Dolabellane Diterpenoids Research Articles

Targeted Isolation of Dolabellane Diterpenoids from the Soft Coral Clavularia viridis Using Molecular Networking.

LC-MS/MS-based molecular networking annotation coupled 1H NMR detection allowed the depiction of the soft coral Clavularia viridis to produce a profile of dolabellane-type diterpenoids. Chromatographic separation of the EtOAc fraction resulted in the isolation of 12 undescribed dolabellane-type diterpenoids, namely, clavirolides J-U (1-12). Their structures were characterized by the extensive analysis of the spectroscopic data, including the calculated ECD and X-ray diffraction for the configurational assignments. Clavirolides J-K are characterized by a 1,11- and 5,9-fused tricyclic tetradecane scaffold fused with a α,β-unsaturated-δ-lactone, and clavirolide L possesses a 1,11- and 3,5-fused tricyclic tetradecane scaffold, which extend the dolabellane-type scaffolds. Clavirolides L and G showed significant inhibition against HIV-1 without RT enzyme inhibition, providing additional non-nucleosides with different mechanisms from efavirenz.

Dolabellane Diterpenoids from the Xisha Soft Coral Clavularia viridis.

Twelve new members (1–12) of the dolabellane family, co-occurring with three related known diterpenoids (13–15), were isolated from the Xisha soft coral Clavularia viridis. Their structures were determined by extensive spectroscopic analysis, modified Mosher’s method, and X-ray diffraction analysis. Clavuperoxylides A (3) and B (4) represent the first examples of dolabellanes containing peroxyl groups, especially the novel peroxide bridge in 4, whereas clavufuranolides A–C (9–11) are the first example of dolabellane diterpenoids comprising a tetrahydrofuran ring. The possible biogenetic relationship of all the isolates was proposed. In bioassay, several compounds exhibited considerable cytotoxicity against A549 and P388 cell lines. Compound 7 exhibited inhibitory activity against protein tyrosine phosphatases 1B (PTP1B), an anti-diabetic target, representing the first report of PTP1B inhibitory activity for dolabellane diterpenoids.

Dolabellane and Clerodane Diterpenoids from the Twigs and Leaves of Casearia kurzii.

A pair of enantiomeric 15-nordolabellane diterpenoids, (-)- and (+)-caseadolabellols A (1a and 1b), three dolabellane diterpenoids, caseadolabellols B-D (2-4), two dolastane diterpenoids, caseadolastols A and B (5 and 6), 10 clerodane diterpenoids, caseakurzins A-J (7-16), and nine known diterpenoids (17-25) were isolated from the twigs and leaves of Casearia kurzii. The structures of the new compounds were established on the basis of extensive spectroscopic data, and those of compounds 1a, 1b, and 2 were verified by single-crystal X-ray crystallographic analysis. The enantiomers 1a and 1b were separated by chiral-phase HPLC. The absolute configurations were determined by experimental and calculated ECD data, the modified Mosher's method, or literature comparison. Compounds 1a and 5 showed significant quinone reductase-inducing activity in Hepa 1c1c7 cells, while 1b showed moderate activity. Molecular docking studies showed that 1a had greater binding affinity with Nrf2 protein (5FNQ) than 1b. The cytotoxic activity of compounds 1a, 1b, 2-12, 15, and 16 was evaluated, among which compounds 8 and 16 exhibited significant inhibitory activity against the A549 cell line. Compounds 8 and 16 induced the A549 cells to arrest at G2/M and S phases, respectively, and both compounds induced apoptosis in A549 cells.

Sangiangols A and B, Two New Dolabellanes from an Indonesian Marine Soft Coral, Anthelia sp.

A new, rare trinor-dolabellane diterpenoid, sangiangol A (1), and one new dolabellane diterpenoid, sangiangol B (2), together with known cembranes and dolabellanes (3–8), were isolated from the ethyl acetate layer of an extract of an Indonesian marine soft coral, Anthelia sp. Compounds 1–8 exhibited moderate cytotoxicity against an NBT-T2 cell line (0.5–10 µg/mL). The structures of the new compounds were determined by analyzing their spectra and a molecular modelling study. A possible biosynthetic pathway for sangiangols A (1) and B (2) is presented. Cytotoxicity requires two epoxide rings or a chlorine atom, as in 4 (stolonidiol) and 5 (clavinflol B).

Cytotoxic components from the Xisha sponge Fascaplysinopsis reticulata

A new dolabellane diterpenoid, clavirolide H (1), together with eleven known compounds, including two dolabellane diterpenoid (2 and 3), a rare cavernosine-type C17 γ-lactone terpenoid (4), a diketopiperazine (5) and seven sterols (6–12), were isolated from the Xisha sponge Fascaplysinopsis reticulata. Their structures were elucidated by extensive spectroscopic analysis, and the four types of compounds of the above isolates were reported from the genus Fascaplysinopsis for the first time. Selected compounds 1, 4–6 and 9–12 were evaluated for cytotoxic activities against K562, HL-60, Hela, HCT-116, A549, L-02 and BEL-7402 cell lines. Compounds 4–6 and 10–12 showed potent cytotoxicitives against HL-60 with IC50 values ranging from 8.8 to 12.4 μM. Compounds 4 and 5 exhibited weak cytotoxic activities against HeLa with IC50 of 20.7 and 27.4 μM, and 5 also has moderate cytotoxicity against HCT-116 with IC50 of 16.3 μM.

Diterpenoids and triterpenoids with potential anti-inflammatory activity from the leaves of Aglaia odorata

Chemical investigation of the leaves of the oriental medicinal plant Aglaia odorata resulted in the isolation of five compounds: two dolabellane diterpenoids, two dammarane triterpenoids and a protostane triterpenoid, along with twenty known compounds. Their structures were elucidated on the basis of extensive spectroscopic analysis and by comparison of their NMR spectroscopic data with those reported in the literature. The anti-inflammatory activities of all compounds were evaluated as inhibitory activities against lipopolysaccharide (LPS) induced nitric oxide (NO) production in RAW264.7 cell lines. Eleven compounds possessed potent nitric oxide inhibitory activity with IC50 values ranging from 2.1 to 14.2μM, these being better than that of the positive control, indomethacin (IC50=14.5μM). In addition, three compounds exhibited significant activity against PGE2 release with IC50 values of 2.6, 16.1 and 23.0μM.

Dolabellane Diterpenoids from the South Atlantic Gorgonian Convexella magelhaenica

Two new dolabellane diterpenoids (1 and 2) were isolated from a small sample of the deep water gorgonian octocoral Convexella magelhaenica collected as a nontarget by-catch by dredging (-93 m) in commercial Patagonian scallop fishing grounds in the South Atlantic. The structures of the new compounds, which are major metabolites in the extract, were established by spectroscopic techniques and chemical transformations. Both compounds were cytotoxic against a human pancreatic adenocarcinoma cell line at micromolar concentrations.

ChemInform Abstract: Conformation of an Eleven-Membered Lactone: Structure of (E,13R,14S)- 13-Hydroxy-17-nor-8,9-secolabd-9(11)-en-8,14-olide.

C19H3203, Mr=308.49, orthorhombic, P212121, a = 7-072 (3), b = 9389 (3), c = 27-888(11)A, v=1852(2)A 3, z=4, Ox = I. 11 Mg m - 3, ,t(Mo Ka) = 0.71069 )k, /z = 0.08 mm-1, F(000) = 680, T = 293 K, R = 0.050 for 1475 independent reflections with I> 2-5o'(/). The conformation of the l l-membered lactone ring is essentially the same as the calculated minimum- energy conformation of trans, trans-cycloundeca- 1,6-diene with differences between corresponding ring torsion angles of only 1-15 ° (mean 6°). This conformation is found in several cytochalasans and dolabellane diterpenoids but not in the pyrrolizidine alkaloids with l l-membered dilactone rings. The cyclohexane ring is distorted to alleviate 1,3-diaxial repulsion between methyl substituents (C(18)-C(20) = 3.291 (7) A); the smallest torsion angles (-47.4 (5), 48.1 (5) °) are at ring bonds between the methyl groups, the largest torsion angles (-55-6 (6), 56.4 (6) °) at bonds remote from these substituents. Introduction. Eleven-membered rings are features of several classes of natural products, e.g. the cyto- chalasans (Tamm, 1980), dolabellane diterpenoids (Matsuo, Kamio, Uohama, Yoshida, Connolly & Sim, 1988) and pyrrolizidine alkaloids (Robins, 1982). Examination of crystallographic results reveals two conformations for the trans, trans- cycloundeca-l,5-diene system in humulene deriva- tives (Khan, MacAlpine, Porte & Sim, 1983) and a number of dolabellane diterpenoids (Matsuo, Uohama, Yoshida, Nakayama, Hayashi, Connolly &

Dolabellane diterpenoids from Aglaia odorata

Dolabellane diterpenoids, (1 R,3 E,7 E,10 S,11 S,12 R)-dolabella-3,7-dien-10,18-diol ( 1), (1 R,3 S,7 E,11 S,12 R)-dolabella-4(16),7-dien-3,18-diol ( 2), (1 R,7 E,11 S,12 R)-18-hydroxydolabella-4(16),7-dien-3-one ( 3), (1 R,3 S,4 S,7 E,11 S,12 R)-3,4-epoxydolabella-7-en-18-ol ( 4), and (1 R,3 R,7 E,11 S,12 R)-dolabella-4(16),7,18-trien-3-ol ( 5), were obtained from the ornamental plant Aglaia odorata. Their structures were characterized on the basis of spectroscopic analyses and further confirmed by X-ray diffraction. Compounds 1 and 5 showed weak cytotoxicity against the human myeloid leukemia HL-60, hepatocellular carcinoma SMMC-7721, and lung cancer A-549 cells.

Terpenoids from the liverwort Chandonanthus hirtellus

A new bicyclogermacrane sesquiterpenoid, two new cembrane diterpenoids and five new dolabellane diterpenoids, along with known terpenoids, have been isolated from the Malaysian liverwort Chandonanthus hirtellus. The structures of the new compounds were established by spectroscopic and chemical methods in addition to X-ray crystallographic studies.

A new dolabellane diterpenoid from the Hainan soft coral Spongodes sp.

A new dolabellane diterpenoid (1R\\ast,3E,7E,9S\\ast,11S\\ast,12Z)-9-hydroxydolabella-3,7,12-triene (1), along with seven known compounds (2–8), has been isolated from the Hainan soft coral Spongodes sp. Their structures were elucidated on the basis of spectroscopic analysis and compared with those previously reported in literature.

Terpenes from Eunicea laciniata and Plexaurella nutans

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Calyculatine: a New Dolabellane Diterpenoid from the Marine Sponge Eunicea calyculata

A new dolabellane diterpenoid, 7(S)-hydroperoxy-13-keto-(1S,11R)-dolabella-3(E),8(17),12(18)-triene (1), and two known compounds, 7(S),8(S)epoxy-13-keto-1(S),11(R)-dolabella-3(E),12 (18)-diene (2) and 13-keto-1(S),11(R)-dolabella-3(E),7(E),12(18)-triene (3), were isolated from the marine sponge Eunicea calyculata. The structure of 1 was elucidated by 1D (1)H- and (13)C-NMR spectra and 2D HMQC, HMBC, and the relative stereochemistry was established by analysis of coupling constants and NOESY spectra. In addition, an X-ray crystallographic analysis on a single crystal of 2 was carried out. Compounds 1 and 2 were inactive in the hyphae formation inhibition assay (HFI) in Streptomyces 85E while compound 3 showed inhibitory activity at a concentration of 20 microg/20 microL in the HFI assay.

Terpenes from Eunicea Laciniata and Plexaurella Nutans

A new 7,8–epoxydolabella–3(E)–12(18)–diene (1), diterpenoid together with three known compounds were isolated from a Honduras gorgonian Eunicea laciniata. The relative stereochemistry of 1 was established by spectroscopic studies and the antiprotozoal and antimicrobial activities of dolabellane diterpenoids 2–4 are reported. Three known cadinane type sesquiterpenes were also isolated from Honduras gorgonian Plexaurella nutans.

Dolabellane Diterpenoids from the Higher Plant Aglaia odorata

AbstractTwo new dolabellane diterpenoids, (1R,3R,7E,11S,12R)‐dolabella‐4(16),7‐diene‐3,18‐diol (1) and (1R,3E,7R,11S,12R)‐dolabella‐3,8(17)‐diene‐7,18‐diol (2), and the known (1R,3E,7E,11S,12R)‐dolabella‐3,7‐dien‐18‐ol (3) were isolated from Aglaia odorata, along with twelve other known compounds. Their structures were elucidated on the basis of spectroscopic data. This is the first time that dolabellane‐type diterpenoids were detected in higher plants.

New Dolabellanes from the Taiwanese Soft Coral Clavularia Inflata

AbstractBioassay‐directed fractionation of the acetone extract of Clavularia inflata collected in Green Island has afforded two new dolabellane diterpenoids, designated as clavinflols A (4) and B (5) in addition to the reported (1R*,12R*)‐dolabella‐4(16),7,10‐triene‐3,13‐dione (1), stolonidiol (2) and stolonidiol monoacetate (3). The structures of compounds 4 and 5 were determined on the basis of 1D and 2D‐NMR techniques including COSY, HSQC, HMBC and NOESY experiments, and acetylation which yielded derivatives 6 and 7, respectively. Pharmacological study revealed that compounds 1–3 and 5 exhibited cytotoxicity against human oral epidermoid carcinoma (KB) cells while compound 4 showed selective activity toward human Hepa cells.

Total synthesis of the dolabellane marine diterpenoids, claenone, palominol and dolabellatrienone

The synthesis of marine dolabellane diterpenoids claenone, palominol and dolabellatrienone was conducted from d-mannitol. In each case, formation of the bicyclo[2.2.1]heptane derivative by sequential Michael reaction, preparation of the tetrasubstituted cyclopentane derivative by retro-aldol reaction and cyclization of sulfone were involved as key steps.

Total synthesis of marine diterpenoid stolonidiol

Marine dolabellane diterpenoid stolonidiol was synthesized from l-ascorbic acid. The method for this total synthesis involves formation of the bicyclo[2.2.1]heptane derivative using a diastereoselective sequential Michael reaction, formation of cyclopentane derivative by the retro-aldol reaction and construction of an 11-membered carbocyclic ring through the intramolecular Horner–Wadsworth–Emmons reaction.

ChemInform Abstract: Structure, Conformation and Absolute Configuration of New Antifeedant Dolabellanes from Trichilia trifolia.

Abstract The structures of three new dolabellane diterpenoids, (1R,3E,7Z,11S,12S)-dolabella-3,7,18-trien-17-oic acid (1), (1R,3E,6R,7Z,11S,12S)-dolabella-3,7,18-trien-6,17-olide (2) and (1R,3S,4R,7Z,11S,12S)-3-hydroxydolabella-7,18-dien-4,17-olide (3), isolated from the wood of Trichilia trifolia, were elucidated by 1D and 2D NMR spectroscopy. The stereochemistry of 1 and 2 was confirmed by X-ray diffraction analysis, while that of 3 was ascertained from NOESY data. Comparison between experimental and calculated 1H–1H vicinal coupling constants and the analysis of molecular mechanics structures revealed that the 11-membered ring of 1 and 2 exists in a conformational equilibrium in solution, while in 3 this ring possesses a more rigid structure. The absolute configuration of 3 was established from its Cotton effects. Dolabellanes 1–3 caused significant feeding reduction by the rice weevil Sitophilus oryzae.

Structure, Conformation and Absolute Configuration of New Antifeedant Dolabellanes from Trichilia trifolia

The structures of three new dolabellane diterpenoids, (1 R,3 E,7 Z,11 S,12 S)-dolabella-3,7,18-trien-17-oic acid ( 1), (1 R,3 E,6 R,7 Z,11 S,12 S)-dolabella-3,7,18-trien-6,17-olide ( 2) and (1 R,3 S,4 R,7 Z,11 S,12 S)-3-hydroxydolabella-7,18-dien-4,17-olide ( 3), isolated from the wood of Trichilia trifolia, were elucidated by 1D and 2D NMR spectroscopy. The stereochemistry of 1 and 2 was confirmed by X-ray diffraction analysis, while that of 3 was ascertained from NOESY data. Comparison between experimental and calculated 1H– 1H vicinal coupling constants and the analysis of molecular mechanics structures revealed that the 11-membered ring of 1 and 2 exists in a conformational equilibrium in solution, while in 3 this ring possesses a more rigid structure. The absolute configuration of 3 was established from its Cotton effects. Dolabellanes 1– 3 caused significant feeding reduction by the rice weevil Sitophilus oryzae.