Xyloccensin E

The title compound (also known as phragmalin triacetate), C35H42O14, is a phragmalin-type limonoid extracted from X. rumphii. The mol­ecule consists of eight rings with the orthoacetate group bridged at positions 1, 8 and 9. The two five-carbocyclic rings (A 1 and A 2) and the dioxolane ring (G) adopt a distorted envelope conformation. The 1,3-dioxane ring (E) exists in a chair conformation. The six-carbocyclic rings (B and C) exhibit a twisted-boat conformation. The lactone ring has a half-chair conformation and the furan ring is planar (r.m.s. deviation = 0.002 Å). Rings A 1/B, A 2/B, B/C, C/D and C/G are all cis-fused. The two acet­oxy groups attached to ring B and the furan ring attached to the lactone ring are in equatorial positions. The porous crystal packing exhibits voids of 688 Å3 and weak inter­molecular C—H⋯O inter­actions. The absolute configuration was assigned on the basis of literature data

7-Deacetyl­gedunin

The title compound [systematic name: (1S,3aS,4aR,4bS,5R,6aR,10aR,10bR,12aS)-1-(furan-3-yl)-5-hy­droxy-4b,7,7,10a,12a-penta­methyl-4b,5,6,6a,7,10a,10b,11,12,12a-deca­hydro­naphtho­[2,1-f]oxireno[2,3-d]isochromene-3,8(1H,3aH)-dione], C26H32O6, which is a limonoid-type triterpene isolated from the seeds of X. moluccensis, crystallizes with three independent mol­ecules with very similar geometries in the asymmetric unit. In each mol­ecule, the four fused six-membered rings of the genudin core adopt distorted half-chair, chair, twist-boat and twisted half-chair conformations. In the crystal, inter­molecular O—H⋯O hydrogen bonds link the mol­ecules into helical chains propagated in [100]. Weak non-classical C—H⋯O contacts further consolidate the crystal packing

Spirobisnaphthalenes from the Mangrove-Derived Fungus Rhytidhysteron sp. AS21B

Three new spirobisnaphthalenes (1–3) were isolated from the mangrove-derived fungus Rhytidhysteron sp., together with five known derivatives (4–8). The structures of the compounds were established on the basis of extensive spectroscopic data, and the relative configurations of their stereogenic carbons were determined by a single-crystal X-ray crystallographic analysis. Compounds 3–5 displayed cytotoxicity against both cancer cell lines, MCF-7 and CaSki, while 2 was active only on CaSKi cells

Rhytidenones A–F, Spirobisnaphthalenes from <i>Rhytidhysteron</i> sp. AS21B, an Endophytic Fungus

Rhytidenone A (<b>1</b>), a unique spirobisnaphthalene with a 1,7-dioxaspiro­[4,4]­nonan-2-one motif, and five new spirobisnaphthalenes, rhytidenones B–F (<b>2</b>–<b>6</b>), were isolated from the extract of a cultured fungal endophyte, <i>Rhytidhysteron</i> sp. AS21B. Their structures were elucidated mainly by analysis of NMR spectroscopic data. The structure and configuration of <b>1</b> were further confirmed by single-crystal X-ray diffraction analysis. Compounds <b>3</b> and <b>4</b> exhibited significant inhibitory activity against nitric oxide production from activated macrophages with IC₅₀ values of 0.31 and 3.60 μM, respectively

Rhytidenones A–F, Spirobisnaphthalenes from <i>Rhytidhysteron</i> sp. AS21B, an Endophytic Fungus

Rhytidenone A (<b>1</b>), a unique spirobisnaphthalene with a 1,7-dioxaspiro­[4,4]­nonan-2-one motif, and five new spirobisnaphthalenes, rhytidenones B–F (<b>2</b>–<b>6</b>), were isolated from the extract of a cultured fungal endophyte, <i>Rhytidhysteron</i> sp. AS21B. Their structures were elucidated mainly by analysis of NMR spectroscopic data. The structure and configuration of <b>1</b> were further confirmed by single-crystal X-ray diffraction analysis. Compounds <b>3</b> and <b>4</b> exhibited significant inhibitory activity against nitric oxide production from activated macrophages with IC₅₀ values of 0.31 and 3.60 μM, respectively

Chamigrane Sesquiterpenes from a Basidiomycetous Endophytic Fungus XG8D Associated with Thai Mangrove Xylocarpus granatum

Six new chamigrane sesquiterpenes, merulinols A‒F (1‒6), and four known metabolites (7‒10) were isolated from the culture of the basidiomycetous fungus XG8D, a mangrove-derived endophyte. Their structures were elucidated mainly by 1D and 2D NMR, while the structures of 1 and 2 were further confirmed by single-crystal X-ray diffraction analysis. The in vitro cytotoxicity of all compounds was evaluated against three human cancer cell lines, MCF-7, Hep-G2, and KATO-3. Compounds 3 and 4 selectively displayed cytotoxicity against KATO-3 cells with IC50 values of 35.0 and 25.3 μM, respectively

Identification of spirobisnaphthalene derivatives with anti-tumor activities from the endophytic fungus Rhytidhysteron rufulum AS21B

The cultivation of the mangrove-derived fungus Rhytidhysteron rufulum AS21B in acidic condition changed its secondary metabolite profile. Investigation of the culture broth extract led to the isolation and identification of two new spirobisnaphthalenes (1 and 2) together with eleven known compounds (313) from the crude extract of the fungus grown under an acidic condition as well as six known compounds (4, 10, 14-17) were isolated from the crude extract of the fungus grown under a neutral condition. Their structures were elucidated on the basis of extensive spectroscopic data. The isolated compounds were evaluated for their cytotoxicity against two human cancer cell lines, Ramos lymphoma and drug resistant NSCLC H1975. Compounds 2 and 10 displayed the most promising anti-tumor activity against both cancer cell lines. (C) 2017 Elsevier Ltd. All rights reserved

Andirobin from X. moluccensis

The title compound (systematic name: methyl 2-{(1R,2R)-2-[(1aS,4S,4aS,8aS)-4-(furan-3-yl)-4a-methyl-8-methylene-2-oxooctahydrooxireno[2,3-d]isochromen-7-yl]-2,6,6-trimethyl-5-oxocyclohex-3-en-1-yl}acetate), C27H32O7, 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 cyclohexane, fused cyclohexane and lactone rings, respectively. In addition, the lactone ring bears in an equatorial orientation an essentially planar furan ring (r.m.s. deviation = 0.004&amp;#8197;&amp;#197;), which forms an angle of 63.87&amp;#8197;(13)&amp;#176; with the mean plane defined by the ten atoms of the two fused six-membered rings (r.m.s. deviation = 0.213&amp;#8197;&amp;#197;). The absolute configuration was fixed on the basis of literature data

Weakly Anti-inflammatory Limonoids from the Seeds of <i>Xylocarpus rumphii</i>

Seven new limonoids, namely, xylorumphiins E–J (<b>1</b>−<b>2</b> and <b>4</b>−<b>7</b>) and 2-hydroxyxylorumphiin F (<b>3</b>), along with three known derivatives (<b>8</b>–<b>10</b>), were isolated from the seeds of <i>Xylocarpus rumphii</i>. 2-Hydroxyxylorumphiin F (<b>3</b>) and xylorumphiin I (<b>6</b>) displayed moderate inhibitory activity against nitric oxide production from lipopolysaccharide-activated macrophages with IC₅₀ values of 24.5 and 31.3 μM, respectively