Records of Natural Products

Two new rearranged abietane diterpenoids (1 and 2), together with eleven previously described analogues (3–13), were obtained from the ethanolic extract of a traditional ethnological herb, Clerodendrum bungei. The structures with absolute configurations of the new compounds were unambiguously characterized via spectroscopic methods, and that of the formerly reported crolerodendrum B (3) was corrected in the present work. Biological assessment of these isolates revealed that diterpenoids 2, 4, 6 and 12 showed significant inhibition against a-glucosidase enzyme with IC50 values in the range of 17.0–25.7 mM.

The chemical compositions of the volatile fractions, produced by the flowers and leaves of two Olea europaea L. cultivars (Chemlal and Sigoise) were investigated. The plant materials were harvested from two different zones in Algeria (Mediterranean and arid regions). The samples were extracted by hydrodistillation using a Clevenger apparatus. GC-MS analysis allowed the identification of 51 compounds. According to the geographic origin and the cultivar, qualitative and semi-quantitative variations were observed, especially with the abundance of the main compounds. Overall, the principal component analysis showed that the environmental condition was mainly affecting the production of the major compounds. Throughout the two regions, the main substances in the samples from the Mediterranean region were (Z)-jasmone (51.8%), nonanal (32.4%), theaspirane II (23.7%) and phenylethyl propionate (17.9%). While those of the arid region were bornyl acetate (26.8%), 3-ethenyl pyridine (17.2%), (E,E)-2,4-heptadienal (16.9%) and (E)-geranylacetone (14.4%), with a significant correlation between the flower volatiles, more than 86% in both regions. These results can add a valuable insight into the effect of arid climate on the production of volatiles by Olea europaea.

Two new Chloratene F (1) and Chlomultin G (2), along with eight known sesquiterpenes (3-10) and six other known compounds (11-16) were isolated from the whole plant of Chloranthus henryi. Their structures were elucidated by HR-ESI-MS, NMR spectroscopic. The absolute configuration of two new compounds were determined by the X-ray crystallographic. All the compounds were reported for the first time from this species.

The chemical compositions and anticandidal activities of the essential oils from the aerial parts, inflorescence, and roots of the endemic P. heyniae H. Duman & M. F.Watson were evaluated. Hydrodistillation was used to isolate the essential oils and the chemical analyses were performed both by GC-FID and GC/MS, respectively. Forty-four compounds constituting 94.4% of aerial parts, thirty-nine compounds constituting 99.5% of inflorescence, and twenty-five compounds representing 100.0% of root essential oil were characterized. The main compounds of the aerial parts oil were elemol (36.2%), b-bisabolenal (14.1%), and germacrene D (12.7%). Main compounds of inflorescence oil were b-bisabolenal (21.6%) germacrene D (15.6%), and germacrene B (12.4%) while the roots oil were a-pinene (44.8%), limonene (15.3%), b-pinene (12.5%), and d-3-carene (10.2%), respectively. The in vitro anticandidal activity of the essential oils were evaluated against several Candida strains by using partly modified CLSI broth microdilution method M27-A2. The tested essential oil showed relatively weak effects against pathogenic Candida strains compared to standard antifungal agents.