M. Amparo Blázquez

Styryl-lactones from Goniothalamus species— A review

Thirty-one bioactive styryl-lactones, with six different basic skeletons, have been isolated from Goniothalamus species. Aspects of their isolation, structural elucidation, biogenesis and biological activity are reviewed. Copyright

Chemical constituents of essential oil of Pelargonium graveolens leaves

Abstract The chemical constituents of the essential oil Pelargonium graveolens leaves were analyzed by GC and GC-MS. Thirty compounds accounting for 99.1% of the oil were identified. The main components identified were citronellol (33.6%), geraniol (26.8%), linalool (10.5%), citronellyl formate (9.7%) and p -menthone (6.0%).

Acetogenins from Annona glabra seeds

Abstract From the cytotoxic ethanol extract of Annona glabra seeds, a new mono-tetrahydrofuranic (mono-THF) acetogenin, glabranin, as well as pair of 22-epimer bis-THF acetogenins, were isolated by semipreparative HPLC. Four known mono-THF acetogenins with an identical threo/trans/threo relative configuration, annonacin, annonacinone, corossolin and corossolone, were found to be potent inhibitors of complex I of the mitochondrial respiratory chain.

Styryl‐lactones from the stem bark of Goniothalamus arvensis

The fractionation of the methanolic extract of Goniothalamus arvensis (Annonaceae) stem bark led to the isolation of two novel styryl-lactones, arvensin and (+)-2-epi-altholactone. The structures of these compounds, which belong to the furano-pyrone group, were established on the basis of mass spectrometry, one- and two-dimensional nuclear magnetic resonance experiments, as well as simple chemical derivatization. The relative and absolute configurations of the compounds are discussed. Copyright

Styryl-pyrones from Goniothalamus arvensis

Two novel styrl-pyrones, (+)-garvensintriol and (+)-etharvendiol, together with a known cytotoxic furano-furone, (+)-goniofufurone, have been isolated from the stem bark of Goniothalamus arvensis. A different relative configuration, cis-erythro-erythro for garvensintriol and cis-threo-erythro for etharvendiol, is established, and their absolute stereochemistry is discussed.

Tetrandrine and Isotetrandrine, Two Bisbenzyltetrahydroisoquinoline Alkaloids from Menispermaceae, with Rat Uterine Smooth Muscle Relaxant Activity

Abstract— The effects of two bisbenzyltetrahydroisoquinoline alkaloids, 1S, 1′S tetrandrine and its isomer 1R, 1′S isotetrandrine, were investigated in rat isolated uterus in order to identify the mechanism of relaxant action and to study the influence of the absolute configuration on the activity of these alkaloids. Both inhibited the uterine contraction induced by high K+, acetylcholine and oxytocin. In Ca2+‐free medium, isotetrandrine relaxed the sustained contraction induced by oxytocin but tetrandrine did not. The relaxant effects of the alkaloids may be due to blockade of calcium influx through specific channels. Tetrandrine and isotetrandrine modify the calcium channel in a nonreversible manner whilst only isotetrandrine acts intracellularly. Tetrandrine shows a more specific relaxant activity as a calcium entry blocker.

Chemical composition and herbicidal activity of the essential oil from a Cistus ladanifer L. population from Spain

The essential oil composition of Cistus ladanifer grown in central Spain was analysed by gas chromatography and gas chromatography/mass spectrometry, revealing it to be rich in oxygenated compounds, with trans-pinocarveol (20.00%), bornyl acetate (7.03%) and terpinen-4-ol (6.37%) as the main monoterpene compounds. Viridiflorol (13.59%) and ledol (4.36%) were the main constituents of the oxygenated sesquiterpene fraction. Large amounts of α-pinene (4.70%) were found in the hydrocarbonated fractions. To study its possible use as a natural herbicide, the oil was tested in vitro against Amaranthus hybridus, Portulaca oleracea, Chenopodium album, Conyza canadensis and Parietaria judaica, completely inhibiting A. hybridus germination, and nearly blocking C. canadensis and P. judaica germination at all concentrations assayed. In P. oleracea, the oil showed less effect, inhibiting its germination at the higher doses studied. It did not control C. album germination. Regarding seedling length, the oil had strong phytotoxic activity, being effective at all concentrations tested.

Chemical Constituents of Gynura cusimbua Aerial Parts

Abstract The essential oil isolated from the aerial parts of Gynura cusimbua was analyzed by GC and GC/MS. Forty-seven constituents totaling 91.92% of the oil were identified. The major constituents of the oil are myrcene (31.0%), β- phellandrene (12.43%), eugenol (6.34%), α-humulene (6.20%), dodecyl acrylate (6.09%), α-copaene (5.61%), phytol (3.21%), germacrene D (3.0%), cryptone (2.04%), 2,4-ditertbutylphenol (1.62%), α-pinene (1.33%), α-cadinene (1.26%), caryophyllene oxide (1.24%) and β-caryophyllene (1.08%).

Commercial Origanum compactum Benth. and Cinnamomum zeylanicum Blume essential oils against natural mycoflora in Valencia rice.

Chemical composition of commercial Origanum compactum and Cinnamomum zeylanicum essential oils and the antifungal activity against pathogenic fungi isolated from Mediterranean rice grains have been investigated. Sixty-one compounds accounting for more than 99.5% of the total essential oil were identified by using gas chromatography (GC) and gas chromatography–mass spectrometry (GC–MS). Carvacrol (43.26%), thymol (21.64%) and their biogenetic precursors p-cymene (13.95%) and γ-terpinene (11.28%) were the main compounds in oregano essential oil, while the phenylpropanoids, eugenol (62.75%), eugenol acetate (16.36%) and (E)-cinnamyl acetate (6.65%) were found in cinnamon essential oil. Both essential oils at 300 μg/mL showed antifungal activity against all tested strains. O. compactum essential oil showed the best antifungal activity towards Fusarium species and Bipolaris oryzae with a total inhibition of the mycelial growth. In inoculated rice grains at lower doses (100 and 200 μg/mL) significantly reduced the fungal infection, so O. compactum essential oil could be used as ecofriendly preservative for field and stored Valencia rice.

Variation of Terpenoids Constituents in Natural Population of Cinnamomum tamala (L.) Leaves

Abstract The leaves of Cinnamomum tamala L. (Lauraceae) were collected from seven plants occurring in seven different areas of Manipur and analyzed for their essential oil and eugenol contents using GC and GC/MS. The yield of the oil was found to vary from 1.5–5.6% (w/w), on a dry weight basis. A total of 79 compounds were identified in the oils. Eugenol was found as a major compound in the leaf oils and its concentration varied from 35.1–94.3% followed by α-phellandrene (1.0–25.4%).