Cembrenene and mayol,two new cembranoid diterpenes from the soft coral sinularia mayi

Two new cembranoid diterpenes, cembrenene (1) and mayol (2), have been isolated from Sinularia mayi L?ttschw, along with the first reported cembrene (3) from marine organism. The structures were determined from spectral data and chemical transformations.     

Xenibellols A and B, new diterpenoids from the formosan soft coral Xenia umbellata

Xenibellols A (1) and B (2), possessing an unprecedented diterpenoid skeleton, were isolated from the soft coral Xenia umbellata. The structures of xenibellols A and B were established by extensive analysis of spectroscopic data.     

Novaxenicins A-D and xeniolides I-K, seven new diterpenes from the soft coral Xenia novaebrittanniae

Seven new diterpenes, novaxenicins A-D (1-4) and xeniolides I-K (5-7), have been isolated from the Kenyan soft coral Xenia novaebrittanniae. The structures and relative stereochemistry of the compounds were elucidated by interpretation of MS, COSY, HSQC, HMBC, and NOESY experiments. The structure of novaxenicin A (1) was secured by X-ray diffraction analysis. Compound 5 possesses anti-bacterial activity at a concentration of 1.25 μg/ml and compound 2 induces apoptosis in transformed mammalian cells at a concentration of 1.25 μg/ml.     

Triangulene C, a new cubitane-based diterpenoid from the soft coral Sinularia triangula

A new cubitane-based diterpenoid, triangulene C (1), was isolated from the soft coral Sinularia triangula and its structure was elucidated on the basis of spectroscopic data. Compound 1 was not cytotoxic (IC50 > 20 microg/mL) toward the four human cancer cell lines tested (HL60, MDA-MB-231, HCT-116 and DLD-1).     

Briaviodiol A, a new Cembranoid from a soft coral Briareum violacea

A new cembrane diterpenoid, briaviodiol A (1), has been isolated from a soft coral Briareum violacea. The structure of 1 was determined by spectroscopic methods and further confirmed by a single-crystal X-ray diffraction analysis.     

Salvinicins A and B, new neoclerodane diterpenes from Salvia divinorum

[reaction: see text] Two new neoclerodane diterpenes, salvinicins A (4) and B (5), were isolated from the dried leaves of Salvia divinorum. The structures of these compounds were elucidated by spectroscopic techniques, including (1)H and (13)C NMR, NOESY, HMQC, and HMBC. The absolute stereochemistry of these compounds was assigned on the basis of single-crystal X-ray crystallographic analysis of salvinicin A (4) and a 3,4-dichlorobenzoate derivative of salvinorin B.     

Genkwalathins A and B,new lathyrane-type diterpenes from Daphne genkwa

Screening for new natural anti-neuroinflammatory compounds was performed with the traditional folk medicine Genkwa Flos, which potently inhibited nitric oxide (NO) production by LPS-activated microglial BV-2 cells. Two new lathyrane-type diterpenes, genkwalathins A (1) and B (2), and 14 known daphnane-type diterpenes (3–16) were isolated. The lathyrane-type diterpenes were isolated for the first time from the Thymelaeaceae family in this study. Compounds 1 and 2 moderately inhibited LPS-induced NO production in BV-2 cells without affecting cell viability, while six daphnane-type diterpenes (3, 4, 6, 7, 9 and 10) potently reduced NO production with IC₅₀ values less than 1 μM, although they did display weak cytotoxicity. A structure–activity relationship study on the daphnane-type diterpenes indicated that the stereochemistry at C-19, the benzoate group at C-20, and the epoxide moiety could be important for their anti-neuroinflammatory effects.     

Cespitulactams A, B, and C, three new nitrogen-containing diterpenes from Cespitularia taeniata May

Three new nitrogen-containing diterpenoids, designated cespitulactams A (1), B (2), and C (3), were isolated from Cespitularia taeniata May. Compounds 1-3 are novel structures having a phenylethyl amino side at C-10 and with an amide function at C-20. Their structures were determined on the basis of extensive spectroscopic analysis and chemical correlation. The cytotoxicity of 1 and its monoacetate (6) were also evaluated against human cancer cell lines.     

Bicunningines A and B, two new dimeric diterpenes from Cunninghamia lanceolata

Two unprecedented dimeric diterpenoids, with a 2,3-dihydrofuran ring fusing an abietane and a 4,5-seco-abietane diterpene, were isolated from Cunninghamia lanceolata. Their structures were elucidated by spectroscopic measurements, and their absolute configurations were determined by quantum chemical TDDFT ECD calculations, chemical transformations, and Mosher's method. The Mosher method carried out with MPA and MTPA esters of the sterically hindered sec-hydroxyl group gave contradictory results, while MPA afforded the correct absolute configuration.     

A new dolabellane diterpene and a new polyacetylene from the soft coral Clavularia viridis

A new dolabellane diterpene (1) and a new polyacetylene (2) were isolated from the soft coral Clavularia viridis. The structures of 1 and 2 were elucidated by spectroscopic analyses including 1D and 2DNMR experiments and HRESIMS data. The absolute configuration of 1 was determined by the modified Mosher’s method and 2 by ECD calculations. Compound 1 exhibited moderate cytotoxicities against MCF-7 and A549 cell lines with IC₅₀ values of 10.5 and 12.6 µM, respectively.     

A new cytotoxic polyhydroxysterol from soft coral Sarcophyton trocheliophorum

A new cytotoxic polyhydroxysterol, 23,24-dimethylcholest-16(17)-E-en-3beta,5alpha,6beta,2 0(S)-tetraol (2), together with nine known compounds was isolated from the soft coral Sarcophyton trocheliophorum. Their structures were determined by spectroscopic methods. Compound 2 showed potent growth inhibitory activity against human HL60 leukemia, M14 skin melanoma, and MCF7 breast carcinoma cells with EC50 values of 2.8, 4.3, and 4.9 microg/ml, respectively, and exhibited minimal toxicity to normal human peripheral blood lymphocytes.     

Melidianolic acid A and B, new antimalarial acyclic diterpenes from Aphanamixis grandifolia

Two new acyclic diterpenes, melidianolic acids A (1) and B (2), have been isolated from the bark of Aphanamixis grandifolia. Their structures were elucidated on the basis of spectroscopic and chemical methods. Melidianolic acids A (1) and B (2) showed antimalarial activity against Plasmodium falciparum 3D7 with IC50 of 6.1 and 7.3 microg/mL, respectively.     

Two new xeniolides from a Taiwanese Xenia soft coral

Chromatographic investigation of an extract of the octocoral Xenia umbellata afforded two new diterpenes, xenibelatols A (1) and B (2), in addition to three known xenicane diterpenes, 7,8-oxidoisoxeniolide (3), 9-hydroxyxeniolide F (4), and florlide C, and a cadinene sesquiterpene, xenitorin A (5). The structures were elucidated through spectroscopic analysis, especially 2D NMR.     

An acetoxygenated analogue of ergosterol from a soft coral of the genus Lobophytum

Chemical investigation of a soft coral of the genus Lobophytum of the Andaman and Nicobar coasts resulted in the isolation of a new marine sterol acetate, (24S)-ergostane-3beta,5alpha,6beta,25-tetraol-3,6,25-triacetate (1) and of two known sterol glycosides 3beta,4alpha-dihydroxypregn-20-ene-4-O-beta-D-arabinopyranoside and 24-methylenecholest-5-ene-3beta,7beta, 16beta-triol-3-O-alpha-L-fucopyranoside-7beta-acetate. The structures of the compounds were elucidated based on spectral studies and chemical conversions.     

Acerolide, a new cytotoxic cembranolide from the soft coral Pseudopterogorgia acerosa

A new cembranolide, acerolide (1) together with the known compound pseudopterolide (2) were isolated from the 2-propanol extract of the soft coral Pseudopterogorgia acerosa. The structure of 1 was determined on the basis of detailed spectroscopic analysis. Compound 1 showed moderate in vitro cytotoxicity against a panel of 14 tumor cell lines.     

Two new abietane diterpenes huperphlegmarins A and B from Huperzia phlegmaria

Two new abietane diterpenes, huperphlegmarin A–B (1–2), were isolated from the aerial parts of Huperzia phlegmaria (L.) Rothm. (Lycopodiaceae), in addition to five known compounds including lycoxanthol (3), 21β-hydroxyserrat-14-en-3β-yl acetate (4), 21α-hydroxyserrat-14-en-3β-yl acetate (5), 21α-hydroxyserrat-14-en-3β-ol (6), and fawcettidine (7). Their structures were determined by the combination analyses of spectroscopy, including 1D-, 2D-NMR, HRESIMS, CD and comparison with the reported data in the literature. Huperphlegmarin B (2) presented the rare 1,11-epoxy group in the molecule. Compounds 3, 4, 5 and 6 were performed for AChE inhibitory activity and compound 3 showed the inhibitory activity against AChE with IC₅₀ of 465.6 μg/mL.     

15-deoxy-isoxeniolide-A,new diterpenoid from a bornean soft coral,Xenia sp.

A new xenicane diterpenoid, 15-deoxy-isoxeniolide-A (1) along with four known compounds 9-deoxy-isoxeniolide-A (2), isoxeniolide-A (3), xeniolide-A (4) and coraxeniolide-B (5) were isolated from the Bornean soft coral Xenia sp. The structures of these metabolites were elucidated on the basis of spectral analysis, NMR and HRESIMS. Compound 5 showed cytotoxic activity against ATL cell line, S1T.