Yuhua Long

Asperterpenoid A, a New Sesterterpenoid as an Inhibitor of Mycobacterium tuberculosis Protein Tyrosine Phosphatase B from the Culture of Aspergillus sp. 16-5c

Asperterpenoid A (1), a novel sesterterpenoid with a new carbon skeleton, has been isolated from a mangrove endophytic fungus Aspergillus sp. 16-5c. Its structure was characterized by extensive spectroscopic methods, and the absolute configuration was determined by single crystal X-ray diffraction analysis. Asperterpenoid A (1) exhibited strong inhibitory activity against Mycobacterium tuberculosis protein tyrosine phosphatase B (mPTPB) with an IC(50) value of 2.2 μM.

Asperterpenols A and B, New Sesterterpenoids Isolated from a Mangrove Endophytic Fungus Aspergillus sp. 085242

Asperterpenol A (1) and asperterpenol B (2), two novel sesterterpenoids with an unusual 5/8/6/6 tetracyclic ring skeleton, were isolated from a mangrove endophytic fungus Aspergillus sp. 085242. The structures were elucidated on the basis of spectroscopic methods and the absolute configurations determined by single-crystal X-ray diffraction analysis. Compounds 1 and 2 inhibit acetylcholinesterase with IC50 values of 2.3 and 3.0 μM, respectively.

Studies on the Synthesis of Derivatives of Marine-Derived Bostrycin and Their Structure-Activity Relationship against Tumor Cells

A series of new derivatives (5–29) of marine-derived bostrycin (1) were synthesized. The in vitro cytotoxic activities of all compounds were evaluated against MCF-7, MDA-MB-435, A549, HepG2, HCT-116 and MCF-10A cells using the MTT method. The compounds 7, 8, 22, 23, 25, 28 and 29 of the total showed comparable activity to epirubicin, the positive control, against the tested cancer cell lines. However, these compounds also exhibited cytotoxicity towards MCF-10A cells. The structure-activity relationship (SAR) of bostrycin derivatives was also discussed based on the obtained experimental data.

Alterporriol-Type Dimers from the Mangrove Endophytic Fungus, Alternaria sp. (SK11), and Their MptpB Inhibitions

A new alterporriol-type anthranoid dimer, alterporriol S (1), along with seven known anthraquinone derivatives, (+)-aS-alterporriol C (2), hydroxybostrycin (3), halorosellinia A (4), tetrahydrobostrycin (5), 9α-hydroxydihydrodesoxybostrycin (6), austrocortinin (7) and 6-methylquinizarin (8), were isolated from the culture broth of the mangrove fungus, Alternaria sp. (SK11), from the South China Sea. Their structures and the relative configurations were elucidated using comprehensive spectroscopic methods, including 1D and 2D NMR spectra. The absolute configurations of 1 and the axial configuration of 2 were defined by experimental and theoretical ECD spectroscopy. 1 was identified as the first member of alterporriols consisting of a unique C-10−C-2′ linkage. Atropisomer 2 exhibited strong inhibitory activity against Mycobacterium tuberculosis protein tyrosine phosphatase B (MptpB) with an IC50 value 8.70 μM.

Synthesis and Antitumor Activities of Derivatives of the Marine Mangrove Fungal Metabolite Deoxybostrycin

Deoxybostrycin (1) is an anthraquinone compound derived from the marine mangrove fungus Nigrospora sp. No. 1403 and has potential to be a lead for new drugs because of its various biological properties. A series of new derivatives (2–22) of deoxybostrycin were synthesized. The in vitro cytotoxicity of all the new compounds was tested against MDA-MB-435, HepG2 and HCT-116 cancer cell lines. Most of the compounds exhibit strong cytotoxicity with IC50 values ranging from 0.62 to 10 μM. Compounds 19, 21 display comparable cytotoxicity against MDA-MB-435 to epirubicin, the positive control. The primary screening results indicate that the deoxybostrycin derivatives might be a valuable source of new potent anticancer drug candidates.

Antioxidative Polyketones from the Mangrove-Derived Fungus Ascomycota sp. SK2YWS-L

Three novel 2,3-diaryl indone derivatives, ascomindones A−C (1−3), and two new isobenzofuran derivatives, ascomfurans A (4) and B (5), together with four know compounds (6−9) were isolated from the culture of a mangrove-derived fungus Ascomycota sp. SK2YWS-L. Their structures were elucidated on the interpretation of spectroscopic data. 1 and 4 were further constructed by analysis of X-ray diffraction. Antioxidant properties based on 2,2-diphenyl-1-picrylhydrazyl (DPPH), hydroxyl radical scavenging activities and the ferric reducing ability power (FRAP) of the new compounds were assayed. All of them exhibited significant effects, of which 1 showed more potent activity than ascorbic acid in scavenging DPPH radical with IC50 value of 18.1 μM.

Talaramide A, an unusual alkaloid from the mangrove endophytic fungus Talaromyces sp. (HZ-YX1) as an inhibitor of mycobacterial PknG

An unusual alkaloid, talaramide A (1), was obtained from the mangrove endophytic fungus Talaromyces sp. (HZ-YX1). The structure of 1 was established by analysis of NMR spectroscopic data, X-ray diffraction data, and electronic circular dichroism (ECD) spectra. Talaramide A (1) is the second example of an alkaloid that possesses a unique oxidized tricyclic system. A possible biosynthetic pathway for 1 was proposed. Compound 1 showed promising inhibition of mycobacterial PknG activity with an IC50 value of 55 μM.

Acetylcholinesterase Inhibitory Meroterpenoid from a Mangrove Endophytic Fungus Aspergillus sp. 16-5c

One new meroterpenoid, named 2-hydroacetoxydehydroaustin (1), together with nine known meroterpenoids, 11-acetoxyisoaustinone (2), isoaustinol (3), austin (4), austinol (5), acetoxydehydroaustin (6), dehydroaustin (7), dehydroaustinol (8), preaustinoid A2 (9), and 1,2-dihydro-acetoxydehydroaustin B (10), were isolated from the mangrove endophytic fungus, Aspergillus sp. 16-5c. These structures were characterized by spectroscopic analysis, further the absolute configurations of stereogenic carbons for Compounds 1, 3, 4, 6, 7, 8, 9, and 10 were determined by single crystal X-ray diffraction analysis using Cu Kα radiation. Moreover, the absolute configurations of stereogenic carbons for Known Compounds 3, 7, 8, and 9 are identified here for the first time. Compounds 3, 7, and 8 showed acetylcholinesterase (AchE) inhibitory activity with IC50 values of 2.50, 0.40, and 3.00 μM, respectively.

Diaporindenes A–D: Four Unusual 2,3-Dihydro-1H-indene Analogues with Anti-inflammatory Activities from the Mangrove Endophytic Fungus Diaporthe sp. SYSU-HQ3

Diaporindenes A-D (1-4), four unusual 2,3-dihydro-1 H-indene isomers, a novel isoprenylisobenzofuran A (5), two new isoprenylisoindole alkaloids diaporisoindoles D and E (6 and 7), and a new benzophenone derivative tenellone D (11), together with four known biogenetic agents (8-10 and 12), were all separated from the endophytic fungus Diaporthe sp. SYSU-HQ3 guided by ultraperformance liquid chromatography high-resolution mass spectrometry. The absolute configurations of 1-7 and 11 were defined by X-ray diffraction, quantum chemical calculations, and spectroscopic analysis. Diaporindenes A-D (1-4) possessed an unprecedented chemical skeleton featuring a 2,3-dihydro-1 H-indene ring and a 1,4-benzodioxan moiety. All of the isolates (1-12) were tested for their inhibitory effects on the production of nitric oxide in lipopolysaccharide-induced microglial cells (RAW 264.7 cells). Compounds 1-5, 8, and 9 were found to exhibit significant inhibitory effects against nitric oxide production with IC50 values from 4.2 to 9.0 μM and SI values from 3.5 to 6.9. In addition, the structure-activity relationships of all compounds were summarized.