Search

Seven undescribed compounds, including four naphthoquinone terpenoids (aculeolatins A - D), one rare 2-nitropyrrole terpenoid (nitropyrrolin F), and two hydroxamate siderophores (aculeolamides A and B) and one further undescribed compound (2,5,7-trihydroxy-3,6-dimethylnaphthalene-1,4-dione), together with eleven known compounds (arromycin, phenaziterpene A, nitropyrrolin A, heronapyrroles A and B, salaceyin A, 5,7-dihydroxy-2-isopropylchromone, 1-hydroxyphenazine, 1-methoxyphenazine, 1-acetyl-β-carboline, and N-(2-phenylethyl) acetamide), were isolated from the cultures of the endophytic Streptomyces aculeolatus MS1-6. The structures of the isolated compounds were determined using NMR spectroscopy and corroborated using chemical modification. These compounds exhibited a broad spectrum of biological activities, including antimalarial (IC

Nine new chromone analogs (1–9) were isolated from the soil actinomycete Microbispora sp. TBRC6027. The chemical structures were determined based upon NMR spectroscopic methods. These compounds were evaluated in vitro by using P19-derived neurons for neuroprotective activity against oxidative stress induced by serum deprivation and showed % viability of neurons at the concentration of 1 ng/mL varied from 43.51% to 52.99% without significant neurotoxicity for P19-derived neurons at the same concentration. Moreover, all tested compounds were inactive for antibacterial activity against both Gram-positive and Gram-negative bacteria and for cytotoxicity against MCF-7 (human breast cancer) and Vero cells at maximum tested concentration 50 μg/mL. However, compounds 4, 6, and 7 displayed weak cytotoxicity against NCI-H187 (human small-cell lung cancer) cells with IC50 in a range of 87.99–91.57 μM.

An actinomycete strain CSR-4 was isolated from the rhizosphere soil of Zingiber montanum. Taxonomic characterization revealed strain CSR-4 was a member of the genus Microbispora. Whole-genome sequence analysis exhibited the highest average nucleotide identity (ANI) value (95.34%) and digital DNA–DNA hybridization (DDH) value (74.7%) between strain CSR-4 and the closest relative M. hainanensis DSM 45428T, which was in line with the assignment to same species. In addition, a new diterpene compound, 2α-hydroxy-8(14), 15-pimaradien-17, 18-dioic acid, and nine known compounds were isolated from the ethyl acetate crude extract of fermentation broth. Interestingly, a new diterpene displayed the suppressive effect on the recombinant human acetylcholinesterase (rhAChE) enzymes (IC50 96.87 ± 2.31 μg/ml). In silico studies based on molecular docking and molecular dynamics (MD) simulations were performed to predict a binding mode of the new compound into the binding pocket of the rhAChE enzyme and revealed that some amino acids in the peripheral anions site (PAS), anionic subsite, oxyanion site and catalytic active site (CAS) of the rhAChE have interacted with the compound. Therefore, our new compound could be proposed as a potential active human AChE inhibitor. Moreover, the new compound can protect significantly the neuron cells (% neuron viability = 88.56 ± 5.19%) from oxidative stress induced by serum deprivation method at 1 ng/ml without both neurotoxicities on murine P19-derived neuron cells and cytotoxicity against Vero cells.

Four previously undescribed compounds, including (Z)-chloromonilinic acid B (1), (E)-chloromonilinic acid C (2), 4-chlorocurvularin (5), and 4-chlorocurvularinic acid (6), together with four known compounds, (E)-chloromonilinic acids A and B, pinselin, and anhydromevalonolactone, were isolated from the fungus Curvularia sp. BCC52426. The chemical structures were determined by comparing their NMR spectra to documented spectra of the related compounds and the isolated compounds were also appraised for antimicrobial activity and cytotoxicity.

Eight new anthrone derivatives, which are (+)-oxanthromicins E (1), F (4), and G (5), (±)-hemi-oxanthromicin D (2), azanthromicin A (7), adxanthromicin A2 (10), 3-methoxy oxanthromicin (11), and (±)-oxanthromicin G (13), along with eight previously described compounds (6, 8, 9, 12, 14–17) have been isolated from the terrestrial actinomycete, Actinomodura sp. BCC47066. The chemical structures have been determined on the basis of NMR spectroscopic information and chemical degradation. The configurations were assigned based upon CD spectral analyses, compared with the related compounds. Furthermore, the isolated compounds were assessed for biological activity. Compounds 10, 12, and 16 showed anti-Bacillus cereus with IC50 in a range of 1.56 − 12.50 μg/mL, while compounds 10 and 12 exhibited anti-phytopathogenic activity against Colletotrichum capsici and C. gloeosporioides with equal IC50 value of 6.25 μg/mL. All tested compounds possessed low cytotoxicity against both malignant and non-malignant cells.

Eleven previously undescribed sesquiterpenes 1 – 4 (named incarnatins A − D) and 6 – 12 (named incarnolactones A − C, incarnatin E, incarnate methyl ester, incarnetic acid, and incarnatenin), together with two known compounds, chondrosterin B ( 13 ) and ( E )-dictyochromenol ( 14 ), were isolated from the mushroom Gloeostereum incarnatum BCC41461. The chemical structures were determined on the basis of 1D and 2D NMR spectroscopic information together with their specific rotation values for identification of the stereochemistry. Compounds were evaluated for antimicrobial activity, including antimalarial, antituberculosis, and anti- Bacillus cereus , along with cytotoxicity against both cancerous and non-cancerous cells. Compounds 1 and 8 exhibited antimalarial (IC 50 9.80 μg/mL) and anti- B. cereus (MIC 25 μg/mL) activities, respectively, with low cytotoxicity. In addition, incarnatin B ( 2 ) and chondrostenin B ( 13 ) displayed strong antimalarial activity with respective IC 50 values of 3.93 and 3.10 μg/mL, while compound 14 showed anti-TB and anti- B. cereus with MIC 12.50 and 1.56 μg/mL, respectively.

Nine new chromone analogs (

Eight previously undescribed naturally-occurring compounds, including abyssomycins Y - Z, methyl aeruginoate, desferri-ferrithocin-4-hydroxyphenethylester, streptomethiocins A - B, furaquinocin I, and streptolactone, along with eleven known compounds were isolated from the endophytic Streptomyces sp. TBRC7642. The chemical structures were determined based on spectroscopic means including 1D, 2D NMR spectroscopy and mass spectrometry. The absolute configurations were assigned by relying on CD spectra and their optical rotations. In addition, the isolated compounds were evaluated for biological activity, such as antimalarial, antitubercular, antibacterial (both Gram-positive and Gram-negative bacteria), as well as for cytotoxicity against MCF-7, NCI-H187, and Vero cells.

Fourteen new compounds including thirteen drimane – phthalide derivatives (fendlerals A – C, fendlerins A – D, fendlerols A – B, fendleric acids A – C, fendlerinine G) and one terphenyl derivative (fendleryl E) along with eight known compounds, fendlerinine A, rickenyls C – D, fendleryls C – D, atromentin, tetramethyl atromentin, and (±)-microsphaerophthalide F, were isolated from the wood fungus Hypoxylon fendleri BCC32408. Compared with the prior work, the results indicated the agitation effect on the production of bioactive drimane – phthalides. The chemical structures were determined based upon spectroscopic analyses and the absolute configurations were verified by comparison of the ECD spectral data with the calculated ECD spectra of the related compounds. Compounds 1–3 exhibited antimicrobial activity against Plasmodium falciparum (IC50 4.15–4.39 μM), Colletotrichum capsici (MIC 6.25–12.5 μg/mL), and Bacillus cereus (MIC 1.56–3.13 μg/mL). All tested compounds displayed broad cytotoxicity against cancerous (MCF-7, KB, and NCI-H187) and non-cancerous (Vero) cells.

Two unknown enantiomeric compounds, named (

Three undescribed abyssomicin derivatives, including microbimisin, abyssomicins Z1, and Z2, were isolated from the soil actinomycete Microbispora rhizosphaerae sp. nov. TBRC6028. Chemical structures were determined by NMR spectroscopic data (1H, 13C, COSY, HSQC, HMBC, and NOESY spectra) and the absolute configurations were verified by single-crystal X-ray diffraction analyses together with the ECD spectral data. Microbimisin and abyssomicin Z1 exhibited weak antibacterial activity against Bacillus cereus with MIC values of 25.0 and 50.0 μg/mL without cytotoxicity against MCF-7 and Vero cells at the concentration of 50 μg/mL.

Six new compounds, including three acremonidins F–H ( 1 , 3 , and 5 ), two acremoxanthones F–G ( 7 and 8 ), and acremonoxide ( 10 ), along with eight known compounds ( 2 , 4 , 6 , 9 , 11 – 14 ) were isolated from Verticillium sp. BCC33181. Their structures were determined based on extensive 1D and 2D NMR spectral analyses, mass spectrometric data and by comparison with the known compounds reported previously. The relative configurations were identified based upon NOESY spectroscopic information as well as comparison of CD spectrum with the known analogs. Both acremonidins and acremoxanthones exhibited anti- Bacillus cereus activity (MIC 0.39–25 μg/mL), while acremonidins F ( 1 ), A ( 2 ), G ( 3 ), and C ( 4 ) also displayed anti- Enterococcus faecium activity (MIC 1.56–25 μg/mL). In addition, acremoxanthones F ( 7 ) and G ( 8 ) showed antimalarial activity against Plasmodium falciparum K1 strain, multidrug–resistant strain, with respective IC 50 values of 2.38 and 1.71 μg/mL, while others were inactive.

A series of bridged biarylbisquinones, QBINOLs 1–4, and their corresponding monomers, QNaphs 5–6, were designed to demonstrate the influence of biaryl conformation on the photo- and electro-chemical properties of the molecules. All target compounds were synthesized from the Diels–Alder reaction between silyl enol ethers of the corresponding naphthyl or binaphthyl derivatives and p-benzoquinone. Addition of an OMe auxochrome or formation of the dimeric structures affect the absorption spectra and the energy band gap (Eg), but not the reduction potentials of the molecules. Narrowing the dihedral angles of the QBINOLs by shortening methylene bridges limited the contribution of bridging OR auxochromes and therefore resulted in lower HOMO levels and larger Eg.

Five new natural products [asperteramide, aspulvinones R and S, astalluminoxide and astepyrazinol B] and five naturally new ones (aspernolide C, astepyrazinoxide, astepyrazinol A, 4-hydroxy-3-(3-methylbut-2-enyl)benzaldehyde and methyl 2-[4-hydroxy-3-(3-methylbut-2-en-1-yl)phenyl]acetate), together with twenty-one previously described compounds were isolated from marine-derived Aspergillus terreus BCC51799. Chemical structures were determined on the basis of spectroscopic evidence (NMR, UV, IR spectral data) and their physical properties. The isolated compounds were tested for their antimalarial, antimicrobial and anticholinesterase activities. Asperteramide exhibited antimicrobial activity against Bacillus cereus and Colletrichum acutatum with MIC values of 25 and 50 μg/mL, respectively. Astechrome showed strong antimalarial activity with an IC50 value of 0.94 μM, while territrem B had significant anticholinesterase activity with an IC50 value of 0.071 μM. All tested compounds, except for astepyrazinoxide and lavastatin, had moderate to weak cytotoxicity against both cancerous and non-cancerous cells.

Two unknown enantiomeric compounds, named (R)- and (S)-taeniolin, along with six known compounds, were isolated from the marine-associated fungus Taeniolella sp. BCC31839. Chemical structures were determined by NMR spectroscopic techniques, and the absolute configurations were confirmed by Mosher application together with CD spectral analyses. Both were inactive for antimicrobial activity against multidrug-resistant malaria parasite (Plasmodium falciparum) and bacteria (Mycobacerium tuberculosis and Bacillus cereus) at maximum tested concentration.

Four new compounds ( 1 – 4 ), which were (−)-( 7R )-7- O -methylsydonic acid, gibellulic acid, gibellulins A and B, together with 14 known compounds ( 5 – 17 and orcinol) were isolated from the insect pathogenic fungus, Gibellula sp. BCC36964. The chemical structures were elucidated by employing NMR spectroscopic techniques, physico-chemical data, and chemical method. These compounds were evaluated for the biological activities including anti-bacterial, anti-phytopathogenic, anti- Herpes simplex virus-type 1 activities, and cytotoxicity against both cancerous (MCF-7, KB, NCI-H187) and non-cancerous (Vero) cells.

Nonomuraea rhodomycinica NR4-ASC07T is a rare actinomycete isolated from soil in Sirindhorn peat swamp forest. The crude extract of its culture broth exhibited antimicrobial and anticancer against diverse human pathogens and cancer cells. The chemical investigation of the crude extract led to the isolation of two new metabolites named nonomuric acid (1) and 3-hydroxy deoxydaunorubicinol aglycone (2), along with two known bioactive compounds [ε-rhodomycinone (3) and 7-deoxy-13-dihydrocarminomycinone (4)]. Compounds 1 and 3 showed antimalarial activity with the half maximal inhibitory concentration (IC50) of 8.00 and 8.88 μg mL−1, respectively. Compound 4 inhibited growth of Mycobacterium tuberculosis and Bacillus cereus at the minimum inhibitory concentrations of 50.0 and 12.50 μg mL−1, respectively. Every compound exhibited cytotoxicity against cancer cells tested at IC50 ≥ 6.34 μg mL−1. These finding are the first report of bioactive metabolites produced by strain NR4-ASC07T, suggesting that rare actinomycetes are yet promising sources for novel drug discovery.

Four new oxaphenalenone dimers (bacillisporins I and J, duclauxamides B and C) together with four known compounds (bacillisporins A – C and duclauxamide A1) were isolated from the soil fungus Talaromyces bacillisporus BCC17645. Duclauxamides B and C were the rare N-containing oxaphenalenone dimers isolated from this fungus. Chemical structures were determined based on the evidence from NMR spectral information and mass spectral analysis. Their absolute configurations were identified by comparison of CD spectra with the related compounds. These isolated compounds exhibited broad antibacterial activity against Mycobacterium tuberculosis H37Ra, Bacillus cereus, and Staphylococcus aureus with MIC values in a range of 3.13 – >50 μg/mL and also had low cytotoxicity against both cancerous (MCF-7 and NCI–H187) and non-cancerous (Vero) cells.

Eight new substances including penicisochromans F–L, and penicibenzoxepinol along with seven known substances were isolated from the endophytic Penicillium sp. BCC18034. Their chemical structures were determined based on 1D and 2D NMR spectroscopic data and HR-ESI-MS analyses. Biological activities against Plasmodium falciparum, MCF-7, NCI-H187, and Vero cells of the isolated compounds were also reported.

Four new streptophenazine derivatives I–L (2, 3, 4, 6), along with two known streptophenazines A (1) and B (5) were isolated from Streptomyces sp. BCC21835. The chemical structures have been determined based on NMR spectroscopic information and their optical rotation values. Apart from streptophenazines B and I, the isolated streptophenazines exhibited antibacterial activity against Bacillus cereus with IC50 in a range of 6.25–12.50 μg/mL. These streptophenazines also showed low cytotoxicity against both cancerous (MCF-7, KB, NCI-H187) and non-cancerous (Vero) cells.

Investigation of the terrestrial Streptomyces sp. BCC27095 led to the isolation of two new ( 1 and 2 ) and two known ( 3 and 5 ) anthraquinone derivatives along with the previously reported compound, steffimycin B ( 4 ). The chemical structures were determined on the basis of NMR spectroscopic data. These compounds exhibited significant antimalarial (against Plasmodium falciparum , K-1 multidrug resistant strain) and antimycobacterial (against Mycobacterium tuberculosis H37Ra) activities with IC 50 values in the range of 0.32–3.20 μg/mL and MIC in a range of 0.0031–1.56 μg/mL, respectively. They were also evaluated for antibacterial activity against Bacillus cereus and for cytotoxicity against both malignant (MCF-7, KB, NCI-H187) and non-malignant (Vero) cells.

The genus Hypoxylon , a member of the family Xylariaceae, has been known to produce significant secondary metabolites in terms of chemical diversity. Moreover, the compounds isolated can also be used as chemotaxonomic characters for differentiation among the two sections, which are sect. Annulata and sect. Hypoxylon . In our continuing chemical screening programme for novel compounds, the crude extracts of H. fendleri BCC32408 gave significant chemical profiles in HPLC analyses. Thus, the chemical investigation of these crude extracts was then carried out. The investigation led to the isolation of ten previously undescribed compounds including three terphenylquinones (fendleryls A – C), one terphenyl (fendleryl D), and six novel drimane – phthalide-type lactone/isoindolinones derivatives (fendlerinines A – F) along with seven known compounds (2- O -methylatromentin, rickenyl E, atromentin, rickenyls C – D, (+)-ramulosin, and O -hydroxyphenyl acetic acid). The chemical structures were determined on the basis of spectroscopic analyses, including 1D, 2D NMR and high-resolution mass spectrometry, as well as chemical transformations. In addition, these isolated compounds were assessed for antimicrobial activity including antimalarial (against Plasmodium falciparum , K-1 strain), antifungal (against Candida albicans ), antibacterial (against Bacillus cereus ) activities. Cytotoxicity against both cancerous (KB, MCF-7, NCI-H187) and non-cancerous (Vero) cells of these compounds were also evaluated.

Five new anthraquinone-xanthone heterodimers (I), (II), and (III) and a new xanthone derivative (IV) are isolated together with eight known compounds.

Investigation of the terrestrial Streptomyces sp. BCC27095 led to the isolation of two new ( 1 and 2 ) and two known ( 3 and 5 ) anthraquinone derivatives along with the previously reported compound, steffimycin B ( 4 ). The chemical structures were determined on the basis of NMR spectroscopic data. These compounds exhibited significant antimalarial (against Plasmodium falciparum , K-1 multidrug resistant strain) and antimycobacterial (against Mycobacterium tuberculosis H37Ra) activities with IC 50 values in the range of 0.32–3.20 μg/mL and MIC in a range of 0.0031–1.56 μg/mL, respectively. They were also evaluated for antibacterial activity against Bacillus cereus and for cytotoxicity against both malignant (MCF-7, KB, NCI-H187) and non-malignant (Vero) cells.