Terpenoid

Gomerolactones A–D along with the known majusculone, obtusol, and elatol were isolated from Laurencia majuscula, and their structures were determined spectroscopically. With the aid of Pirkle's reagent at low temperature, NMR spectroscopy was used to determine the absolute configuration at the ring closure carbon atom of a α-alkylidene-γ-lactone and an α-alkylidene-δ-lactone unit embedded in the chamigrene network of compounds 1 and 2, respectively. The absolute stereochemistry of compounds 3 and 4 was determined by X-ray analysis. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)

Labrador tea (Ledum groenlandicum Retzius) is an ericaceae widely distributed in North America. The leaves and twigs were used in Native American traditional medicine to treat several inflammatory pathologies such as asthma, rheumatisms and burns. Reactive oxygen species as well as reactive nitrogen species such as nitric oxide (NO) contribute significantly to these pathologies. In this study, the antioxidant, anti-inflammatory

A novel pharmacological mechanism of action for the anxiolytic botanical Melissa officinalis L. (lemon balm) is reported. The methanol extract was identified as a potent in vitro inhibitor of rat brain GABA transaminase (GABA-T), an enzyme target in the therapy of anxiety, epilepsy and related neurological disorders. Bioassay-guided fractionation led to the identification and isolation of rosmarinic acid (RA) and the triterpenoids, ursolic acid (UA) and oleanolic acid (OA) as active principles. Phytochemical characterization of the crude extract determined RA as the major compound responsible for activity (40% inhibition at 100 µg/mL) since it represented approximately 1.5% of the dry mass of the leaves. Synergistic effects may also play a role. Copyright © 2009 John Wiley & Sons, Ltd.

Agarwood, one of the valuable non-timber products in tropical forest, is a fragrant wood, whose ethereal fragrance has been prized in Asia for incense in ceremony, as well as sedatives in traditional medicine. We separated the 70% EtOH extract of Vietnamese agarwood, which showed significant induction effect on brain-derived neurotrophic factor (BDNF) mRNA expression in rat cultured neuronal cells, to isolate a new compound and a 2-(2-phenylethyl)chromone derivative. The new compound was determined to be a spirovetivane-type sesquiterpene, (4R,5R,7R)-1(10)-spirovetiven-11-ol-2-one, by spectroscopic data and showed induction effect of BDNF mRNA.The new sesquiterpenoid, (4R,5R,7R)-1(10)-spirovetiven-11-ol-2-one, isolated from agarwood significantly induced brain-derived neurotrophic factor (BDNF) exon III–V mRNA expression.

Pigments are present in all living matter and provide attractive colors and play basic roles in the development of organisms. Human beings, like most animals, come in contact with their surroundings through color, and things can or cannot be acceptable based on their color characteristics. This review presents the basic information about pigments focusing attention on the natural ones; it emphasizes the principal plant pigments: carotenoids, anthocyanins, and betalains. Special considerations are given to their salient characteristics; to their biosynthesis, taking into account the biochemical and molecular biology information generated in their elucidation; and to the processing and stability properties of these compounds as food colorants.

Volatile oil from the rhizomes of Curcuma haritha Mangaly and Sabu from the Western Ghats, southern India, was isolated by hydrodistillation and characterized by a combination of GC–FID, GC–MS, co-GC, database and literature search, linear retention indices, prep. TLC, IR, NMR and MS. Refractive index, specific rotation and specific gravity of C. haritha rhizome oil were measured. Fifty constituents, comprising 99.9% of C. haritha rhizome oil, were identified, of which monoterpene hydrocarbons, oxygenated monoterpenes, sesquiterpene hydrocarbons and oxygenated sesquiterpenes constituted 7.7%, 72.0%, 1.9% and 18.2%, respectively. Camphor (36.0%), 1,8-cineole (13.9%), isoborneol (10.6%), camphene (5.7%) and linalool (4.7%) were the major monoterpenes, while curdione (6.9%), furanogermenone (3.3%) and germacrone (2.8%) were the major sesquiterpenoids in C. haritha rhizome oil. Camphor and curdione were quantified by external standardization. Copyright © 2008 John Wiley & Sons, Ltd.

The rose-scented geranium (Pelargonium sp.) cultivar ‘Kelkar’, grown in the agroclimatic conditions of the western Himalayas, was processed by various hydrodistillation methods, which revealed that water distillation of the herb gave a higher oil yield (0.16–0.22%) than the water–steam distillation (0.09–0.12%) and steam distillation methods (0.06–0.18%). The samples were analysed by GC and GC–MS to study and compare the essential oil compositions which revealed that the oil distilled by the water–steam distillation method contained a higher content of monoterpene hydrocarbons (1.7%), followed by steam distillation without cohobation and without recycling (1.5%). A higher content of sesquiterpene hydrocarbons (4.4%) was found in cumulative oil followed by ‘direct oil’ (4.2%) obtained by steam distillation with cohobation and without recycling of hydrosol, followed by the water–steam distillation method (3.4%). ‘Decanted oil’, recovered from redistilling the hydrosol obtained by steam distillation with cohobation and without recycling, contained maximum monoterpene cyclic ethers (1.1%) and carbonyl content (9.9%), closely followed by water–steam distillation method (1.1% and 7.2%, respectively). Steam distillation without cohobation and without recycling of hydrosol yielded essential oil with a higher percentage of esters (21.1%), followed by ‘direct oil’ (16.6%). Lower ester content (5.3%) was noticed in ‘decanted oil’, followed by oil distilled by steam distillation with cohobation and with recycling (11.8%) and oil distilled in a Clevenger apparatus by the water distillation method (12.2%), whereas maximum total alcohols were found in the ‘decanted oil’ (75.1%), followed by oil from the Clevenger apparatus (72.8%) and steam distillation with cohobation and with recycling (69.1%). A lower alcohol content was found in the ‘direct oil’ (55.2%) closely followed by ‘cumulative oil’ (55.8%). The variation in total alcohol and ester contents in geranium oil samples, distilled by using different processing techniques on pilot scale distillation, is mainly due to hydrolysis of some volatile constituents. This was further supported by acid values of the oils, along with other physicochemical properties, such as specific gravity, optical rotation, refractive index, solubility in alcohol, ester value with cold and hot methods, estimation of ester content as geranyl formate and geranyl tiglate, ester number after acetylation, and ester number after formylation with aceto-formic acid and formic acid. Methods have been standardized and proposed for distillations of specific quality, e.g. ester-rich and alcohol-rich geranium oils, to meet different requirements of the industry. Copyright © 2004 John Wiley & Sons, Ltd.

A combination of gas chromatographic (GC) and mass spectrometric (MS) techniques, including direct exposure-MS (DE-MS), high-temperature GC–MS (HTGC–MS) and GC–MS of neutral and acid fractions, was employed to study the composition and recognise origin of the ...

Enantiospecific synthesis of ABC-ring systems of A-nor and abeo 4(3→2) tetra and pentacyclic triterpenes has been accomplished starting from the readily available monoterpene (R)-carvone. (R)-Carvone was used as the B-ring of the target molecules. A lithium-liquid ammonia mediated cyclisation of δ,ɛ-unsaturated ester was employed for the cyclopentannulation at the C-5 and C-6 carbons of carvone and an RCM reaction was employed for the cyclohexannulation to generate the ABC-ring system of A-nor tetra and pentacyclic triterpenes. The strategy has been extended for the synthesis of the ABC-ring system of abeo 4(3→2) tetra and pentacyclic triterpenes.