Bioactive Clerodane Diterpenoids from the Twigs of Casearia balansae

Abstract

Eight new clerodane diterpenes, balanspenes A-H (1-8), along with two known analogues (9 and 10), were isolated from the twigs of Casearia balansae. The structures of 1-8 were elucidated on the basis of extensive 1D and 2D NMR spectroscopic data analysis, and the absolute configurations of compounds 1, 4, and 7 were confirmed by comparing their experimental CD spectra with those calculated by the time-dependent density functional theory method. Compounds 4-7, 9, and 10 were found to possess the property of being able to stimulate NGF-mediated neurite outgrowth from PC12 cells.

Clerodane diterpenes: sources, structures, and biological activities

“…15 An equilibrium mixture of ptychonal ( 380 ) and ptychonal hemiacetal ( 329 ), 6α,7α-dihydroxyannonene ( 382 ), and 7α,20-dihydroxyannonene ( 383 ), significantly enhanced NGF-mediated neurite outgrowth in PC12 cells at concentrations ranging from 0.1 to 50.0 μM, 0.1 to 30.0 μM, and 0.1 to 10.0 μM, respectively. 130,474 At 10, 30, and 100 μmol, compounds 435 and 436 had no effect on neurite outgrowth from PC12D cells in the absence of NGF, but at 100 μmol, decidedly increased the NGF (2 ng mL −1 )-induced proportion of neurite-bearing PC 12D cells by 49% and 53%, respectively.…”

Diastereoselective Total Syntheses of (±)‐Caseabalansin A and (±)‐18‐Epicaseabalansin A via Intramolecular Robinson‐type Annulation

“…Their structures, including their relative configurations, have been elucidated by one‐dimensional (1D) and two‐dimensional (2D) NMR analyses and high‐resolution mass spectra (HRMS). Although the absolute configurations of 1 and 2 are yet to be determined, they are more likely to be ent ‐ neo ‐clerodane diterpenoids because several ent ‐ neo ‐clerodane diterpenoids with structures similar to 1 and 2 have been isolated from the same genus . The structural features of 1 and 2 include a fused tetracyclic framework bearing cyclic acetal and hemiacetal moieties, a conjugated diene embedded in the side chain, and eight stereogenic centers, two of which are quaternary carbons.…”

“…Although the absolutec onfigurations of 1 and 2 are yet to be determined, they are more likely to be ent-neoclerodane diterpenoidsb ecauses everal ent-neo-clerodane diterpenoids with structures similar to 1 and 2 have been isolated from the same genus. [9] The structural features of 1 and 2 include af used tetracyclic framework bearing cyclic acetal and hemiacetal moieties, ac onjugated diene embedded in the side chain, and eight stereogenic centers, two of which are quaternary carbons. Since 1 and 2 are inseparable, evaluation of their bioactivity was conducted after O-acetylation.…”

Isolation and Characterization of Sesquiterpenes from Celastrus orbiculatus and Their Antifungal Activities against Phytopathogenic Fungi

“…Subfraction F [3][4] was further purified by preparative HPLC (YMC-pack ODS-AM, 250 × 20 mm i.d., 85% MeOH in H 2 O) to afford compound 1 (t R = 29 min, 14.7 mg). Fraction F 5 (eluted by petroleum ether/acetone, 100:10 and 100:15), using the above MPLC (67−87% MeOH in H 2 O), provided 12 subfractions F 5-1 −F [5][6][7][8][9][10][11][12] , and the following purification of F 5-1 by the Computational Methods. Details have been previously reported.…”

“…Details have been previously reported. 11,12 Antifungal Activity Assay. The antifungal activities of the isolated compounds were tested against six pathogenic fungi (Gibberella zeae, Physalospora piricola, Alternaria solani, Cercospora arachidicola, Cladosporium cucumerinum, and Phytophthora capsici) using a mycelium growth inhibition method.…”