Triterpenoid saponins from the stem bark of pentaclethra eetveldeana

Two previously undescribed triterpenoid saponins together with 4 known ones were isolated from the stem bark of Pentaclethra eetveldeana De Wild. & Th. Dur. Their structures were elucidated by spectroscopic methods including 1D and 2D NMR experiments in combination with mass spectrometry as 3- O-β- d -glucopyranosyl- (1→2)- [β- d -glucopyranosyl- (1→3)]-β- d -glucopyranosyl- (1→4)- β- d -glucopyranosyl- (1→3)-α- l -rhamnopyranosyl- (1→2)-[β- d-glucopyranosyl- (1→4)]-α- l -arabinopyranosyloleanolic acid and 3- O -β- d -glucopyranosyl- (1→2)-[β- d -glucopyranosyl- (1→3)]-β- d -glucopyranosyl- (1→4)-β- d -glucopyranosyl- (1→3)- α -l -rhamnopyranosyl- (1→2)-[β- d -glucopyranosyl- (1→4)]-α- l -arabinopyranosylhederagenin. © The Author(s) 2019

Triterpenoid saponins from the root bark of haplocoelum congolanum

peer reviewedTwo undescribed triterpenoid saponins together with 5 known ones were isolated from the root bark of Haplocoelum congolanum Hauman. Their structures were elucidated by spectroscopic methods including one-dimensional and two-dimensional nuclear magnetic resonance experiments in combination with mass spectrometry as 3-O-(4-O-[3-hydroxy-3-methylglutaryl])-α-l-arabinopyranosyl-(1→3)-α-l-rhamnopyranosyl-(1→2)-[β-d-glucopyranosyl-(1→4)]-α-l-arabinopyranosyloleanolic acid and 3-O-α-l-arabinofuranosyl-(1→3)-α-l-rhamnopyranosyl-(1→2)-[β-d-glucopyranosyl-(1→4)]-α-l-arabinopyranosyloleanolic acid. © The Author(s) 201

Chemical analysis of carbon stars in the Local Group: I. The Small Magellanic Cloud and the Sagittarius dwarf spheroidal galaxy

We present the first results of our ongoing chemical study of carbon stars in the Local Group of galaxies. We used spectra obtained with UVES at the 8.2 m Kueyen-VLT telescope and a new grid of spherical model atmospheres for cool carbon-rich stars which include polyatomic opacities, to perform a full chemical analysis of one carbon star, BMB-B~30, in the Small Magellanic Cloud (SMC) and two, IGI95-C1 and IGI95-C3, in the Sagittarius Dwarf Spheroidal (Sgr dSph) galaxy. Our main goal is to test the dependence on the stellar metallicity of the s-process nucleosynthesis and mixing mechanism occurring in AGB stars. For these three stars, we find important s-element enhancements with respect to the mean metallicity ([M/H]), namely [s/M]$\approx$+1.0, similar to the figure found in galactic AGB stars of similar metallicity. The abundance ratios derived between elements belonging to the first and second s-process abundance peaks, corresponding to nuclei with a magic number of neutrons N=50 (88Sr, 89Y, 90Zr) and N=82 (138Ba, 139La, 140Ce, 141Pr), agree remarkably well with the theoretical predictions of low mass (M $<3$~M$\_\odot$) metal-poor AGB nucleosynthesis models where the main source of neutrons is the $^{13}$C$(\alpha,n)^{16}$O reaction activated duringthe long interpulse phase, in a small pocket located within the He-rich intershell. The derived C/O and $^{12}$C/$^{13}$C ratios are, however, more difficult to reconcile with theoretical expectations. Possible explanations, like the extrinsic origin of the composition of these carbon stars or the operation of a non-standard mixing process during the AGB phase (such as the {\it cool bottom process}), are discussed on the basis of the collected observational constraints

First case of nasal transitional carcinoma in a goat infected with Enzootic Nasal Tumor Virus in Belgium

An eleven-year-old, female goat was presented for evaluation of breathing difficulties and epistaxis. Radiographs and computed tomographic (CT) examination of the head revealed the presence of a space-occupying lesion involving the right nasal passage and invading the cranial vault and retrobulbar space. Histologic examination and detection of viral genome from the nasal mass led to the diagnosis of nasal transitional carcinoma with concomitant infection with Enzootic Nasal Tumor Virus (ENTV-2). In this case report, the presence of a nasal transitional carcinoma is described in a goat; a very rare tumor which, to the authors' knowledge, has not been previously reported in goats. Reverse transcription polymerase chain reaction (RT-PCR) detected the genome of ENTV-2 within the neoplastic tissue, suggesting an infectious etiology

Triterpene saponins from four species of the polygalaceae family

Twelve triterpene saponins were isolated by successive M PLC over silica gel from four species of Polygalaceae: From Polygala ruwenzoriensis, five new saponins 1-5 of which 1-4 as two pairs of (E)/(Z)-isomers, together with the four known compounds tenuifoline, (E)- and (Z)-senegasaponin b, (E)- and (Z)-senegin II, and polygalasaponin XXVIII, from the genus Carpolobia. one new saponin 6 from C alba and the known arillo-side (11) from C. lutea, and another new triterpene glycoside 7 from Polygala arenaria. Their structures were established mainly by 600-MHz 2D-NMR techniques (H-1,H-1-COSY, TOCSY, NOESY, HSQC, HMBC) as 3-O-(beta-D-glucopyranosyl)presenegenin 28-[O-alpha-L-arabinopyranosyl-(1 -> 4)-O-beta-D-xylopyranosyl-(1 -> 4)-O-alpha-L-rhamnopyranosyl-(1 -> 2)-4-O-[(E)-4-methoxycinnamoyl]-beta-D-fucopyranosyl] ester (1) and its (Z)-isomer 2, 3-O-(beta-D-glucopyranosyl)presenegenin 28-[O-alpha-L-arabinopyranosyl-(1 -> 4)-O-beta-D-xylopyranosyl-(1 -> 4)-O-alpha-L-rhamnopyranosyl-(1 -> 2)-4-O-[(E)-3,4-dimethoxycinnamoyl]-beta-D-fucopyranosyl] ester (3) and its (Z)-isomer 4, 3-O-(beta-D-glucopyranosyl)presenegenin 28-[O-beta-D-galactopyranosyl-(1 -> 4)-O-beta-D-xylopyranosyl-(1 -> 4)-O-alpha-L-rhamnopyranosyl-(1 -> 2)-beta-D-fucopyranosyl] ester (5), 3-O-(beta-D-glucopyranosyl)presenegenin 28-[O-alpha-L-arabinopyranosyl-(1 -> 3)-O-[beta-D-galactopyranosyl-(1 -> 4)]-O-beta-D-xylopyranosyl-(1 -> 4)-O-alpha-L-rhamnopyranosyl-(1 -> 2)-O-[beta-D-apiofuranosyl-(1 -> 3)]-4-O-acetyl-beta-D-fucopyranosyl] ester (6), and 3-O-(beta-D-glucopyranosyl)presenegenin 28-[O-beta-D-galactopyranosyl-(1 -> 4)-O-[beta-D-glucopyranosyl-(1 -> 3)]-O-beta-D-xylo-pyranosyl-(1 -> 4)-O-alpha-L-rhamnopyranosyl-(1 -> 2)-beta-D-fucopyranosyl] ester (7) (presenegenin = (2 beta, 3 beta, 4 alpha)-2,3,27-trihydroxyolean-12-ene-23,28-dioic acid). acid)