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A total of 80 individuals collected from eight populations growing wild in different geographic zones were considered to assess the intraspecific variability of essential oil composition, genetic diversity and population structure of Artemisia herba-alba. The essential oil composition varied significantly between populations. Essential oil profiles were classified into four chemotypes (trans-sabinyl acetate, α-thujone/trans-sabinyl acetate, camphor and α-thujone/camphor/β-thujone). Despite significant correlation between the amount of some essential oil compounds and a set of climatic data, the global chemical divergence among populations was not related to their bioclimatic and geographic appurtenances. A high level of genetic diversity within populations was revealed either with RAPD and ISSR markers (Na = 1.67, PPL = 66.5%, H = 0.26, I = 0.38 and Na = 1.7, PPL = 69.8%, H = 0.26, I = 0.38, respectively). The level of genetic diversity varied across populations and chemotypes. Populations from the α-thujone/trans-sabinyl acetate chemotype exhibited the highest genetic diversity as revealed by the RAPD markers. However, populations from α-thujone/camphor/β-thujone chemotype showed the important genetic variation determined by ISSR markers. A significant genetic differentiation among populations and among chemotypes was detected. The combined analysis showed a significant correlation (r = 0.484, p = .032) between the chemical and molecular markers. The PCA, performed on percentages of major oil compounds and the frequencies of polymorphic RAPD and ISSR bands, divided populations according to their chemotypic classification. Taking into consideration the current situation of A. herba-alba populations and their endangered habitats, these results are of value in order to ensure the in-situ and ex-situ conservation of this medicinal species.

The aerial parts of Artemisia herba-alba subsp. valentine yielded, in addition to known compounds, a new germacranolide, six new eudesmanolides and ilicic acid methyl ester.

Extraction of aerials parts of Artemisia herba-alba and chromatographic separation yielded, in addition to several known eudesmanolides, a new eudesmanolide which has been named herbalbin. The structure was elucidated by high field NMR techniques.

The extract of the aerial parts of Artemisia herba-alba afforded, in addition to known compounds, two new eudesmanolides, a germacranolide, an eudesmane derivative, a hydroxylyratrol and a germacrane triol.

Extraction of aerial parts of Artemisia herba-alba subsp. herba-alba and chromatographic separation yielded, in addition to known compounds, three new germacranolides and four new eudesmanolides. The question about the structures of artesin and its 11-epimer is discussed.

Seventeen flavonoid glycosides were isolated and identified from Artemisia judaica : the 7-glucoside, 7-glucuronide, 4′-glucoside, 7-gentiobioside

The structures of herbolides A, B and C, new sesquiterpene lactones isolated from Artermisia herba alba , were determined by chemical and spectroscopic methods.

The essential oils of Artemisia herba alba populations, four from Israel and one from Sinai, were analysed. Identification of components was achieved either by isolation of pure components or by GC and GC/MS. The composition of the oils differed in the various populations. All the oils contained 1,8-cineole in varying concentrations. Irregular monoterpenes were found in two populations, in one of them at high concentration. Two main types of oils were discerned, the cineole-thujane-bornane type and the pinane type. The differences in the composition of the essential oils in the A . herba alba populations investigated are in line with the variations of their sesquiterpene lactones.

The structures of two sesquiterpene lactones isolated from Artemisia herba-alba subsp. valentina have been determined by spectroscopic methods. One of these was dihydroreynosin, the other was a new compound assigned the name torrentin. The chemical compositions of a wax and a hydrocarbon fraction from the essential oil have also been investigated.

The sesquiterpene lactones of two additional Israeli Artemisia herba alba populations, one from Elat the other from Mizpe Ramon, were investigated. While the Elat population was devoid of any sesquiterpene lactones, the Mizpe Ramon variety contained herbolides A, B and C desacetylherbolide A. Furthermore, it was found to contain the hitherto unknown herbolide D. On the basis of these and previous results the presence of at least five different chemotypes in the Middle Eastern populations of A. herba alba is established.

Two new sesquiterpene lactones, herbolides E and F, have been isolated from a further chemotype of Artemisia herba alba .

The composition of the essential oil from a Spanish population of Artemisia herba-alba has been compared with that of Israeli populations of the same plant. The chemotaxonomic affinity of the two populations was not reflected in the compositions of the oils.

The structure of the eudesmanolide torrentin from Artemisia herba-alba subs valentine has been revised on the basis of high-field 1 H NMR spectroscopy and chemical correlations.

A new chemotype of Artemisia herba alba has been analysed and been shown to contain two known sesquiterpene lactones, herbolides E and F, and three new ones, herbolides G, H and I.