COX-2 and iNOS inhibitory abietane diterpenoids from Pinus yunnanensis exudates

Pinuskesiols A-F (1-6), six new structurally diverse abietane diterpenoids were isolated from Pinus yunnanensis resins. Their structures including absolute configurations were characterized by using spectroscopic and computational methods. All the compounds bear a carbonyl functionality at C-4 with 1 and 2 behaving as a lactone thereof. The isopropyl group is attached to C-13 via O-atom in 3. In addition, the presence of a Δ⁵⁽⁶⁾ double bond and a ketone at C-7 makes 2 a large conjugated system. Biological evaluation revealed that 1, 2, and 4 could concentration-dependently inhibit iNOS and COX-2 expression in lipopolysaccharide-induced RAW 264.7 cells with 2 to be the most active toward COX-2 inhibition.

Diterpenoids from the Root Bark of Pinus massoniana and Evaluation of Their Phosphodiesterase Type 4D Inhibitory Activity

Thirty-two diterpenoids were obtained from the root bark of Pinus massoniana, and, among them, five compounds (pinmassins A-E) were identified as undescribed analogues. Spectroscopic methods, X-ray single-crystal diffraction analysis, and ECD calculations were applied to establish the structure of the new isolates. Pinmassin D (4) and abieta-8,11,13,15-tetraen-18-oic acid (23) showed moderate phosphodiesterase type 4D (PDE4D) inhibitory effects with IC₅₀ values of 2.8 ± 0.18 and 3.3 ± 0.50 μM, respectively, and their binding modes were investigated by a molecular docking study.

Synthesis and Biological Studies of (+)-Liquiditerpenoic Acid A (Abietopinoic Acid) and Representative Analogues: SAR Studies

The first semisynthesis and biological profiling of the new abietane diterpenoid (+)-liquiditerpenoic acid A (abietopinoic acid) (7) along with several analogues are reported. The compounds were obtained from readily available methyl dehydroabietate (8), which was derived from (-)-abietic acid (1). Biological comparison was conducted according to the different functional groups, leading to some basic structure-activity relationships (SAR). In particular, the ferruginol and sugiol analogues 7 and 10-16 were characterized by the presence of an acetylated phenolic moiety, an oxidized C-7 as a carbonyl, and a different functional group at C-18 (methoxycarbonyl, carboxylic acid, and hydroxymethyl). The biological properties of these compounds were investigated against a panel of six representative human tumor solid cells (A549, HBL-100, HeLa, SW1573, T-47D, and WiDr), five leukemia cellular models (NALM-06, KOPN-8, SUP-B15, UoCB1, and BCR-ABL), and four Leishmania species ( L. infantum, L. donovani, L. amazonensis, and L. guyanensis). A molecular docking study pointed out some targets in these Leishmania species. In addition, the ability of the compounds to modulate GABA_A receptors (α₁β₂γ_2s) is also reported. The combined findings indicate that these abietane diterpenoids offer a source of novel bioactive molecules with promising pharmacological properties from cheap chiral-pool building blocks.

Diterpenoids from the shed trunk barks of the endangered plant Pinus dabeshanensis and their PTP1B inhibitory effects

11 new (including an unprecedented skeleton, 3) and 28 related known diterpenoids with interesting PTP1B inhibitory effects were identified.

Diterpenoids of terrestrial origin

This review covers the isolation and chemistry of diterpenoids from terrestrial as opposed to marine sources and includes, labdanes, clerodanes, pimaranes, abietanes, kauranes, gibberellins, cembranes and their cyclization products. The literature from January to December, 2014 is reviewed.