23 research outputs found
Cytotoxic and Antibacterial Quinone Sesquiterpenes from a <i>Myrothecium</i> Fungus
Six new quinone sesquiterpenes, myrothecols
A–F (<b>1</b>–<b>6</b>), and hymenopsin
B (<b>7</b>) were isolated
from cultures of <i>Myrothecium</i> sp. SC0265 by bioassay-guided
fractionation. Their structures were elucidated on the basis of 1D
and 2D NMR and MS data. The absolute configurations of the new compounds
were assigned by CD/TDDFT calculations, and that of and hymenopsin
B was confirmed by X-ray diffraction analysis. Compounds <b>1</b>–<b>5</b> and hymenopsin demonstrated cytotoxic activity
against human carcinoma A549, HeLa, and HepG2 cells. Compounds <b>1</b>–<b>5</b> also exhibited antibacterial activity
against <i>Staphylococcus aureus</i> and <i>Bacillus
cereus</i>
Penicillitone, a Potent <i>in Vitro</i> Anti-inflammatory and Cytotoxic Rearranged Sterol with an Unusual Tetracycle Core Produced by <i>Penicillium purpurogenum</i>
A rearranged sterol
with an unusual tetracycle core skeleton, penicillitone
(<b>1</b>), and a new sterol, penicillisterol (<b>2</b>), were obtained from the culture of the fungus <i>Penicillium
purpurogenum</i> SC0070. Their structures were characterized
by spectroscopic analysis, DFT/TDDFT compuations, and X-ray diffraction.
Compound <b>1</b> demonstrated potent inhibitory effects on
tumor cell growth and key pro-inflammatory cytokine production in
macrophages. A biogenetic pathway with oxidative cleavage and vinylogous
aldol addition as key reactions is proposed for <b>1</b>
Penicillitone, a Potent <i>in Vitro</i> Anti-inflammatory and Cytotoxic Rearranged Sterol with an Unusual Tetracycle Core Produced by <i>Penicillium purpurogenum</i>
A rearranged sterol
with an unusual tetracycle core skeleton, penicillitone
(<b>1</b>), and a new sterol, penicillisterol (<b>2</b>), were obtained from the culture of the fungus <i>Penicillium
purpurogenum</i> SC0070. Their structures were characterized
by spectroscopic analysis, DFT/TDDFT compuations, and X-ray diffraction.
Compound <b>1</b> demonstrated potent inhibitory effects on
tumor cell growth and key pro-inflammatory cytokine production in
macrophages. A biogenetic pathway with oxidative cleavage and vinylogous
aldol addition as key reactions is proposed for <b>1</b>
A novel icariin type flavonoid from <i>Epimedium pseudowushanense</i>
<p>A novel icariin type flavonoid glycoside with a malonaldehydic acid intramolecular ester and two known flavonoid glycosides were isolated from <i>Epimedium pseudowushanense</i>. Their structures were elucidated on the basis of spectroscopic analysis and comparison of their data to the values reported in the literatures. The anti-inflammatory activities of these compounds icariin 3′′′-<i>O</i>-malonaldehydic acid intramolecular 1′′′′, 2′′′ ester (1), icariin (2) and epimedin C (3) were tested. The results indicated that compounds 1, 2 and 3 showed maximal inhibitory ratio of 27.91, 44.80 and 46.61%, respectively in <i>in vitro</i> anti-inflammatory activity on LPS-induced TNF-α secretion in RAW264.7 cells. Compounds icariin (2) and epimedin C (3) were found to inhibit the secretion of TNF-α to a comparable degree as quercetin.</p
Anti-inflammatory neolignans from <i>Epimedium pseudowushanese</i>
<p>One new 8-<i>O</i>-4′ neolignan has been isolated from <i>Epimedium pseudowushanese</i> B. L. Guo, together with nine other known neolignans. The structures of these neolignans were elucidated using spectroscopic and chemical techniques, and their anti-inflammatory activities were also evaluated. The results of these experiments revealed that compound <b>6</b> was the most potent of the 10 different compounds tested in the current study, with a maximal inhibitory ratio of 79% for its <i>in vitro</i> anti-inflammatory activity towards lipopolysaccharide-induced tumour necrosis factor alpha secretion in RAW264.7 cells. The other nine compounds exhibited only moderate inhibitory effects.</p
Bisacremines A–D, Dimeric Acremines Produced by a Soil-Derived Acremonium persicinum Strain
Four dimeric acremines, bisacremines
A–D (<b>1</b>–<b>4</b>), with a novel carbon
skeleton and a new monomer, acremine T (<b>5</b>), were obtained
from cultures of the soil-derived fungus Acremonium
persicinum SC0105. Their structures were characterized
by analysis of spectroscopic data, ECD/TDDFT computations, and X-ray
diffraction. Compounds <b>1</b> and <b>2</b> exhibited
weak cytotoxicity against HeLa cells, and <b>2</b> also showed
modest activity against A549 and HepG2 cells
Versicorin, a new lovastatin analogue from the fungus <i>Aspergillus versicolor</i> SC0156
<div><p>A new lovastatin analogue versicorin (<b>1</b>), together with three related compounds, decumbenones A (<b>2</b>) and B (<b>3</b>) and versiol (<b>4</b>), were isolated from mycelial solid cultures of <i>Aspergillus versicolor</i> SC0156. Their structures were elucidated on the basis of MS data and NMR spectroscopic analysis. The new compound versicorin (<b>1</b>) possesses a hexahydro-2<i>H</i>-naphtho[1,8-<i>bc</i>]furan moiety, which is a rare type of the lovastatin-analogous compounds. A hypothetical biosynthetic pathway for compounds <b>1</b>–<b>4</b> was proposed.</p></div
Xylaropyrones B and C, new γ-pyrones from the endophytic fungus <i>Xylaria</i> sp. SC1440
<p>Two new γ-pyrones, xylaropyrones B (<b>1</b>) and C (<b>2</b>), together with three known compounds, xylaropyrone (<b>3</b>), annularin A (<b>4</b>) and annularin C (<b>5</b>), were isolated from solid cultures of the endophytic fungus <i>Xylaria</i> sp. SC1440. The structures of these compounds were determined mainly by analysis of their NMR spectroscopic data. The relative configurations of <b>1</b> and <b>2</b> were assigned on the basis of <i>J</i>-based configurational analysis, and the absolute configurations were established by experimental and TDDFT calculated ECD spectra. The isolated compounds were evaluated for cytotoxic and tyrosinase inhibitory activity.</p
Antifungal and Cytotoxic β‑Resorcylic Acid Lactones from a <i>Paecilomyces</i> Species
Eight new β-resorcylic acid
lactones (RALs), including the hypothemycin-type compounds paecilomycins
N–P (<b>1</b>–<b>3</b>) and the radicicol-type
metabolites dechloropochonin I (<b>4</b>), monocillins VI (<b>5</b>) and VII (<b>6</b>), 4′-hydroxymonocillin IV
(<b>7</b>), and 4′-methoxymonocillin IV (<b>8</b>), along with nine known RALs (<b>9</b>–<b>17</b>), were isolated from the cultures of <i>Paecilomyces</i> sp. SC0924. Compounds <b>1</b> and <b>2</b> feature
a novel 6/11/5 ring system, and <b>3</b> is the first 5′-keto
RAL. The structures of <b>1</b>–<b>8</b> were elucidated
on the basis of extensive spectroscopic analysis, X-ray diffraction
analysis, and theoretical calculations of ECD spectra. Compounds <b>3</b>, <b>5</b>, and <b>6</b> exhibit cytotoxicity
against MCF-7, A549, and HeLa cells, and compounds <b>5</b> and <b>7</b> display antifungal activity against <i>Peronophythora
litchii</i>
Flavonoids from the Pericarps of <i>Litchi chinensis</i>
A new methylene-linked flavan-3-ol
dimer, bisÂ(8-epicatechinyl)Âmethane
(<b>1</b>), was isolated from the pericarps of <i>Litchi
chinensis</i> Sonn. (Sapindaceae), together with dehydrodiepicatechin
A (<b>2</b>), proanthocyanidin A1 (<b>3</b>), proanthocyanidin
A2 (<b>4</b>), (−)-epicatechin (<b>5</b>), 8-(2-pyrrolidinone-5-yl)-(−)-epicatechin
(<b>6</b>), (−)-epicatechin 8-<i>C</i>-β-d-glucopyranoside (<b>7</b>), naringenin 7-<i>O</i>-(2,6-di-<i>O</i>-α-l-rhamnopyranosyl)-β-d-glucopyranoside (<b>8</b>), and rutin (<b>9</b>). It was the first report of compound <b>2</b> as a natural
product and compounds <b>6–8</b> from this species. Compounds <b>1</b>, <b>2</b>, and <b>6–8</b> were evaluated
for antioxidant activity. The ferric reducing antioxidant powers (FRAP)
of compounds <b>1</b> and <b>6</b> were comparable to
that of l-ascorbic acid, and the scavenging activities of
compounds <b>1</b>, <b>2</b>, <b>6</b>, and <b>7</b> toward 1,1-diphenyl-2-picrylhydrazyl (DPPH) radicals and
2,2′-azinobisÂ(3-ethylbenzthiazoline-6-sulfonic acid) radical
cations were more potent than those of l-ascorbic acid; compound <b>8</b> was weak in FRAP and DPPH assays