Rearranged Diterpenoids Research Articles

Strophioblachins A-K, Structurally Intriguing Diterpenoids from Strophioblachia fimbricalyx with Potential Anticardiac Hypertrophic Inhibitory Activity.

Three new rearranged diterpenoids, strophioblachins A-C (1-3), eight new diterpenoids, strophioblachins D-K (4-11), and seven previously described diterpenoids (12-18) were purified from the aerial parts of Strophioblachia fimbricalyx. Compounds 1 and 2 contain a rare 6/6/5/6 ring system, while 3 has an uncommon tricyclo[4.4.0.08,9]tridecane-bridged unit, and their diterpenoid skeletons are being reported for the first time. Utilizing spectroscopic and HRESIMS data analysis, the structures of the new compounds (1-11) were established, and ECD and 13C NMR calculations were used to confirm the relative and absolute configurations of 11 and 9. The absolute configurations of compounds 1, 3, and 10 were established using single-crystal X-ray diffraction. The results of testing for anticardiac hypertrophic activity demonstrated that compounds 10 and 15 dose-dependently lowered the mRNA expression of Nppa and Nppb. Protein levels were confirmed by Western blotting, which also demonstrated that compounds 10 and 15 lowered the expression of the hypertrophic marker ANP. The cytotoxic activity against neonatal rat cardiomyocytes was assayed in vitro by the CCK-8 and ELISA methods, and the results showed that compounds 10 and 15 were only very weakly active in the range.

Rearranged Terpenoids from the Marine Sponge Darwinella cf. oxeata and Its Predator, the Nudibranch Felimida grahami.

Marine sponges are a rich source of terpenoids with rearranged spongian carbon skeletons. Investigation of extracts from the sponge Darwinella cf. oxeata yielded four new rearranged diterpenoids, oxeatine (2) and oxeatamides H-J (3-5), as well as the known metabolites oxeatamide A (6), oxeatamide A methyl ester (7), and membranolide (1). Oxeatine (2) has a new heterocyclic skeleton, while oxeatamide J (5) has an N-methyl urea group included in a γ-lactam moiety. UPLC-QTOF analysis of the extract obtained from the mantle of the nudibranch Felimida grahami indicated the presence of 1 and 4.

Rearranged diterpenoids from the seeds of Caesalpinia sappan

Two new rearranged diterpenoids, tomocinol C (1) and spirocaesalmin C (2) were isolated from the seeds of Caesalpinia sappan. Their structures were elucidated based on comprehensive analysis of spectroscopic data, and their absolute configurations were established by single crystal X-ray crystallography.

A rearranged labdane-type diterpenoid and other constituents from Vitex negundo var. cannabifolia

► A new rearranged diterpenoid was isolated from Vitex negundo var. cannabifolia . ► The diterpenoid exhibited weak activities against some spoilage microorganisms. ► Lamiaceae s.l. has a closer taxonomy relationship with Vitex than Verbenaceae s.str.

Unsaturated Diterpenoids with a Novel Carbocyclic Skeleton from Salvia xalapensis

Two diterpenoids with an unprecedented carbocyclic skeleton, salvixalapadiene (3) and isosalvixalapadiene (4), have been obtained from the leaves of Salvia xalapensis. The rearranged skeleton of these products may be derived biogenetically from a salvigenane precursor. In addition, two new rearranged diterpenoids (1 and 2) belonging to already known skeletons were isolated. The structures of the new compounds (1-4) were elucidated on the basis of spectroscopic data interpretation.