Hepialiamides A-C: Aminated Fusaric Acid Derivatives and Related Metabolites with Anti-Inflammatory Activity from the Deep-Sea-Derived Fungus Samsoniella hepiali W7.

A systematic investigation combined with a Global Natural Products Social (GNPS) molecular networking approach, was conducted on the metabolites of the deep-sea-derived fungus Samsoniella hepiali W7, leading to the isolation of three new fusaric acid derivatives, hepialiamides A-C (1-3) and one novel hybrid polyketide hepialide (4), together with 18 known miscellaneous compounds (5-22). The structures of the new compounds were elucidated through detailed spectroscopic analysis. as well as TD-DFT-based ECD calculation. All isolates were tested for anti-inflammatory activity in vitro. Under a concentration of 1 µM, compounds 8, 11, 13, 21, and 22 showed potent inhibitory activity against nitric oxide production in lipopolysaccharide (LPS)-activated BV-2 microglia cells, with inhibition rates of 34.2%, 30.7%, 32.9%, 38.6%, and 58.2%, respectively. Of particularly note is compound 22, which exhibited the most remarkable inhibitory activity, with an IC50 value of 426.2 nM.

Penicopeptide A (PPA) from the deep-sea-derived fungus promotes osteoblast-mediated bone formation and alleviates ovariectomy-induced bone loss by activating the AKT/GSK-3ß/ß-catenin signaling pathway.

The potential of marine natural products as effective drugs for osteoporosis treatment is an understudied area. In this study, we investigated the ability of lead compounds from deep-sea-derived Penicillium solitum MCCC 3A00215 to promote bone formation in vitro and in vivo. We found that penicopeptide A (PPA) promoted osteoblast mineralization among bone marrow mesenchymal stem cells (BMSCs) in a concentration-dependent manner, and thus, we selected this natural peptide for further testing. Our further experiments showed that PPA significantly promoted the osteogenic differentiation of BMSCs while inhibiting their adipogenic differentiation and not affecting their chondrogenic differentiation. Mechanistic studies showed that PPA binds directly to the AKT and GSK-3ß and activates phosphorylation of AKT and GSK-3ß, resulting in the accumulation of ß-catenin. We also evaluated the therapeutic potential of PPA in a female mouse model of ovariectomy-induced systemic bone loss. In this model, PPA treatment prevented decreases in bone volume and trabecular thickness. In conclusion, our in vitro and in vivo results demonstrated that PPA could promote osteoblast-related bone formation via the AKT, GSK-3ß, and ß-catenin signaling pathways, indicating the clinical potential of PPA as a candidate compound for osteoporosis prevention.

Chemical Constituents of the Deep-Sea-Derived Penicillium citreonigrum MCCC 3A00169 and Their Antiproliferative Effects.

Six new citreoviridins (citreoviridins J-O, 1-6) and twenty-two known compounds (7-28) were isolated from the deep-sea-derived Penicillium citreonigrum MCCC 3A00169. The structures of the new compounds were determined by spectroscopic methods, including the HRESIMS, NMR, ECD calculations, and dimolybdenum tetraacetate-induced CD (ICD) experiments. Citreoviridins J-O (1-6) are diastereomers of 6,7-epoxycitreoviridin with different chiral centers at C-2-C-7. Pyrenocine A (7), terrein (14), and citreoviridin (20) significantly induced apoptosis for HeLa cells with IC50 values of 5.4 µM, 11.3 µM, and 0.7 µM, respectively. To be specific, pyrenocine A could induce S phase arrest, while terrein and citreoviridin could obviously induce G0-G1 phase arrest. Citreoviridin could inhibit mTOR activity in HeLa cells.

Solitumergosterol A, a unique 6/6/6/6/5 steroid from the deep-sea-derived Penicillium solitum MCCC 3A00215.

A unique C30 steroid, solitumergosterol A (1), was isolated from the deep-sea-derived fungus Penicillium solitum MCCC 3A00215. The planar structure and relative configuration of 1 were established mainly on the basis of extensive analysis of its 1D and 2D NMR as well as HRESIMS data, while its absolute configuration was clarified by comparison of the experimental and theoretical ECD spectra. Noteworthily, 1 is a Diels-Alder adduct of a heterogeneous steroid bearing a 6/6/6/6/5 pentacyclic carbon skeleton. Solitumergosterol A (1) exhibited weak in vitro anti-tumor activity against MB231 cells by a RXRα-dependent mechanism.

Chemical Constituents of the Marine Fungus Penicillium sp. MCCC 3A00228.

One new (d-arabinitol-anofinicate, 1) and fourteen known (2-15) compounds were isolated from the marine Penicillium sp. MCCC 3A00228. The structure of the new compound was established mainly by extensive spectroscopic analyses. Compound 1 exhibited weak transcriptional effect on Nur77. While compound 13 showed moderate in vitro anti-proliferative effect against QGY7701, H1299, and HCT116 tumor cells with IC50 values of 21.2 µM, 18.2 µM, and 17.6 µM, respectively.

Anti-Food Allergic Compounds from Penicillium griseofulvum MCCC 3A00225, a Deep-Sea-Derived Fungus.

Ten new (1-10) and 26 known (11-36) compounds were isolated from Penicillium griseofulvum MCCC 3A00225, a deep sea-derived fungus. The structures of the new compounds were determined by detailed analysis of the NMR and HRESIMS spectroscopic data. The absolute configurations were established by X-ray crystallography, Marfey's method, and the ICD method. All isolates were tested for in vitro anti-food allergic bioactivities in immunoglobulin (Ig) E-mediated rat basophilic leukemia (RBL)-2H3 cells. Compound 13 significantly decreased the degranulation release with an IC50 value of 60.3 µM, compared to that of 91.6 µM of the positive control, loratadine.

Discovery of andrastones from the deep-sea-derived Penicillium allii-sativi MCCC 3A00580 by OSMAC strategy.

Andrastones are unusual 6,6,6,5-tetracyclic meroterpenoids that are rarely found in nature. Previously, three andrastones were obtained from the rice static fermentation extract of the deep-sea-derived fungus Penicillium allii-sativi MCCC 3A00580. Inspired by one strain many compounds (OSMAC) approach, the oat static fermentation on P. allii-sativi was conducted. As a result, 14 andrastones were isolated by UV-guided isolation. The chemical structures of the nine new compounds (1-9) was established by comprehensive analysis of the NMR, MS, ECD, and X-ray crystallography and the five known ones (10-14) were assigned by comparing their NMR, MS, and OR data with those reported in literature. Compound 1 bears a novel hemiketal moiety while 2 is the first example to possess a novel tetrahydrofuran moiety via C-7 and C-15. All isolates were tested for anti-allergic bioactivity. Compound 10, 3-deacetylcitreohybridonol, significantly decreased degranulation with the IC50 value of 14.8 µM, compared to that of 92.5 µM for the positive control, loratadine. Mechanism study indicated 10 could decrease the generation of histamine and TNF-α by reducing the accumulation of Ca2+ in RBL-2H3 cells. These findings indicate andrastones could be potential to discover new anti-allergic candidate drugs.

Cytotoxic p-terphenyls from the deep-sea-derived Aspergillus candidus.

From the deep-sea-derived fungus Aspergillus candidus, one novel (1) and three known (2-4) p-terphenyl derivates were isolated. The structure of the new compound was established mainly on the basis of extensive analysis of 1D and 2D NMR data. All four isolates were tested for in vitro anti-food allergic and antitumor bioactivities. Compounds 3 and 4 showed potent antiproliferative effect against four cancer cells of Hela, Eca-109, Bel-7402, and PANC-1 with IC50 values ranging from 5.5 µM to 9.4 µM.

Asperochratides A-J, Ten new polyketides from the deep-sea-derived Aspergillus ochraceus.

Ten new C9 polyketides (asperochratides A-J, 1-10) and 14 known miscellaneous compounds (11-24) were isolated from the deep-sea-derived fungus Aspergillus ochraceus. Structures of the new compounds were elucidated by extensive spectroscopic analyses, modified Mosher's method, Mo2(OAc)4 induced circular dichroism (ICD) experiments, and ECD calculations. Structurally, compounds 1-11 and 16-18 share the same polyketide origin of the skeleton and belong to aspyrone co-metabolites. All isolates were tested for cytotoxic, anti-food allergic, anti-H1N1 virus, anti-microbe, and anti-inflammatory activities in vitro. Results showed that compounds 5-8 and 13-17 exerted significant cytotoxic effects on BV-2 cell line, and compound 16 showed the potential of anti-inflammatory activities.

Chemical Constituents and Bioactivities of Starfishes: An Update.

Starfishes produce various structurally unique secondary metabolites with diverse biological activities. This review is an update summary of the new compounds and their bioactivities from starfish (the Asteroidea Class) with 71 references covering from January 2007 to December 2018. During this period, 216 new compounds were obtained from 36 species. The chemical constituents are mostly steroids, steroidal glycosides, and gangliosides. These components have been found to possess various bioactivities, including anticancer, anti-inflammation, etc.

Antiproliferative Sorbicillinoids From the Deep-Sea-Derived Penicillium allii-sativi.

Two new (1-2) and three known (3-5) sorbicillinoids were isolated from the deep-sea-derived fungus Penicillium allii-sativi MCCC 3A00580. Compounds 1 and 2, named sorbicatechols C and D, were two new hybrid dihydrosorbillinoids. Their structures were established mainly by spectroscopic analyses and electronic circular dichroism (ECD) calculations. All five isolates were tested for antiproliferative activities against four tumor cell lines of MCF-7, HT-29, HuH-7, and LNCap. Compounds 2 and 5 inhibited HT-29 cells in a good dose-dependent manner. Mechanism investigation uncovered that they could significantly induce cell cycle G2-M phase arresting by increasing the protein levels of p-H3 and cyclin B1.

Botryotins A-H, Tetracyclic Diterpenoids Representing Three Carbon Skeletons from a Deep-Sea-Derived Botryotinia fuckeliana.

Eight unprecedent diterpenoids, botryotins A-H (1-8), were obtained from Botryotinia fuckeliana. They represent three novel carbon skeletons with 6/6/5/5 (1), 6/6/5/6 (2-6), and 6/6/6/5 (7 and 8) tetracyclic scaffolds. Their structures were determined by detailed spectroscopic analysis and chemical derivatization as well as quantum chemical calculation of the ECD and OR data. Botryotin A (1) exhibited a moderate antiallergic effect (IC50 = 0.2 mM). A plausible biosynthetic pathway for 1-8 was proposed.

Chemical constituents from the deep sea-derived Streptomyces xiamenensis MCCC 1A01570 and their effects on RXRα transcriptional regulation.

From the deep sea-derived Streptomyces xiamenensis MCCC 1A01570, eight cyclic dipeptides (1-8) and five phenolics (9-13) were obtained. Cyclo-(I-Pro-D-Leu) (4) could moderately promote the gene transcriptional function of nuclear receptor RXRα, while 2, 3, and 13 showed weak reduction in RXRα gene transcriptional activities induced by 9-cis-retinoid acid (RA). These compounds might have beneficial effects against intractable diseases with relation to RXRα, such as cancer and metabolic diseases, due to their potential activities on regulating the transcriptional activation function of RXRα. In addition, 1-6, 8, 10, and 12 (20 µM) showed mild in vitro cytotoxicity against three cancer cell lines of ECA-109, Hela-S3 and PANC-1 with the inhibition rates arranging from 50% to 65%.

Andrastone A From the Deep-Sea-Derived Fungus Penicillium allii-sativi Acts as an Inducer of Caspase and RXRα-Dependent Apoptosis.

Two new (1, 2) and one known (3) meroterpenoids were isolated from the deep-sea-derived fungus Penicillium allii-sativi. The relative structures of new compounds were determined on the basis of an extensive analysis of the NMR and MS data, and the absolute configurations were established by ECD calculations. Andrastone A (1) is a rare andrastin bearing an unusual cyclopentan-1,3-dione. It shows a selectively antiproliferative effect against HepG2 tumor cells with an IC50 value of 7.8 µM. Mechanism study showed that apoptosis via Caspase and RXRα pathways are responsible for the inhibitory effect.

A New Pimarane Diterpenoid from the Botryotinia fuckeliana Fungus Isolated from Deep-Sea Water.

A new pimarane diterpenoid, named botryopimarene A (1), was discovered from the fungus Botryotinia fuckeliana MCCC 3 A00494 isolated from the deep-sea water, together with ten known compounds. The planar structure of 1 was established based on the extensive spectroscopic analyses. The absolute configurations of tricyclic system in 1 were resolved by the theoretical ECD calculation, while the 15,16-diol moiety in the side chain was resolved by the Mo2 (OAc)4 -induced ECD spectrum. Compound 1, featuring a Δ9(11) double bond, was rarely discovered in pimarane family. Compounds 1-11 were tested for their cytotoxic activities using six human cancer cell lines by the MTT method. However, none of the compounds exhibited detectable cytotoxicities (IC50 >20 µm).

Penigrisacids A-D, Four New Sesquiterpenes from the Deep-Sea-Derived Penicillium griseofulvum.

Four new (penigrisacids A-D, 1-4) and one known (5) carotane sesquiterpenoids were isolated from the deep-sea-derived fungus Penicillium griseofulvum, along with four known compounds (6-9). The planar structures and relative configurations of the new compounds were determined by extensive analysis of the NMR and HRESIMS data. The absolute configurations were established by comparison of the experimental and calculated ECD (electronic circular dichroism) spectra or OR (optical rotation) value. Compound 9 exhibited potent anti-food allergic activity with IC50 value of 28.7 µM, while 4 showed weak cytotoxicity against ECA-109 tumor cells (IC50 = 28.7 µM).

Nesteretal A, A Novel Class of Cage-Like Polyketide from Marine-Derived Actinomycete Nesterenkonia halobia.

An intriguing cage-like polyhemiketal, nesteretal A (1), was isolated from the coral-derived actinomycete Nesterenkonia halobia. Its structure was established by extensive spectroscopic and computational methods. Nesteretal A is a highly oxygenated compound featuring an unprecedented 5/5/5/5 tetracyclic scaffold. A possible biosynthetic pathway of 1 from naturally occurring diacetyl was proposed. Compound 1 showed a weak retinoid X receptor-α (RXRα) transcriptional activation effect.

Aphidicolin Chemistry of the Deep-Sea-Derived Fungus Botryotinia fuckeliana MCCC 3A00494.

Aphidicolin, a potent DNA polymerase α inhibitor, has been explored in clinical trials for the treatment of cancer. So far, about 300 modified aphidicolins have been discovered. However, none have shown a stronger effect. Herein, we report 71 new (aphidicolins A1-A71, 1-71) and eight known (72-79) aphidicolin congeners from Botryotinia fuckeliana MCCC 3A00494, a fungus isolated from the western Pacific Ocean (-5572 m). The structures of 1-71 were determined through extensive spectroscopic analysis, X-ray crystallography, chemical derivatization, modified Mosher's method, and the ECD exciton chirality method. Compounds 54-57 and 58-64 are novel 6/6/5/6/5 pentacyclic aphidicolins featuring tetrahydrofuran and dihydrofuran rings, respectively, while compounds 65-71 are rare noraphidicolins. Aphidicolin A8 (8) significantly induced apoptosis in T24 (IC50 = 2.5 µM) and HL-60 (IC50 = 6.1 µM) cancer cells by causing DNA damage. By docking its structure to the human DNA polymerase α binding pocket, 8 was found to form tight intermolecular contacts, elaborating aphidicolin A8 as a potently cytotoxic lead compound.

Graphostromols A-K, Eleven New Chained Polyketides from the Deep-Sea-Derived Graphostroma sp.

Chromatographic separation of the AcOEt extract of the fermented cultures of the deep-sea-derived fungus Graphostroma sp. resulted in the isolation of 11 new chained polyketides, namely graphostromols A-K (1-11). The structures of the new compounds were established by the extensive analyses of their NMR and HR-ESI-MS data. The absolute configuration at C-11 in 1 was determined on the basis of the modified Mosher's method. Compounds 1-5, bearing a 2,2,10,10-tetramethyldodecane skeleton, were discovered for the first time from nature. All isolates were evaluated for their cytotoxicities against five different cancer cell lines (HeLa, Eca-109, Biu-87, Bel-7402, and PANC-1). However, none showed positive effects.

Sarocladione, a unique 5,10:8,9-diseco-steroid from the deep-sea-derived fungus Sarocladium kiliense.

A novel ergostane, sarocladione (1), was isolated from the deep-sea-derived fungus Sarocladium kiliense, along with 20 known compounds. The structure of 1 was determined mainly by a detailed analysis of its experimental and calculated NMR spectroscopic data. It is worth noting that 1 was the first steroid bearing a 5,10:8,9-diseco moiety. All 21 compounds were tested for in vitro antitumor activities against five cancer cell lines. ß-Sitostenone (7) and 4,6-dihydroxyeudesmane (20) showed significant effects on HeLa-S3 cells with the IC50 values of 9.2 µM and 9.3 µM, respectively.