Cynanchoside,a highly oxygenated iridoid glucoside from Macfadyena cynanchoides

The elucidation of the structure and stereochemistry of cynanchoside, a new highly oxygenated iridoid glucoside isolated from Macfadyena cynanchoides (Bignoniaceae), has been accomplished using mainly ¹H and ¹³C NMR spectral data and further confirmed by simple chemical transformations.     

Structure and configuration of unedide,an iridoid glucoside from Arbutus unedo

Unedide, a novel iridoid glucoside isolated from Arbutus unedo (Ericaceae), has been established to be 6,7-dihydro-6β-hydroxymonotropein by detailed analysis of ¹H and ¹³ C NMR spectral data.     

6β-Hydroxyipolamiide,an iridoid glucoside from Stachytarpheta mutabilis

A new iridoid glucoside has been isolated from Stachytarpheta mutabilis and assigned the structure and configuration of 6β-hydroxyipolamiide on the basis of ¹H NMR and ¹³C NMR evidence. The conversion of this compound into penta- acetyllamiol proved the above assignment.     

5-deoxystansioside,an iridoid glucoside from Tecoma stans

In addition to plantarenaloside and stansioside, a new iridoid glucoside with a formyl group at C-4 has been isolated from Tecoma stans. The new glucoside was shown to be 5-deoxystansioside by ¹³C NMR and ¹H NMR spectroscopy.     

New indanone compounds from Onychium japonicum

A new indanone glucoside pteroside M has been isolated from fronds of Onychium japonicumPteridaceae. The structure of its aglycone pterosin M has been established by ¹³C NMR, PMR spectra and degradation with nitric acid.     

Iridoid glucosides in Griselinia, Aralidium and Toricellia

From three of five investigated species of Griselinia a new iridoid glucoside, griselinoside, was isolated. It was found to be present also in foliage of Aralidium pinnatifidum and Toricellia angulata, accompanied in the former by aralidioside another novel iridoid glucoside. The structures and absolute configurations of the two iridoids were elucidated by NMR spectroscopy and chemical conversions. From G. littoralis and T. angulata the glucosides magnolioside and syringoside respectively were isolated. ¹³C NMR spectra are given for thirteen iridoid derivatives.     

Triterpenoid acids from Sapium sebiferum

Sebiferenic acid, isolated from the bark of Sapium sebiferum, has been characterized as 2α,3β-dihydroxytaraxer-14-en-28-oic acid on the basis of ¹H NMR, ¹³C NMR and mass spectral evidence and chemical transformations. The structure of sebiferic acid has been revised.     

5,7-Bisdeoxycynanchoside,an iridoid glucoside from Macfadyena cynanchoides

A new iridoid glucoside from Macfadyena cynanchoides leaves has been identified by spectral (¹H and ¹³C NMR) and chemical procedures as 5,7     

Structure of a cyanoglucoside of Lithospermum purpureo-caeruleum

A new glucoside has been isolated from roots of Lithospermum officinale and L. caeruleum. It is not cyanogenetic although containing nitrile group in the aglycone moiety. Its structure has been elucidated by ¹H and ¹³C NMR spectroscopy as 6-O-β-d-glucopyranosyl-1-cyanomethylene-4, 5-dihydroxy-2-cyclohexene.     

New siphulin derivatives from the lichen Siphula ceratites

From the lichen, Siphula ceratites, two new metabolities, protosiphulin and oxysiphulin, were isolated besides the known compound, siphulin. The structures of the two new chromenones were proved by ¹H NMR and ¹³C NMR spectral analysis in comparison with those of siphulin.     

Ferulenol and ω-hydroxyferulenol,toxic coumarins from Ferula communis var. genuina

From the root sap of Ferula communis, two isoprenylated 4-hydroxycoumarins, the known ferulenol and the new ω-hydroxyferulenol, were isolated, which both show haemorrhagic action. Their structures were established from MS, IR, ¹H and ¹³C NMR spectral analysis.     

13C NMR and IR analyses of structure,aging and botanical origin of Dominican and Mexican ambers

¹³C NMR analysis of Oligocene amber from the Dominican Republic, Oligo-Miocene amber from Mexico and trunk resins from certain extant species of Hymenaea, suggests a polylabdane structure for all and gives insights into structural changes during aging. Additionally, IR spectra, some aspects of the ¹³C NMR spectra and paleobotanical data suggest a close relationship between Dominican amber and H. verrucosa. By contrast, spectral evidence shows that Mexican amber differs, not only from the former polymers, but from the H. courbaril polymer.     

Canthinones from Simaba cuspidata

Two new alkaloids, 8-methoxycanthin-6-one and 3-methoxycanthin-2,6-dione, were isolated from the EtOH extract of the bark of Simaba cuspidata Spruce ex Engl. Elucidation of the structure of the latter compound included ¹³C NMR spectral comparison with 2-methoxypyridine-N-oxide and N-methoxy-2-pyridone.     

Betulin isolated from Pyrola incarnata Fisch. inhibited lipopolysaccharide (LPS)-induced neuroinflammation with the guidance of computer-aided drug design

This study aims to investigate active phytochemicals isolated from Pyrola incarnata Fisch. (P. incarnata) and their protection against neuroinflammation induced by LPS. Betulin, accompanied with other 9 compounds, were isolated from P. incarnata and elucidated by spectroscopic analysis (¹H-, ¹³C NMR). ELISA kits and the measurement of NO production based on Griess reaction showed that betulin (5) (250 μg/mL) could suppress LPS-induced activation of microglial cell BV-2 better than others by inhibiting inflammatory cytokines (TNF-α, IL-6, IL-1β) expression and NO production. With the guidance of computer-aided drug design and the analysis of biological experiment, we demonstrated betulin could reduce LPS-induced iNOS expression, prevent JNKs pathways, and down-regulate the phosphorylation levels of NF-κB/p65. In conclusion, betulin isolated from P. incarnata possessed outstanding anti-neuroinflammation potential, presumably related to iNOS expression, JNKs and NF-κB/p65 pathways. Therefore, Pyrola incarnata may be a valuable natural resource and betulin is a potential drug for the treatment of neurodegenerative disorders by inhibiting inflammatory mediators.     

Argophyllone-B,a sesquiterpene lactone from Helianthus argophyllus

The sesquiterpene lactone, 2-methyl-2-butenoic acid dodecahydro-4-(hydroxymethyl)-10a-methyl-8-methylene-3,7-dioxooxineno[5,6]cyclodeca[1,2-b]furan-9-yl ester [1aR^*-[1aS^*,4R^*,5aS^*,8aR^*,9R^*(E)]], argophyllone-B, was isolated from acetone extracts from the leaves of Helianthus argophyllus. Its structure has been determined by single crystal X-ray analysis. Complete ¹H NMR and ¹³C NMR assignments have been made.     

Chemical constituents from the fruits of Melia azedarach (Meliaceae)

A new apotirucallane-type triterpenoid, 3α-benzoate triterpenoid A (1), along with six known triterpenoids (2–7), one aromatic ester (8) and eight lignans (9–16), were isolated from the fruits of Melia azedarach Linn. The structure of 1 was determined by spectral analyses, including HR-ESI-MS, 1D NMR (¹H NMR and ¹³C NMR) and 2D NMR (HSQC and HMBC) analyses. 10, 11 and 16 were reported for the first time from the family Meliaceae, 8 was identified from the genus Melia for the first time, and 2, 3, 5, 7, 9 and 12–15 were obtained from M. azedarach for the first time. The chemotaxonomic significance of these compounds is discussed.     

Isolimonic acid,a new citrus limonoid

Isolimonic acid was isolated as its methyl ester from seeds of Citrus aurantium, C. reticulata and C. paradisi, and its structure was determined by ¹H and ¹³C NMR. The isomeric limonoid ichangin was also isolated from C. aurantium and C. paradisi.     

Ent-labdane derivatives from gutierrezia grandis

Two new diterpenes, 3α-angeloyloxy-18-hydroxy-13-furyl-ent-labda-8(17)-ene and 3α-hydroxy-18-angeloyloxy- 13-furyl-ent-labda-8(17)-ene and an only recently reported third diterpene, 3α, 18-dihydroxy-13-furyl-ent-labda-8(17)-ene, were isolated from the leaves of Gutierrezia grandis. Their structures were determined by mass spectral, IR, ¹H NMR and ¹³C NMR data was well as chemical evidence.     

Microtropiosides A–F: ent-Labdane diterpenoid glucosides from the leaves of Microtropis japonica (Celastraceae)

From a 1-BuOH-soluble fraction of a MeOH extract of the leaves of Microtropis japonica, collected in the Okinawa islands, six ent-labdane glucosides, named microtropiosides A–F, were isolated together with one known acyclic sesquiterpene glucoside. Their structures were elucidated by a combination of spectroscopic analyses, and their absolute configurations determined by application of the β-d-glucopyranosylation-induced shift-trend rule in ¹³C NMR spectroscopy and the modified Mosher’s method.     

Peptide alkaloids of Scutia buxifolia

From the bark extract of S. buxifolia, the known alkaloids scutianines B, C, D and E, and the new one, scutianine H, have been isolated. The structure of scutianine H, based mainly on its MS fragmentation and on the MIKES (mass-analysed ion kinetic energy spectrum) of the base ion peak, is suggested. From the ¹³C NMR spectral analysis of the diastereoisomeric scutianines D and E, information for the assignment of the stereochemistry of the β-hydroxyleucine unit in related alkaloids was also obtained.