not improve the results. In the course of this study, two compounds were isolated from the ethanolic extracts of olive wood collected during the olives’ harvesting season and identified as (7′′R)-7′′-ethoxyoleuropein (1) and (7′′S)-7′′-ethoxyoleuropein (2).

Three drimanes, polygodial (2), albicanyl acetate (3) and 7-oxo-8,12-drimen-11-al (5), and two homodrimanes, 13,14,15,16-tetranorlabd-7-en-12,17-dial (6) and 7-oxo-13,14,15,16-tetranorlabd-8(17)-en-12-al (7), were synthesized from (−)-sclareol (1), and their antifeedant, antitumor and antimicrobial properties tested. In most cases, 6 and 7 were found to be more active than 2.

Two new carboxylic acids, 1 and 6 , have been isolated from the aerial parts of Lafuentea rotundifolia Lag. (Scrophulariaceae). The structural determination was performed by spectroscopic methods and chemical correlations, the absolute stereochemistry being established by Mosher's method. Both substances have a fatty acid-type structure with an unusual pattern.

The isomerization of β-caryophyllene (3), under treatment with SeO2, is described. Chemical correlations, between 3 14--hydroxy-β-caryophylllene (6z) from Juniperus oxycedrus, are establised. High resolution 1H NMR spectra and analysis by molecular mechanics of 3, 6 and 14-acetoxy-β-caryophyllene (7) indicate the existence of two conformational isomers, βα and ββ, in each compound. At 35°C, the βα conformer predominates in 3 and 7 but the ββ conformer predominates in 6. The higher precentage of 6ββ possibly derives from an intramolecullar hydrogen bond. The treatment of 3, 6 and 7 with m-CPBA generates, in each case, two diasteromeric 4,5-epoxi-derivatives. The epoxides obtained from 6 have been isolated and analysed separately.

The enantiospecific synthesis of drimenyl acetate (8), a key intermediate in the synthesis of biologically active drimanes, and albicanyl acetate (14), potent fish antifeedant, from sclareol (1), are described. Also a short and efficient synthesis of polygodial (22), from albicanyl acetate (14), is shown.

The synthesis of nor-ambreinolide (2) from cis-abienol (1) was carried out by direct treatment with OsO4-NaIO4 or RuO4-NaIO4. The oxymercuriation-demercuriation of 1 led to a mixture of 8,12-epoxylabdanes (5–17) which was also converted into nor-ambreinolide by treatment with RuO4-NaIO4. The formation pathways of such epoxy derivatives are discussed.

Two routes for preparing Ambrox® (1) from the methyl esters of trans-communic acid (2b) and/or cis-communic acid (3b), via selective degradation of their side chains, stereoselective formation of the tetrahydrofurane ring, and reduction of the axial methoxycarbonyl group, are described.

The analysis of the 13 C NMR spectra of 91 labdane-type compounds, classified into ten different series, is reported

Short and efficient syntheses of (−)-Ambrox® (12) from (−)-sclareol (1) and (+)-cis-abienol (11) are described. In constrast to previously described procedures, the transformation of 1 to 12, involving in the key step, an oxidative degradation by catalytic osmium tetroxide, in the presence of sodium periodate, has the advantage of using the more suitable sodium borohydride, as the reducing agent. The isolation and characterization of some reaction intermediates allowed us to confirm the degradation mechanism.

A mixture of the methyl esters of communic acids ( 3b, 4b, 5b ) was used in the synthesis of the ambergris-type odorants Ambrox ® ( 1 ) and ambracetal ( 2 ). Both syntheses involve methyl ketone 7 as the key intermediate.

The oxymercuriation-demercuriation (OM–DM) of methyl (E)-communate with mercury(II) acetate yielded mainly the hydration product of the 14,15-double bond. The isopimarane oxide methyl (8R,12R)-epoxyisopimar-15-en-19-oate, the endoperoxide methyl (8S,12R,13S)-13,17-epidioxy-8,12-epoxylabd-14-en-19-oate and the diorganomercurial bis-(4β-methoxycarbonyl-19-norlabda- 8,12E-14-trien-17-yl)mercury were also obtained when NaBH4–NaOH was used as the reducing agent. The organomercurial regenerated methyl (E)-communate on prolonged treatment with NaBH4 in excess. The OM–DM of methyl (E)-communate using Na(Hg) as the reducing agent achieved partial isomerization of the 8(17)-double bond, giving methyl 1 4-hydroxylabda-8,1 2E-dien- 1 9-oate and methyl labda-8,12E,14-trien-19-oate; the oxide methyl (8S,12R)-8,12-epoxylabd-13E-en-19-oate, instead of the aforementioned isopimarene oxide, endoperoxide, and diorganomercurial; relatively important amounts of the product of stereoselective 1,4-addition, methyl (12R)-12-hydroxylabda-8(17),13E-dien-19-oate, and the hydration product of the 8(17)-double bond on the (a priori) most hindered, β side, methyl (8S)-8-hydroxylabda-12E,14-dien-19-oate. Besides these, small amounts of the doublehydration product methyl (8S)-8,14-dihydroxylabd-12E-en-19-oate were also obtained. Finally, methyl (Z)-communate 2 showed similar behaviour to its E-isomer in OM–DM reactions.

Two routes for preparing Ambrox® (1) from the methyl esters of trans-communic acid (2b) and/or cis-communic acid (3b), via selective degradation of their side chains, stereoselective formation of the tetrahydrofurane ring, and reduction of the axial methoxycarbonyl group, are described.

A mixture of the methyl esters of communic acids ( 3b, 4b, 5b ) was used in the synthesis of the ambergris-type odorants Ambrox ® ( 1 ) and ambracetal ( 2 ). Both syntheses involve methyl ketone 7 as the key intermediate.

The enantiospecific synthesis of drimenyl acetate (8), a key intermediate in the synthesis of biologically active drimanes, and albicanyl acetate (14), potent fish antifeedant, from sclareol (1), are described. Also a short and efficient synthesis of polygodial (22), from albicanyl acetate (14), is shown.

The synthesis of nor-ambreinolide (2) from cis-abienol (1) was carried out by direct treatment with OsO4-NaIO4 or RuO4-NaIO4. The oxymercuriation-demercuriation of 1 led to a mixture of 8,12-epoxylabdanes (5–17) which was also converted into nor-ambreinolide by treatment with RuO4-NaIO4. The formation pathways of such epoxy derivatives are discussed.

Three drimanes, polygodial (2), albicanyl acetate (3) and 7-oxo-8,12-drimen-11-al (5), and two homodrimanes, 13,14,15,16-tetranorlabd-7-en-12,17-dial (6) and 7-oxo-13,14,15,16-tetranorlabd-8(17)-en-12-al (7), were synthesized from (−)-sclareol (1), and their antifeedant, antitumor and antimicrobial properties tested. In most cases, 6 and 7 were found to be more active than 2.

The replacement of some synthetic food antioxidants by safe natural antioxidants has fostered research on the screening of raw materials to find new vegetable sources of antioxidants. In this study the antioxidant activity of eight wild-growing Colombian plants was assessed by four complementary assays.An evaluation of the antioxidant activity of ten ethanolic extracts from Baccharis chilco, Cinnamomum triplinerve, Ilex laurina, Lachemilla orbiculata, Lepechinia conferta, Quercus humboldtii, Rubus urticifolius and Tephrosia cinerea was carried out. Furthermore, the total phenolic content was determined by the Folin-Ciocalteu method, and the relationship between phenolic content and activity was also statistically investigated. Cinnamomum triplinerve, L. conferta and I. laurina were found to have the highest phenolic contents. Baccharis chilco, C. triplinerve, I. laurina, L. conferta, Q. humboldtii and R. urticifolius showed higher radical-scavenging activity (DPPH and superoxide assays) than commercial rosemary oleoresin (reference). Lachemilla orbiculata and R. urticifolius showed higher antioxidant activity (β-carotene-bleaching test) than the reference. The protection factor of all studied plant extracts was below that of the reference according to the Rancimat test.On the basis of the results obtained, C. triplinerve, Q. humboldtii and R. urticifolius seem to be the most promising species for further investigation in order to identify the compounds responsible for their activity.

An investigation of the essential oil from the flowers of Tanacetum annuum led to the identification of 43 components, two of them having a homoditerpene skeleton. Five of these substances are new natural products.

Polyphenols, such as rosmarinic acid, are widely distributed natural products with relevant antioxidant activity. Oxidative stress plays an important role in the pathogenesis of a number of disorders. Here, we report on the synthesis and biological effects of the polyphenolic esters hydroxytyrosyl gallate (1), hydroxytyrosyl protocatechuate (2) and hydroxytyrosyl caffeate (3), structurally related to rosmarinic acid. The three compounds showed a greater free radical scavenging activity than their precursors and also than rosmarinic acid. Esters 1 and 3 significantly reduced thrombin-evoked platelet aggregation, which is likely mediated to the attenuation of thrombin-stimulated Ca(2+) release and entry. The three compounds reduced the ability of platelets to accumulate Ca(2+) in the intracellular stores, probably by enhancing the Ca(2+) leakage rate and reduced store-operated Ca(2+) entry in these cells. These observations suggest that the structurally-simplified analogs to rosmarinic acid, compounds 1 and 3, might be the base of therapeutic strategies to prevent thrombotic complications associated to platelet hyperaggregability due to oxidative stress.

Reactions of methyl 12,13-epoxy-cis-communates ( 3 , 4 ) and methyl 12,13-epoxy-trans-communates ( 5 ), 6 ) with BF3:etherate at 0°C are reported. They occur in a stereoselective and stereospecific way yielding mainly C-12 oxygenated pimaranes. When the reaction was carried out from 5 and 6 two tetracyclic ketones ( 17 , 18 ) were also isolated. Reaction mechanisms and stereochemical implications are discussed.

The oxymercuriation-demercuriation (OM–DM) of methyl (E)-communate with mercury(II) acetate yielded mainly the hydration product of the 14,15-double bond. The isopimarane oxide methyl (8R,12R)-epoxyisopimar-15-en-19-oate, the endoperoxide methyl (8S,12R,13S)-13,17-epidioxy-8,12-epoxylabd-14-en-19-oate and the diorganomercurial bis-(4β-methoxycarbonyl-19-norlabda- 8,12E-14-trien-17-yl)mercury were also obtained when NaBH4–NaOH was used as the reducing agent. The organomercurial regenerated methyl (E)-communate on prolonged treatment with NaBH4 in excess. The OM–DM of methyl (E)-communate using Na(Hg) as the reducing agent achieved partial isomerization of the 8(17)-double bond, giving methyl 1 4-hydroxylabda-8,1 2E-dien- 1 9-oate and methyl labda-8,12E,14-trien-19-oate; the oxide methyl (8S,12R)-8,12-epoxylabd-13E-en-19-oate, instead of the aforementioned isopimarene oxide, endoperoxide, and diorganomercurial; relatively important amounts of the product of stereoselective 1,4-addition, methyl (12R)-12-hydroxylabda-8(17),13E-dien-19-oate, and the hydration product of the 8(17)-double bond on the (a priori) most hindered, β side, methyl (8S)-8-hydroxylabda-12E,14-dien-19-oate. Besides these, small amounts of the doublehydration product methyl (8S)-8,14-dihydroxylabd-12E-en-19-oate were also obtained. Finally, methyl (Z)-communate 2 showed similar behaviour to its E-isomer in OM–DM reactions.

Twenty-one sesquiterpene components were identified in the essential oil from the wood of Juniperus oxycedrus . Three of these, as well as the preliminary reported 14-hydroxy-9- epi -β-caryophyllene, are new natural products.

Oleuropein and (+)-cycloolivil are natural polyphenolic compounds with a significant radical scavenging activity present in olive tree. We have investigated the antiaggregant effects of oleuropein and (+)-cycloolivil isolated from an ethyl acetate extract of olive tree wood. Oleuropein and (+)-cycloolivil reduced the ability of thrombin to stimulate platelet aggregation. Both compounds reduced thrombin-evoked Ca 2+ release and entry to a similar extent to hydroxytyrosol. This effect was greater in platelets from patients with type 2 diabetes mellitus than in controls. Thrombin-, thapsigargin- and 2,5-di-(tert-butyl)-1,4-hydroquinone (TBHQ)-evoked protein tyrosine phosphorylation, which is involved in Ca 2+ signalling and platelet aggregation, is inhibited by oleuropein and (+)-cycloolivil. oleuropein and (+)-cycloolivil are natural oxygen radical scavengers that reduce thrombin-induced protein tyrosine phosphorylation, Ca 2+ signalling and platelet aggregation. These observations suggest that oleuropein and (+)-cycloolivil may prevent thrombotic complications associated to platelet hyperaggregability and be the base for the development of antiaggregant therapeutic strategies.

Type 2 diabetes mellitus induces a number of cardiovascular disorders, including platelet hyperactivity and hyperaggregability, which is associated to an increased oxidant production and abnormal cytosolic Ca2+ mobilization. In the present study, we have investigated the effect of cinnamtannin B-1 obtained from bay wood on oxidants production, Ca2+ mobilization and aggregation in platelets from type 2 diabetic donors. Pretreatment of platelets with cinnamtannin B-1 reversed the enhanced oxidants production and Ca2+ mobilization, including Ca2+ entry, evoked by thapsigargin plus ionomycin or thrombin, observed in platelets from diabetic subjects, so that in the presence of cinnamtannin B-1 Ca2+ entry was similar in platelets from healthy and diabetic subjects. In addition, cinnamtannin B-1 reduced thrombin-induced aggregation in platelets from type 2 diabetic subjects. We conclude that cinnamtannin B-1 exerts an effective antioxidant action in platelets from patients with type 2 diabetes mellitus and reverses the enhanced Ca2+ mobilization and hyperaggregability.

Proanthocyanidins, such as cinnamtannin B-1, are polyphenolic compounds with antioxidant activity that induce apoptosis in a number of tumoral cells. We have now investigated the pro- or anti-apoptotic effects of cinnamtannin B-1 in human platelets. Platelet stimulation with thrombin induced cellular apoptosis, as detected by phosphatidylserine exposure and the activation of caspases-3 and -9. Pretreatment for 30 min with cinnamtannin B-1 impaired thrombin-induced apoptosis in platelets. Thrombin has been shown to induce H(2)O(2) generation in platelets, which induced similar apoptotic events than thrombin in these cells. Pretreatment with cinnamtannin B-1 reduced H(2)O(2)-induced phosphatidylserine exposure and caspase activation. Finally, platelet stimulation with thrombin induced translocation of caspases-3 and -9 to the cytoskeletal (Triton-insoluble) fraction, which is important for their activation and the development of apoptotic events. Pretreatment with cinnamtannin B-1 impaired translocation of caspases-3 and -9 to the cytoskeleton and, as a result, procaspases are accumulated in the Triton-soluble fraction. Our results provide evidence for the antiapoptotic actions of cinnamtannin B-1 in human platelets.

Several extracts of Olea europaea wood (Picual olive cultivar) were obtained with solvents of different polarity and their antioxidant activities determined. The active compounds were detected in fractions of an ethyl acetate extract using HPLC with on-line radical scavenging detection. After applying different separation techniques, hydroxytyrosol, tyrosol, cycloolivil, 7-deoxyloganic acid, oleuropein and ligustroside were isolated and characterized. Hydroxytyrosol showed a higher activity than the natural antioxidant rosmarinic acid in scavenging the DPPH model radical. Cycloolivil and oleuropein showed stronger activities than the synthetic antioxidant BHT against the same radical. Ligustroside, tyrosol and 7-deoxyloganic acid showed little activity. The latter compound has not been previously identified in the genus Olea.

The dichloromethane and ethanol extracts of Olea europaea wood (picual olive cultivar) were screened for antioxidant activity, determined by the DPPH free radical scavenging assay. The ethanol extract displayed potent antioxidant activity. (c) 2005 Elsevier B.V. All rights reserved.

The antifungal activity of the essential oil of the aerial parts of Bupleurum gibraltarium was evaluated against Plasmopara halstedii. Fungus spores were inoculated in sunflower seedlings, previously treated with several essential oil solutions, and the sporulation percentage was measured after an 11-day treatment. The oil at a concentration of 5.0 mL/L clearly inhibited the fungus sporulation. The contact between fungus sporangia and essential oil was minimized, so it seems that the oil pretreatment could activate the defense response of the sunflower seedlings against the pathogen invasion. The main compounds in the oil were sabinene (31.1%), α-pinene (15.6%), and 2,3,4-trimethylbenzaldehyde (10.9%), among a total of 65 components identified. Keywords: Plasmopara halstedii; mildew; sunflower; Bupleurum gibraltarium; Apiaceae; essential oil composition; antifungal activity; sabinene; α-pinene; 2,3,4-trimethylbenzaldehyde

A solution of bromine (0.3 mL, 5.90 mmol) in CCl4 (2 mL) was slowly added over a stirred mixture of 3-methyl-butan-2-one (1) (505 mg, 5.90 mmol) and AcOH (0.33 mL) at room temperature.[...]

Leaf and (unripe and ripe) berry essential oils of Juniperus oxycedrus ssp. badia (H. Gay) Debeaux grown wild in Spain have been analysed by capillary GC and GC-MS in combination with retention indices. A seasonal investigation of both leaf and berry oils was also performed. Among the approximately 80 constituents investigated (representing 90-98% of the oils) 60-68 were identified (80-97% of the oil composition). The leaf oils were mainly composed of alpha-pinene (40-57%) and manoyl oxide (5-10%). The (unripe) berry oils were dominated by alpha-pinene (65%) with moderate amounts of myrcene, limonene, germacrene D or gamma-muurolene. Several differences in yields and chemical composition from a qualitative and quantitative point of view were detected when comparing all the oil samples analysed. In addition, two oil samples were examined, but found inactive, against the replication of HIV-1(III(B)) and HIV-2(ROD) in cell culture, whereas the samples were toxic for the cells at a 50% cytotoxic concentration of 106 and 123 microg/ml, respectively.

The oils from the umbel rays, stems, leaves, fruits and the whole aerial parts of Bupleurum gibraltarium Lam. have been examined by means of GC/MS and retention indices. The dominant constituents in the oil from the whole aerial parts were found to be α-pinene (5.9%), sabinene (9.2%), limonene (6.5%), 2,3,4-trimethylbenzaldehyde (17.2%), terpinen4-ol (5.1%), trans-chrysanthenyl acetate (4.7%), elemol (4.3%) and guaiol (5.3%). The major components of the umbel rays oil were α-pinene (17.6%), sabinene (33.8%), limonene (7.3%), and 2,3,4-trimethyl-benzaldehyde (8.4%). The stem oil was characterized by the presence of α-pinene (6.0%), sabinene (21.8%), limonene (7.2%), 2,3,4-trimethylbenzaldehyde (10.7%), guaiol isomer (5.1%), elemol(5.5%) and guaiol (5.4%). The leaf oil had as main components α-pinene (130%), sabinene (50%) and limonene (10.0%), whereas in the oil from the fruits, α-pinene (42.7%), sabinene (28.3%), and limonene (9.0%) were found to be themost important ones. © 1998, Taylor & Francis Group, LLC. All rights reserved.

The selective syntheses of the cyclic monoterpenoids α-terpineol or α-cyclogeraniol from the acyclic monoterpenoid nerol using p-toluenesulfonic acid or chlorosulfonic acid as cyclizing agents, respectively, are described. The different behavior of nerol under diverse experimental conditions such as nature of the acid agents, solvents, and reaction temperatures is analyzed. The didactic usefulness of these experiments has been rationalized.

A 40% aqueous solution of sulfuric acid (0.5 mL) was added to a stirred solution of 3,3-dimethyl- 4-hydroxy-5-(2,2,3-trimethyl-3-cyclopentenyl)-pentan-2-one (1) (630 mg, 2.65 mmol) in methanol (5 mL) and the mixture refluxed for 1.5 h.[...]

Sodium (241 mg, 10.48 mmol) was added to absolute ethanol (40 mL) and the mixture refluxed until sodium reacted completely.

p-Toluenesulfonic acid (48 mg, 0.25 mmol) was added to a stirred mixture of ethyl 2-methyl-acetoacetate (1) (346 mg, 2.40 mmol) and a-methylbenzylamine (2) (358 mg, 2.95 mmol) in toluene (13 mL) [1].[...]

p-Toluenesulfonic acid (35 mg, 0.20 mmol) was added to a stirred mixture of campholenic aldehyde (1) (725 mg, 3.81 mmol) and p-toluenesulfonamide (1.22 g, 6.96 mmol) in toluene (20 mL).[...]

To a stirred solution of a mixture of E/Z isomers 1 (81 mg, 0.22 mmol, 45:55 ratio) in acetone (5 mL) was added a mixture of KMnO4 (122 mg, 0.77 mmol) and anhydrous MgSO4 (120 mg) at 10 oC [1].[...]

Acetic anhydride (0.53 mL, 5.61 mmol) and N,N-dimethylaminopyridine (17 mg, 0.14 mmol) were added to a stirred solution of the alcohol 1 (442 mg, 1.31 mmol) in freshly distilled triethylamine (1.3 mL) [1].[...]

A sample (0.85 mL, 6.5 mmol) of formic acid-acetic anhydride mixture (FAM), prepared from Ac2O and formic acid as described in the literature [1], was added to the alcohol 1 [2](255 mg, 0.79 mmol) at 10 oC.[...]

A sample (0.03 mL, 0.45 mmol) of formic acid-acetic anhydride mixture (FAM), prepared from Ac2O and formic acid as described in the literature [1], was added to the alcohol 1 [2] (29 mg, 0.09 mmol) at 10 oC.[...]

To a stirred solution of a mixture of E/Z isomers 1 (174 mg, 0.52 mmol, 45:55 ratio) in acetone (8 mL) was added a mixture of KMnO4 (260 mg, 1.64 mmol) and anhydrous MgSO4 (230 mg) at 10 oC [1].[...]

The composition of six essential oil samples, obtained by steam distillation of twigs of spike lavender (Lavandula latifolia Med.) harvested in three different locations from southern Spain during the full flowering and fruiting phenological stages, has been analyzed by capillary GC and GC/MS in combination with retention indices. Yields of the oils during flowering (1.5–2.2%) were 2.5–7 times higher than during fruiting (0.3–0.6%). Among the 56 identified constituents (accounting for 96.0–97.5% of the oils), the main and characteristic components were linalool (27.2–43.1%), 1,8-cineole (28.0–34.9%), camphor (10.8–23.2%), borneol (0.9–3.6%), β-pinene (0.8–2.6%), (E)-α-bisabolene (0.5–2.3%), β-pinene (0.6–1.9%), β-caryophyllene (0.5–1.9%), α-terpineol (0.8–1.6%), sabinene (0.3–0.8%), myrcene (0.3–0.8%), camphene (0.4–0.6%), terpinen-4-ol (0.3–0.5%) and limonene (0.2–0.9%). The volatile chemical composition and oil production of both full flowering and fruiting plants allowed to assess the type and...

This review summarizes the chemical composition reported up to date on Laurus nobilis L. (Lauraceae), an evergreen shrub or tree cultivated for its aromatic leaves and ornamental interest. It has been focused on non-volatile phytochemicals such as sesquiterpene lactones, flavonoids and proanthocyanidins, among others. Moreover, biological activities of laurel extracts and pure compounds have also been reviewed.