Terpenoids from a Chinese Gorgonian Anthogorgia sp. and Their Antifouling Activities

Chemical examination of a Chinese gorgonian Anthogorgia sp. resulted in the isolation of seven terpenoids, including two new compounds, an rearranged serrulatane‐type diterpenoid anthogorgiene P ( 1 ) and a guaiazuene‐based terpenoid anthogorgiene Q ( 2 ). Anthogorgiene P ( 1 ) contains an unprecedented cubebane nucleus which is rarely found from nature. The structures of new compounds were elucidated on the basis of extensive spectroscopic methods (IR, UV, MS, CD and NMR). Compound 7 showed potent antifouling activity against the larval settlement of Balanus amphitrite, while 1 and 4 possessed moderate inhibition.     

Suberosanones A – C,New Metabolites Possessing Cyclopentenone System from the South China Sea Gorgonian Coral Subergorgia suberosa

Two unusual novel bicyclic lactones, suberosanones A and B ( 1 and 2 , resp.), characterized by the co‐occurrence of cyclopentenone and butanolide rings within the same molecule, along with one tricyclic cyclopentenone derivative, suberosanone C ( 3 ), were isolated from the South China Sea gorgonian coral Subergorgia suberosa. Their structures were unambiguously established by detailed spectroscopic analyses (NMR, IR, and HR‐MS). The absolute configurations of 1 and 2 were determined by quantum‐chemical calculations using the time‐dependent density‐functional theory (TDDFT) method. All compounds showed neither antifouling activity against Balanus amphitrite larvae settlement nor antibacterial activity against a panel of bacterial strains at concentrations up to 25 μg/ml.     

Four New Briarane Diterpenoids from the Gorgonian Coral Junceella fragilis

Chemical investigation of the gorgonian coral Junceella fragilis, collected by scuba diving in Taiwan, resulted in the isolation of four new briarane‐type diterpenoids, frajunolides A–D ( 1 – 4 ), along with three known briaranes. Their structures were elucidated on the basis of spectroscopic studies, especially 1‐ and 2D‐NMR as well as HR‐MS experiments. The inhibitory effect of all isolated metabolites towards superoxide‐anion generation and elastase release by human neutrophils in response to formylmethionyl‐leucyl‐phenylalanine/dihydrocytochalasin B (FMLP/CB) was evaluated.     

Two New Polyhydroxylated Steroids from the Hainan Soft Coral Sinularia sp.

Two new polyhydroxylated steroids, (2β,3β,4α,5α,8β,11β)‐4‐methylergost‐24(28)‐ene‐2,3,8,11‐tetrol‐( 1 ) and (3β,5α,6β)‐ergosta‐22,24(28)‐diene‐3,5,6,19‐tetrol ( 3 ), together with the six known related steroids 2 and 4 – 8 , were isolated from the Hainan soft coral Sinularia sp. Their structures were elucidated on the basis of spectroscopic analysis and by comparison with previously reported data. The structure of the known compound 9 (hyrtiosterol) was revised as 2 by extensive analysis of the ROESY data and by the NOE difference experiment.     

Sesquiterpenoids from Fusarium sp., an Endophytic Fungus in Agriminia pilosa

Cultivation of the endophytic fungus isolated from the stems of Agriminia pilosa provided four new sesquiterpenoids, namely agripilols A–D ( 1 – 4 , resp.). Structures of these isolates were elucidated by NMR and MS data. The isolation of drimane‐ and cadinane‐type sesquiterpenoids from the genus of Fusarium is reported for the first time.     

Seven Novel Linear Polyketides from Xylaria sp. NCY2

Seven novel polyketides, namely, 1‐(xylarenone A)xylariate A ( 1 ), xylarioic acid B ( 2 ), xylariolide A ( 3 ), xylariolide B ( 4 ), xylariolide C ( 5 ), methyl xylariate C ( 6 ), and xylariolide D ( 7 ), together with the known one taiwapyrone ( 8 ), were isolated from the endophytic fungal strain Xylaria sp. NCY2 of Torreya jackii Chun . Their structures were elucidated by spectroscopic analyses, including 1D‐ and 2D‐NMR experiments, and on the basis of HR‐Q‐TOF mass spectrometry. Antitumor and antibacterial assays of compounds 1 – 8 were carried out, which show moderate activities.     

Polyhydroxylated Sterols from the South China Sea Gorgonian Verrucella umbraculum

Two new polyhydroxylated sterols, named verumbsteroids A and B ( 1 and 2 , resp.), along with seven known analog, 3 – 9 , were isolated from the gorgonian Verrucella umbraculum collected from the South China Sea. The structures and relative configurations of the new compounds were elucidated by comprehensive spectroscopic investigations. The absolute configuration of 1 was determined by using modified Mosher method with the acetonide derivative of 1 . Compounds 1 and 3 – 5 were found to show cytotoxicities against five human tumor cell lines (HL‐60, K562, HeLa, A‐549, and HCT‐116) with the IC₅₀ values ranging from 2.76 to 9.62 μM .     

Four New Pregnane Steroids from Aglaia abbreviata and Their Cytotoxic Activities

Four new pregnane steroids, aglaiasterols A–D ( 1 – 4 ), have been isolated from the EtOH extract of stems of Aglaia abbreviata. They were identified as (3α,5α,17Z)‐3‐hydroxypregn‐17‐en‐16‐one ( 1 ), (3β,5α,17E)‐3‐hydroxypregn‐17‐en‐16‐one ( 2 ), (3β,5α,17Z)‐3‐hydroxypregn‐17‐en‐16‐one ( 3 ), and (3α,5α,20S*)‐3‐hydroxy‐16‐oxopregnan‐20‐yl acetate ( 4 ) on the basis of spectroscopic methods, including 1D‐ and 2D‐NMR techniques. Compounds 1 – 4 were evaluated for their cytotoxic activities against K562 (human leukemia), MCF‐7 (human breast cancer), and KB (human oral epithelium cancer) cells, and drug‐resistant cells of K562/A02, MCF‐7/ADM, and KB/VCR. These isolates showed weak to moderate inhibitory effects on the growth of the tested cell lines.     

Taccalonolides W – Y,Three New Pentacyclic Steroids from Tacca plantaginea

Three new pentacyclic steroids, taccalonolides W–Y ( 2 – 4 , resp.), have been isolated from the whole plants of Tacca plantaginea. Their structures were elucidated on the basis of spectroscopic methods including extensive 1D‐ and 2D‐NMR experiments.     

Steroidal Saponins from the Rhizomes of Smilacina henryi

Five steroidal saponins, namely henryiosides A–E ( 1 – 5 ), were isolated from the EtOH extract of the rhizomes of Smilacina henryi. Their structures were elucidated by the extensive use of 1D‐ and 2D‐NMR experiments, along with HR‐MALDI‐MS analysis and the results of acid hydrolysis. The aglycones of henryiosides A–E possess a C(7)?C(8) or C(9)?C(11) bond and were not previously found in saponins.     

Six New Cembranolides from the Hainan Soft Coral Lobophytum sp.

Six new cembrane diterpenes, lobophytolides A–F ( 1 – 6 , resp.), along with six known related cembranoids, 7 – 12 , were isolated from the Hainan soft coral Lobophytum sp. Their structures, including their relative configuration, were elucidated by extensive analyses of the spectroscopic data and by comparison with related known compounds.     

Further Highly Oxygenated Guaiane Lactones from the South China Sea Gorgonian Menella sp.

Four new highly oxygenated guaiane lactones, 1‐epimenverin B ( 1 ), menverin F ( 2 ), 1‐deoxymenverin F ( 3 ), and menverin G ( 4 ), together with the two known related analogues menverins B ( 5 ) and C ( 6 ), were isolated from the South China Sea gorgonian Menella sp. Their structures and relative configuration were elucidated by analysis of spectroscopic data and by comparison with those of known related compounds.     

Three New Polyoxygenated Steroids from Two Species of the South China Sea Gorgonian Muricella flexuosa and Menella verrucosa Brundin

Three new polyoxygenated steroids, muricesteroid ( 1 ), and menellsteroids A ( 2 ) and B ( 3 ), were isolated from two species of the South China Sea gorgonian Muricella flexuosa and Menella verrucosa Brundin , respectively. The structures of these new compounds were elucidated on the basis of extensive spectroscopic analysis, chemical methods and comparison with known related compounds.     

南中国海柳珊瑚网状软柳珊瑚Subergorgia reticulata中的多氧化甾醇

Two new polyoxygenated steroids, reticulatic acid （1） and reticulatin （2）, together with a known compound 3,22,25-trihydroxy-16-24,20-24-bisepoxy-3β,16β,20S,22R,24S-cholest-5-ene （3）, were isolated from the CH2Cl2/ EtOH extract of the South China Sea gorgonian coral Subergorgia reticulata. Their structures were established on the basis of extensive spectroscopic analysis. The absolute stereochemistry of compounds 2 and 3 was determined by the X-ray crystallographic analysis and the Mosher ester determination.     

Clintoniosides A – C,New Polyhydroxylated Spirostanol Glycosides from the Rhizomes of Clintonia udensis

Phytochemical analyses were carried out on the rhizomes of Clintonia udensis (Liliaceae) with particular attention paid to the steroidal glycoside constituents, resulting in the isolation of three new polyhydroxylated spirostanol glycosides, named clintonioside A ( 1 ), B ( 2 ), and C ( 3 ). On the basis of their spectroscopic data, including 2D‐NMR spectroscopy, in combination with acetylation and hydrolytic cleavage, the structures of 1 – 3 were determined to be (1β,3β,23S,24S,25R)‐1,23,24‐trihydroxyspirost‐5‐en‐3‐yl O‐β‐D ‐glucopyranosyl‐(1→4)‐O‐[α‐L ‐rhamnopyranosyl‐(1→2)]‐β‐D ‐glucopyranoside ( 1 ), (1β,3β,23S,24S)‐3,21,23,24‐tetrahydroxyspirosta‐5,25(27)‐dien‐1‐yl O‐α‐L ‐rhamnopyranosyl‐(1→2)‐O‐[β‐D ‐xylopyranosyl‐(1→3)]‐β‐D ‐glucopyranoside ( 2 ), and (1β,3β,23S,24S)‐21‐(acetyloxy)‐24‐[(6‐deoxy‐β‐D ‐gulopyranosyl)oxy]‐3,23‐dihydroxyspirosta‐5,25(27)‐dien‐1‐yl O‐α‐L ‐rhamnopyranosyl‐(1→2)‐O‐[β‐D ‐xylopyranosyl‐(1→3)]‐β‐D ‐glucopyranoside ( 3 ).     

Iridoids from the Bark of Alstonia scholaris

Four new 11‐noriridoids named scholareins A–D ( 1 – 4 ), along with three known derivatives, isoboonein ( 5 ), alyxialactone ( 6 ), and loganin ( 7 ), were isolated from EtOH extracts of the bark of Alstonia scholaris by chromatographic methods. Their structures were identified by extensive mass‐spectrometric and spectroscopic (especially 2D‐NMR) experiments.     

New Eunicellin Diterpenes and 9,10‐Secosteroids from the Gorgonian Muricella sibogae

Bioactivity‐guided isolation of the rare gorgonian Muricella sibogae (Nutting ) yielded the two new eunicellin diterpenes sibogin A and B ( 1 and 2 ), the three new 9,10‐secosteroids sibogol A–C ( 6 – 8 ), together with the three known eunicellin diterpenes 3 – 5 and the five known 9,10‐secosteroids 9 – 13 . Their structures were established by extensive spectral analysis (1D‐ and 2D‐NMR, IR, and MS). The cytotoxicity of the isolates 1 – 13 was evaluated in vitro against the selected tumor cell lines P388 and BEL‐7402. All the compounds showed only weak activity against P388 cell lines, with an inhibition rate ranging from 10 to 60% at a concentration of 50 μg/ml, whereas the were inactive against BEL‐7402 cell lines.     

Sarcoglycosides A – C,New O‐Glycosylglycerol Derivatives from the South China Sea Soft Coral Sarcophyton infundibuliforme

Chemical examination of the soft coral Sarcophyton infundibuliforme collected from the South China Sea resulted in the isolation of the three new O‐glycosylglycerol derivatives sarcoglycosides A–C ( 1 – 3 ), together with two known compounds, chimyl alcohol ( 4 ) and hexadecanol ( 5 ). Their structures were elucidated by combined spectral and chemical methods. All the compounds showed moderate toxicity to brine shrimps Artemia salina.     

Trichodermates A–F,New Cytotoxic Trichothecenes from the Plant Pathogenic Fungus Trichoderma sp.

Trichodermates A – F ( 1 – 6 , resp.), six new trichothecene polyunsaturated octadioic acid esters, and (?)‐harzianum B ( 7 ) were isolated from the fermentation extract of Trichoderma sp., a plant pathogenic fungus isolated from stem rot of an unidentified tree in Thailand. The structures of 1 – 7 were elucidated by NMR experiments. The absolute configuration at C(12) in 3 was assigned by in situ dimolybdenum circular dichroism method, whereas that in 7 was deduced after hydrolysis of 7 to 8 via modified Mosher's method. Compounds 1 and 2 showed modest cytotoxic activities against the K562 (human myelogenous leukemia) cell line with IC₅₀ values of 12.12 and 13.08 μM , respectively.     

Dysideasterols A–E,Five New Uncommon Polyhydroxylated Steroids from the South China Sea Sponge Dysidea sp.

Five new uncommon polyhydroxylated steroids, dysideasterols A–E ( 1 – 5 ), were isolated from the South China Sea sponge Dysidea sp. Their structures were established by detailed analysis of spectral data and verified via single‐crystal X‐ray‐diffraction analysis of compound 1 . The absolute configuration of 1 was determined by the modified Mosher method.