Removal of organic pollutants in shale gas fracturing flowback and produced water: A review.

Shale gas has been developed as an alternative to conventional energy worldwide, resulting in a large amount of shale gas fracturing flowback and produced water (FPW). Previous studies focus on total dissolved solids reduction using membrane desalination. However, there is a lack of efficient and stable techniques to remove organic pollutants, resulting in severe membrane fouling in downstream processes. This review focuses on the concentration and chemical composition of organic matter in shale gas FPW in China, as well as the hazards of organic pollutants. Organic removal techniques, including advanced oxidation processes, coagulation, sorption, microbial degradation, and membrane treatment are systematically reviewed. In particular, the influences of high salt on each technique are highlighted. Finally, different treatment techniques are evaluated in terms of energy consumption, cost, and organic removal efficiency. It is concluded that integrated coagulation-sorption-Fenton-membrane filtration represents a promising treatment process for FPW. This review provides valuable information for the feasible design, practical operation, and optimization of FPW treatment.

Bioactive 9,11-secosteroids from Gorgonian Subergorgia suberosa collected from the South China sea.

Five new 9,11-secosteroids 1, 2, and 4-6, and seven known analogs, 3 and 7-12, with the same steroid skeleton, (5αH)-3ß,6α,11-trihydroxy-9,11-secocholest-7-en-9-one, were isolated from the South China Sea gorgonian Subergorgia suberosa. Among them, 2/3 and 4/5 are C(24)-epimeric mixtures, and 6/7 is an (E)/(Z) mixture of (C(24)C(28)). Their structures and relative configurations were elucidated by using comprehensive spectroscopic methods including NOESY spectra. The absolute configuration of the steroidal nucleus was established by the modified Mosher method applied to 10 and on the basis of a common biogenesis for all of these compounds. All isolated compounds, 1-12, and five synthetic acetylated derivatives, 12a-12e, were evaluated for their cytotoxicities in vitro. Compounds 4/5, 11, 12, and 12b-12d showed cytotoxic activities against K562 cell line with the IC50 values ranging from 1.09 to 8.12 µM.

Ochracenoids A and B, guaiazulene-based analogues from gorgonian Anthogorgia ochracea collected from the South China Sea.

Two new guaiazulene-based analogues, ochracenoids A (1) and B (2), along with four known analogues (3-6), were isolated from the gorgonian Anthogorgia ochracea collected from the South China Sea. The planar structures of the new compounds were elucidated by comprehensive spectroscopic data. The absolute configuration of 1 was determined as 3R by the comparison of TDDFT calculated electronic circular dichroism with its experimental spectrum. Compound 1 is a rare guaiazulene-based analogue possessing a unique C16 skeleton. The possible generation process of 1 through an intermolecular one-carbon-transfer reaction was also discussed. Compound 2 was previously described as a presumed intermediate involved in the biogenesis of anthogorgienes A and I. Compound 3 exhibited antiproliferative effects on the embryo development of zebrafish Danio rerio.

Tephrosin-induced autophagic cell death in A549 non-small cell lung cancer cells.

Anticancer effect of tephrosin (1) has been documented; however, the molecular mechanisms underlying the cytotoxicity of tephrosin in cancer cells remain unclear. In the present paper, the proliferation inhibition rate of several cancer cells was tested using the MTT assay; cell cycle, reactive oxygen species (ROS), and mitochondrial membrane potential (MMP) were determined by flow cytometry; poly(ADP-ribose) polymerase (PARP) cleavage and heat shock protein 90 (Hsp90) expression were evaluated by Western blotting; autophagy was examined by confocal microscopy and light chain 3 (LC3) conversion assay. The results showed that exposure of the cells to tephrosin induced significant proliferation inhibition in a dose-dependent manner, especially on A549 with G(2)/M being arrested. Tephrosin was not found to induce cell apoptosis as PARP cleavage was not detected after 24 h treatment, but the formation of acidic vesicular organelle of autophagy character was found, and autophagy was further confirmed by the increase in the ratio of LC3-II to LC3-I. It was observed that tephrosin induced ROS generation and Hsp90 expression inhibition. These results indicate that tephrosin induces A549 cancer cell death via the autophagy pathway, and the roles of ROS generation and Hsp90 expression inhibition in this process need further study in the future.

Resin glycoside constituents of Ipomoea pes-caprae (beach morning glory).

Eight new resin glycosides, pescapreins X-XVII (1-8), were isolated from a lipophilic fraction of an ethanol extract of the entire plant of beach morning glory, Ipomoea pes-caprae. Their structures were elucidated by spectroscopic data analysis and by chemical transformation. These compounds were evaluated biologically in terms of cancer cell line cytotoxicity, antibacterial and antifungal activity, and effects on the mu-opioid receptor.

Cytotoxic polyketides from a marine-derived fungus Aspergillus glaucus.

Eight new aromatic polyketides (2, 4-6, 8, 14, 16, and 17) together with eight known analogues (3, 7, 9-13, and 15) were isolated from the marine-derived fungus Aspergillus glaucus. The structures and stereochemistry of the new compounds were elucidated by spectroscopic and chemical methods, and their cytotoxicities were evaluated against the HL-60 and A-549 cell lines.

GPR12 selections of the metabolites from an endophytic Streptomyces sp. associated with Cistanches deserticola.

An endophytic Streptomyces sp. (AC-2) was isolated from the root of Cistanches deserticola Y.C.Ma.. Chemical investigations of the culture broth of AC-2 afforded fifteen compounds including K1115 A (1), tyrosol (2), phenylethylamine derivatives (3, 4), cyclic dipeptides (5-8), nucleosides and their aglycones (9-13), N-acetyltryptamine (14), and pyrrole-2-carboxylic acid (15). Only tyrosol can promote an increase of intracellular cAMP special on GPR12 transfected cells, such as CHO and HEK293, which means it may be a possible ligand for GPR12.

Cytotoxic alkaloids and antibiotic nordammarane triterpenoids from the marine-derived fungus Aspergillus sydowi.

Three new diketopiperazine alkaloids, 6-methoxyspirotryprostatin B (1), 18-oxotryprostatin A (2), and 14-hydroxyterezine D (3), with an oxaspiro[4.4]lactam moiety, 14-norpseurotin A (4), and the 29-nordammarane triterpenoid 6beta,16beta-diacetoxy-25-hydroxy-3,7-dioxy-29-nordammara-1,17(20)-dien-21-oic acid (5), as well as 12 known compounds (6- 17), were isolated from the ethyl acetate extract of a marine-derived fungal strain, Aspergillus sydowi PFW1-13. The structures of compounds 1- 5 were elucidated by comprehensive spectroscopic analysis. Compounds 1- 3 exhibit weak cytotoxicity against A-549 cells, with IC 50 values of 8.29, 1.28, and 7.31 microM, respectively. Compound 1 also shows slight cytotoxicity against HL-60 cells, with an IC 50 value of 9.71 microM. Compounds 4 and 5 display significant antimicrobial activities against Escherichia coli, Bacillus subtilis, and Micrococcus lysoleikticus with MICs of 3.74, 14.97, and 7.49 microM and 10.65, 5.33, and 10.65 microM, respectively.

Novel open-chain cytochalsins from the marine-derived fungus Spicaria elegans.

Six novel open-chain cytochalasins (1-6) and one known [12]-cytochalasin (7) have been isolated from the fermentation broth of a marine-derived fungus, Spicaria elegans. Cytochalasins Z10-Z15 (1-6) are the first reported cytochalasins that contain an open chain to date. The structures of these new compounds were elucidated by spectroscopic methods. The cytotoxic effects on P388, A-549, HL-60, and BEL-7402 cell lines of all compounds were evaluated by the MTT method.

Chrysogenamide A from an endophytic fungus associated with Cistanche deserticola and its neuroprotective effect on SH-SY5Y cells.

Chrysogenamide A (1), a new member of the macfortine group of alkaloids, along with four known compounds (2 approximately 5) were identified from Penicillium chrysogenum No. 005, an endophytic fungus associated with Cistanche deserticola Y. C. Ma. The new structure was elucidated on the basis of comprehensive spectral analysis. 1 exhibited a neurocyte protection effect against oxidative stress-induced cell death in SH-SY5Y cells.

Penicillenols from Penicillium sp. GQ-7, an endophytic fungus associated with Aegiceras corniculatum.

Six new tetramic acids derivatives, penicillenols A(1), A(2), B(1), B(2), C(1), and C(2) (1-6), together with citrinin, phenol A acid, phenol A, and dihydrocitrinin, were identified from Penicillium sp. GQ-7, an endophytic fungus associated with Aegiceras corniculatum. Their structures were elucidated on the basis of comprehensive spectral analysis. All the new compounds were evaluated for their cytotoxic effects on four cell lines by the MTT method. Penicillenols A(1) and B(1) showed cytotoxicities against HL-60 cell line with IC(50) values of 0.76 microM and 3.20 microM, respectively.

Gentisyl alcohol derivatives from the marine-derived fungus Penicillium terrestre.

Nine new gentisyl alcohol derivatives, namely, the trimeric terrestrol A (8), dimeric terrestrols B-H (1-7), and a monomeric derivative (12), together with four known analogues (9-11, 13) were isolated from the marine-derived fungus Penicillium terrestre. The structures of the new compounds were elucidated by spectroscopic methods including one- and two-dimensional NMR as well as low- and high-resolution mass spectrometric analysis. These new compounds (1-8, 12) showed cytotoxic effects on HL-60, MOLT-4, BEL-7402, and A-549 cell lines with IC50 values in the range 5-65 microM. Compound 6 also showed moderate inhibitory activity against protein tyrosine kinases (Src and KDR). Furthermore, all new compounds exhibited moderate radical scavenging activity against DPPH with IC50 values in the range 2.6-8.5 microM.

Polyketides from Penicillium sp. JP-1, an endophytic fungus associated with the mangrove plant Aegiceras corniculatum.

Four polyketides, leptosphaerone C (1), penicillenone (2), arugosin I (3) and 9-demethyl FR-901235 (4), as well as five known compounds, bacillosporin A (5), bacillosporin C (6), sequoiamonascin D (7), sequoiatone A (8), and sequoiatone B (9) were isolated from the Penicillium sp. JP-1, an endophytic fungus isolated from Aegiceras corniculatum. Their structures were determined by spectroscopic methods, mainly by 2D NMR spectroscopic analyses. Compound 1 showed cytotoxicity against A-549 cells with an IC50 value of 1.45 microM, while compound 2 showed cytotoxicity against P388 cells with an IC50 value of 1.38 microM.

Six new ergosterols from the marine-derived fungus Rhizopus sp.

Six new ergosterols, including 3beta-hydroxyl-(22E, 24R)-ergosta-5,8,22-trien-7,15-dione (1), 3beta-hydroxyl-(22E, 24R)-ergosta-5,8,14,22-tetraen-7-one (2), 3beta,15beta-dihydroxyl-(22E, 24R)-ergosta-5,8(14),22-trien-7-one (3), 3beta,15alpha-dihydroxyl-(22E, 24R)-ergosta-5,8(14),22-trien-7-one (4), 3beta-hydroxyl-(22E, 24R)-ergosta-5,8(14),22-trien-7,15-dione (5), and 5alpha,8alpha-epidioxy-23,24(R)-dimethylcholesta-6,9(11),22-trien-3beta-ol (6), have been isolated from the marine-derived fungus Rhizopus sp., along with four known ones (7-10). The structures of the new compounds were determined on the basis of extensive spectroscopic data. All compounds were evaluated for their cytotoxic activities on P388, A549, HL-60, and BEL-7420 cell lines by the MTT and SRB methods.

Three novel, structurally unique spirocyclic alkaloids from the halotolerant B-17 fungal strain of Aspergillus variecolor.

During our search for novel antitumor lead compounds from microorganisms living under extreme conditions, three novel alkaloids, variecolortides A-C (1-3), were isolated from the mycelia of the halotolerant fungal strain Aspergillus variecolor B-17. The new compounds were found to share an unprecedented 'spiro-anthronopyranoid diketopiperazine' structure, with a stable hemiaminal function, as corroborated by in-depth NMR-spectroscopic and mass-spectrometric analyses, as well as by a single-crystal X-ray analysis of 1. All compounds were shown to exhibit weak cytotoxic and antioxidant activities.

Two new metabolites with cytotoxicities from deep-sea fungus, Aspergillus sydowi YH11-2.

Two new compounds, 2, 3, 5-trimethyl-6-(3-oxobutan-2-yl)-4H-pyran-4-one (1) and (2R)-2, 3- dihydro-7-hydroxy-6, 8-dimethyl-2-[(E)-prop-1-enyl] chromen-4-one (2), together with six known compounds (3-8), were isolated from a deep-sea fungus, identified as Aspergillus sydowi, by a bioassay-guided method. Their structures were elucidated by spectroscopic methods and the cytotoxicities were evaluated by SRB method.

Two new cytotoxic quinone type compounds from the halotolerant fungus Aspergillus variecolor.

Two new quinone type compounds, variecolorquinones A (1) and B (2) together with eleven known related compounds 3 approximately 13 have been isolated from the metabolites produced by the halotolerant fungal strain Aspergillus variecolor B-17. The structures of 1 and 2 were determined by spectroscopic methods. 1 exhibited selective cytotoxicity against A-549 cells with the IC50 values of 3.0 microM. 2 showed cytotoxicity against HL60 and P388 cells with the IC50 values of 1.3 and 3.7 microM, respectively.

Isoechinulin-type alkaloids, variecolorins A-L, from halotolerant Aspergillus variecolor.

Twelve new compounds, variecolorins A-L ( 1- 12), together with eleven known analogues ( 13- 23) were isolated from the broth of a halotolerant fungus, Aspergillus variecolor. The structures of compounds 1- 12 were determined by chemical and spectroscopic methods. Compounds 1- 11, 13- 15, and 20- 23 exhibited weak radical scavenging activity against DPPH, with IC 50 values from 43 to 103 microM. The new compounds 1- 12 all were essentially nontoxic against the P388, HL-60, BEL-7402, and A-549 cell lines with IC 50 values from 70 to 260 microM.

Isocoumarin Derivatives from the Sea Squirt-derived Fungus Penicillium stoloniferum QY2-10 and the Halotolerant Fungus Penicillium notatum B-52.

Two isocoumarin derivatives, stoloniferol A (1) and B (2), a known 5alpha, 8alpha-epidioxy-23-methyl-(22E, 24R)-ergosta-6, 22-dien-3beta-ol (3), and a known dihydrocitrinone (4) were isolated from the ethyl acetate extract of the sea squirt-derived fungus, Penicillium stoloniferum QY2-10, and a halophilic fungus, Penicillium notatum B-52, respectively. Their structures were elucidated by spectroscopic methods and optical rotation. The stereochemistry of 2 was determined on the basis of different NOE experiments and chemical transformation. Compound 3 showed cytotoxicity against P388 cells, with an IC50 value of 4.07 microM.

Aurantiomides A-C, quinazoline alkaloids from the sponge-derived fungus Penicillium aurantiogriseum SP0-19.

Three new quinazoline alkaloids, aurantiomides A (1), B (2), and C (3), along with the known metabolite anacine (4) were isolated from the sponge-derived fungus strain Penicillium aurantiogriseum SP0-19 by bioassay-guided fractionation. Their structures were elucidated by spectroscopic and chemical methods. Their absolute configurations were deduced by comparison of their Cotton effects with anacine (4) and by chemical transformations. Compounds 2 and 3 showed moderate cytotoxicities against HL-60, P388 and BEL-7402, P388 cell lines, respectively.