30 research outputs found
Oxygenated heterocyclic metabolites with dual cyclooxygenase-2 and 5-lipoxygenase inhibitory potentials from Rhizophora annamalayana
Previously undescribed oxygenated heterocyclic metabolites were purified from the ethyl acetate fraction of natural
mangrove hybrid Rhizophora annamalayana. The purified metabolites were characterized as 11-(tetrahydro-14α-hydroxy-
13β-methylfuran-12-yl)-10β-methylbutyl benzoate (1), 13-(tetrahydro-15β,16α-dimethyl-18-oxo-2H-pyran-14-yl)-10β-
methylhept-12(E)-enyl benzoate (2), and dihydro-11-((7E)-2-hydroxy-8β-methyl-2H-chromen-9-yl)-13-methylpent-12(E)-
enyl)-17β-methylfuran-19(3H)-one (3) by the combined spectroscopic experiments. These metabolites were assessed for
their antioxidant and anti-inflammatory activities, and compared with the commercially available standards. The purified
compound 3 exhibited greater antioxidant activities as deduced by 2, 2’-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid and
2, 2-diphenyl-1-picrylhydrazyl quenching properties (IC50 2.10 and 2.22 mM, respectively) compared to the positive control
(α-tocopherol, IC50 1.46 and 1.69 mM, respectively). Consequently, the anti-inflammatory activity of compound 3 with
regard to the inhibitory property towards pro-inflammatory 5-lipoxygenase was greater (IC50 2.16 mM) than that exhibited
by the synthetic anti-inflammatory drug ibuprofen (IC50 4.51 mM). Electronic and hydrophobic parameters were deduced to
find the target bioactivities of the studied compounds. These oxygenated heterocyclic metabolites could be used as potential
therapeutic lead compounds in the pharmaceutical applications
Biogenic guaianolide-type sesquiterpene lactones with antioxidative and anti-inflammatory properties from natural mangrove hybrid Rhizophora annamalayana
Previously undescribed guaianolide-type sesquiterpene lactones were isolated from the chloroform fraction of the natural hybrid mangrove Rhizophora annamalayana, and were characterised as (Z)-3α,4,5,6-tetrahydro-5α-isobutyl-2β-(methoxymethyl)-7-methyl-3H-cyclohepta[b]carbolactone (1) and (7Z)-isopentyl 3α,4,5,6,7,8-hexahydro-2β-((E)-11-methylbut-10-enyl)-1-oxo-2H-cyclohepta[b]furan-6-carboxylate (2). Compound 2 displayed greater antioxidative activities {1, 1-diphenyl-2-picrylhydrazyl (DPPH) and 2, 2'-azino-bis-3 ethylbenzothiozoline-6-sulphonic acid diammonium salt (ABTS), IC50 0.65 and 0.62 mg/mL, respectively)} compared to 1 (IC50 0.83 and 1.14 mg/mL, respectively) (p < 0.05). Compound 2 recorded no significant difference in DPPH. scavenging activities (IC50 0.65 mg/mL) compared to α-tocopherol (IC50 0.63 mg/mL). Pro-inflammatory 5-lipoxygenase inhibitory activity of 2 was found to be comparable (IC50 0.98 mg/mL) to that displayed by synthetic anti-inflammatory drug ibuprofen (IC50 0.93 mg/mL). Compound 2 showed significantly greater selectivity index (anti-cyclooxygenase-1/anti-cyclooxygenase-2 = 2.15) than non-steroidal anti-inflammatory ibuprofen (<0.5) (p < 0.05), and therefore, might be used as selective cyclooxygenase-2 inhibitor. The hitherto undescribed guaianolide lactones might be used as potential anti-inflammatory and antioxidative pharmacophore leads
Long chain n-3 polyunsaturated fatty acid enriched oil emulsion from sardine oil
Dietary fats are used to build every cell in the
body and cell membranes are made of a variety of
individual fatty acids which are carboxylic acids with
long hydrocarbon chains (usually C12-22). The
essential fatty acids from marine fish have protective
mechanisms against coronary heart disease, which
became apparent in the investigations of the health
status of Greenland Eskimos who consumed diets very
high in fat from seals,whales, fish etc, and yet had a
low rate of coronary heart disease
Two rare antioxidant and anti-inflammatory oleanenes from loop root Asiatic mangrove Rhizophora mucronata
Two oleanenes, olean-18(19)-en-3b-yl-(3,6-dimethyl-3E,6Z-dienoate) and (13a)-27-frido-olean-14(15)-
en-(17a)-furanyl-3b-ol representing a class of rare natural pentacyclic triterpenoids were isolated from
the chloroform extract of Asiatic mangrove, Rhizophora mucronata Lam. (Family: Rhizophoraceae). The
furanyl oleanene exhibited significantly greater antioxidative activities (IC50 0.73e0.76 mg/mL), than
prenylated oleanene (IC50 0.84e0.96 mg/mL) (P < 0.05). No significant differences in anti-5-lipoxygenase
activities of these compounds with the synthetic drug ibuprofen was discernable (IC50 0.8e0.9 mg/mL),
whilst furanyl oleanene demonstrated significantly greater anti-cyclooxygenase-2 (IC50 0.84 mg/mL) and
anti-5-lipoxygenase activities (IC50 0.78 mg/mL) over prenylated oleanene (IC50 > 0.90 mg/mL). These
compounds exhibited lesser activity against cyclooxygenase-1 than cyclooxygenase-2 isoform, and
therefore, their selectivity indices remained significantly greater (anti-cyclooxygenase-1IC50/anti-cyclooxygenase-
2IC50 > 1) than the aspirin (0.02) and ibuprofen (0.44). The lipophilic and steric molecular
descriptors were found to occupy a prominent role in determining the bioactivities of the compounds.
These previously undescribed oleanenes might serve as potential antioxidative and anti-inflammatory
lead molecules in medicinal formulations and food industries
Not Available
Not AvailableTwo oleanenes, olean-18(19)-en-3b-yl-(3,6-dimethyl-3E,6Z-dienoate) and (13a)-27-frido-olean-14(15)-
en-(17a)-furanyl-3b-ol representing a class of rare natural pentacyclic triterpenoids were isolated from
the chloroform extract of Asiatic mangrove, Rhizophora mucronata Lam. (Family: Rhizophoraceae). The
furanyl oleanene exhibited significantly greater antioxidative activities (IC50 0.73e0.76 mg/mL), than
prenylated oleanene (IC50 0.84e0.96 mg/mL) (P < 0.05). No significant differences in anti-5-lipoxygenase
activities of these compounds with the synthetic drug ibuprofen was discernable (IC50 0.8e0.9 mg/mL),
whilst furanyl oleanene demonstrated significantly greater anti-cyclooxygenase-2 (IC50 0.84 mg/mL) and
anti-5-lipoxygenase activities (IC50 0.78 mg/mL) over prenylated oleanene (IC50 > 0.90 mg/mL). These
compounds exhibited lesser activity against cyclooxygenase-1 than cyclooxygenase-2 isoform, and
therefore, their selectivity indices remained significantly greater (anti-cyclooxygenase-1IC50/anti-cyclooxygenase-
2IC50 > 1) than the aspirin (0.02) and ibuprofen (0.44). The lipophilic and steric molecular
descriptors were found to occupy a prominent role in determining the bioactivities of the compounds.
These previously undescribed oleanenes might serve as potential antioxidative and anti-inflammatory
lead molecules in medicinal formulations and food industries.Not Availabl
Two rare antioxidative prenylated terpenoids from loop-root Asiatic mangrove Rhizophora mucronata (Family Rhizophoraceae) and their activity against pro-inflammatory cyclooxygenases and lipoxidase
Two new biogenic prenylated terpenoids were isolated from the methanol
extract of Rhizophora mucronata. The extended C20 sesquiterpenoid
with prenylated guaiane framework was characterised as (4E, 8Z)-3,
3a, 6, 7-tetrahydro-3, 9-dimethyl-5-(6-methylheptan-2-yl) cycloocta[b]
furan-2-(9aH)-one (1). (35E)-1,2,3,5,6,6-icosahydro-4,4,8b,10,14,17,20,20-
octamethylpicen-3-yl-34,35-dimethyloct-31-enoate (2) represents
the first example of naturally occurring C40 prenylated oleanane-type
triterpenoid, whereas one 4,5-dimethyloct-5-enoate side chain remains
attached at C-3 position of the oleanane framework formed by the E-ring
closure of C30 saccharide moiety. The structures of the compounds were
elucidated using NMR and mass spectrometric analysis. Compound 1 was
found to have significantly greater antioxidant activities (IC50 ~ 0.75 mg/
mL) compared to 2 (IC50 > 0.80 mg/mL). No significant differences in
anti-cyclooxygenase-2 of these compounds were discernable (IC50
0.8 – 0.9 mg/mL), whilst compound 1 showed greater anti-5-lipoxidase
activities (IC50 ~ 0.8 mg/mL) those that of 2 (IC50 0.96 mg/mL). Bioactivities
of the prenylated terpenoids were inversely proportional to lipophilic
and bulk descriptors
Not Available
Not AvailableTwo new biogenic prenylated terpenoids were isolated from the methanol
extract of Rhizophora mucronata. The extended C20 sesquiterpenoid
with prenylated guaiane framework was characterised as (4E, 8Z)-3,
3a, 6, 7-tetrahydro-3, 9-dimethyl-5-(6-methylheptan-2-yl) cycloocta[b]
furan-2-(9aH)-one (1). (35E)-1,2,3,5,6,6-icosahydro-4,4,8b,10,14,17,20,20-
octamethylpicen-3-yl-34,35-dimethyloct-31-enoate (2) represents
the first example of naturally occurring C40 prenylated oleanane-type
triterpenoid, whereas one 4,5-dimethyloct-5-enoate side chain remains
attached at C-3 position of the oleanane framework formed by the E-ring
closure of C30 saccharide moiety. The structures of the compounds were
elucidated using NMR and mass spectrometric analysis. Compound 1 was
found to have significantly greater antioxidant activities (IC50 ~ 0.75 mg/
mL) compared to 2 (IC50 > 0.80 mg/mL). No significant differences in
anti-cyclooxygenase-2 of these compounds were discernable (IC50
0.8 – 0.9 mg/mL), whilst compound 1 showed greater anti-5-lipoxidase
activities (IC50 ~ 0.8 mg/mL) those that of 2 (IC50 0.96 mg/mL). Bioactivities
of the prenylated terpenoids were inversely proportional to lipophilic
and bulk descriptors.Not Availabl
Not Available
Not AvailableSeaweed-associated heterotrophic bacterial communities were screened to isolate potentially useful antimicrobial
strains, which were characterized by phylogenetic analysis. The bacteria were screened for the presence of metabolite genes
involved in natural product biosynthetic pathway, and the structural properties of secondary metabolites were correlated with the
genes. Bioactivity-guided isolation of polyene antibiotic 7-O-methyl-5′-hydroxy-3′-heptenoate−macrolactin from Bacillus subtilis
MTCC10403 associated with seaweed Anthophycus longifolius using mass spectrometry and extensive 2D-NMR studies was
carried out. The newly isolated macrolactin compound is a bactericidal antibiotic with broad spectrum activity against human
opportunistic clinical pathogens. The biosynthetic pathway of 7-O-methyl-5′-hydroxy-3′-heptenoate−macrolactin by means of a
stepwise, decarboxylative condensation pathway established the PKS-assisted biosynthesis of the parent macrolactin and the sidechain
5-hydroxyhept-3-enoate moiety attached to the macrolactin ring system at C-7. Antimicrobial activity analysis combined
with the results of amplifying genes encoding for polyketide synthetase and nonribosomal peptide synthetase showed that
seaweed-associated bacteria had broad-spectrum antimicrobial activity. The present work may have an impact on the exploitation
of macrolactins for pharmaceutical and biotechnological applications.Not Availabl
Previously Undescribed Antibacterial Polyketides from Heterotrophic Bacillus amyloliquefaciens Associated with Seaweed Padina gymnospora
A heterotrophic marine bacterium Bacillus amyloliquefaciens isolated from seaweed Padina gymnospora exhibited broad spectra of antibacterial activities against pathogenic bacteria Aeromonas hydrophila, Vibrio harveyi, Vibrio vulnificus, and Vibrio parahaemolyticus. The seaweed-associated B. amyloliquefaciens was recognized to possess functional type I polyketide synthase-1 (pks-1) gene, and was used to isolate four homologous compounds with polyketide frameworks. The compounds were characterized as 11-(15-butyl-13-ethyl-tetrahydro-12-oxo-2H-pyran-13-yl) propyl-2-methylbenzoate (1), 9-(tetrahydro-12-isopropyl-11-oxofuran-10-yl)-ethyl-4-ethoxy-2-hydroxybenzoate (2), 12-(aminomethyl)-11-hydroxyhexanyl-10-phenylpropanoate (3), and 7-(14-hydroxypropan-13-yl)-8-isobutyl-7,8-dihydrobenzo[c]oxepin-1(3H)-one (4) by comprehensive nuclear magnetic resonance and mass spectroscopic experiments. The compounds 1–4 displayed significant antibacterial activities against clinically important pathogens V. parahaemolyticus and V. vulnificus (inhibitory zone diameter of ≥15 mm, 100 mcg on disk). The electronic and hydrophobic parameters appeared to hold a conspicuous part in directing the antibacterial properties of the compounds. This study revealed seaweed-associated B. amyloliquefaciens as potential source of antimicrobial polyketides for pharmaceutical applications
Polyketide Family of Novel Antibacterial 7‑O‑Methyl-5′-hydroxy-3′- heptenoate−Macrolactin from Seaweed-Associated Bacillus subtilis MTCC 10403
Seaweed-associated heterotrophic bacterial communities were screened to isolate potentially useful antimicrobial
strains, which were characterized by phylogenetic analysis. The bacteria were screened for the presence of metabolite genes
involved in natural product biosynthetic pathway, and the structural properties of secondary metabolites were correlated with the
genes. Bioactivity-guided isolation of polyene antibiotic 7-O-methyl-5′-hydroxy-3′-heptenoate−macrolactin from Bacillus subtilis
MTCC10403 associated with seaweed Anthophycus longifolius using mass spectrometry and extensive 2D-NMR studies was
carried out. The newly isolated macrolactin compound is a bactericidal antibiotic with broad spectrum activity against human
opportunistic clinical pathogens. The biosynthetic pathway of 7-O-methyl-5′-hydroxy-3′-heptenoate−macrolactin by means of a
stepwise, decarboxylative condensation pathway established the PKS-assisted biosynthesis of the parent macrolactin and the sidechain
5-hydroxyhept-3-enoate moiety attached to the macrolactin ring system at C-7. Antimicrobial activity analysis combined
with the results of amplifying genes encoding for polyketide synthetase and nonribosomal peptide synthetase showed that
seaweed-associated bacteria had broad-spectrum antimicrobial activity. The present work may have an impact on the exploitation
of macrolactins for pharmaceutical and biotechnological applications