Showing papers in "Phytochemistry in 1991"

TL;DR: Tannin toxicity for fungi, bacteria and yeasts is reviewed and compared to toxicity of related lower molecular weight phenols and the dependence of toxicity on tannin structure is examined.

TL;DR: The development of medicinal plant research over the last 30 years is reviewed with reference to the search for new active principles, and difficulties inherent to activity guided isolation and the specific requirements of bioassays are discussed.

TL;DR: In this article, the authors compared two cucumber cultivars, Poinsett and Ashley, for four weeks from planting in unshaded greenhouses at 0 or 12.2 kJ m−2 day−1 of biologically effective ultraviolet-B (UY-BBE) radiation, which corresponded to a decrease in stratospheric ozone of ca 20% for clear sky conditions at Beitsville, MD on 21 June.

TL;DR: In this paper, a grape seed extract yielded various natural procyanidin dimers and trimers isolated and identified for the first time in grapes: Procyanids B5 [epicatechin-(4β → 6)-epicatechim, B6 [catechin-( 4α → 6]-catechim], B7 [cATEchim] and B8 [CATECHim-(4α→ 6)-cATEchin] along with five galloyl trimers: B2 3-O-gallate, B1

TL;DR: Seed samples from 22 species of the Capparidaceae (eight genera), one Caricaceae, 259 Cruciferae (88 genera) and two Tropaeolaceae were analysed for total and individual glucosinolate compositions.

TL;DR: In this paper, the authenticity of the ethylene-forming enzyme was fully recovered in vitro for the first time, and the enzyme was extracted in a soluble form from fruits of melon (Cucumis melo ).

TL;DR: Salicylic acid induced potato tuberization in vitro at concentrations greater than 10−5 M and the natural occurrence of SA was not detected in the leaves of potato plants that had been grown under tuber-inducing conditions and had begun to form tubers, appearing to exclude the possibility of the involvement of SA in the natural tuberization of Potato plants.

TL;DR: In this article, three new procyanidin natural products were isolated: epicatechin-(2β→5,4β→6)-epicatechin, 3T-O-β-d -galactopyranosylent-ent-epicatechine-(2α→7,4α→8)-epicateschine, and 3T O-l -arabinopyranoyl-entepicate chine.

TL;DR: In this article, Sapwood and heartwood samples of sweet chestnut (Castanea sativa) and sessile oak (Quercus petraea) were extracted with aqueous acetone.

TL;DR: A new procedure combining chemical degradation with 1H NMR spectroscopy has been developed for determination of the composition and molecular size of oligomeric/polymeric proanthocyanidins.

TL;DR: The changes in amino acid and glycine betaine content in response to cold stress in wheat seedlings were investigated using HPLC and NMR and changes were not accompanied by a reduction in leaf water potential.

TL;DR: Two ellagitannins with antiviral properties were isolated from the leaves and stems of Spondias mombin by means of a bioguided assay and showed pronounced antiviral activity against Coxsackie and Herpes simplex viruses.

TL;DR: The content of docosahexaenoic acid (DHA) and arachidonic acid, in the best EPA producers was low, or negligible, which has important advantages in simplifying EPA recovery.

TL;DR: MGDG and DGDG were the major glycolipids in green algae and marine grasses, respectively, and almost equal quantities of monoglycosyldiacylglycerol ( MGDG), diglycosylglycersol (DGDG) and sulphaquinovosylduacyl- glycerol with some exceptions.

TL;DR: Detailed knowledge of light and elicitor regulation of flavonoid genes, of the molecular mode of action of certain herbicides, and are beginning to form an understanding of the regulation of alkaloid biosynthesis are revealed.

TL;DR: T tobacco cells treated with cryptogein, an extracellular protein produced by Phytophthora cryptogea, accumulated ethylene and sesquiterpenoid compounds, mainly capsidiol, which makes tobacco resistant to the pathogen P. parasitica var.

TL;DR: Brassicanal C, a new sulphur-containing phytoalexin, and two dioxindoles were isolated from cabbage inoculated with Pseudomonas cichorii and appears structurally to be a possible precursor to spirobrassinin.

TL;DR: Three new phenethyl alcohol glycosides together with six known compounds have been isolated from the leaves of Stachys sieboldii on the basis of chemical and spectral analyses.

TL;DR: A phytotoxic metabolite has been isolated from liquid cultures of Eutypa lata and structurally characterized as 4-hydroxy-3-(3-methylbut-3-en-1-ynyl)benzaldehyde, named eutypine, which was detected in the crude sap and the inflorescences of diseased plants and was not present in healthy material.

TL;DR: Two novel nortriterpenoids and two representatives of the rare malabaricane and polypodane type, respectively, were found in the neutral fraction of gum mastic, the resin of Pistacia lentiscus as mentioned in this paper.

TL;DR: The naturally occurring tetrahydrofurofuran-lignan-(syringaresinol, pinoresinol)-mono- and bis-glucosides were synthesized and their structures thereby confirmed as mentioned in this paper.

TL;DR: The mechanism of enzymic methylenedioxy bridge group formation from an o -methoxyphenol function is discussed and both enzymes were drastically induced 20 hr after challenging the cell suspension culture with elicitor.

TL;DR: Rhodojaponin III, grayanotoxin III, and kalmanol, three grayanoid diterpenes, were isolated and identified as the most active constituents in dried flowers of the Chinese insecticidal plant, Rhododendron molle.

TL;DR: Cell suspension cultures of Orthosiphon aristatus were shown to accumulate rosmarinic acid (RA) at concentrations of 1.0–2.0 μmol g −1 fr.

TL;DR: Two new friedelane-type triterpenes, named as cangoronine and ilicifoline respectively, have been isolated from Maytenus Ilicifolia by spectroscopic and X-ray analyses and the cytotoxic activities of these compounds are reported.

TL;DR: Despite varietal differences, the high hypericin concentrations in the flowers of both varieties indicate both must be considered dangerous weeds.

TL;DR: The fatty acid data indicate that P. salina and the two unnamed species of Pavlova studied are possible substitutes for P. lutheri as microalgal foods in tropical mariculture hatcheries.

TL;DR: In this article, a review of acetylenes and related compounds, such as thiophenes, alkamides, unsaturated alkyl ketones and hydrocarbons, which have been isolated from the tribe Heliantheae (Asteraceae) are listed.

TL;DR: It is suggested that fatty acid composition might be utilized for the classification of Spirulina strains.