Weakly anti-inflammatory limonoids from the seeds of Xylocarpus rumphii.

Seven new limonoids, namely, xylorumphiins E-J (1-2 and 4-7) and 2-hydroxyxylorumphiin F (3), along with three known derivatives (8-10), were isolated from the seeds of Xylocarpus rumphii. 2-Hydroxyxylorumphiin F (3) and xylorumphiin I (6) displayed moderate inhibitory activity against nitric oxide production from lipopolysaccharide-activated macrophages with IC50 values of 24.5 and 31.

Rearranged limonoids and chromones from Harrisonia perforata and their anti-inflammatory activity.

Two new rearranged limonoids, harperforatin (1) and harperfolide (2), and a new chromone, harperamone (3), were isolated from fruits and roots of Harrisonia perforata, together with eight known compounds. Their structures were elucidated on the basis of spectroscopic data. Harperfolide (2) exhibited potent anti-inflammatory activity by suppressing nitric oxide (NO) production from activated macrophages with IC50 value of 6.

Antiangiogenetic effects of anthranoids from Alternaria sp., an endophytic fungus in a Thai medicinal plant Erythrina variegata.

Endophytic fungi are known as a prolific source for the discovery of structurally interesting and biologically active secondary metabolites, some of which are promising candidates for drug development. In the present study, three anthranoids were isolated from an Alternaria sp. endophytic fungus and evaluated for their antiangiogenic activity in a rat aortic sprouting assay, an ex vivo model of angiogenesis.

Andirobin from X. moluccensis.

methyl 2-{(1R,2R)-2-[(1aS,4S,4aS,8aS)-4-(furan-3-yl)-4a-methyl-8-methyl-ene-2-oxoocta-hydro-oxireno[2,3-d]isochromen-7-yl]-2,6,6-trimethyl-5-oxocyclo-hex-3-en-1-yl}acetate), C(27)H(32)O(7), was isolated from X. moluccensis seeds from Thailand. The conformations of the six-membered rings are distorted half-chair, chair and half-chair for the isolated cyclo-hexane, fused cyclo-hexane and lactone rings, respectively.

Antiangiogenic effect of chamigrane endoperoxides from a Thai mangrove-derived fungus.

As part of our ongoing efforts to investigate natural products with potential for use as cancer treatments, we have recently disclosed the cytotoxicity of unique nor-chamigrane (1) and chamigrane (2, 3) endoperoxides from a Thai mangrove-derived fungus. Reinvestigation of this fungus in a large-scale fermentation led to the isolation of an additional new chamigrane endoperoxide (4) and one known analogue (5). Among these isolated metabolites, compound 3 (merulin C) exhibited potent antiangiogenic activity mainly by suppression of endothelial cell proliferation and migration in a dose-dependent manner, and its effect is mediated by reduction in the phosphorylation of Erk1/2.

Limonoids from seeds of Thai Xylocarpus moluccensis.

A new andirobin, thaimoluccensin A (1), and two new phragmalin-type limonoids, thaimoluccensins B (2) and C (3), were isolated from seeds of a Thai mangrove plant, Xylocarpus moluccensis, together with eight known compounds. The structures of these compounds were elucidated on the basis of spectroscopic data. Only 7-deacetylgedunin (7), a gedunin-type limonoid, exhibited significant inhibitory activity against nitric oxide production from activated macrophages with IC(50) value less than 10 μM, suggesting that the compound has anti-inflammatory activity.

Butenolide and furandione from an endophytic Aspergillus terreus.

A new butenolide, aspernolide D (1), and furandione, asperterone (2), together with four known butenolides, butyrolactones I-IV and aspernolide B, were obtained from cultures of the endophytic fungus Aspergillus terreus, isolated from the flowering plant Mammea siamensis. The structures of these compounds were elucidated by analysis of NMR spectroscopic and mass spectrometric data.

Cytotoxic nor-chamigrane and chamigrane endoperoxides from a basidiomycetous fungus.

A new nor-chamigrane endoperoxide, merulin A (1), and two new chamigrane endoperoxides, merulins B and C (2, 3), were isolated from the culture broth extract of an endophytic fungus of Xylocarpus granatum. Their structures were elucidated on the basis of spectroscopic, mainly NMR and MS, data. X-ray crystallographic analysis confirmed the structure of 1.

Moluccensins H-J, 30-ketophragmalin limonoids from Xylocarpus moluccensis.

Three new phragmalin limonoids, moluccensins H-J (1-3), were isolated from seed kernels of the cedar mangrove, Xylocarpus moluccensis. Their structures were established by extensive spectroscopic analysis. Compound 2 displayed weak antibacterial activity against Staphylococcus hominis and Enterococcus faecalis.

Protoxylocarpins F-H, protolimonoids from seed kernels of Xylocarpus granatum.

Three new protolimonoids, protoxylocarpins F-H (1-3), along with 11 known limonoids, were isolated from seed kernels of Xylocarpus granatum. Their structures were elucidated on the basis of extensive spectroscopic data analyses. All compounds isolated were evaluated for cytotoxic activity against five human tumor cell lines.

11-Hydroxymonocerin from the plant endophytic fungus Exserohilum rostratum.

A new analogue of monocerin, 11-hydroxymonocerin (2), along with monocerin (1) and 12-hydroxymonocerin (3) were isolated from cultures of Exserohilum rostratum, a fungal strain endophytic in Stemona sp. The structure of 2 was determined by analysis of NMR and MS data and by comparison of spectroscopic data to those of 1. Monocerin (1) and 11-hydroxymonocerin (2) displayed activity against Plasmodium falciparum (K1, multidrug-resistant strain) with IC50 values of 0.

Cassane furanoditerpenoids from the seed kernels of Caesalpinia bonduc from Thailand.

Three new cassane furanoditerpenoids ( 1- 3), together with 13 known cassane diterpenes ( 4- 16), were isolated from the EtOAc extract of the seed kernels of Caesalpinia bonduc. Their structures were elucidated on the basis of spectroscopic analysis, mainly NMR and MS. Compounds 1- 3 exhibited good antimalarial activity against the multidrug-resistant K1 strain of Plasmodium falciparum, while compound 4 was inactive.

Furanocembranoids from the stem bark of Croton oblongifolius.

Four novel furanocembranoids (1-4) were isolated from the stem bark of Croton oblongifolius. Their structures were elucidated on the basis of spectroscopic analysis, mainly NMR and MS. Compounds 1, 3, and 4 exhibited good cytotoxicity against several human tumor cell lines.

Cytotoxic activity of natural labdanes and their semi-synthetic modified derivatives from Croton oblongifolius.

Labda-7,12( E),14-triene-17-oic acid, previously isolated from Croton oblongifolius, and its derivatives were investigated for cytotoxicity against five human tumor cell lines. Six of these compounds, labda-7,12( E),14-triene-17-al, 17-hydroxylabda-7,12( E),14-triene, 17-acetoxylabda-7,12( E),14-triene, 15-hydroxylabda-7,13( E)-diene-17,12-olide, labda-7,13( E)-diene-17,12-olide, and 12,17-dihydroxylabda-7,13( E)-diene showed non-specific, moderate, cytotoxicity against all cell lines, whereas the other compounds were inactive.