Polyhydroxy steroids isolated from starfish (Asterina pectinifera) and their embryotoxicity.

Many marine organisms possess an essential capacity to produce secondary metabolites that exhibit toxic characteristics. A new polyhydroxy steroid, 24-methyl-5α-cholestane-24(28)-ene-3ß, 4ß, 6α, 7α, 8, 15ß, 16ß, 26-octol-6-O-sodium sulphate (1) was isolated from starfish (Asterina pectinifera), along with five polar steroid compounds (2-6) that were previously identified. NMR (1H and 13C NMR, 1H-1H COSY, HSQC, HMBC, and NOESY) and HR-ESI-MS were employed for structure elucidations. The embryotoxicity and teratogenicity of the isolated compounds were assessed using embryos of marine medaka (Oryzias melastigma). Compound 5 exhibited moderate embryotoxicity (96h-LC50: 65 µM).

Epidermal oxysterols function as alarm substances in zebrafish.

Alarm substances signal imminent predation thread and enable anti-predation strategies. In shoaling fish, alarm cues diffuse from injured skins that induce intense fear and anti-predation behaviors in other members. While these "fear substances" are shown to be present in numerous fishes and thought to exist in roughly 8,000 Ostariophysan species, their chemical nature remains largely unknown. We posited that fish alarm cues comprise small compounds and induce specific behaviors characteristic of fish exposed to skin extracts. Using the behaviors as bioassays, we tracked the alarm function of zebrafish skin extract to two compounds, 24-methyl-5α-cholestane-3α,7α,12α,24,28-pentahydroxy 28-sulfate, an oxysterol sulfate, and 5α-cyprinol sulfate. At concentrations of less than one nanomolar, each compound induced anti-predator behaviors and increased cortisol levels in zebrafish. Their mixture, at the natural ratio, replicated the skin extract in eliciting the full suite of anti-predator behavior patterns. Our findings reveal a molecular mechanism whereby fish escape predation danger.

Sea Cucumber Viscera Contains Novel Non-Holostane-Type Glycoside Toxins that Possess a Putative Chemical Defense Function.

Sea cucumbers frequently expel their guts in response to predators and an aversive environment, a behavior perceived as releasing repellents involved in chemical defense mechanisms. To investigate the chemical nature of the repellent, the viscera of stressed sea cucumbers (Apostichopus japonicus) in the Yellow Sea of China were collected and chemically analyzed. Two novel non-holostane triterpene glycosides were isolated, and the chemical structures were elucidated as 3ꞵ-O-[ꞵ-D-glucopyranosyl-(1→2)-ꞵ-D-xylopyranosyl]-(20S)-hydroxylanosta-7,25-diene-18(16)-lactone (1) and 3ꞵ-O-[ꞵ-D-quinovopyranosyl-(1→2)-ꞵ-D-xylopyranosyl]-(20S)-hydroxylanosta-7,25-diene-18(16)-lactone (2) by spectroscopic and mass-spectrometric analyses, exemplifying a triterpene glycoside constituent of an oligosaccharide containing two sugar-units and a non-holostane aglycone. Zebrafish embryos were exposed to various doses of 1 and 2 from 4 to 96 hpf. Compound 1 exposure showed 96 h-LC50 41.5 µM and an increased zebrafish mortality rates in roughly in a dose- and time-dependent manner. Compound 2, with different sugar substitution, exhibited no mortality and moderate teratogenic toxicity with a 96 h-EC50 of 173.5 µM. Zebrafish embryos exhibited teratogenic effects, such as reduced hatchability and total body length. The study found that triterpene saponin from A. japonicus viscera had acute toxicity in zebrafish embryos, indicating a potential chemical defense role in the marine ecosystem.

Triterpene Glycosides from the Viscera of Sea Cucumber Apostichopus japonicus with Embryotoxicity.

Sea cucumbers release chemical repellents from their guts when they are in danger from predators or a hostile environment. To investigate the chemical structure of the repellent, we collected and chemically analyzed the viscera of stressed sea cucumbers (Apostichopus japonicus) in the Yellow Sea of China. Two undescribed triterpene glycosides (1 and 2), together with a known cladoloside A (3), were identified and elucidated as 3ß-O-{2-O-[ß-d-quinovopyranosyl]-4-O-[3-O-methyl-ß-d-glucopyranosyl-(1→3)-ß-d-glucopyranosyl]-ß-d-xylopyranosyl}-holosta-9(11),25(26)-dien-16-one (1), 3ß-O-{2-O-[ß-d-glucopyranosyl]-4-O-[3-O-methyl-ß-d-glucopyranosyl-(1→3)-ß-d-glucopyranosyl]-ß-d-xylopyranosyl}-holosta-9(11),25(26)-dien-16-one (2), 3ß-O-{2-O-[3-O-methyl-ß-d-glucopyranosyl-(1→3)-ß-d-xylopyranosyl-(1→4)-ß-d-quinovopyranosyl]-ß-d-xylopyranosyl}-holosta-9(11),25(26)-dien-16-one (3) by spectroscopic analysis, including HR-ESI-MS and NMR spectra. Compounds 1, 2, and 3 display embryonic toxicity, as indicated by their 96-hour post-fertilization lethal concentration (96 hpf-LC50) values of 0.289, 0.536, and 0.091 µM, respectively. Our study discovered a class of triterpene glycoside compounds consisting of an oligosaccharide with four sugar units and a holostane aglycone. These compounds possess embryotoxicity and may serve as chemical defense molecules in marine benthic ecosystems.

A New Harziane Diterpene, Harziaketal A, and a New Sterol, Trichosterol A, from the Marine-Alga-Epiphytic Trichoderma sp. Z43.

One new diterpene, harziaketal A (1), and one new highly degraded sterol, trichosterol A (2), along with three known compounds, including one diterpene, harzianone (3), and two steroids, (22E,24R)-5α,6α-epoxy-ergosta-8(14),22-dien-3ß,7α-diol (4) and isoergokonin B (5), were isolated from the culture of the marine-alga-epiphytic fungus Trichoderma sp. Z43 by silica gel column chromatography (CC), Sephadex LH-20 CC, and preparative thin-layer chromatography (TLC). Their structures and relative configurations were assigned by nuclear magnetic resonance (NMR) and high resolution electrospray ionisation mass spectrometry (HR-ESI-MS) data, and the absolute configuration of 1 was established by X-ray diffraction. Compound 1 features a hemiketal unit situated at the four-membered ring of harziane-type diterpenes for the first time, while 2 represents the rare occurrence of sterols with rings A and B being degraded. Compounds 1 and 2 displayed weak inhibition against the tested phytoplankton (Amphidinium carterae, Heterocapsa circularisquama, Heterosigma akashiwo, and Prorocentrum donghaiense) with half maximal inhibitory concentration (IC50 ) ranging from 14 to 53 µg/mL.

Trichoderols B-G, Six New Lipids from the Marine Algicolous Fungus Trichoderma sp. Z43.

Six new lipids, trichoderols B-G (1-6), along with a known one, triharzianin B (7), were isolated from the culture of Trichoderma sp. Z43 obtained from the surface of the marine brown alga Dictyopteris divaricata. Their structures and relative configurations were identified by interpretation of 1D/2D NMR and MS data. Compounds 1-7 were assayed for inhibiting the growth of three phytopathogenic fungi (Fusarium graminearum, Gaeumannomyces graminis, and Glomerella cingulata), four marine phytoplankton species (Amphidinium carterae, Heterocapsa circularisquama, Heterosigma akashiwo, and Prorocentrum donghaiense), and one marine zooplankton (Artemia salina). Compounds 1, 4, and 7 exhibited weak antifungal activities against three phytopathogenic fungi tested with MIC ≥ 64 µg/mL. All compounds displayed moderate antimicroalgal activity with IC50 ≥ 15 µg/mL and low toxicity to the brine shrimp Artemia salina.

New ophiobolin sesterterpenoid and drimane sesquiterpenoids from a marine-alga-derived fungus Aspergillus sp.

Further investigation of secondary metabolites of a marine-alga-derived fungus Aspergillus sp. RR-YLW-12 led to isolate one new ophiobolin-type sesterterpenoid (1), four new drimane-type sesquiterpenoids (2-5) and one natural occurring compound (6), together with seven known compounds (7-13). Their structures and stereochemistry were elucidated by extensive spectroscopic analysis of NMR and HRMS experiments, and by comparison with the literature data. All isolates were evaluated for growth inhibition of five marine harmful microalgae. The new compounds exhibited significant to moderate inhibitory effects towards all tested microalgae species with IC50 values ranging from 5.8 to 54.5 µg/mL.

Myrochromanol analogues and trichothecene derivatives from the shellfish-derived fungus Albifimbriaverrucaria.

Eight myrochromanol analogues, including three pairs of epimers at C-2 with the myrochromanol scaffold and two examples of myrochromanol with sugar moiety linked at C-4, together with twelve trichothecene derivatives were isolated from the cultures of a shellfish-derived fungus Albifimbria verrucaria CD1-4. Among them, eight compounds named 2-epi-myrochromanol, ent-myrochromanol B, 4-epi-myrochromanol B, 2-epi-myrochromanol A, myrochromanosides A and B, 6',7'-erythro-(2'E,4'Z)-trichoverrol B, 3R,8S-dihyroxyroridin H were previously undescribed fungal metabolites. Their planar structures and relative configurations were established by 1D and 2D NMR, and HR-MS data analysis, and their absolute configurations were determined using the modified Mosher's method and electronic circular dichrosim calculations. Almost all isolates were evaluated for growth rate inhibition of three marine harmful microalgae Chattonella marina, Heterosigma akashiwo, and Prorocentrum donghaiense, and lethal activity to one marine zooplankton, Artemia salina. Myrochromanosides A and B exhibited obvious inhibitory against three tested microalgae with IC50 values in the range of 9.2-108.9 µM. 8α-Hydroxyroridin H, roridin A and verrucarin A exhibited significant inhibition against P. donghaiense with IC50 values of 6.1, 5.8, and 6.0 µM and toxicity against brine shrimp larvae with LC50 values of 1.4, 2.8, and 0.26 µM, respectively.

Cyclopentenone and wickerol derivatives from the marine algicolous fungus Trichoderma atroviride A-YMD-9-4.

A new cyclopentenone derivative, 4-hydroxyhypocrenone A, and a new naturally-occurring wickerol derivative, 8-acetoxywickerol A, as well as two known compounds, hypocrenone A and wickerol B, were purified from Trichoderma atroviride A-YMD-9-4, an endophytic fungus isolated from the marine red alga Gracilaria verrucosa. The structures and relative configurations of two new isolates were established by a combination of 1 D/2D NMR, IR, and mass spectroscopic methods, and the absolute configuration of 1 was assigned on the basis of ECD data analyzed by quantum chemical calculations. Compounds 1 and 2 exhibited weak inhibition of one or two marine phytoplankton species.

A new lanostane-type triterpenoid from the marine shellfish symbiotic fungus Ceriporia lacerata CD7-5.

One new lanostane-type triterpenoid, 3ß-acetoxy-7,11-dioxolanosta-8,24-dien-21-oic acid (1), together with six known analogues (2-7), were isolated from the cultures of a marine fungus Ceriporia lacerata CD7-5, which was derived from the shellfish Ostrea denselamellosa. Their structures were determined by detailed analysis of spectroscopic data and comparison with the literature reported. The biological activities of these lanostane triterpenoids against marine-derived microalgae, zooplankton, and pathogenic bacteria were also evaluated in this study.

Serum α-Klotho associated with oral health among a nationally representative sample of US adults.

Background: Low klotho is associated with aging-related traits. However, no study has assessed the association between klotho and oral health in a large sample of population. This study aimed to explore the association between serum α-klotho and oral health in US Adults. Methods: Data were from the National Health and Nutrition Examination Survey. Oral health parameters included periodontitis, self-rated oral health, and tooth loss. Logistic regression and restricted cubic spline models were adopted to evaluate the associations. Results: A total of 6187 participants were included in the study. The median of the α-klotho level was 815.2 pg/mL. Serum α-Klotho was significantly lower in participants with poor oral health (all P <0.01). Compared with the highest tertile, the lowest tertile of α-klotho was associated with moderate/severe periodontitis, poor-rated oral health, and tooth loss, with OR (95% CI) being 1.21 (1.01, 1.48), 1.26 (1.01, 1.56) and 1.38 (1.05, 1.84), respectively. An increment of per 1 standard deviation in the α-klotho concentration was associated with lower odds of moderate/severe periodontitis (OR: 0.93; 95% CI: 0.87, 0.99). Linear dose-response relationships were found between α-klotho and the odds of moderate/severe periodontitis (P for non-linearity=0.88) and poor-rated oral health (P for non-linearity=0.66). An L-shaped dose-response relationship was found between levels of α-klotho and the odds of tooth loss (P for non-linearity=0.04). Conclusions: Serum α-klotho was associated with oral health. Further studies are necessary to clarify the potential mechanisms and demonstrate the predictive ability of klotho in oral diseases.

Antimicrobial Terpenoids and Polyketides from the Algicolous Fungus Byssochlamys spectabilis RR-dl-2-13.

Four new carotane sesquiterpenoids, byssocarotins A-D (1-4), two new nor-sesquiterpenoids, byssofarnesin (5) and byssosesquicarin (6), and three new polyketides, byssoketides A and B (7 and 8) and (8R)-paecilocin A (9a), were obtained from a macroalga-associated strain (RR-dl-2-13) of the fungus Byssochlamys spectabilis. These isolates were identified by a combination of spectroscopic methods, including mass spectroscopy, nuclear magnetic resonance, electronic circular dichroism, and X-ray diffraction. Compounds 1-4 greatly contribute to the diversity of rarely occurring 2,15-epoxycarotane sesquiterpenoids, while 5 and 6 are degradation products of farnesane and sesquicarane precursors, respectively. Compound 7 is a structurally unique furan fatty acid derivative that possesses an aldehyde group and a large conjugated unit, and 8 features a hemiketal group. During antimicrobial assays, 8 showed antagonism against the phytopathogenic fungi Glomerella cingulata, Fusarium oxysporum f. sp. cucumerium, and F. oxysporum f. sp. cubense and the marine-derived bacteria Vibrio parahaemolyticus and V. harveyi with MIC values of 13 to 50 µg/mL.

UPLC-TOF-MS Method for Simultaneous Quantification of Steroid Hormones in Tissue Homogenates of Zebrafish with Solid-Phase Extraction.

The quantification of steroid hormones of individual zebrafish (Danio rerio) provides perspective to understand endogenous hormone function. A UPLC-TOF-MS method was developed to provide a reproducible, sensitive, and efficient assay to determine the concentration of steroid hormones, including cortisol, testosterone, androstenedione, 11-deoxycortisol, 11-deoxycorticosterone, and 17-hydroxyprogesterone in whole-body homogenates of each zebrafish. Solid-phase extraction was used to sample matrix clean-up and acquired a recovery from 89.7% to 107.9%. The analytes were separated on an Aquity BEH C18 column using gradient elution. Mass spectrometric analysis was performed by single reaction monitoring (SRM) using positive electrospray ionization mode. The total running time was 6 min, which was greatly shortened compared with a previously reported method. The developed method exhibited excellent linearity for all the analytes, with regression coefficients higher than 0.99. The limit of detection varied between 0.1 and 0.5 ng/L and the limit of quantification was 0.5-1.7 ng/L for all analytes. The precision of the method was assessed on replicate measurements and was found to be in the ranges of 1.9 % to 6.6% and 4.3% to 8.6%, for intra- and inter-day analysis, respectively. This method was validated according to FDA guidance and applied to determine steroid hormone levels in the tissue homogenate of zebrafish acutely treated with caffeine and ethanol.

Sesquiterpenoids and a steroid from the algicolous Trichoderma brevicompactum.

Six new sesquiterpenoids including three bisabolane derivatives, trichobisabolins O1, O2, and P (1-3), two nerolidol derivatives, trichonerolins A and B (4 and 5), one acorane, trichoacorin A (6), along with one new steroid, isoergokonin B (7), were isolated from the culture of Trichoderma brevicompactum A-DL-9-2 obtained from the inner tissue of the red alga Chondria tenuissima. Their structures and relative configurations were assigned by interpretation of 1D/2D NMR and MS data. As acyclic sesquiterpenoids, compounds 4 and 5 were discovered from Trichoderma for the first time. Compounds 1-7 were evaluated for the inhibition of some marine-derived organisms, in which, 3 and 4/5 exhibited potent inhibition against Amphidinium carterae and Chattonella marina with IC50 of 1.8 µg/mL and 1.2 µg/mL, respectively. In addition, compound 7 could inhibit the growth of Pseudoalteromonas citrea with an MIC value of 64 µg/mL.

Terpenoids from the Marine-Derived Fungus Aspergillus sp. RR-YLW-12, Associated with the Red Alga Rhodomela confervoides.

Two new meroterpenoids, aspermeroterpenes D and E (1 and 2), two new ophiobolin-type sesterterpenoids, the C-18 epimers of 18,19-dihydro-18-methoxy-19-hydroxyophiobolin P (6 and 7), and two new drimane-type sesquiterpenoids, 3S-hydroxystrobilactone A (8) and 6-epi-strobilactone A (9), along with 11 known terpenoids (3-5 and 10-17) were isolated from the cultures of the algicolous fungus Aspergillus sp. RR-YLW-12, derived from the red alga Rhodomela confervoides. The structures and relative configurations of new compounds were established by detailed spectroscopic analysis of NMR and HRMS experiments, and the absolute configurations were assigned by X-ray diffraction experiments and comparison of their experimental and calculated ECD spectra. Compound 1 features a rare 6/6/6/6/5 pentacyclic system with a meroterpenoid skeleton, and the structure of terretonin E (3) was revised in this study. Compound 4 showed significant inhibitory activities against three microalgae, Prorocentrum donghaiense, Heterosigma akashiwo, and Chattonella marina, with IC50 values of 10.5, 5.2, and 3.1 µg/mL, respectively.

Antimicrobial bisabolane-type sesquiterpenoids from the deep-sea sediment-derived fungus Aspergillus versicolor SD-330.

One new aromatic bisabolene-type sesquiterpenoid (1), along with four known analogues (2-5) were isolated and identified from the deep-sea sediment-derived fungus Aspergillus versicolor SD-330. Their structures were elucidated by NMR, HRESIMS, X-ray crystallographic analysis, and quantum chemical ECD calculations as well as comparison of those data with literature data. Compounds 1-5 were evaluated for antimicrobial activities against human and aquatic pathogenic bacteria. Compounds 1, 2 and 5 exhibited selective inhibitory activities against zoonotic pathogenic bacteria such as Aeromonas hydrophilia, Escherichia coli, Edwardsiella tarda and Vibrio harveyi, with the MIC values ranging from 1.0 to 8.0 µg/mL.

Outcomes of combination treatment with MARS and TIPS for hepatic veno-occlusive disease: a report of 12 cases.

BACKGROUND: In patients with acute liver injury caused by hepatic veno-occlusive disease (HVOD), molecular adsorbent recirculation system (MARS) may be used to improve liver function in conjunction with transjugular intrahepatic portosystemic shunt (TIPS) to reduce portal hypertension. METHODS: Twelve patients were admitted to our hospital following treatment for HVOD for 10 to 21 days at other hospitals. All patients were treated with a combination of MARS and TIPS, and they were evaluated clinically including liver function tests. RESULTS: After the initial treatment with MARS, liver function improved significantly in all patients. TIPS placement decreased the hepatic venous pressure gradient (HVPG) to 10.17 ± 2.26 mmHg from a pre-TIPS HVPG of 23.58 ± 9.43 mmHg. The outcomes of combination treatment with MARS and TIPS in 12 patients with HVOD were as follows: 1) improvement of various clinical and biological parameters leading to full recovery in 1 year in 6 patients; 2) full recovery following liver transplantation for acute liver failure in three patients; and 3) three patients died due to hepatic failure after TIPS placement. CONCLUSION: The combination of MARS and TIPS creation is promising as a potential treatment for acute HVOD, and it showed an improvement in overall survival.

Antimicrobial Sesquiterpenoid Derivatives and Monoterpenoids from the Deep-Sea Sediment-Derived Fungus Aspergillus versicolor SD-330.

Two new antimicrobial bisabolane-type sesquiterpenoid derivatives, ent-aspergoterpenin C (compound 1) and 7-O-methylhydroxysydonic acid (2), and two new butyrolactone-type monoterpenoids, pestalotiolactones C (3) and D (4), along with a known monoterpenoid pestalotiolactone A (5) and four known bisabolane sesquiterpenoids (6-9), were isolated and identified from the deep-sea sediment-derived fungus Aspergillus versicolor SD-330. The structures of these compounds were elucidated on the basis of spectroscopic analysis, and the absolute configurations of the new compounds 1-4 were determined by the combination of NOESY and TDDFT-ECD calculations and X-ray crystallographic analysis. Additionally, we first determined and reported the absolute configuration of the known monoterpenoid pestalotiolactone A (5) through the X-ray crystallographic experiment. All of these isolated compounds were evaluated for antimicrobial activities against human and aquatic pathogenic bacteria. Compounds 1, 2, 6 and 9 exhibited selective inhibitory activities against zoonotic pathogenic bacteria such as Escherichia coli, Edwardsiella tarda, Vibrio anguillarum and V. harveyi, with MIC values ranging from 1.0 to 8.0 µg/mL.

Redox-dependent phosphorus burial and regeneration in an offshore sulfidic sediment core in North Yellow Sea, China.

Phosphorus (P) pollution can trigger severe marine eutrophication, which further leads to harmful algal blooms, and a deterioration of sea water quality. The P burial and regeneration in offshore sediments can directly affect the eutrophication levels of estuarine and coastal ecosystems. Although many researches on redox-dependent P burial and regeneration were studied, such process in the presence of silicate is still poorly understood, and the effects of pyrite formation on organic P (OP) burial and regeneration also remain unclear. In this study, a sulfidic sediment core was collected in the offshore of an estuary in the north Yellow Sea, China. Results indicated that indigenous biological input was found to be the primary source of organic matter in upper sediments. The regenerated P under reducing conditions was dominated by labile FeP and OP. The PO43- released from FeP and OP that could be captured by Al/Fe/Mn (oxyhydr) oxides in surface sediments and Ca minerals in deep sediments. CaP, AlP, unreactive Al/Fe-Si-P and some stable metal chelated OP were the main burial P fractions. Sulfate reduction and formation of insoluble metal sulfides including the pyrite promoted OP decomposition by anaerobic decomposition, removing metal ions from the "metal-OP" chelates and restoring the phosphatase activity.

Cyclonerane Derivatives from the Algicolous Endophytic Fungus Trichoderma asperellum A-YMD-9-2.

Seven previously unreported cyclonerane derivatives, namely, 3,7,11-trihydroxycycloneran-10-one, cycloneran-3,7,10,11-tetraol, cycloneran-3,7,11-triol, 11,12,15-trinorcycloneran-3,7,10-triol, 7,10S-epoxycycloneran-3,15-diol, 7,10R-epoxycycloneran-3,15-diol, and (10Z)-15-acetoxy-10-cycloneren-3,7-diol, were isolated in addition to the known (10Z)-cyclonerotriol, (10E)-cyclonerotriol, catenioblin C, and chokol E from the culture of Trichoderma asperellum A-YMD-9-2, an endophytic fungus obtained from the marine red alga Gracilaria verrucosa. The structures of previously unreported compounds were established by spectroscopic techniques, including 1D/2D NMR, MS, and IR. The isolation of these new cyclonerane derivatives greatly adds to the structural diversity of unusual cyclonerane sesquiterpenes, and several isolates exhibit potent inhibition against some marine phytoplankton species.