Parvitexins A–E, Clerodane-Type Diterpenes Isolated from the in Vitro -Cultured Liverwort, Scapania parvitexta

Terpenoids from Chinese Liverworts Scapania spp

An investigation of the chemical composition of Chinese liverworts led to the isolation of six new caged clerodane-type diterpenoids, scaparins A-C (1-3) from Scapania koponenii and scaparins D-F (4-6) from S. verrucosa. An unknown ent-trachylobane diterpenoid (7) and three known terpenoid derivatives (8-10) were obtained from S. verrucosa. The structures of the compounds were established on the basis of physical data (IR, UV, HRESIMS, and 1D and 2D NMR), and the absolute configurations were unequivocally confirmed by comparison of the experimental and calculated electronic circular dichroism spectra. Preliminary bioassays showed that compounds 1-7 exhibited moderate to weak quinone reductase-inducing activity in Hepa-1c1c7 cells.

Clerodane diterpenoids from the Chinese liverwort Jamesoniella autumnalis and their anti-inflammatory activity

Nine previously undescribed clerodane-type diterpenoids, jamesoniellides M-T and one ent-labdane-type diterpenoid, as well as one known analogue, were isolated from the Chinese liverwort Jamesoniella autumnalis (DC.) Stephani. Their structures were determined using MS, NMR spectroscopy, and electronic circular dichroism (ECD) calculations. Inhibition on LPS-induced NO production in RAW 264.7 murine macrophages was investigated, and the results showed that jamesoniellides Q-S exhibited moderate anti-inflammatory activity, with 50-80% maximum inhibition rate of NO production under the nontoxic tested concentration.

Clerodane diterpenes: sources, structures, and biological activities

Covering: 1990 to 2015The clerodane diterpenoids are a widespread class of secondary metabolites and have been found in several hundreds of plant species from various families and in organisms from other taxonomic groups. These substances have attracted interest in recent years due to their notable biological activities, particularly insect antifeedant properties. In addition, the major active clerodanes of Salvia divinorum can be used as novel opioid receptor probes, allowing greater insight into opioid receptor-mediated phenomena, as well as opening additional areas for chemical investigation. This article provides extensive coverage of naturally occurring clerodane diterpenes discovered from 1990 until 2015, and follows up on the 1992 review by Merritt and Ley in this same journal. The distribution, chemotaxonomic significance, chemical structures, and biological activities of clerodane diterpenes are summarized. In the cases where sufficient information is available, structure activity relationship (SAR) correlations and mode of action of active clerodanes have been presented.

Scapairrins A-Q, Labdane-Type Diterpenoids from the Chinese Liverwort Scapania irrigua and Their Cytotoxic Activity

Seventeen new labdane-type diterpenoids, scapairrins A-Q (1-17), including six pairs of diastereoisomers, and three known analogues (18-20) were isolated from the Chinese liverwort Scapania irrigua. The structures of 1-17 were determined based on a combination of the analysis of their MS and NMR spectroscopic data, single-crystal X-ray diffraction, and electronic circular dichroism calculations. Cytotoxicity testing showed that compounds 7-10 exhibited inhibitory activities against a small panel of human cancer cell lines.

Phytotoxic cis-clerodane diterpenoids from the Chinese liverwort Scapania stephanii

Five cis-clerodane diterpenoids, stephanialides A-E, along with seven known cis-clerodanes, scaparvins A-C, parvitexins B and C, 3-chloro-4-hydroxy-parvitexin A, and scapanialide B, were isolated from the Chinese liverwort Scapania stephanii. Their structures were established unequivocally on the basis of spectroscopic data. The absolute configuration of stephanialide A was determined by analysis of CD data using the octant rule. Phytotoxic activity evaluation showed that this type of diterpenoids can significantly inhibit root elongation of the seeds of Arabidopsis thaliana, Lepidium sativum and Brassica pekinensis.