Quinone/hydroquinone meroterpenoids with antitubercular and cytotoxic activities produced by the sponge-derived fungus Gliomastix sp. ZSDS1-F7.

Fifteen compounds, including six quinone/hydroquinone meroterpenoids, purpurogemutantin (1), macrophorin A (2), 4'-oxomacrophorin (3), 7-deacetoxyyanuthone A (4), 2,3-hydro-deacetoxyyanuthone A (5), 22-deacetylyanuthone A (6), anicequol (7), three roquefortine derivatives, roquefortine C (8), (16S)-hydroxyroquefortine C (9), (16R)-hydroxyroquefortine C (10), dihydroresorcylide (11), nectriapyrone (12), together with three fatty acid derivatives, methyl linoleate (13), phospholipase A2 (14), methyl elaidate (15), were isolated from the sponge-derived fungus Gliomastix sp. ZSDS1-F7 isolated from the sponge Phakellia fusca Thiele collected in the Yongxing island of Xisha. Their structures were elucidated mainly by extensive NMR spectroscopic and mass spectrometric analyses. Among these compounds, compounds 1-3 and 5-7 showed significant in vitro cytotoxicities against the K562, MCF-7, Hela, DU145, U937, H1975, SGC-7901, A549, MOLT-4 and HL60 cell lines, with IC50 values ranging from 0.19 to 35.4 µM. And compounds 2-4 exhibited antitubercular activity with IC50 values of 22.1, 2.44 and 17.5 µM, respectively. Furthermore, compound 7 had anti-enterovirus 71 activity with MIC value of 17.8 µM. To the best of our knowledge, this is the first report to product two quinone/hydroquinone meroterpenoids skeletons (linear skeleton and drimane skeleton) from the same fungal strain.

Design, synthesis and cytotoxic activities of novel 2,5-diketopiperazine derivatives.

A series of novel N-1-monoallylated 2,5-diketopiperazine derivatives were designed, synthesized, and evaluated as cytotoxic agents against eight cancer cell lines by using CCK8 assay. These derivatives were substituted with methoxyphenyl groups at C-6 position, and various long alkyl side chains at C-3-position of the 2,5-diketopiperazine ring. The cytotoxic results showed that 4-methoxyphenyl group was better than 2-methoxyphenyl group as optimal substitutive group, while 3-methoxyphenyl group was not a suitable one. When the number (n value) of the methylene groups for the long alkyl side chain was 3 (compounds 1c and 3c), the derivatives had the strongest cytotoxicities. Compound 3c substituted with 4-methoxyphenyl group and pentylidene side chain exhibited strong activity (IC50 = 0.36-1.9 µM) against all cancer cell lines, and could obviously induce apoptosis of cancer cell line U937 at 1.0 µM after 48 h treatment.

Asteltoxins with Antiviral Activities from the Marine Sponge-Derived Fungus Aspergillus sp. SCSIO XWS02F40.

Two new asteltoxins named asteltoxin E (2) and F (3), and a new chromone (4), together with four known compounds were isolated from a marine sponge-derived fungus, Aspergillus sp. SCSIO XWS02F40. The structures of the compounds (1-7) were determined by the extensive 1D- and 2D-NMR spectra, and HRESIMS spectrometry. All the compounds were tested for their antiviral (H1N1 and H3N2) activity. Compounds 2 and 3 showed significant activity against H3N2 with the prominent IC50 values of 6.2 ± 0.08 and 8.9 ± 0.3 µM, respectively. In addition, compound 2 also exhibited inhibitory activity against H1N1 with an IC50 value of 3.5 ± 1.3 µM.

Compounds from the insect Blaps japanensis with COX-1 and COX-2 inhibitory activities.

Blapsols A-D (1-4), four new compounds possessing a 2,3-dihydrobenzo[b][1,4]dioxin group, together with five known N-acetyldopamine dimers (5-9), were isolated from Blaps japanensis. Their structures including the absolute configuration of (+)-1 were determined by means of spectroscopic and X-ray crystallographic methods. Chiral HPLC was used to separate (-)- and (+)-enantiomers of compounds 1-4, which were isolated from this insect as racemic mixtures. All the compounds were found to have inhibitory effects towards COX-2 with IC50 values in the range of 1.3-17.8µM.

Dihydrothiophene-condensed chromones from a marine-derived fungus Penicillium oxalicum and their structure-bioactivity relationship.

Four dihydrothiophene-condensed chromones including two new compounds oxalicumones D-E (1-2) and known oxalicumones A-B (3-4), along with five other known chromones were isolated from a culture broth of the marine gorgonian-associated fungus Penicillium oxalicum SCSGAF 0023. The structures of 1-2 were elucidated by spectroscopic analysis. Eleven derivatives 3a-3i and 4a-4b were obtained from the acylation of 3 and 4, respectively. Compounds 1-4, 3a-3e, 3g-3h, and 4b showed significant cytotoxicity against several carcinoma cell lines with IC50 ≤ 10 µM. And their structure-bioactivity relationship was discussed.

[Green synthesis of silver nanoparticles and their application in SERS].

In the present paper, we have successfully synthesized silver nancomparticles by reducing of silver nitrate in alkaline solution via 60 degrees C water bath for 20 minutes with the use of tyrosine, a nontoxic and green macromolecule, as a reducing and stabilizing agent. The formation of silver nanoparticles was observed visually by color change of the solutions (from faint yellow to brown yellow). The morphologies of the Ag NPs were characterized by UV-Vis absorption spectroscopy and transmission electron microscopy (TEM). The UV-Vis absorption peak of silver nanoparticles located at 412 nm. The TEM image of silver nanoparticles indicated that the diameters of nanospheres are mainly in the range 15-25 nm. In order to evaluate the SERS activity of the silver nancomparticles, crystal violet and folic acid were used as the Raman probe molecule. The experimental results indicated that there are two ascendancies, firstly, the approach is convenient and the reaction condition is facile, secondly, tyrosine is a water-soluble, nontoxic and biodegradable macromolecule, which makes this approach provide a green strategy to prepare Ag NPs. Significantly, the synthesized Ag NPs exhibits good surface enhanced Raman scattering (SERS) activity as SERS substrates to detect crystal violet and folic acid in aqueous solution.