Lancea tibetica as the Tibetan herb: A review of its phytochemistry and pharmacology

This review, based on nearly 25 literary sources, discusses the chemical nature and biological effects of the whole plant of Lancea tibetica Hook. f. et Thoms (Scrophulariaceae). Several types of chemical constituents have been isolated from Lancea tibetica (LT) including 34 phenolpropanoids (16 lignans, 5 neolignans, 5 nonanones, 4 phenylpropanoid glycosides, and 4 propanediols), 9 flavones, 6 triterpenoids, and 11 amino acids. Various extracts and individual compounds derived from this species have been determined to possess a variety of pharmacological effects, such as anti-tumour and antioxidant functions. The results of data analysis on the chemical and pharmacological characteristics of LT support the view that this plant has many therapeutic properties, suggesting its potential as an effective herbal remedy. Finally, suggestions for further avenues of research on the chemical and pharmacological properties of LT and ways in which to further exploit LT are presented in this review.     

Thermally induced chemical artifacts in lichens

Unsuspected thermal degradation of secondary products in lichens prior to chemical study, although probably uncommon, can lead to mistaken conclusions and taxonomic error. Thermally induced artifacts were found in the chemistries of Hypotrachyna partita from a site of volcanic activity in Costa Rica and in the type of H. prolongata from Haiti that had been dried for the herbarium with heat. In the Southern Appalachian Mountains normal material of H. prolongata has been considered a chemically different species. Thermal stability of secondary products may be an important factor in the chemical evolution of lichens inhabiting extreme environments.     

Tylophorinicine,a phenanthroindolizidine alkaloid from tylophora asthmatica and pergularia pallida

Tylophorinicine, a minor alkaloid isolated from the roots of Tylophora asthmatica and Pergularia pallida has been characterized as 14-hydroxytylophorine from physical and chemical evidence.     

New diterpenes from Porella perrottetiana

Perrottetianal A and perrottetianal B, two new diterpene dialdehydes and a new ent-labdane-type diterpene diol have been isolated from the liverwort Porella perrottetiana and their structures have been elucidated by the chemical and spectral evidence.     

Florigenic Acid from fungal culture

The extraction procedures which have been successfully employed in the preparation of a florigenic principle from the tissues of Xanthium, are applicable to the derivation of an entity of similar activity from Calonectria culture. The Xanthium principle is acedic, with pK_a values characteristic of a carboxylic acid (6). Although definitive chemical comparisons have not been completed, the extraction and solvent partition procedures that have been applicable to the extraction of the active entity from higher plant tissues have yielded florigenic preparations from fungal culture. The chemical principle from higher plant tissue may be the same or similar to the florigenic agent of Calonectria.

The many responses of higher plants to growth regulators produced by micro-organisms are well known. The presence of a flower-producing principle from Calonectria (Fusarium) rigidiuscula parallels closely the pattern exhibited by those fungal species capable of the production of auxin and gibberellins.

     

Monoterpenoid differentiation in relation to the morphology of Pinus remota

Wood of Pinus remota from 126 trees sampled in 13 localities throughout of its ranges in the United States and Mexico has been analysed for monoterpenes. The trees of P. remota produced mainly α-pinene and limonene with ranges for population means of 68.0–92.3% and 3.2–16.9%, respectively. Limonene was useful for distinguishing this species from subsp. cembroides. Small chemical differences were found between the eastern and western variants of P. remota. The chemical differences between the trees of P. remota from the United States and the trees of the newly described species, P. catarinae, from Mpo Santa Catarina near Saltillo, Mexico, were also very few and quantitatively small. The variations in morphological characteristics paralleled the chemical differentiation. The chemical and morphological data substantiated the species status of P. remota, and suggested the status of a mere marginal variant for P. catarinae.     

Sesquiterpene lactones,waxes and volatile compounds from Artemisia herba-alba subspecies Valentina

The structures of two sesquiterpene lactones isolated from Artemisia herba-alba subsp. valentina have been determined by spectroscopic methods. One of these was dihydroreynosin, the other was a new compound assigned the name torrentin. The chemical compositions of a wax and a hydrocarbon fraction from the essential oil have also been investigated.     

Aquillochin,a coumarinolignan from Aquilaria agallocha

Aquillochin, isolated from the whole plant of Aquilaria agallocha, has been shown to be a coumarinolignan, and a structure has been proposed on the basis of chemical and physical studies.     

Phenolic constituents of Coelogyne ovalis

The structure of 3′-O-methylbatatasin III, a new bibenzyl of the East Himalayan orchid, Coelogyne ovalis, has been established on the basis of spectral and chemical data. Known 9,10-dihydrophenanthrene derivatives, a bibenzyl and sterols have also been isolated from the orchid.     

Diterpenoids from sideritis pusilla subsp. flavovirens

Several new 14-hydroxybeyerene acetates have been isolated from the aerial parts of Sideritis pusilla subsp. flavovirens. In addition, an ent-kaur-15-ene (siderol) and a new ent-7α, 18-dihydroxybeyer-15-ene (flavovirol) have been obtained from the same source. The structures of these new acetates have been established by chemical and spectroscopic means and the structure of flavovirol has been confirmed by ¹³C NMR.     

Deuterium isotope effects in carbohydrates revisited. Cryoprobe studies of the anomerization and NH to ND deuterium isotope induced 13C NMR chemical shifts of acetamidodeoxy and aminodeoxy sugars

Complete ¹H and ¹³C NMR chemical shift assignments have been generated from a series of acetamidodeoxy and aminodeoxy sugar derivatives. For free sugars, the enhanced sensitivity of an NMR cryoprobe allowed simple 1D and 2D NMR spectra to be obtained from essentially single anomers, before significant mutarotation had occurred. The NMR assignments have been used to characterize deuterium isotope effects on ¹³C chemical shifts measured under conditions of slow NH to ND exchange in single solutions. Within a range of 0 to −0.138 ppm, β, γ, δ, and ζ deuterium isotope effects have been observed, thus providing additional reference data for assignment of the ¹³C NMR spectra of nitrogenous saccharides.     

Glycolone,a quinolone alkaloid from Glycosmis pentaphylla

Glycolone, a quinolone alkaloid has been isolated from the leaves of Glycosmis pentaphylla. The structure of the compound has been established as 4,8-dimethoxy-3-(3-methyl but-2-enyl)-2-quinolone from physical and chemical evidences.     

Novel nor-harmal alkaloid from Adhatoda vasica

A novel alkaloid and a galactoside isolated from the roots of Adhatoda vasica have been characterized as 9-acetamido-3,4-dihydropyrido-(3,4-b)-indole and O-ethyl-α-D-galactoside respectively by chemical and spectroscopic methods. In addition sitosterol β-D-glucoside, D-galactose and deoxyvasicinone have also been isolated from the roots of this plant.     

Isolation and structural studies on the alkaloids of Petchia ceylanica

(19R)-Epimisiline and (19S)-epimisiline, two new Aspidosperma alkaloids, have been isolated from the leaves of Petchia ceylanica. The structures have been deduced on the basis of chemical and spectroscopic data.     

(−)-Allo-pertusaric acid and (−)-dihydropertusaric acid from the lichen Pertusaria albescens

The structures of two γ-lactone carboxylic acids from the lichen Pertusaria albescens, (−)-allo-pertusaric acid and (−)dihydropertusaric acid, have been elucidated by spectroscopic and chemical methods. From P. ophthalmiza, taraxerone and a mixture of long chain aliphatic alcohols and fatty acids have been isolated.     

Aristoloside,an aristolochic acid derivative from stems of Aristolochia manshuriensis

Aristoloside, a new companion aristolochic acid derivative isolated from stems of Aristolochia manshuriensis has been shown to be 6-O-β-d-glucopyranoside of aristolochic acid-D on chemical and physicochemical evidence. Three known acids, aristolochic acids I, IV (both as their corresponding methyl esters), and -D have also been characterized from stems of the plant.     

Nummularine-O,a cyclopeptide alkaloid from Zizyphus nummularia

In addition to the known peptide alkaloid jubanine-B, a new peptide alkaloid, nummularine-O, has been isolated from the stem bark of Zizyphus nummularia and their structures have been elucidated by chemical and spectroscopic methods.     

Heliangolides from Leucanthemopsis pulverulenta

The structure of hispanolide (4,5-cis-3-oxogermacranolide) and three other related germacranolides, isolated from Leucanthemopsis pulverulenta, have been established by a series of chemical transformations and spectral data.     

An acridone alkaloid from the root bark of Atalantia monophylla

Atalaphylline 3,5-dimethyl ether, a new acridone alkaloid from Atalantia monophylla, has been characterized on the basis of spectral data and chemical transformations.     

(−)-Ent-12β-acetoxylongipin-2(10)-en-3-one,an Ent-longipinane derivative from the liverwort Marsupella aquatica

The structure of a new ent-longipinane type of sesquiterpenoid, (?)-ent-12β-acetoxylongipin- 2(10)-en-3-one from the liverwort Marsupella aquatica, has been elucidated by spectroscopic and chemical methods.