GFP-expressing mammalian cells for fast, sensitive, noninvasive cell growth assessment in a kinetic mode

Flavonoids from Milletia leucantha and Their Cytotoxicity

Two known chalcones (1–2), five known flavonol derivatives (3 and 5–8) and one flavone (4) were isolated for the first time from fruits of Millettia leucantha Kurz. In addition, 5 was found for the first time from this genus. Their structures were elucidated on the basis of IR, MS, 1D and 2D NMR techniques. Chalcone 1 exhibited moderate cytotoxicity against the MCF-7 cell line with an IC50 value of 50.93 μM, whereas this compound showed inactive cytotoxicity against Vero cells. Compound 2 exhibited cytotoxicity against the KB, NCI-H187 and Vero cell lines with IC50 values of 63.64, 114.44 and 28.44 μM, respectively. Compound 8 only showed cytotoxic activity against the KB cell line with an IC50 value of 110.23 μM.

Asperidines A-C, pyrrolidine and piperidine derivatives from the soil-derived fungus Aspergillus sclerotiorum PSU-RSPG178

One new pyrrolidine derivative, asperidine A (1), and two new piperidine derivatives, asperidines B (2) and C (3), were isolated from the soil-derived fungus Aspergillus sclerotiorum PSU-RSPG178 together with two known alkaloids. Compound 3 possessed an unprecedented 7-oxa-1-azabicyclo[3.2.1]octane skeleton with four chiral centers. Their structures were determined by spectroscopic evidence. The absolute configurations of compounds 2 and 3 were established using Mosher's method and further confirmed for compound 3 by X-ray crystallographic data. Compound 2 dose-dependently inhibited the CFTR-mediated chloride secretion in T84 cells with an IC₅₀ value of 0.96 μM whereas 3 displayed the same activity with the IC₅₀ value of 58.62 μM. Compounds 2 and 3 also significantly reduced intracellular ROS under both normal and H₂O₂-treated conditions compared with their respective controls in a dose-dependent manner without cytotoxic effect on Caco-2 cells. In addition, compound 3 was inactive against noncancerous Vero cells whereas compound 2 was considered to be inactive with the IC₅₀ value of >10 μM.

New bioactive cyclopeptide alkaloids with rare terminal unit from the root bark of Ziziphus cambodiana

Six new 14-membered ring cyclopeptide alkaloids, cambodines A–F (1–6), and two known compounds, frangufoline (7) and lotusanine B (8), were isolated from the root bark extract of Ziziphus cambodiana Pierre. Their structures and configurations were established based on 1D and 2D NMR, HRMS, ECD, and X-ray crystallographic data. Compounds 1 and 3 are rare 5(14)-type cyclopeptide alkaloids that possess an imidazolidin-4-one ring in the terminal unit. The cyclopeptides were tested for their in vitro antiplasmodial, antitubercular, and cytotoxic effects against three cancer cell lines. Compound 3 showed significant antiplasmodial activity against the malarial parasite Plasmodium falciparum, with an IC₅₀ value of 6.09 μM.

Six new 14-membered ring cyclopeptide alkaloids, cambodines A–F (1–6), and two known compounds, frangufoline (7) and lotusanine B (8), were isolated from the root bark extract of Ziziphus cambodiana Pierre.

Naphthoquinones from the leaves of Rhinacanthus nasutus having acetylcholinesterase inhibitory and cytotoxic activities

Four new naphthoquinones (1-4), named rhinacanthins S (1), T (2), U (3) and V (4), together with 13 known naphthoquinones were isolated from the leaf extract of Rhinacanthus nasutus. The structures of isolated compounds were elucidated by spectroscopic methods, especially 1D and 2D NMR spectroscopy and mass spectrometry. Rhinacanthin S (1) exhibited acetylcholinesterase inhibition activity with a % inhibition value of 48.04±3.25. The known rhinacanthin A (5) showed cytotoxicity against a MCF-7 cell line with an IC₅₀ value of 8.79μM, while rhinacanthin N (15) was active against the NCI-H187 cell line with an IC₅₀=2.24μM and Vero cells (IC₅₀=3.00μM).

Depsidones and an α-pyrone derivative from Simplicillium sp. PSU-H41, an endophytic fungus from Hevea brasiliensis leaf [corrected]

Nine previously undescribed depsidones (simplicildones A-I) and one previously undescribed α-pyrone (simplicilopyrone) were isolated from the endophytic fungus Simplicillium sp. PSU-H41 along with 11 known compounds. Their structures were established by extensive spectroscopic analysis. Simplicildone A and known botryorhodine C displayed weak antibacterial against Staphylococcus aureus with equal MIC values of 32 μg/mL. Additionally, botryorhodine C was active against methicillin-resistant S. aureus with the same MIC value. Simplicildone C exhibited weak antifungal activity against Cryptococcus neoformans with an MIC value of 32 μg/mL. In addition, simplicildones A and C and botryorhodine C were noncytotoxic against noncancerous Vero cells.

Antiproliferative activities of alkaloid-like compounds

Tricyclic alkaloid-like compounds were synthesised in a few steps, via the bridging Ritter reaction.

Tricyclic alkaloid-like compounds were synthesised in a few steps, via the bridging Ritter reaction. The compounds were evaluated for their antiproliferative activity against the MCF-7 and the aggressive MDA-MB-231 breast cancer cells. The anti-cancer activities of 2c were found to be selective towards the aggressive and more challenging to treat triple negative (MDA-MB-231) cell line while exhibiting no antiproliferative activities towards the MCF-7 cells at the highest concentration tested (50 μM). The IC₅₀ of compound 2c was determined to be 7.9 μM for the MDA-MB-231 cell line. Furthermore, 2c arrested cell cycle at the G₂/M phase and induced apoptosis in a dose-dependent manner. Besides in-house anti-cancer screening, compound 3 was selected for anti-cancer screening by the National Cancer Institute and was found to have broad anti-cancer activity with selectivity against particular leukaemia, colon, melanoma, and breast cancer cell lines. Cytotoxicities of compounds 2c and 3 were also tested against noncancerous mammalian cells (VERO cell line), and found to be selective towards cancerous cells. The facile synthetic route, unique chemical structures and the biological data make these alkaloid-like compounds worthwhile lead compounds for further anti-cancer drug development.

Antitubercular Activity of Mycelium-Associated Ganoderma Lanostanoids

In a continuation of our research into antitubercular lanostane triterpenoids from submerged cultures of Ganoderma species, three strains, Ganoderma orbiforme BCC 22325, Ganoderma sp. BCC 60695, and Ganoderma australe BCC 22314, have been investigated. Fourteen new lanostane triterpenoids, together with 35 known compounds, were isolated. Antitubercular activities of these mycelium-associated Ganoderma lanostanoids against Mycobacterium tuberculosis H37Ra were evaluated. Taken together with the assay data of previously isolated compounds, structure-activity relationships of the antitubercular activity are proposed. Most importantly, 3β- and 15α-acetoxy groups were shown to be critical for antimycobacterial activity. The most potent compound was (24E)-3β,15α-diacetoxylanosta-7,9(11),24-trien-26-oic acid (35).

γ-Butenolide and furanone derivatives from the soil-derived fungus Aspergillus sclerotiorum PSU-RSPG178

Chromatographic separation of the broth extract of the soil-derived fungus Aspergillus sclerotiorum PSU-RSPG178 resulted in isolation of four γ-butenolide-furanone dimers, aspersclerotiorones A-D, a furanone derivative, aspersclerotiorone E, and two γ-butenolide derivatives, aspersclerotiorones F and G, together with six known compounds, penicillic acid, dihydropenicillic acid, 5,6-dihydro-6-hydroxypenicillic acid, 6-methoxy-5,6-dihydropenicillic acid, coculnol and (4R,5R)-4,5-dihydroxy-3-methoxy-5-methylcyclohex-2-en-1-one. Their structures were determined by spectroscopic evidence. For aspersclerotiorones A and B, the structures were confirmed by single-crystal X-ray diffraction crystallography. Penicillic acid displayed weak antibacterial activity against Staphylococcus aureus and Escherichia coli with equal MIC values of 128 μg/mL, and it was noncytotoxic towards African green monkey kidney fibroblast cells.

Alliacane sesquiterpenoids from submerged cultures of the basidiomycete Inonotus sp. BCC 22670

Nine alliacane sesquiterpenoids, inonoalliacanes A-I, were isolated from culture broth of the basidiomycete Inonotus sp. BCC 22670. The structures were elucidated on the basis of NMR spectroscopic and mass spectrometry data. The absolute configuration of inonoalliacane F was determined by application of the modified Mosher's method. Inonoalliacane A, the most abundant sesquiterpene constituent, exhibited moderate antibacterial activity against Bacillus cereus, whereas inonoalliacane B showed antiviral activity against herpes simplex virus type 1.

Mycotoxins from the Fungus Botryotrichum piluliferum

Two new sterigmatocystin derivatives, oxisterigmatocystins E and F (1 and 2, respectively), along with nine known compounds, oxisterigmatocystins G and H (3 and 4, respectively), sterigmatocystin (5), N-0532B (6), O-methylsterigmatocystin (7), N-0532A (8), 6-O-methylversicolorin A (9), 6,8-O-dimethylversicolorin A (10), and 8-O-methylaverufin (11), were isolated from the fungus Botryotrichum piluliferum. The structures of these mycotoxins were elucidated by spectroscopic evidence. Among these, compounds 3, 4, and 9 were discovered as natural products for the first time. Compounds 1, 3, and 4 displayed antimalarial activity toward Plasmodium falciparum (IC₅₀ = 7.9-23.9 μM). In addition, compounds 1-6 and 8-11 exhibited cytotoxicity against KB, MCF-7, and NCI-H187 cell lines (IC₅₀ = 0.38-78.6 μM). However, compounds 1-9 showed cytotoxic effects against the Vero cell line (IC₅₀ = 0.65-12.3 μM). This finding should promote awareness of the contamination of B. piluliferum in the food chain and agricultural soil.

Bicyclic lactones and racemic mixtures of dimeric styrylpyrones from the leaves of Miliusa velutina

Eight new bicyclic lactones and three new dimeric styrylpyrones from the leaves of Miliusa velutina were reported with their bioactivities.

Chevalone C analogues and globoscinic acid derivatives from the fungus Neosartorya spinosa KKU-1NK1

Four meroterpenoids, 1-hydroxychevalone C, 1-acetoxychevalone C, 1,11-dihydroxychevalone C, and 11-hydroxychevalone C and two ester epimers, 2S,4S-spinosate and 2S,4R-spinosate, together with seven known compounds, chevalones B, C, and E, tryptoquivaline, nortryptoquivaline, tryptoquivaline L, and quinadoline A were isolated from the fungus Neosartorya spinosa. Their structures were established based on spectroscopic data analyses. The theoretical ECD spectra of epimers, 2S,4S-spinosate and 2S,4R-spinosate were calculated to support the experimental results of their CD spectra. 1-hydroxychevalone C exhibited antimycobacterial activity against Mycobacterium tuberculosis with a MIC value of 26.4 μM. 1-Acetoxychevalone C and tryptoquivaline showed antimalarial activity against Plasmodium falciparum with IC₅₀ values of 6.67 and 2.65 μM, respectively. In addition, 1-hydroxychevalone C, 1-acetoxychevalone C, 1,11-dihydroxychevalone C and quinadoline A showed cytotoxicity against KB and NCI-H187 cancer cell lines with IC₅₀ values in the range of 32.7-103.3 μM.

Evaluation of the anti-malarial activity and cytotoxicity of 2,4-diamino-pyrimidine-based kinase inhibitors

A series of 2,4 diamino-pyrimidines have been identified from an analysis of open access high throughput anti-malarial screening data reported by GlaxoSmithKline at the 3D7 and resistant Dd2 strains. SAR expansion has been performed using structural knowledge of the most plausible parasite target. Seventeen new analogs have been synthesized and tested against the resistant K1 strain of Plasmodium falciparum (Pf). The cytotoxicity of the compounds was assessed in Vero and A549 cells and their selectivity towards human kinases including JAK2 and EGFR were undertaken. We identified compound 5n and 5m as sub-micromolar inhibitors, with equivalent anti-malarial activity to Chloroquine (CQ). Compounds 5d and 5k, μM inhibitors of Pf, displayed improved cytotoxicity with weak inhibition of the human kinases.

Lovastatin Analogues from the Soil-Derived Fungus Aspergillus sclerotiorum PSU-RSPG178

Three new lovastatin analogues (1, 4, and 5) together with four known lovastatin derivatives, namely, lovastatin (2), α,β-dehydrolovastatin (3), α,β-dehydrodihydromonacolin K (6), and α,β-dehydro-4a,5-dihydromonacolin L (7), were isolated from the soil-derived fungus Aspergillus sclerotiorum PSU-RSPG178. Their structures were established using spectroscopic evidence. Compound 5 exhibited the most potent activity against HMG-CoA reductase, with an IC50 value of 387 μM. In addition, the present study indicated the direct interaction of compound 5 with HMG-CoA reductase. Compound 5 was considered to be noncytotoxic against noncancerous Vero cells, with an IC50 value of 40.0 μM, whereas compound 2 displayed much stronger activity, with an IC50 value of 2.2 μM.

Cytotoxic Labdane Diterpenes from Hedychium ellipticum Buch.-Ham. ex Sm

In order to reveal the constituents and their biological activities, we carried out a phytochemical study on Hedychium ellipticum Buch.-Ham. ex Sm. (Zingiberaceae). Ten labdane diterpenoids (1–10) were isolated from the rhizomes of H. ellipticum for the first time. Their structures were identified on the basis of spectroscopic analyses including two-dimensional NMR and comparison with literature data. All of these compounds were evaluated for their antimycobacterial activity against Mycobacterium tuberculosis and cytotoxicity against KB, MCF7, NCI-H187 and Vero cells. The result showed that compounds 1 and 7 exhibited moderate activity against Mycobacterium tuberculosis and compounds 4, 6 and 7 displayed remarkable cytotoxic activity. This is the first report on the presence of all compounds in H. ellipticum and the first time that their structure activity relationship has been discussed.

Synthesis and cytotoxic activities of semisynthetic zearalenone analogues

Zearalenone is a β-resorcylic acid macrolide with various biological activities. Herein we report the synthesis and cytotoxic activities of 34 zearalenone analogues against human oral epidermoid carcinoma (KB) and human breast adenocarcinoma (MCF-7) cells as well as noncancerous Vero cells. Some zearalenone analogues showed moderately enhanced cytotoxic activities against the two cancer cell lines. We have discovered the potential lead compounds with diminished or no cytotoxicity to Vero cells. Preliminary structure-activity relationship studies revealed that the double bond at the 1' and 2' positions of zearalenone core was crucial for cytotoxic activities on both cell lines. In addition, for zearalenol analogues, the unprotected hydroxyl group at C-2 and an alkoxy substituent at C-4 played key roles on cytotoxic effects of both cell lines.

Antimalarial Oxoprotoberberine Alkaloids from the Leaves of Miliusa cuneata

Five new oxoprotoberberine alkaloids, miliusacunines A-E (1-5), along with nine known compounds, 6-14, were isolated from an acetone extract of the leaves and twigs of Miliusa cuneata. Their structures were elucidated by spectroscopic analysis. All isolated compounds were evaluated for their cytotoxicities against the KB and Vero cell lines and for antimalarial activities against the Plasmodium falciparum strains TM4 and K1 (a sensitive and a multi-drug-resistant strain, respectively). Compound 1 showed in vitro antimalarial activity against the TM4 strain, with an IC50 value of 19.3 ± 3.4 μM, and compound 2 demonstrated significant activity against the K1 strain, with an IC50 value of 10.8 ± 4.1 μM. Both compounds showed no discernible cytotoxicity to the Vero cell line at the concentration levels evaluated.

Terezine derivatives from the fungus Phoma herbarum PSU-H256

Investigation of the fungus Phoma herbarum PSU-H256 isolated from a leaf of Hevea brasiliensis resulted in the isolation of eight terezine derivatives (E-L) together with four known compounds. Their structures were established by analysis of spectroscopic evidence. For terezines E and H, their structures were confirmed by single-crystal X-ray diffraction crystallography. In addition, the absolute configuration at C-7 in terezine E was established by Mosher's method. Terezines K and L were tested for antibacterial, antimalarial, antimycobacterial and cytotoxic activities, but were inactive.

Penicillanthone and penicillidic acids A–C from the soil-derived fungus Penicillium aculeatum PSU-RSPG105

A new xanthone (penicillanthone, 1) and three new diphenyl ether derivatives (penicillidic acids A–C, 2–4) together with 14 known compounds (5–18) were isolated from the soil-derived fungus Penicillium aculeatum PSU-RSPG105.

Cytotoxic and Antimalarial Alkaloids from the Twigs of Dasymaschalon obtusipetalum

One new p-quinonoid aporphine alkaloid, obtusipetadione (1), and eleven known compounds (2–12) were isolated from the acetone extract of the twigs of Dasymaschalon obtusipetalum. Their structures were elucidated by spectroscopic methods. The cytotoxic and antimalarial activities of the isolated compounds were evaluated. Compound 1 showed significant in vitro antiplasmodial activity against the P. falciparum strains TM4 and K1 (multidrug resistant strain) with IC50 values of 2.46±0.12 and 1.38±0.99 μg/mL, respectively with no cytotoxicity. Compound 9 had more modest antiplasmodial activity, but significant cytotoxicity.

Eremophilane Sesquiterpenes and Diphenyl Thioethers from the Soil Fungus Penicillium copticola PSU-RSPG138

Four new compounds including two eremophilane sesquiterpenes, penicilleremophilanes A (1) and B (2), as well as two sulfur-containing biphenols, penicillithiophenols A (3) and B (4), were isolated from the soil fungus Penicillium copticola PSU-RSPG138 together with 16 known compounds. Their structures were elucidated by spectroscopic methods. Known sporogen AO-1 exhibited significant antimalarial activity against Plasmodium falciparum with an IC50 value of 1.53 μM and cytotoxic activity to noncancerous (Vero) cell lines with an IC50 value of 4.23 μM. Although compound 1 was approximately half as active against P. falciparum with the IC50 value of 3.45 μM, it showed much weaker cytotoxic activity.

Antioxidative and antimicrobial activities of the extracts from the seed coat of Bambara groundnut (Voandzeia subterranea)

Antioxidative and antimicrobial activities of extracts from Bambarra groundnut seed coat, prepared using water, ethanol and acetone as the media at various temperatures (30, 60, 90 °C) were investigated.

γ-Butyrolactone, cytochalasin, cyclic carbonate, eutypinic acid, and phenalenone derivatives from the soil fungus Aspergillus sp. PSU-RSPG185

Purification of an extract from the broth of the soil fungus Aspergillus sp. PSU-RSPG185 resulted in the isolation of two new cyclic carbonate derivatives, aspergillusols A (1) and B (2), and one new eutypinic acid derivative, aspergillusic acid (3), along with six known secondary metabolites. Compounds 1 and 2 contain an unusual cyclic-carbonate functionality. In addition, the mycelial extract afforded two new phenalenones, aspergillussanones A (4) and B (5), one new cytochalasin, aspergilluchalasin (6), and one new γ-butyrolactone, aspergillulactone (7). Their structures were established by interpretation of spectroscopic evidence. Compound 4 exhibited weak activity toward KB and Vero cells with IC50 values of 48.4 and 34.2 μM, respectively.

Fluorescent labeling for clonal selection of Marc 145 cells secreting high levels of recombinant protein PBD-1

Despite the powerful impact gene expression markers like the green fluorescent protein (GFP) or enhanced GFP (EGFP) exert on linking the expression of recombinant protein for selection of high producers in recent years, there is still a strong incentive to develop more economical and efficient methods for isolating mammalian cell clones secreting high levels of recombinant proteins. Here we present a new method based on the co-expression of EGFP that allows clonal selection in standard 96-well cell culture plates. The genes encoding the EGFP protein and the related protein are linked by an internal ribosome entry site and thus are transcribed into the same mRNA in an independent translation process. Since both proteins arise from a common mRNA, the EGFP expression level correlates with the expression level of the therapeutic protein in each clone. By expressing recombinant porcine β-defensin 1 in Marc 145 cells, we demonstrate the robustness and performance of this technique. The method can be served as an alternative to identify high-producer clones with various cell sorting methods.

Extracts from Vatica diospyroides type SS fruit show low dose activity against MDA-MB-468 breast cancer cell-line via apoptotic action

Very strong antiproliferative action of V. diospyroides type SS fruit extracts (IC₅₀ range of 1.60-17.45 µg/mL) in MDA-MB-468 cell-line was observed in an MTT assay. After dosing of an extract concentration at half IC₅₀ to cell line for 24 to 72 hours, treated cells were subjected to Annexin V-FITC/PI binding assay, followed by FACS and western blot analyses. Significant apoptotic death was observed with all extract treatments and both exposure times. Dosing with acetone extract of pericarp and cotyledon induced the highest apoptotic populations (33 and 32%, resp.), with the lowest populations of viable cells (65 and 67%, resp.). During 24 to 72 hours of dosing with methanolic extract of pericarp, the populations of viable and early apoptotic cells decreased significantly from 72.40 to 71.32% and from 12.00 to 6.36%, respectively, while the late apoptotic and nonviable cell populations continuously increased from 15.30 to 19.18% and from 0.30 to 3.14%, respectively. The expression of Bax increased within 12–48 hours of dosing, confirming apoptosis induced by time-dependent responses. The mutant p53 of MDA-MB-468 cells was expressed. Our results indicate that apoptosis and time-dependent therapeutic actions contribute to the cytotoxic effects of V. diospyroides type SS fruit on MDA-MB-468 cell.