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

Abstract

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.

Secondary Metabolites from the Fresh Leaves of Pinus yunnanensis Franch

“…The 1 H-NMR spectrum of compound 1 was presented in Table 1, which showed the signals attributable to the ring-A aromatic protons (δ H 5.99 and 5.95, each d, 1.7) and the ring-C (δ H 5.12, 1H, d, 11.6, H-2; and δ H 4.41, 1H, d, 11.6, H-3). The big coupling constant of the H-2 and H-3 suggested the 2,3-trans configuration, which is related to that of (+)-taxifolin (2). The remaining proton signals were assigned to one olefinic moiety (δ H 6.36, 1H, br.…”

Bioactive Constituents from the Bryophyta Hypnum plumaeforme

“…The known compounds were identified as acrenol ( 2 ), [11] momilactones A ( 3 ) and B ( 4 ), [8] dehydroabietic acid ( 5 ), [12] 15‐hydroxydehydroabietic acid ( 6 ), [12,13] 13‐hydroxy‐8,11,13‐podocatpatrien‐18‐oic acid ( 7 ), [13] 8(14)‐podocarpen‐13‐on‐18‐oic acid ( 8 ), [14] abiesanordine E ( 9 ), [14] (13 S )‐15‐hyhroxylabd‐8(17)‐en‐19‐oic acid ( 10 ), [15] 14,15,16‐trisnor‐8(17)‐labdene‐13,19‐dioic acid ( 11 ), [16] labda‐8(17),13 Z ‐dien‐15,18‐dioic acid ( 12 ), [17] pinyunin A ( 13 ), [18,19] loliolide ( 14 ), [20] oleanolic acid ( 15 ), [21] ursolic acid ( 16 ), [21] (2 S ) ‐ 2,3‐dihydroxypropyl hexanoate ( 17 ), [22] and 3′,3′′′‐binaringenin ( 18 ) [23] based on their spectroscopic data in comparison with reported literature and/or thin layer chromatography with standards ( 15 and 16 , previously isolated and structural elucidated). Pinyunin A ( 13 ) was isolated from bryophytes for the first time.…”

9-Step synthesis of (−)-larikaempferic acid methyl ester enabled by skeletal rearrangement

“…The failure of converting 16 to larikaempferic acid methyl ester (2) indicates that the trans ring junction stereochemistry of the 5,7-fused ring system is important for the oxa-Michael addition. Thus, we needed to tune the transannular aldol reaction to provide the desired trans 5,7-fused system.…”

“…With a better understanding of the transannular aldol reaction and 19 in hand, we moved forward to complete the synthesis of larikaempferic acid methyl ester (2). Saegusa-Ito oxidation of 19 occurred smoothly to deliver enone 20 in 70% yield over two steps.…”

“…Interestingly, Zhao et al recently discovered larikaempferic acid from the root bark of Pinus massoniana as well. 2 Biologically, larikaempferic acid methyl ester was found to have potent inhibitory effect on Epstein–Barr virus early antigen (EBV-EA) activation in Raji cells induced by 12- O -tetradecanoylphorbol 13-acetate (TPA). It's more effective than β-carotene, 3 which has been heavily investigated in cancer prevention in animal models.…”