Fernando A. Camou

Diterpenoids of Conyza coulteri

Abstract Four furanoditerpenoids, including three furanoclerodanes, have been identified in the extract of the aerial parts of Conyza Coulteri . One of the terpenoids, 2β-hydroxyhardwickiic acid, was found as a natural product for the first time.

Sesquiterpenoid glycosides and an acetogenin glucoside from Lessingia glandulifera

Abstract An extract of Lessingia glandulifera yielded, besides five known compounds, a new acetogenin glucoside (heptane 2- O -β- d -glucopyranoside) and nine new sesquiterpene glycosides: 11- O -α- d -arabinopyranosyl-4-hydroxyisobulnesol (=lessingioside) and the 11- O -α- d -arabinopyranosyl and 11- O -α- d -(3′,4′- O -diacetyl)-arabinopyranosyl derivatives of the isomeric alcohols, isobulnesol, α- and β-eudesmols, and elemol.

A new diterpenoid from Ericameria laricifolia

Abstract An acid fraction of the methylene chloride extract of Ericameria laricifolia gave, in addition to four known grindelanes, a new diterpenoid acid possessing an ent -labdane skeleton. Its structure, based on the spectral properties of its methyl ester derivative, has been determined as 15-succinyloxy- ent -labd-13 E -en-8β-ol.

Hydroxygrindelane derivatives by microbial transformation

Abstract The microbial transformation of methyl 7α,8α-epoxygrindelate and 6,8(17)-dehydrogrindelic acid by cultures of Aspergillus niger and Penicillium brevicompactum produced the corresponding 3α-hydroxygrindelanes.

Diterpenoids and acetogenins of Blepharizonia plumosa

Abstract The chemical investigation of the methylene chloride extract of Blepharizonia plumosa has resulted in the isolation of eight new compounds in addition to two known isomeric labdane diterpenoids [13 R ,14 R ,15-tri-hydroxylabd-(8,9)-ene and 7-ene]. The new compounds include three acetogenins [3 R ,11 R -dihydroxy-, 3 R -acetoxy-11 R -hydroxy- and 3 R -hydroxy-11-ketododecanoic acid (isolated as Me esters)], the E and Z isomers of 2-cinnamoyl-3-butanol, and three diterpenoids [7α,13 R ,14 R ,15-tetrahydroxylabd-8(17)-ene (blepharizol A), S R ,13 R -oxido-14 R ,15-dihydroxylabd-9(11)-ene (blepharizol B) and 8-keto-8,9-seco-9,14 R ,15-trihydroxygrindelane (blepharizone)].

Kolavane diterpenoids of Vanclevea stylosa

Abstract From the aerial parts of Vanclevea stylosa , 19 new kolavane diterpenoids were isolated as their methyl ester derivatives and two were also isolated as the free acids. Their structures were elucidated from the NMR and mass spectra and a few chemical transformations. All the compounds are kolavenol derivatives having a succinyloxy group either at C-17 or C-18, with widely differing C-9 side chains; in four cases carbons have been lost from this side chain. Three known flavonoids, identified as kaempferol 3,7,4′-trimethyl ether, quercetin 3,7,3′,4′-tetramethyl ether (retusine) and quercetin 3,3′-dimethyl ether, were also isolated.

Wrightol, a sesquiterpene of the eremophilane type from Solidago wrightii

Abstract The dichloromethane extract of the aerial parts of Solidago wrightii furnished a new eremophilane sesquiterpene, wrightol (6β-cinnamoyloxy-1gb-hydroxy-7α (H)-11,12-dihydroeremophil-9-ene),in addition to a known isomeric eudesmane sesquiterpene (6β-cinnamoyloxy-1β-hydroxyeudesm-4(15)-ene)and ga-spinasterol.

Sesquiterpenoids from Coreocarpus arizonicus

Abstract Ten sesquiterpenoids were isolated from the methylene chloride extract of Coreocarpus arizonicus . Five were new, identified on the basis of spectral data as 1 ( R ), 4( R ), 7( S )- and 1( S ), 4( S ), 7( S )-bisabol-2-en- 1,4-diols and dimers of perezone (biperezone) and its 12-(2-methylbutyroxyl) and 12-isovaleroxyl derivatives oxidatively coupled through C-4. The known sesquiterpenoids were costunolide, dihydrocostunolide, perezone, α-pipitzol and spathulenol.

Terpenoids from Acamptopappus sphaerocephalus and A. shockleyi

Abstract Eight new labdane diterpenoids were isolated from the sodium carbonate-soluble acid fraction of Acamptopappus sphaerocephalus and their structures were deduced from the spectral properties of their methyl esters and other derivatives. They are 7, E -13- or 8, E -13-labdadienes having oxygen-containing substituents at C-2, C-7, C-15 and/or C-19. These same diterpenoids were also present in A. shockleyi . Eight previously reported sesquiterpenoids, namely, bisabolene-1,4-endoperoxide, caryophyllene oxide, β-eudesmol, trans -nerolidol, 1-oxobisabolene, shiromool, spathulenol and viridiflorol, were isolated from the non-polar fraction of A. sphaerocephalus and identified by their 1 H NMR spectra.

The bromination product of santonic acid in wet chloroform

Abstract The bromination product of santonic acid in wet chloroform is found to be a dibromide closely related to the tribromosantonin characterized by Woodward, Levine and Yates.