Sinugibberosides A-E, new terpenoids with cyclic peroxyhemiketal from the soft coral Sinularia gibberosa

The organic extract of the soft coral Sinularia gibberosa, collected from the northern Taiwan, has been investigated and resulted in the isolation of five new xeniaphyllane-type diterpenoids with a rare cyclic peroxyhemiketal (3,6-dihydro-1,2-dioxin-3-ol) moiety, sinugibberosides A-E (1-5). The structures of the new terpenoids, including their stereochemistries, were established on the basis of extensive spectroscopic analysis, including 1D and 2D NMR (¹H-¹H COSY, HMQC, HMBC, and NOESY), and by comparison of their NMR data with those of related compounds. Metabolites 1-5 represent the first example of marine terpenoids possessing a cyclic peroxyhemiketal moiety.     

A new cadinane sesquiterpenoid from cultures of the Basidiomycete Panus conchatus

A new cadinane sesquiterpenoid, named panutorulon A (1), was isolated from cultures of the basidiomycete Panus conchatus. The new structure was elucidated by means of spectroscopic methods. Compound 1 was tested for its cytotoxicity against five human cancer cell lines and for its inhibitory activity against isozymes of 11β-hydroxysteroid dehydrogenases (11β-HSD).     

Phenylglycol Metabolites from Cultures of the Basidiomycete Mycena pruinosoviscida BCC 22723

Mycenadiols A–D ( 1 – 4 , resp.), phenylglycols possessing an ethynyl or vinyl (ethenyl) group were isolated from cultures of the basidiomycete Mycena pruinosoviscida BCC 22723. The structures were elucidated on the basis of NMR‐spectroscopic and mass spectrometric data. The absolute configurations of 1 and 2 were determined by synthesis. Compounds 1 – 4 are synthetically known, but, they have not been previously isolated from natural sources.     

Seco‐Tremulanes from Cultures of the Basidiomycete Flavodon flavus BCC 17421

A new seco‐tremulane, 11,12‐epoxy‐5,6‐secotremula‐1,6(13)‐dien‐5,12‐olide ( 1 ), was isolated together with the known compounds, conocenolides A ( 2 ) and B ( 3 ), tremulenediol A ( 4 ), tremulenolide A ( 5 ), and two lanostane triterpenoids, trametenolic acid B ( 6 ), and pinicolic acid A ( 7 ), from cultures of the basidiomycete Flavodon flavus BCC 17421. Interconversion of conocenolides A/B was demonstrated. Compound 1 exhibited weak cytotoxic activities, whereas tremulenediol A showed antiplasmodial activity (IC₅₀ 8.6 μg/ml). Pinicolic acid A exhibited activity against herpes simplex virus type‐1 (IC₅₀ 15 μg/ml) as well as cytotoxic activities.     

Hirsutellones A-E, antimycobacterial alkaloids from the insect pathogenic fungus Hirsutella nivea BCC 2594

Five new alkaloids, hirsutellones A-E, were isolated from the insect pathogenic fungus Hirsutella nivea BCC 2594. Their structures were elucidated by spectroscopic analysis and X-ray crystallography. Hirsutellones displayed significant growth inhibitory activity against Mycobacterium tuberculosis H₃₇Ra.     

Naucleamides A-E,new monoterpene indole alkaloids from Nauclea latifolia

Five new monoterpene indole alkaloids, naucleamides A-E (1-5), were isolated from the bark and wood of Nauclea latifolia, and the structures and relative stereochemistry were elucidated from the spectroscopic data. Naucleamide E (5) is a unique monoterpene indole alkaloid possessing a pentacyclic ring system with an amino acetal bridge.     

Myrseguinosides A-E, five new glycosides from the fruits of Myrsine seguinii

Chemical investigation of the 1-BuOH soluble fraction of the dried fruits of Myrsine seguinii (Myrsinaceae) led to the isolation of five new glycosides, named myrseguinosides A-E (1-5), together with eight known compounds (6-13). The absolute structures of the new glycosides were elucidated by spectroscopic and chemical analyses to be a monoterpene glucoside (1), two flavonol glycosides (2, 3), and two oleanane-type triterpene saponins (4, 5). Myrseguinosides B (2), D (4), and E (5) exhibited 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical-scavenging activity and growth inhibitory activity toward human cancer cells, respectively.     

Aigialomycins A-E, new resorcylic macrolides from the marine mangrove fungus Aigialus parvus

Aigialomycins A-E (2-6), new 14-membered resorcylic macrolides, were isolated together with a known hypothemycin (1) from the mangrove fungus, Aigialus parvus BCC 5311. Structures of these compounds, including absolute configuration, were elucidated by spectroscopic methods, chemical conversions, and X-ray crystallographic analysis. Hypothemycin and aigialomycin D (5) exhibited in vitro antimalarial activity with IC(50) values of 2.2 and 6.6 microg/mL, respectively, while other analogues were inactive. Cytotoxicities of these compounds were also evaluated.     

Pavidolides A-E, new cembranoids from the soft coral Sinularia pavida

Five new cembrane-based diterpenoids, namely pavidolides A-E (1-5) were isolated from the marine soft coral Sinularia pavida, together with sarcophytin and chatancin. The structures of new compounds were determined on the basis of extensive spectroscopic data analysis. Pavidolide B (2) possesses an unprecedented 6,5,7-tricarbocyclic nucleus, whereas pavidolide C (3) is characteristic of an unusual C-5 and C-9 conjuncted cembranoid. Pavidolides C and D showed moderate antifouling activity against the larval settlement of barnacle Balanus amphitrite, while pavidolides B and C exhibited inhibitory activity against the human leukemia cell line HL-60.     

Cladieunicellins A-E, new eunicellins from an Indonesian soft coral Cladiella sp

Five new eunicellin-type diterpenoids, cladieunicellins A-E (1-5), were isolated from an Indonesian soft coral identified as Cladiella sp. The structures of diterpenoids 1-5 were established using spectroscopic methods. Eunicellins 2 and 5 were found to be cytotoxic against DLD-1 and HL-60 tumor cells, respectively, and 3 displayed inhibitory effects against superoxide anion generation by human neutrophils.     

Jaspolides A-F, six new isomalabricane-type terpenoids from the sponge Jaspis sp

A chemical investigation of Jaspis sp., the marine sponge collected from the South China Sea led to the isolation of six new isomalabaricane-type compounds, jaspolides A-F (1-6). The structures of those compounds were elucidated by extensive spectroscopic methods. The structure-types of 1 to 6 could be classified into triterpenes (1, 2), sesterterpene (6), diterpenes (3, 4), and nortriterpene (5). The biogenetic transformation of the isolated compounds was also speculated.     

Axiplyns A-E, new sesquiterpene isothiocyanates from the marine sponge Axinyssa aplysinoides

Five new isothiocyanate sesquiterpenes, designated axiplyns A-E (1-5) have been isolated, together with two known isothiocyanate sesquiterpenes (6, 7), from the sponge Axinyssa aplysinoides collected at Misali Island, Tanzania. Axiplyns 4 and 5 embody a new indane sesquiterpene skeleton, and compounds 1, 2, and 5 contain unprecedented ring systems, namely a 6,8-dioxabicyclo[3.2.1]octane and a 2-oxabicyclo[2.2.1]heptane. Axiplyns A, B, and C are potent brine shrimp toxins with LD₅₀ values between 1.5 and 1.8 μg/mL.     

Two new terpenoids from fruits of Ziziphus jujuba

One new ceanothane-type triterpene and one new sesquiterpene,together with two known triterpenes were isolated from the fruits of Ziziphus jujuba Mill.(Rhamnaceae).Based on the spectral analyses,the structures of two new compounds were elucidated as 2α-aldehydo-A(1)-norlup-20(29)-en-27,28-dioic acid(zizyberanal acid)(1),and zizyberanone(2).While the two known triterpenes were identified as zizyberanalic acid(3)and ursofic acid(4).     

New metabolites from the fungus Stereum purpureum

Two new sterpurene sesquiterpenes, 4,12-dihydroxysterpurene (1) and 5,12-dihydroxysterpurene (3), have been isolated from Stereum purpureum, and identified mainly on the basis of mass spectra and extensive nuclear magnetic resonance spectrometry, especially two-dimensional NMR.     

Dichotellides A-E, five new iodine-containing briarane type diterpenoids from Dichotella gemmacea

Five new briarane type diterpenoids, dichotellides A−E (1−5), were isolated from the South China Sea gorgonian Dichotella gemmacea together with four known analogues (6−9). Compounds 1−5 represent the first examples of iodine-containing briarane type diterpenoids from nature. The structures of these diterpenoids were elucidated by spectroscopic analysis, including 1D, 2D-NMR, and HRESIMS, and the absolute configuration of 1 was further confirmed by single crystal X-ray diffraction analysis. All the isolates were evaluated for cytotoxicity activity against four human tumor cell lines, and only 3 exhibited marginal activity against SW1990 (human pancreatic cancer).     

Fargosides A-E, triterpenoid saponins from Holboellia fargesii

Five new triterpenoid saponins, fargosides A, B, C, D, and E, were isolated from the roots of Holboellia fargesii. The structures of fargosides A-E were elucidated on the basis of chemical and physicochemical evidence and found to be 3beta,20alpha-dihydroxy-29-norolean-12-en-28-oic acid 3-O-beta-D-xylopyranosyl-(1-->2)-beta-D-glucopyranoside (1), 3beta,20alpha,24-trihydroxy-29-norolean-12-en-28-oic acid 23-O-beta-D-fucopyranosyl-(1-->2)-[alpha-L-arabinopyranosyl-(1-->3)]-beta-D-glucopyranoside (2), 3beta,23-dihydroxy-30-norolean-2,20(29)-dien-28-oic acid 3-O-alpha-L-arabinopyranosyl-(1-->2)-[beta-D-glucopyranosyluronic acid-(1-->3)]-alpha-L-arabinopyranoside (3), 3beta,23-dihydroxy-30-norolean-12,20(29)-dien-28-oic acid 3-O-methyl beta-D-glucopyranosyluronate-(1-->3)-alpha-L-arabinopyranoside (4), and 3beta,23-dihydroxy-olean-12-en-28-oic acid 3-O-methyl beta-D-glucopyranosyluronate-(1-->3)-alpha-L-arabinopyranoside (5), respectively.     

Yezo’otogirins A-C, new tricyclic terpenoids from Hypericum yezoense

Three new tricyclic terpenoids, yezo’otogirins A-C (1-3), were isolated from aerial parts of Hypericum yezoense. The structures including absolute stereochemistry of 1-3 were elucidated from the spectroscopic data and conformational analysis.     

Rhodiolosides A-E, monoterpene glycosides from Rhodiola rosea

Five new monoterpene glycosides, rhodiolosides A-E (1-5), were isolated from the roots of Rhodiola rosea (Crassulaceae). Their structures were elucidated as (2E,6E,4R)-4,8-dihydroxy-3,7-dimethyl-2,6-octadienyl beta-D-glucopyranoside (1), (2E,4R)-4-hydroxy-3,7-dimethyl-2,6-octadienyl alpha-D-glucopyranosyl(1-->6)-beta-D-glucopyranoside (2), (2E,4R)-4-hydroxy-3,7-dimethyl-2,6-octadienyl beta-D-glucopyranosyl(1-->3)-beta-D-glucopyranoside (3), (2E,4R)-4,7-dihydroxy-3,7-dimethyl-2-octenyl beta-D-glucopyranoside (4), and (2E)-7-hydroxy-3,7-dimethyl-2-octenyl alpha-L-arabinopyranosyl(1-->6)-beta-D-glucopyranoside (5), on the basis of various spectroscopic analyses and chemical degradation.     

Gelegamines A-E: five new oxindole alkaloids from Gelsemium elegans

Five new oxindole alkaloids, gelegamines A-E (1-5), were isolated from the roots of Gelsemium elegans. Their structures were extensively elucidated on the basis of spectroscopic analysis. Among them, the epoxy ring (C-19/C-20) of gelegamine A (1) was assigned as α-orientation by ROESY experiment and DFT method at B3LYP/6-31g(d) level, and gelegamine B (2) is the first humantenine-type alkaloid with 19-(E) ethylidene configuration. The absolute configurations of gelegamines A-E (1-5) were established on biosynthetic consideration coupled with CD experiments.