Biosynthesis of abscisic acid from farnesol derivatives in Cercospora rosicola

(E,E)?[1?¹⁴C]Farnesyl phosphate and (E,E)?[1?¹⁴C]farnesyl pyrophosphate were both converted to abscisic acid by Cercospora rosicola resuspensions. (E,E)?[1?¹⁴C]Farnesol, (E,Z)?[1?¹⁴C]farnesol, (E,Z)?[1?¹⁴C]farnesyl pyrophosphate, (E,E)?[1?¹⁴C]farnesic acid, and (E,Z)?[1?¹⁴C]farnesic acid were not converted to abscisic acid by the fungus. These findings provide information on the sequence of the reactions involved in converting farnesyl pyrophosphate to abscisic acid. Specifically, they suggest that the transformations involving the three terminal carbons in the side chain occur after one or more changes elsewhere in the molecule.     

Eudesmanolides and costic acid derivatives from Flourensia macrophylla

The aerial parts of Flourensia macrophylla afforded, in addition to compounds similar to those from other Flourensia species, four new eudesman     

Enantio-eudesmane sesquiterpenes from it Verbesina rupestris

The leaves and stems of Verbesina rupestris contain enantio-eudesmane sesquiterpenes, isolated as esters of cinnamic acid. This finding supports th     

Sesquiterpene acids from Dittrichia viscosa

Dittrichia viscosa afforded in addition to compounds reported previously, ilicic acid and two new sesquiterpene acids. The structures of the new compounds were established by chemical and spectral methods.     

Sesquiterpenoid lactones from the liverwort Frullania tamarisci

Four isomeric sesquiterpenoid lactones have been isolated from the liverwort Frullania tamarisci They have been identified as the simple eudesmanolides (I–III) and costunolide (IV).     

Sesquiterpenoid stress compounds from Nicotiana species

Solavetivone, 3-hydroxysolavetivone, solanascone, phytuberin and phytuberol were identified as stress compounds in leaves of Nicotiana tabacum cv Samsun NN. N. sylvestris, which is the maternal progenitor of N. tabacum, produced all the above compounds except 3-hydroxysolavetivone. In the F₁, hybrid of N. tabacum and N. glutinosa, all the stress compounds produced by N. tabacum and N. glutinosa, respectively, were accumulated.     

Sesquiterpenes from Perezia carpholepis

The previously unknown curcuquinol monoisovalerate and the known sesquiterpenes cyperene, cyperone, parvifoline, perezone, and α- and β-pipitzol were found in the roots of Perezia carpholepis. The structure of the new sesquiterpene was deduced from spectral data and by transformation into curcuquinone. Parvifoline and its derived acetate, previously thought to be oily materials, were characterized as crystalline compounds.     

Sesquiterpenes from Artemisia princeps

Copaene, cyperene, caryophyllene, β-farnesene, α-himachalene, γ-humulene and farnesyl acetate were isolated from the root of Artemisia princeps. As a result of isomerization studies on γ-humulene, the main constituent, a preferred conformation was proposed.     

Biosynthesis of (2E,4E,6E)-5-acetoxymethyltetradeca-2,4,6-trienoic acid in Eremophila oppositifolia

Evidence is presented indicating that the triple conjugated branched chain fatty acid from Eremophila oppositifolia R.Br. arises by the acetate-malonate pathway with the side chain carbon atom originating from the S-methyl group of methionine.     

Sesquiterpenoid stress compounds of the solanaceae

The sesquiterpenes isolated from species of the Solanaceae under various conditions of stress are reviewed, with brief references to other solanaceous stress metabolites. The chemistry and selected physical properties of the sesquiterpenoidal compounds are summarized with special emphasis on their ¹H and ¹³C NMR spectra. The close biogenetic relations between the compounds are discussed, and their possible biological function as antifungal agents (“phytoalexins”) is considered.     

Sesquiterpenes from Cacalia hastata

From the roots of Cacalia hastata L. subsp. orientalis Kitamura 5 sesquiterpenes were isolated; fukinone (I), dehydrofukinone (II), bakkenolide A (III), cacalohastine (IV) and dehydrocacalohastine (V).     

Sesquiterpenes from Pityrogramma calomelanos

Pterosin Z has been obtained from Pityrogramma calomelanos. A related compound calomelanolactone has also been isolated and its structure assigned from chemical, spectral, biogenetic and X-ray evidence.     

Origin of cyclohexanecarboxylic acid in Bacillus acidocaldarius

In Bacillus acidocaldarius, shikimic acid is converted into the cyclohexancearboxylic acid precursor of fatty acids by way of cyclohexene-l-carboxylic acid, but not by way of cyclohexene-3- or -4-carboxylic acid or benzoic acid.     

Tricyclic sesquiterpenes from Eremophila georgei

The structures of three new tricyclic sesquiterpenes from Eremophila georgei are described. The absolute stereochemistry of these sesquiterpenes is shown to be antipodal to that of the zizane sesquiterpenes of vetiver oil.     

Amides and other constituents from acmella ciliata

Fourteen highly unsaturated amides were isolated from Acmella ciliata. Their structures were determined by means of high field ¹H NMR including 2D-NMR, high resolution mass spectrometry and GC-MS. Some considerations on the biosynthesis of the amides are made.     

Biosynthesis of sesquiterpenes in Hymenaea inferred from their quantitative co-occurrence

Leaf pocket resins of 11 species of the tropical arborescent genus Hymenaea are virtually identical qualitatively, but of widely varying quantitative proportions. Within this large range of variability, several strong positive quantitative correlations between resin constituents were found, especially between caryophyllene and β-humulene and between γ-muurolene and δ-cadinene. These data lead to clarification of sesquiterpene biosynthetic routes in Hymenaea. In addition, quantitative relationships found among caryophyllene, α- and β-selinene, γ-muurolene and δ-cadinene are explained only with difficulty by long accepted biosynthetic pathways, and the intermediacy of germacrenes is suggested.     

Tetrahydrofuran-type terpenoids from Tanacetum vulgare

Investigation of a rare genotype of Tanacetum vulgare afforded a series of tetrahydrofuran-type terpenoids, whose pattern was different in flowers and leaves. The major constituent of the flowers was the trans Δ^3,4-hydroperoxide of davanone, whereas the leaves gave mostly a peroxyhemiketalic compound resulting from the intramolecular cyclization of the cis Δ^3,4-hydroperoxide of davanone. Structures were elucidated by spectral data and chemical reactions, including correlation with natural (+)-davanone. The peroxyhemiketalic compound upon acylation of its hydroxyl group gave an instantaneous complex reaction, resulting in the formation of a β-acyloxyenone and loss of one molecule of acetone. Among the minor constituents of the leaves, a C-10 carboxylic acid biogenetically related with davanone was isolated.     

Carotane sesquiterpenes from Ferula lancerottensis

Six new carotane sesquiterpenes, the p-hydroxybenzoate of epoxyjaeschkeanadiol the p-methoxybenzoate and p-hydroxybenzoate of lancerodiol, lancerodiol, the p-hydroxybenzoate of lancerotriol and the p-methoxybenzoate of linkitriol, and the already known p-hydroxybenzoate of jaeschkeanadiol have been isolated from Ferula lancerottensis.     

Sesquiterpenoid stress compounds from Nicotiana rustica inoculated with TMV

Sesquiterpenoid stress compounds, occidol, occidol isomer-1 occidol isomer-2, occidol acetate and phytuberin have been isolated from the leaves of Nicotiana rustica inoculated with TMV. Isomers 1 and 2 and the acetate are sesquiterpenoids not previously reported in nature.