The structure of a triterpenoid ketol from Cetraria nivalis

A triterpenoid ketol isolated from a Norwegian species of Cetraria nivalis is identified as 22α-hydroxy-stictan-3-one, a triterpenoid present in some Pseudocyphellaria lichens.     

Bacogenin-A3: A new sapogenin from Bacopa monniera

The structure of bacogenin A₃, one of the sapogenins of the bacosides has been established by various chemical and spectral methods.     

Pseudocyphellarins A and B two fully substituted depsides from the lichen Pseudocyphellaria endochrysea

The structures of two fully substituted depsides, pseudocyphellarins A and B, have been elucidated by spectroscopic and chemical methods from the lichen Pseudocyphellaria endochrysea.     

甘草属植物化学成分研究概况

甘草是一种传统中草药。本文概述了10种甘草属植物的化学成分,主要对其中黄酮类和三萜类化合物进行了归纳总结。     

Triterpenoids from Mangifera indica

From the neutral fraction of the n-hexane extract of stem bark of Mangifera indica, (var./cv Banganpalli) six new tetracyclic triterpenoids, cycloart-24-ene-3β,26-diol, the C-24 epimers of cycloart-25-ene-3β,24,27-triol, the C-24 epimers of cycloartane-3β,24,25-triol and 3-ketodammar-24E-ene-20S,26-diol together with the known compounds cycloartenol, α-amyrin, β-amyrin, sitosterol 3β-hydroxycycloart-25-en-26-al, dammarenediol II, the C-24 epimers of cycloart-25-ene-3β,24-diol, 24-methylenecycloartane-3β,26-diol, ψ-taraxastane-3β,20-diol and ocotillol II have been isolated. The acidic fraction of the same extract, on esterification with diazomethane followed by chromatography, yielded methyl mangiferonate, methyl isomangiferolate, methyl mangiferolate and the diazomethane adduct of methyl mangiferolate. The structures were elucidated by spectroscopic and chemical methods.     

Laticifers and the classification of Euphorbia: the chemotaxonomy of Euphorbia esula L.

Laticifers and the classification of Euphorbia: the chemotaxonomy of Euphorbia esula L. Articulated and non-articulated laticifer cells represent distinctive cell types of relatively recent origin and occur in only a few families. Both types are of separate phylogenetic origin, reflecting independent evolutionary trends in the Euphorbiaceae. Supra-generic groupings of this family can be segregated into three taxonomic units using the laticifer character; with either articulated laticifers, non-articulated laticifers, or no laticifers. Such units may reflect more natural assemblages than now represented in the classification of this family. Laticifers possess chemical and morphological features of potential application as taxonomic characters to aid in delimiting species and interpreting evolutionary trends. The triterpenoid profile from latex of Euphorbia species has been shown to be diagnostic for a taxon. The qualitative and quantitative composition show a high level of stability under diverse environmental and physiological conditions indicating a genetic basis for triterpenoid synthesis. Triterpenoid profiles of known accessions of European E. esula L. and related presumptive taxa from North America readily separated them into distinctive chemotaxa that include one for E. esula L., whereas morphological features were found inadequate for separating accessions to presumptive taxa. Identification of adventive spurges in North America requires diagnostic analyses of Eurasian leafy spurges for comparison. Laticifer characters used in conjunction with relevant morphological features will provide a broadened insight into phylogenetic relationships with the Euphorbiaceae.     

Karachic acid: A new triterpenoid from Betula utilis

Karachic acid, from the bark of Betula utilis, has been shown to be 3β-hydroxy 6α-acetoxy oleanoic acid, a new triterpenoid of the oleanoic acid type.     

Characterization of dopa betaine,tyrosine betaine and N-dimethyltyrosine from Lobaria laetevirens

DOPA betaine, tyrosine betaine and N-dimethyltyrosine were isolated from the lichen Lobaria laetevirens. Their structures were determined by ra     

Triterpenoids and steroids of some Sapotaceae and their chemotaxonomic significance

Extraction of the bark and timber of four Madhuca and five Palaquium species has yielded β-amyrin, β-amyrin acetate, β-amyrin cinnamate,     

Loranthol: A new pentacyclic triterpenoid from Loranthus grewinkii

Loranthol (VIII) has been shown by chemical and physical methods to be lup-20(30)-en-3β,7β-diol, a new triterpenoid of the lupane series. The stereochemistry was established by its degradation to the parent hydrocarbon, lup-20(30)-ene.     

Sesquiterpene lactones of Cichorium intybus and Leontodon autumnalis

8-Deoxylactucin, lactucin and lactupicrin were isolated from Cichorium intybus. 8-Deoxylactucin and jacquilenin were isolated from Leontodon autumnalis and were found in particular abundance in flowers of the latter species. Flowers of L. autumnalis do not produce pentacyclic triterpenoid diols. Thus this species is the first noted exception to the Zimmermann rule, which correlates the co-occurrence of triterpenoid diols and carotenoids in flowers of Compositae plants.     

Triterpenoids of Lycopodium megastachyum

Eight triterpenes of the serratane type have been isolated from Lycopodium megastachyum Baker. They are serratenediol, 21-epi-serratenediol, serratenediol-3-acetate, 21-epi-serratenediol-3-acetate, lycoclavanol, tohogenol diacetate, phlegmanol-D and serratenonediol diacetate.