Anti‐inflammatory effect of isopimarane diterpenoids from Kaempferia galanga

Abstract

Two new isopimarane diterpenes, 1α‐hydroxy‐14α‐methoxyisopimara‐8(9),15‐diene (7) and 1α,14α‐dihydroxyisopimara‐8(9),15‐diene (9) and eight known isopimarane diterpenes including (‐)‐sandaracopimaradiene (1), 6β‐acetoxysandaracopimaradiene‐9α‐ol (2), sandaracopimaradiene‐7β,9α‐diol (3), sandaracopimaradiene‐1α,9α‐diol (4), 6β‐acetoxysandaracopimaradiene‐9α‐ol‐1‐one (5), 6β‐acetoxysandaracopimaradiene‐1α,9α‐diol (6), 6β,14α‐dihydroxyisopimara‐8(9),15‐diene (8), and 6β,14β‐dihydroxyisopimara‐8(9),15‐diene (10) were isolated from hexane fraction of Kaempferia galanga ethanol extract. Compounds 5, 6, 8, and 9 exerted the good anti‐inflammatory effect on lipopolysaccharide‐stimulated nitric oxide production from RAW264.7 cells with IC50 of 11.2, 7.7, 14.3, and 12.1 μM, respectively. These four compounds inhibited nitric oxide synthase (iNOS) mRNA expression. Compounds 5 and 6 also suppressed cyclooxygenase 2 (COX‐2) mRNA expression; in addition, compound 6 had mild inhibitory effect on TNF‐α mRNA. Among these compounds, 5 dramatically inhibited iNOS and COX‐2 mRNA expression. The influential structures were proposed to be oxygen substitute at C‐1, C‐6, and α‐OH at C‐14.

Functional identification of the terpene synthase family involved in diterpenoid alkaloids biosynthesis in Aconitum carmichaelii

“…The product of AcKSL3-2 was found to be ent -13- epi -sandaracopimaradiene, making it the first enzyme to be identified to synthesize this diterpene. Other ent -sandaracopimaradiene-like compound derivatives have been isolated from several species including rice 45 , Kaempferia galanga 47 , and Guarea rhophalocarpa 48 ; however, it has not reported previously in Aconitum . On the other hand, beside ent -13- epi -sandaracopimaradiene, it also produced ent -kaurene and another unknown diterpene in the engineered E. coli .…”

Succinum extracts inhibit microglial-derived neuroinflammation and depressive-like behaviors

“…For further process to identify the bioactive compound of succinum, we confirmed that EtOAc PSF was most similar to the PSE effect among the three fractions ( Supplementary Figures S2A,B ). In recent, isopimarane diterpenes showing anti-inflammation properties have been proposed as a bioactive compound of succinum, and it ameliorated cognitive impairment via inhibiting hippocampal apoptosis ( Tungcharoen et al, 2020 ; Wei et al, 2022 ). As mentioned above, we speculate that terpenes-based compounds may involve with the anti-neuroinflammatory and antidepressant-like effects.…”

Functional characterization and structural bases of two class I diterpene synthases in pimarane-type diterpene biosynthesis

“…EIMS analysis afforded an M + ion at m/z 272.2. Compound 9 was identified as isopimara-8( 14),15-diene based on the comparison of its 1 H NMR data (Table S5) and 13 C NMR data (Table S6) with authentic data published before 41 . The absolute configuration assignments of 2-7 were also benefitted by the structure of syn-CPP, whose absolute configurations have already been set from the catalysis of the class II DTS OsCPS4.…”