Seven Novel Linear Polyketides from Xylaria sp. NCY2

Seven novel polyketides, namely, 1‐(xylarenone A)xylariate A ( 1 ), xylarioic acid B ( 2 ), xylariolide A ( 3 ), xylariolide B ( 4 ), xylariolide C ( 5 ), methyl xylariate C ( 6 ), and xylariolide D ( 7 ), together with the known one taiwapyrone ( 8 ), were isolated from the endophytic fungal strain Xylaria sp. NCY2 of Torreya jackii Chun . Their structures were elucidated by spectroscopic analyses, including 1D‐ and 2D‐NMR experiments, and on the basis of HR‐Q‐TOF mass spectrometry. Antitumor and antibacterial assays of compounds 1 – 8 were carried out, which show moderate activities.     

Rhusemialins A-C, new cyclolignan esters from the roots of Rhus javanica var. roxburghiana

Three new cyclolignan esters and seven known compounds including two cyclolignan isolariciresinol, lynoiresinol, and five aromatic compounds methyl ferulate, vanillin, 4-hydroxy-3,5-dimethoxybenaldehyde, 4-methoxygallic acid, gallic acid were isolated from n-butanol extract of Rhus semialata (Anacardiaceae). The structural elucidations of rhusemialins A (1), B (2), and C (3) were based on FAB-MS, 1D and 2D NMR spectra.     

Die Glykoside der Wurzeln von Xysmalobium dilatatum Weimarck. 2. Mitteilung: Teilstruktur der Dilatoside. Glykoside und Aglykone, 328. Mitteilung

The four dilatosides A, B, C and D (ester glycosides isolated from Xysmalobium dilatatum) differ from each other only in the sugar portion. They all contain the same aglycone: 12-O-acetyl-17-isolineolone (=12-O-acetyl-17-isodeacyl-cynanchogenin) ( 6 ). Its mass spectrum is discussed. In dilatoside A ( 1 ) three molecules of D -oleandrose ( 7 ) are linked to this aglycone, in dilatoside B ( 2 ) one D -canarose ( 8 ) and two oleandrose units, in dilatoside C ( 3 ) two canarose and three oleandrose, and in dilatoside D ( 4 ) probably three canarose and two oleandrose units.     

Two new tremulane sesquiterpenes from a mangrove endophytic fungus,Coriolopsis sp. J5

Two new tremulane sesquiterpenes coriolopsin A (1) and coriolopsin B (2), together with two known ones conocenol C (3) and ceriponol E (4), were isolated from the fermentation extract of endophytic fungus Coriolopsis sp. J5 from Ceriops tagal. The structures and absolute configuration of compounds 1 and 2 were determined based on HR-ESI-MS and spectroscopic data (IR, UV, 1D, 2D NMR and X-ray crystallographic analysis).     

Medicinal flowers. XXI. Structures of perennisaponins A, B, C, D, E, and F, acylated oleanane-type triterpene oligoglycosides, from the flowers of Bellis perennis

Six new acylated oleanane-type triterpene oligoglycosides, perennisaponins A (1), B (2), C (3), D (4), E (5), and F (6), were isolated from the flowers of Bellis perennis (Daisy flower) together with 14 saponins, nine flavonoids, and two glycosides. The structures of 1-6 were elucidated on the basis of chemical and physicochemical evidence.     

A new ent-kaurane diterpenoid from Rabdosia pseudo-irrorata C. Y. Wu

A new ent-kaurane diterpenoid, Pseurata H (1), was isolated from the aerial parts of Rabdosia pseudo-irrorata C. Y. Wu, along with three known compounds, Pseurata B (2), Pseurata C (3) and Pseurata F (4). Their structures were established by extensive spectroscopic techniques (MS, IR, 1D and 2D NMR experiments).     

Beyond two-state conical intersections. Three-state conical intersections in low symmetry molecules: the allyl radical

Using multireference configuration interaction expansions comprised of over 7 million configuration state functions, three-state conical intersections are reported for the closely spaced, spectroscopically observed (tilde)B(2A1), (tilde)C(2B1), and (tilde)D(2B2) states (in C(2v) symmetry) of the allyl radical. These conical intersections of states which were previously assigned as the 3,4,5(2)A states and are here reassigned as the 4,5,6(2)A states, are expected to be accessible using optical probes. This conclusion is obtained from the structure of the minimum energy point on the 4,5,6(2)A three-state conical intersection seam which is similar to the equilibrium structure of the ground (tilde)X(2A2) state and only 1.1 eV above the (tilde)D(2B2) state at its equilibrium geometry. The seam of three-state degeneracies joins two two-state seams of conical intersection, the 4,5(2)A and 5,6(2)A conical intersection seams. The energy of the minimum energy point on the 4,5(2)A two-state seam is only 0.15 eV above that of the (tilde)D(2B2) state at its equilibrium structure. Three-state intersections are also reported for the 3,4,5(2)A states.     

alpha-TEPHOS: a cyclodextrin-derived tetraphosphine for multiple metal binding

The tetraphosphine 6(A),6(B),6(D),6(E)-tetradeoxy-6(A),6(B),6(D),6(E)-tetra(diphenylphosphinyl)-2(A),2(B),2(C),2(D),2(E),2(F),3(A),3(B),3(C),3(D),3(E),3(F),6(C),6(F)-tetradeca-O-methyl-alpha-cyclodextrin (alpha-TEPHOS) has been prepared in high yield by reacting 6(A),6(B),6(D),6(E)-tetra-O-methylsulfonyl-2(A),2(B),2(C),2(D), 2(E),2(F),3(A),3(B),3(C),3(D),3(E),3(F),6(C),6(F)-tetradeca-O-methyl-alpha-cyclodextrin with excess PPh(2)Li. The product was purified in its BH(3)-protected form. alpha-TEPHOS is the first optically active tetraphosphine in which the four phosphine units are tethered to a cavity-shaped scaffold. When reacted with [AuCl(tetrahydrothiophene)], alpha-TEPHOS led to the corresponding tetragold complex [(alpha-TEPHOS)(AuCl)(4)] in which the four gold atoms are all located close to the primary face of the cyclodextrin. Reaction with [PdCl(o-C(6)H(4)CH(2)NMe(2))](2) gave the C(2)-symmetrical complex [(alpha-TEPHOS){PdCl(o-C(6)H(4)CH(2)NMe(2))}(4)]. Treatment of the ligand with two equiv. of [Rh(norbornadiene)(tetrahydrofuran)(2)]BF(4) afforded selectively the bimetallic complex [(alpha-TEPHOS){Rh(norbornadiene)}(2)](BF(4))(2) in which each metal centre is coordinated to two phosphorus atoms belonging to adjacent glucose units.     

Medicinal foodstuffs. XX. Vasorelaxant active constituents from the roots of Angelica furcijuga Kitagawa: structures of hyuganins A, B, C, and D

From the methanolic extract with vasorelaxant activity obtained from Angelica furcijuga Kitagawa, four new khellactone-type coumarins, hyuganins A, B, C, and D, were isolated together with twelve known coumarins, two known acetylenic compounds, and a known lignan. The structures of hyuganins A, B, C, and D were determined on the basis of chemical and physicochemical evidence. Nine principal coumarins (hyuganin A, anomalin, pteryxin, isopteryxin, isoepoxypteryxin, praerosides II and IV, apiosylskimmin, (R)-peucedanol 7-O-beta-D-glucopyranoside), two acetylenic compounds [(-)-falcarinol and falcarindioll, and related compounds were examined for inhibitory activities on high concentration of K+ (High K+)- and dl-norepinephrine (NE)-induced contractions. The results indicate that the 3'- and 4'-acyl groups of khellactone-type coumarins are essential for the inhibitory activity on the contractions by High K+. Hyuganin A and anomalin showed inhibitory effects on High K+-induced contraction, but not on NE-induced contraction. Other active coumarins (pteryxin, isopteryxin, isoepoxypteryxin) and an acetylenic compound (falcarindiol) non-selectively inhibited both contractions by High K+ and NE.     

New naphthopyrones from aspergillus fonsecaeus

Four new dimeric naphthopyrones, fonsecinones A (7), B (8), C (9), and D (10), and two known ones, aurosperones A (6) and B (11), were isolated from Aspergillus fonsecaeus (N.R.R.L. 67, 0 16-1).     

Temperature dependence of the crystal lattice organization of coordination compounds involving nitronyl nitroxide radicals: a magnetic and structural investigation

Four new mononuclear complexes of formula Cd(PN)(4)(NCS)(2) (A), Cd(PNN)(4)(N(3))(2) (B), Zn(PNN)(4)(N(3))(2) (C), and Zn(PNN)(2)(NCS)(2) (D), where PNN stands for 2-(4-pyridyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide and PN for 2-(4-pyridyl)-4,4,5,5-tetramethylimidazoline-1-oxyl, were synthesized and structurally and magnetically characterized. The X-ray structures of compounds B and C were also determined at 90 K. Compounds A[bond]C crystallize in the triclinic space group P 1 macro (No. 2), and D crystallizes in the monoclinic space group P2(1)/m (No. 11). A[bond]C adopt a centrosymmetric distorted octahedral geometry in which the metal ions are bonded to four radical ligands through the nitrogen atom of the pyridyl rings and the azido or thiocyanato ligands occupy the apical positions. Compound D adopts a distorted tetrahedral geometry in which the zinc ion is bonded to two radicals and two thiocyanato ligands. As suggested by their magnetic behavior, the low-temperature X-ray structures of B and C show that these compounds undergo a clear structural change with respect to the room-temperature structures. The experimental magnetic behaviors were perfectly reproduced by a dimer model for A[bond]C and an alternating chain model for D while the sudden breaks observed in the chi(M)T versus T curves for B and C were well accounted for by the high- and low-temperature X-ray structures. For all these complexes the crystal structures favor significant overlap between molecular magnetic orbitals leading to rather strong intermolecular antiferromagnetic interactions.     

Five unique compounds: xyloketals from mangrove fungus Xylaria sp. from the South China Sea coast

Five unique metabolites, xyloketals A (1), B (2), C (3), D (4), and E (5), and the known 6 were isolated from mangrove fungus Xylaria sp. (no. 2508), obtained from the South China Sea. The structures of these compounds were elucidated by spectroscopic and X-ray diffraction experiments. Xyloketal A is a ketal compound with a C(3) symmetry and xyloketals B-E are its analogues. It was found that xytoketal C slowly rearranged to xytoketal B in DMSO-d(6)() solution at room temperature. Xyloketal A exhibited the activity of inhibiting acetylcholine esterase.     

Structures of novel epipolythiodioxopiperazines, emethallicins B, C, and D, potent inhibitors of histamine release, from Emericella heterothallica

Novel compounds designated emethallicins B (1), C (2), and D (3), along with emethallicin A (4), were isolated from the mycelium of the heterothallic fungus, Emericella heterothallica (mating type a). The structures of emethallicins B (1), C (2), and D (3) were determined on the basis of spectroscopic and chemical investigations. Emethallicins B (1) and C (2) are epitetrathiodioxopiperazines, which have the same basic carbon skeleton as apoaranotin (19) and acetylaranotin (17), respectively, whereas emethallicin D (3) is an epitrithiodioxopiperazine derivative, which has the same carbon skeleton as apoaranotin (19). It is very interesting that a large amount of the disulfide, emethallicin A (4), was isolated from the strain of mating type A and that the corresponding tetrasulfide, emethallicin B (1), and trisulfide, emethallicin D (3), were isolated from the other mating type strain, along with a small amount of the disulfide (4). Emethallicins B (1), C (2), and D (3) have potent inhibitory activity against compound 48/80-induced histamine release from mast cells, like emethallicin A (4).     

Araguspongines B, C, D, E, F, G, H, and J, new vasodilative bis-1-oxaquinolizidine alkaloids from an okinawan marine sponge, Xestospongia sp

Nine new vasodilative alkaloids, araguspongines A, B (1), C (2), D (3), E (4), F (5), G (6), H (7), and J (8), were isolated from an Okinawan marine sponge, Xestospongia sp. On the basis of chemical and physicochemical evidence, the absolute stereostructures of araguspongines B, D, E, F, G, H, and J were determined respectively as 1, 3, 4, 5, 6, 7, 8, and the relative stereostructure of araguspongine C was determined as 2 having two 1-oxaquinolizidine moieties. Araguspongines B, D, and E each comprised a pair of the enantiomers, 1a and 1b, 3a and 3b, and 4a and 4b, respectively.     

New C18-diterpenoid alkaloids from Delphinium anthriscifolium var. savatieri

Five new C18-diterpenoid alkaloids, anthriscifolcines A (1), B (2), C (3), D (4), and E (5), together with a known C19-diterpenoid alkaloid delcorine (6), were isolated from the whole herb of Delphinium anthriscifolium var. savatieri. The structures of these new alkaloids were established on the basis of spectral data (1D- and 2D-NMR, HR-ESI-MS).     

14‐Membered Cyclopeptides from Paliurus ramosissimus and P. hemsleyanus

Six 14‐membered cyclopeptide alkaloids, i.e., ramosines A–C, mucronine J, and lotusines A and D, were isolated from the roots of Paliurus ramosissimus, and an additional four, hemsines A–D, from the roots of P. hemsleyanus. Among these, ramosines A–C ( 1, 5 , and 6 , resp.) and hemsines A and B ( 7 and 8 , resp.) are new bases of the amphibine‐B type, and hemsines C and D ( 9 and 10 , resp.) are new integerrine‐type alkaloids. Additionally, ramosine C ( 6 ) represents the first 14‐membered cyclopeptide alkaloid possessing a substitution (? OH) at C(13′). Their structural elucidations were based on spectral analysis and molecular‐modeling studies. Pronounced solvent effects in the ¹H‐ and ¹³C‐NMR spectra of these two types of alkaloids were observed.     

From supramolecular porphyrin tweezers to dynamic A(n)B(m)C(l)D(k) multiporphyrin arrangements through orthogonal coordination

A dynamic, supramolecular, three-component A(n)B(m)C(l) bis(zinc porphyrin) tweezer has been prepared quantitatively using the heteroleptic bisphenanthroline (HETPHEN) concept. Upon addition of nitrogenous spacers of different length, namely, the extended bipyridine 3 a, 4,4'-bipyridine (3 b), and 1,4-diazabicyclo[2.2.2]octane (DABCO; 3 c), to set up an additional orthogonal binding motif (Zn(Por)-N(spacer)), three structurally different, still dynamic, four-component A(n)B(m)C(l)D(k) assemblies were cleanly formed, as indicated by UV/Vis and NMR titrations as well as by DOSY investigations. The structures were identified as a bridged monotweezer A(2)BC(2)D, a doubly bridged double tweezer A(4)B(2)C(4)D(2), and a triply bridged double tweezer A(4)B(2)C(4)D(3), the latter resembling a porphyrin stack. Notably, the same structures were equally formed directly from a mixture of the constituents A, B, C, and D put together in any sequence if the correct stoichiometry was applied.     

Self-Inclusion Complexes Derived from Cyclodextrins: Synthesis and Characterization of 6(A),6(B)-Bis-O-[p-(allyloxy)phenyl]-Substituted beta-Cyclodextrins

The syntheses, structures, and spectroscopic properties of 6(A),6(B)-bis-O-[p-(allyloxy)phenyl]-substituted beta-cyclodextrins have been investigated. Selective activation of the 6(A),6(B)-hydroxy groups was carried out by treating heptakis(2,3-di-O-methyl)-beta-cyclodextrin (1) with 2,4-dimethoxybenzene-1,5-disulfonyl chloride to give 6(A),6(B)-bissulfonate ester 2 in a yield of only 3%. This material was treated with sodium p-(allyloxy)phenoxide in DMF to form 6(A),6(B)-bis-O-[p-(allyloxy)phenyl]-heptakis(2,3-di-O-methyl)-beta-cyclodextrin (3), which had two isomers. One (3A) has the two p-(allyloxy)phenyl arms directed away from the cyclodextrin cavity, and the other (3B) has one of the p-(allyloxy)phenyl groups through the cavity to form a self-inclusion complex. When either 3A or 3B was treated with methyl iodide and sodium hydride, the resulting permethylated 6(A),6(B)-bis-O-[p-(allyloxy)phenyl]heptakis(2,3-di-O-methyl)-6(C),6(D),6(E),6(F),6(G)-penta-O-methyl-beta-cyclodextrin (4) was composed of two isomers, in which 4B is a self-inclusion complex. 3A and 3B also can be converted into a mixture of 3A and 3B in strong base but not when melted in the absence of base. 4A and 4B do not isomerize. Detailed 1D and 2D NMR spectroscopic studies were carried out to characterize the structures of these new compounds, and molecular mechanics techniques were used to explain the experimental facts.     

Enantiomeric Sesquiterpene Lactones from Senecio tsoongianus

From Senecio tsoongianus,two pairs of enantiomeric isomers,tsoongianolides A(1) and B(2),tsoongianolides C (3) and D(4) were isolated. Their structures were elucidated by 1D and 2D-NMR techniques and X-ray diffractions. The cytotoxicity to KB cell of 1 and 2 is also reported.     

Total Synthesis of Siomycin A: Completion of the Total Synthesis

The total synthesis of siomycin A ( 1 ), a representative compound of the thiostrepton family of peptide antibiotics, was achieved by incorporating the five synthetic segments A ( 2 ), B ( 3 ), C ( 4 ), D ( 5 ), and E ( 6 ). The dehydropiperidine segment A ( 2 ) was esterified with the dihydroquinoline segment C ( 4 ), and the subsequent coupling with the β‐phenylselenoalanine dipeptide segment D ( 5 ) at the segment C portion followed by lactamization between the segments A and D gave segment A‐C‐D ( 27 ). This was amidated with the pentapeptide segment B ( 3 ) at the segment A portion followed by one‐pot cyclization (between segments A and B) and elongation (with the β‐phenylselenoalanine dipeptide segment E ( 6 ) at the segment A portion), thus furnishing siomycin A ( 1 ).