Modiolin and phthalide derivatives from the endophytic fungus Microsphaeropsis arundinis PSU-G18

One new modiolin, microsphaerodiolin (1), and seven new phthalides, microsphaerophthalides A-G (2-8), together with 12 known compounds were isolated from the endophytic fungus Microsphaeropsis arundinis PSU-G18. Their structures were elucidated by spectroscopic methods. The new 3-oxygenated phthalides are rare natural products. The known 1-(2,5-dihydroxyphenyl)-2-buten-1-one exhibited significant antifungal activity against Microsporum gypseum SH-MU-4 with an MIC value of 8 μg/mL, moderate antimalarial activity with an IC₅₀ value of 9.63 μg/mL and strong radical scavenging potency with the IC₅₀ value of 0.018 mg/mL. The new compounds 2 and 6 showed moderately antifungal activity against M. gypseum SH-MU-4 and Cryptococcus neoformans, respectively, with equal MIC values of 64 μg/mL.     

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.     

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.     

Bioactive polyketides from the fungus Astrocystis sp. BCC 22166

Five new compounds, phthalide 1, dihydroisocoumarin 2, and 3, pyrone 4, and benzophenone 5, together with nine known compounds, 3,4-dihydro-4,5,8-trihydroxy-3-methylisocoumarin, sclerotinin A, methyl-8-hydroxy-6-methylxanthone-1-carboxylate, sydowinin A, conioxanthone A, 1,3,8-trihydroxy-6-methylxanthone, 1,8-dihydroxy-3-methoxy-6-methylxanthone, coniochaetone B, and xylaranol B, were isolated from the fungus Astrocystis sp. BCC 22166. Structures of these compounds were elucidated using NMR spectroscopic and MS spectrometric analyses. Compound 1 exhibited antibacterial activity against Bacillus cereus (IC₅₀=12.5 μg/mL) while compound 2 showed cytotoxicity to KB and Vero cells (IC₅₀=22.6 and 48.2 μg/mL).     

Two lignans,one alkaloid,and flavanone from the twigs of Feroniella lucida

Four new compounds, two lignans; lucidenal and lucidanin (1 and 2), one alkaloid (3), and one flavanone (4) together with 26 known compounds (5–30), were isolated from the twigs of Feroniella lucida. The structures of the new compounds were determined on the basis of spectroscopic analyses. Lucidenal 1 showed cytotoxicity against HuCCA-1, A549, MOLT-3 and HepG2 cancer cell lines with IC₅₀ values of 4.27, 9.59, 2.31, and 6.50 μg/mL, respectively. A plausible biosynthetic pathway of 1 was proposed.     

Dihydronaphthalenones from endophytic fungus Fusarium sp. BCC14842

Eleven new dihydronaphthalenones 1-11, together with five known compounds; 5-hydroxydihydrofusarubin C (12), javanicin, bostrycoidin, anhydrofusarubin, and 3-O-methylfusarubin, were isolated from the endophytic fungus Fusarium sp. BCC14842. Structures were elucidated by analyses of the NMR spectroscopic and mass spectrometry data. Javanicin, 3-O-methylfusarubin, compounds 3 and 7 exhibited antimycobacterial and cytotoxic activities. Javanicin also displayed antifungal activity with IC₅₀ of 6.16 μg/mL, while compounds 2, 4, 5, 8, and 12 showed only cytotoxic activity.     

Kehokorins A-C, novel cytotoxic dibenzofurans isolated from the myxomycete Trichia favoginea var. persimilis

Kehokorins A (1)-C (3), three novel dibenzofurans, have been isolated from field-collected fruit bodies of the myxomycete, Trichia favoginea var. persimilis, and their structures were elucidated by spectral data. Kehokorin A (1) was a α-l-rhamnopyranoside of kehokorin B (2), while kehokorin C (3) was a 1-demethoxy analog of 2. Kehokorin A (1) was cytotoxic against HeLa cells with an IC₅₀ value of 1.5 μg/mL.     

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).     

Polyketides from the mangrove-derived endophytic fungus Acremonium strictum

Five new polyketide derivatives, 6′-hydroxypestalotiopsone C (1), acropyrone (2), bicytosporone D (3), waol acid (4), and pestalotiopene C (5), together with seven known metabolites (6–12), were obtained from extracts of the endophytic fungus Acremonium strictum, isolated from the mangrove tree Rhizophora apiculata. The structures of the isolated compounds were elucidated on the basis of comprehensive NMR and MS analysis. Compounds 6, 7, and 9 showed moderate cytotoxic activity against human cisplatin-sensitive (IC₅₀ values 27.1, 76.2, and 8.3 μM, respectively) and resistant A2780 cell lines (IC₅₀ values 12.6, 30.1, and 19.0 μM, respectively), whereas only 9 exhibited antibacterial activity against Staphylococcus aureus (MIC value 14.3 μM).     

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.     

Pleosporin A,an antimalarial cyclodepsipeptide from an elephant dung fungus (BCC 7069)

Cyclodepsipeptides SCH 217048 (1), SCH 218157 (2), and a new analog, pleosporin A (3), were isolated from cultures of an unidentified elephant dung fungus of the family Pleosporaceae. The structure of 3 was elucidated on the basis of detailed spectroscopic interpretation. The absolute configurations of 1–3 were determined by chiral column HPLC analysis and Marfey’s method. Cyclodepsipeptides 1–3 exhibited antimalarial activity against Plasmodium falciparum K1 with respective IC₅₀ values of 1.6, 6.4, and 1.6 μg/mL, while they did not show cytotoxicity against KB, MCF-7 and NCI-H187 cell-lines or non-cancerous Vero cells at 50 μg/mL.     

Novel cyclopropyl diketones and 14-membered macrolides from the soil fungus Hamigera avellanea BCC 17816

Two novel cyclopropyl diketones, hamavellone A (1) and B (2), and two new 14-membered nonaketide macrolactones, hamigeromycin A (3) and B (4), together with six known compounds, 89-250904-F1 (radicicol analogue A, 5), pseurotin A (6), emodin (7), ω-hydroxyemodin (8), and emodin bianthrones (9 and 10) were isolated from the soil fungus Hamigera avellanea BCC 17816. The structures of the new compounds were defined by analysis of NMR and MS data. The absolute stereochemistry of 3 was addressed by chemical correlation to 5. Hamavellone B (2) exhibited antimalarial activity with an IC₅₀ of 5.2 μg/mL, whereas it also showed comparable cytotoxicity.     

Abiesanordines A-N: fourteen new norditerpenes from Abies georgei

Fourteen new norditerpenoids (abiesanordines A-N, 1-14), including a novel podocarpene bearing a rare enolic structure (abiesanordine A, 1), were isolated from Abies georgei together with eight known ones. Their structures were determined mainly by detailed analysis of 1D and 2D NMR spectroscopic data including HSQC, DQF COSY, HMBC, and NOESY. All the isolates were tested for inhibitory activities against LPS-induced NO production in RAW264.7 macrophages, abiesanordine I (9) showed the strongest activity with the IC₅₀ value of 17.0 μg/mL. Furthermore, it exhibited no cytotoxicity against RAW264.7 macrophages under the concentration of 50 μg/mL.     

Fascioquinols A-F: bioactive meroterpenes from a deep-water southern Australian marine sponge, Fasciospongia sp.

Chemical investigation of a southern Australian deep-water marine sponge, Fasciospongia sp., returned the new meroterpene sulfate fascioquinol A (1) together with a series of acid mediated hydrolysis/cyclization products, fascioquinols B (2), C (3) and D (4), and strongylophorine-22 (5). Additional co-metabolites include the new meroterpenes fascioquinol E (6) and fascioquinol F (8), together with the known sponge metabolite geranylgeranyl 1,4-hydroquinone (7). Structures were assigned to 1-8 on the basis of detailed spectroscopic analysis, chemical interconversion, mechanistic and biosynthetic considerations, and literature comparisons. The known 1,4-hydroquinone 7 was identified as the dominant cytotoxic principle in the Fasciospongia sp. extract, with selective inhibitory activity against gastric adenocarcinoma (AGS, IC₅₀ 8 μM) and neuroblastoma (SH-SY5Y, IC₅₀ 4 μM) cell lines. By contrast, while the fascioquinols displayed little or no inhibitory activity towards human cell lines, 1 and 2 displayed promising Gram-positive selective antibacterial activity towards Staphylococcus aureus (IC₅₀ 0.9-2.5 μM) and Bacillus subtilis (IC₅₀ 0.3-7.0 μM).     

Zyzzyanone A, a novel pyrrolo[3,2-f]indole alkaloid from the Australian marine sponge Zyzzya fuliginosa

A new dipyrroloquinone, zyzzyanone A 1, having a pyrrolo[3,2-f]indole-4,8(1H,7H)-dione skeleton, was isolated from the Australian marine sponge Zyzzya fuliginosa, along with the known pyrroloquinoline alkaloids, makaluvamines C, E, G, H, and L, and damirones A and B. The structure of 1 was determined by spectroscopic data. Zyzzyanone A 1 shows moderate cytotoxic activity against mouse Ehrlich carcinoma cells (IC₅₀ 25 μg/mL), inhibits the cell division of fertilized sea urchin eggs at a concentration of 25 μg/mL, and exhibits UV-A and UV-B absorbing activity.     

Chloctanspirones A and B, novel chlorinated polyketides with an unprecedented skeleton, from marine sediment derived fungus Penicillium terrestre

Two novel chlorinated sorbicillinoids named chloctanspirones A (1) and B (2), possessing an unprecedented bicyclo[2.2.2]octane-2-spiro cyclohexane skeleton, together with their quasi-precursors terrestrols K (3) and L (4), two additional new chlorinated compounds, were isolated from a marine sediment derived fungus Penicillium terrestre. Their structures including absolute stereochemistries were elucidated by analysis of NMR, MS data, and TDDFT CD calculations. The cytotoxic effects of 1-4 were preliminarily evaluated in HL-60 and A-549 cells. Compound 1 was active against both HL-60 and A-549 cells with IC₅₀s 9.2 and 39.7 μM, respectively, while 2 showed weaker activity only against HL-60 cells (IC₅₀ 37.8 μM).     

Diterpenes and sesquiterpenes with anti-Coxsackie virus B3 activity from the stems of Illicium jiadifengpi

Seven new diterpenes, jiadifenoic acids J–P (1–7), two new sesquicarane sesquiterpenes, sesquicaranoic acids A and B (8 and 9), and four known compounds, were isolated from the stems of Illicium jiadifengpi. The trans-fused A/B ring junction in diterpenes was deduced from NMR data analysis and confirmed by single-crystal X-ray crystallography of 3. The absolute configurations of compounds 1 and 5 were determined using the Mo₂(OAc)₄-induced circular dichroism (ICD) method. Compounds 8 and 9 are a pair of C-10 epimers, and their absolute configurations were confirmed by analyzing their CD and ICD data. All of the isolated compounds were evaluated in vitro for their antiviral activities against Coxsackie virus B3 (CVB3). Among the isolated compounds, 4, 5, 7, 10, and 11 exhibited reasonable activity against CVB3, with IC₅₀ values of 7.0–22.2 μmol/mL and selective index values (SI=TC₅₀/IC₅₀) of 49.3, 37.1, 31.3, 45.6 and 40.9, respectively.     

Isolation and biological evaluation of chromone alkaloid dysoline,a new regioisomer of rohitukine from Dysoxylum binectariferum

The chromone alkaloid dysoline (1), a new regioisomer of rohitukine (2) along with rohitukine and rohitukine-N-oxide (3) were isolated from the stem barks of Dysoxylum binectariferum. The structure of dysoline (1) was determined by extensive 2D-NMR studies and the absolute configuration was established by NOESY and CD spectra. Dysoline (1) consisted of a 5,7-dihydroxy-2-methylchromone nucleus substituted with a 2′-hydroxylated N-Me piperidine ring at the C-6 position. Dysoline differs from rohitukine by the position of the piperidine ring on the chromone nucleus. Dysoline displayed promising cytotoxicity in HT1080 fibrosarcoma cells with an IC₅₀ of 0.21 μM, and also displayed significant inhibition of proinflammatory cytokines TNF-α and IL-6.     

Torrubiellutins A-C, from insect pathogenic fungus Torrubiella luteorostrata BCC 12904

Investigation of the insect pathogenic fungus Torrubiella luteorostrata led to the isolation of three new macrocyclic torrubiellutins A-C (1-3) and the known pyrone diterpene 4. Structures were elucidated by spectroscopic data including 1D, 2D NMR, and MS spectral data. The absolute stereochemistry was determined by chemical means using Mosher reactions and Marfey's reagent, together with NOESY spectral data. Torrubiellutin C showed biological activities against KB, MCF-7, NCI-H187, and Vero cell lines with IC₅₀ varying from 0.78 to 4.36 μg/mL, while compound 4 exhibited antimalaria and anti-inflammatory activity with IC₅₀ values of 3.49 and 1.21 μg/mL, respectively.