José M. Arteaga

Five new labdane diterpene oxides from Eupatorium jhanii

The authors would like to thank Dr. A. Morales, University of Merida (Venezuela) for gathering the plant and for the sustained interest he has shown in the progress of this work.

Dehydroabietane diterpenes from Nepeta teydea

Abstract The new diterpenes dehydroabietan-18-ol acetate, teideadiol 18-monoacetate, teideadiol 18-malonate and teidic acid have been isolated from the aerial parts of Nepeta teydea . The known diterpenes dehydroabietan-18-ol (pomiferin A) and teideadiol have also been obtained from this species. The 13 C NMR spectra of several dehydroabietane derivatives have been assigned.

Nor-sesquiterpenes from Teucrium heterophyllum

A new sesquiterpene, 7-epi-teucrenone, and six novel nor-sesquiterpenes, teuhetone, teuhetenone A, teuhetenone B, tephyllone, 9β-hydroxy-tephyllone and 9-oxo-tephyllone, have been isolated from the aerial parts of Teucrium heterophyllum. This plant also contains the known terpene 3-oxo-α-ionol (3,4-dehydro-blumenol C)

Diterpenes from sideritis dendrochahorra and s. cystosiphon

Abstract A new diterpene, sidendrodiol (ent-16β,18-dihydroxykaur-11-ene), has been isolated from Sideritis dendrochahorra. From S. cystosiphon two new diterpenic esters, the 18-palmitate of epicandicandiol and the diacetate of epicandicandiol have been identified. The 13CNMR spectra of ent-16β-hydroxykaur-11-ene and ent-16β-hydroxykaurane derivatives have been assigned.

Elemanolides from Centaurea melitensis

Abstract Two new elemanolides isolated from Centaurea melitensis L. have been shown to correspond to the β-hydroxyisobutyrates of melitensin (1c) and its 11(13)-dehydro derivative (1a).

Eudesmane sesquiterpenes from Teucrium heterophyllum. The x-ray structure of teucdiol a

Abstract Three new eudesmane sesquiterpenes, teucdiol A, teucdiol B and teucrenone, have been isolated from the aerial parts of Teucrium heterophyllum. The structure of teucdiol A has been determined by X-ray analysis. Molecules of teucdiol A and water are linked by hydrogen bond chains. These chains have a core of water molecules surrounded by a hydrophobic spiral of hydroxyl groups of teucdiol A molecules.

Diterpenes from Sideritis ferrensis

Abstract The new diterpenes candol A acetate, trachinodiol diacetate, ent -18-acetoxy-16α-hydroxy-atisane, and ent -17,18-dihydroxy-kaur-15-ene (ferrediol) have been isolated from Sideritis ferrensis .

Diterpenes from Sideritis sventenii and S. cystosiphon

Abstract The new diterpenes, 7β-monoacetate of episinfernal, 7β-monoacetate of sideritriol, and sventenic acid, have been isolated from Sideritis sventenii . From S. cystosiphon , three new diterpenic esters, the 7β-acetate, 18-palmitate of epicandicandiol, the 18-acetate of epicandicandiol, and the 7β,17-diacetate of sideritriol, have been obtained.

Abietane diterpenes from Nepeta teydea

The structures of two abietane diterpenes previously isolated from Nepeta teydea have been corrected and they have now been named netidiol A and netidiol B. The new diterpenes netidiol A 7α-monoacetate, netidiol A 18-monoacetate, 8α,14α-epoxy-netidiol A, netidiol A 7α-propyl ether, netidiol B 14α-monoacetate, netidiol B 18-monoacetate and netiol have also been isolated from this species.

The structure of jhanilactone

The molecular structure and absolute configurationI was assigned to jhanilactone, a new lactone fromEupatorium jhanii Robinson, on the basis of X-ray crystallography and circular dichroism data.