Two sesquiterpenes from Senecio species

The investigation of further Senecio species gave, in addition to known compounds, two new sesquiterpenes, an eremophilane and a eudesmane derivative.     

New germacranolides and other constituents from Trichogoniopsis morii

Trichogoniopsis morii afforded, in addition to known compounds, a new toxol derivative, two diterpenes, a labdane and an ent-kaurane derivative, an eudesmanolide and five germacranolides, a furanoheliangolide and four 1-oxo-germacranolides. The structures were elucidated by spectroscopic methods and a few chemical transformations. The chemotaxonomy of the genus Trichogoniopsis is discussed briefly.     

Types of sesquiterpenes from Artemisia filifolia

The roots of Artemisia filifolia afforded in addition to known compounds an oxo-longipinane, a longibornan endoperoxide, two seco-longibornane derivatives and a himachalene derivative. The structures of the new sesquiterpenes were elucidated by several chemical transformations and by NMR spectroscopic investigations. Possible biogenetic pathways are discussed briefly.     

A labdane derivative from Chromolaena collina and a p-hydroxyacetophenone derivative. From Stomatanthes corumbensis

A new labdane derivative, 7α-acetoxy-trans-communic acid was isolated from Chromolaena collina. Extraction of Stomatanthes corumbensis yielded a new p-hydroxyacetophenone derivative which was identified as 4-methoxy-3- [3′-methyl-4′-angeloyloxy-but-2-en- 1′-yl ]-acetophenone.     

Neue sesquiterpene aus Liabum-arten

The reinvestigation of the roots of Liabum eggersii afforded, in addition to compounds reported before, several sesquiterpene hydrocarbons with unusual carbon skeletons and the first derivative of the propellane modhephene which itself is also present. The roots of L. floribundum contain a tricyclic sesquiterpene with three five-membered rings. This ketone most probably is a derivative of the sesquiterpene silphiperfolene. The structures of the new compounds were elucidated by extensive NMR studies and by some chemical transformations. Two further species only afforded known compounds. The chemotaxonomic situation is discussed briefly.     

Ein neues germacren-derivat sowie ein diterpenmalonat aus Baccharis-arten

The investigation of the aerial part of B. scandens afforded a new ketone, a germacrene derivative. The aerial parts of B. tricuneata var. lineata yielded, in addition to known ent-clerodane derivatives, a malonate of a further diterpene of this type. The structures are elucidated by spectroscopic methods.     

Neue sesquiterpenlactone aus Aster umbellatus

The investigation of Aster umbellatus afforded six new eudesmanolides and a new selina-triene and from Aster exilis a new tremetone derivative was isolated. The structures were elucidated by spectroscopic methods and by some chemical transformations. The chemotaxonomic situation is discussed briefly.     

A tetracyclic sesquiterpene,further isocedrene and guaiene derivatives from Jungia stuebelii

The aerial parts of Jungia stuebelii afforded, in addition to known compounds, two guaiene derivatives, a pseudoguaiane derivative, nine isocedrene     

A further dithienylacetylene from Eclipta erecta

The roots and the aerial parts of Eclipta erecta afforded, in addition to compounds reported previously, a new dithienyl derivative.     

Phenylpropanoid and flavonoid glycosides from the leaves of Clerodendrum infortunatum (Lamiaceae)

Clerodendrum infortunatum L. (syn.: Clerodendrum viscosum Vent.), a member of the Lamiaceae, yielded one undescribed jasmonic acid derivative, ten acteosides, and two flavonoids. The jasmonic acid derivative was identified as 6'-O-caffeoyl-12-glucopyranosyloxyjasmonic acid. The acteosides were identified as isoacteoside, acteoside, 2''-O-acetyl-martyonside, 3''-O-acetyl-martyonside, martynoside, brachynoside, leucosceptoside A, jionoside C, jionoside D, incanoside C. The flavonoids were identified as apigenin 7-O-glucuronide and acacetin 7-O-glucuronide. The structures of the isolated components have been identified by UHPLC-HRMS, 1D and 2D NMR spectroscopic analyses, spectrometric techniques, and in comparison with published NMR data. The absolute sugar configuration was determined by GLC-MS/MS analysis of the octylated derivative of the sugar moiety after hydrolysis. Among the known compounds, ten are reported for the first time from this species, while the acteoside leucosceptoside A and the two flavonoids have been isolated for the first time from the genus Clerodendrum. The chemophenetic significance of the compounds obtained from C. infortunatum is summarized in comparison to those found in other Clerodendrum species.     

N-docosanoylanthranilic acid from inula oculus-christi

The aerial parts of Inula oculus-christi afforded a new anthranilic acid derivative, acylated at the nitrogen by docosanoic acid.     

A guaianolide and other constituents from Lychnophora species

A new guaianolide, 11 β,13-dihydroeremanthine, together with a caryophyllene derivative and pentacyclic triterpenes, has been isolated from Lychnophora species.     

Riccardin C,a novel cyclic bibenzyl derivative from Reboulia hemisphaerica

Riccardin C, a novel cyclic bibenzyl derivative with a biphenyl ether and biphenyl linkages, and the previously known ent-aristolone have been isolated from the liverwort Reboulia hemisphaerica. Riccardin C trimethyl ether was identical to the dimethoxy derivative of riccardin A isolated from the liverwort Riccardia multifida.     

3-[(7Z-Hexadecenyli-4-methylfuran-2,5-dione from Piptoporus australiensis

The structure of a new citraconic anhydride derivative from Piptoporus australiensis is established by spectroscopic and chemical methods as 3-[(7Z-hexadecenyl]-4-methylfuran-2,5-dione.     

New germacranolides from Isocarpha species

The investigation of two Isocarpha species has yielded eight new germacranolides most of them belonging to the heliangolides. In addition to known p-hydroxyacetophenone-derivatives, a new dihydroeuparine derivative was isolated. The chemotaxonomical aspects are discussed.     

A kolavane derivative from Liatris scariosa

A new kolavane derivative, 18-acetoxy-kolav-3-en-15-oic acid, has been isolated from Liatris scariosa.     

Cadina-4,11-diene from Viguiera oblongifolia

Viguiera oblongifolia afforded two known furanoheliangolides and a new cadinane derivative whose structure was established by spectroscopic methods. From V. lanceolata 17,18-dihydrobudlein A was isolated.     

Labdane derivatives from Planaltoa lychnophoroides

The investigation of a representative of the small Brazilian genus Planaltoa afforded, in addition to known compounds, a new toxol derivative and two ent-labdane derivatives, closely related to austrofolin. The structures were elucidated by high field ¹H NMR spectroscopy. The chemotaxonomic situation is discussed briefly.     

A carotane derivative and a eudesmanolide from Inula crithmoides*

The aerial parts of Inula crithmoides afforded a new carotane derivative and a eudesmanolide, inucrithmolide. The most probable structures were elucidated by the spectroscopic data and by some chemical transformations.     

24-Branched Δ5 sterols from Laurencia papillosa red seaweed with antibacterial activity against human pathogenic bacteria

Methanol extract of thirty-eight seaweeds samples were first screened against Gram-positive (Staphylococcus aureus ATCC 25923 and Bacillus subtilis ATCC 6051) and -negative (Escherichia coli ATCC 8739 and Pseudomonas aerugenosa ATCC 9027) bacteria. Laurencia papillosa (Ceramiales, Rhodomelaceae, Rhodophyta) gave maximum antimicrobial activity against these bacteria. It was finally tested against four clinical Gram-negative isolates (E. coli, P. aerugenosa, Klebsiella pneumoniae and Shigella flexineri) and exhibited antibacterial activity. The extract was fractionated by column chromatography and the active fraction was identified as a cholesterol derivative, 24-propylidene cholest-5-en-3β-ol using gas chromatography mass spectrometry (GC–MS). The electrospray ionization mass spectrometry (ESI-MS) and FT-IR spectroscopic analysis also supported the structure of the compound. The minimum inhibitory concentration ranged from 1.2 to 1.7 μg/mL (IC₅₀) against clinical isolates. This is the first report of antibacterial activity of this cholesterol derivative. This compound could be exploited as potential lead molecule against broad spectrum drug development. The results also affirm the potential of seaweeds as an important natural source of antimicrobial compounds for pharmaceutical industries.