An anti-herpes simplex virus-type 1 agent from Xylaria mellisii (BCC 1005)

A structurally unique polyketide, mellisol (1) and 1,8-dihydroxynaphthol 1-O-α-glucopyranoside (3), were isolated from the fungus Xylaria mellisii (BCC 1005). The relative stereostructure of 1 was determined on the basis of X-ray crystallographic data. Compounds 1 and 3 exhibited activity against herpes simplex virus-type 1 with IC₅₀ values of 10.50 and 8.40 μg/mL, respectively. They also showed cytotoxic activity against vero cells at the concentration of 40-50 μg/mL.     

Antimalarial 20-membered macrolides from Streptomyces sp. BCC33756

Two new natural products, samroiyotmycins A (1) and B (2), along with two naturally new novclobiocin 101 (3) and 4-hydroxy-3-(3-methylbut-2-enyl)benzamide (5), and five known substances including neoantimycin, clorobiocin (4), 29-O-methylabierixin, daidzein, and 1-(3-indolyl)-2,3-dihydroxypropan-1-one have been isolated from Streptomyces sp. BCC33756. Their chemical structures were determined based on NMR spectral information and the relative stereochemistry of compound 1 was determined by X-ray crystallographic data. Both samroiyotmycins A and B exhibited antimalarial activity against Plasmodium falciparum K1—multi-drug resistant strain, with IC₅₀ values of 3.65 and 3.16 μg/mL, respectively. Compound 1 was inactive against both cancerous (MCF-7, KB) and non-cancerous (Vero) cells, while compound 2 displayed cytotoxicity against Vero cell with IC₅₀ value of 29.57 μg/mL.     

Synthesis of pyrrolo[1,2-f]phenanthridine-annulated polycyclic heterocycles from palladium-catalyzed intramolecular direct arylation reaction

Abstract  

A concise synthesis of pyrrolo[1,2-f]phenanthridine-annulated polycyclic heterocycles has been achieved in good yields by palladium-catalyzed intramolecular direct arylation reaction.     

Salicylaldehyde and dihydroisobenzofuran derivatives from the marine fungus Zopfiella marina

Two salicylaldehyde derivatives (1 and 2), a hydroxymethylphenol (3), five dihydroisobenzofuran (4–8) derivatives, and a 5-chloro-3-deoxyisoochracinic acid (9), together with a known 3-deoxyisoochracinic acid (10) were isolated from the marine fungus Zopfiella marina BCC 18240 (or NBRC 30420). The structures of these compounds were elucidated by extensive spectroscopic analysis. Compound 1 showed weak antituberculous activity against Mycobacterium tuberculosis H37Ra, and antibacterial activity against Bacillus cereus with MIC values of 25 and 12.5 μg/mL, respectively.     

A characterization of some q-orthogonal polynomials

We show that the only orthogonal polynomials satisfying a q-difference equation of the form π(x)D _q P _n (x) = (α _n x + β _n )P _n (x) + γ _n P _n−1(x) where π(x) is a polynomial of degree 2, are the Al-Salam Carlitz 1, little and big q-Laguerre, the little and big q-Jacobi, and the q-Bessel polynomials. This is a q-analog of the work carried out in [1]. 2000 Mathematics Subject Classification Primary—33C45, 33D45     

3-Oxyanthranilic acid derivatives from Actinomadura sp. BCC27169

Eight new compounds including 9′-[2-amino-3-(4″-O-methyl-α-rhamnopyranosyloxy) phenyl]nonanoic acid (1), 9′-[2-amino-3-(4″-O-methyl-α-ribopyranosyloxy)phenyl] nonanoic acid (2), 11′-[2-amino-3-(4″-O-methyl-α-rhamnopyranosyloxy)phenyl]undecanoic acid (3), 11′-[2-amino-3-(4″-O-methyl-α-ribopyranosyloxy)phenyl]undecanoic acid (4), 8-(4′-O-methyl-α-rhamnopyranosyloxy)-3,4-dihydroquinolin-2(1H)-one (5), 8-(4′-O-methyl-α-ribopyranosyloxy)-3,4-dihydroquinolin-2(1H)-one (6), 8-(4′-O-methyl-α-rhamnopyranosyloxy)-2-methyquinoline (7), and 8-(4′-O-methyl-α-ribopyranosyloxy)-2-methylquinoline (8) were isolated from Actinomadura sp. BCC27169. The chemical structures of these compounds were determined based on NMR and high-resolution mass spectroscopy. The absolute configurations of these monosaccharides were revealed by the hydrolysis of compounds 7 and 8. Compounds 3 and 8 exhibited antitubercular activity at MIC 50 μg/mL. Only compound 3 showed cytotoxicity against KB cell at IC₅₀ 18.63 μg/mL, while other isolated compounds were inactive at tested maximum concentration (50 μg/mL).     

Antiplasmodial and antiviral cyclohexadepsipeptides from the endophytic fungus Pullularia sp. BCC 8613

Four new cyclohexadepsipeptides, pullularins A-D, were isolated from the endophytic fungus Pullularia sp. BCC 8613. Structures of these compounds were elucidated by interpretation of NMR spectroscopic and mass spectrometric data. The absolute configurations of amino acid and hydroxy acid residues were determined by HPLC analysis of depsipeptide acid hydrolyzates using a chiral column and Marfey's method. Pullularin A exhibited activities against the malarial parasite Plasmodium falciparum K1 (IC₅₀ 3.6 μg/mL) and herpes simplex virus type 1 (HSV-1; IC₅₀ 3.3 μg/mL), whereas it showed weak cytotoxicity to Vero cells (IC₅₀ 36 μg/mL).     

Highly Conjugated Ergostane‐Type Steroids and Aranotin‐Type Diketopiperazines from the Fungus Aspergillus terreus BCC 4651

Two new ergostane derivatives, 12β,15α,25,26‐tetrahydroxyergosta‐4,6,8(14),22‐tetraen‐3‐one ( 1 ) and 12β,15α,25,28‐tetrahydroxyergosta‐4,6,8(14),22‐tetraen‐3‐one ( 2 ), and a new aranotin‐type diketopiperazine, bisdethiobis(methylsulfanyl)apoaranotin ( 3 ), were isolated from the fungus Aspergillus terreus BCC 4651. The structures of the new compounds were elucidated by means of NMR spectroscopic and MS analyses.     

Antimalarial and antituberculosis substances from Streptomyces sp. BCC26924

Two new carbazomycin dimers (6 and 7) and 3-hydroxy-1,2-dimethyl-2,3-dihydro-1H-carbazol-4-one (9) together with six known compounds, carbazomycins A-D, cyclomarin C, and pimprinine have been isolated from Streptomyces sp. BCC26924. Carbazomycins B, C, and cyclomarin C exhibited antimalarial activity (against Plasmodium falciparum, K1 multi-drug resistant strain) with IC₅₀ in a range of 0.24-2.37 μg/mL. Cyclomarin C exhibited anti-TB activity with a minimum inhibitory concentration value of 0.10 μg/mL, while carbazomycin D, compound 7, and pimprinine displayed MIC values in a range of 12.5-25.0 μg/mL. In addition, compounds 2, 5, 6, and 7 showed weak cytotoxicity against cancerous (MCF-7, KB, NCI-H187) and non-cancerous (Vero) cells.