Ingrid Hook

• B.Sc. (Pharm); M.Sc.; M.A.
• Trinity College Dublin

Paclitaxel is a diterpenoid produced by Taxus and is used to treat various forms of cancer. It was originally extracted from the bark of the Pacific yew, Taxus brevifolia, which severely threatened its populations. It is now semi‐synthesised from the needles of T. baccata. We characterised two genes, Taxadiene synthase (TS) and 10‐deacetyl baccatin...

Mature plants of S. dunnii Hook. f. produce naphthoquinones in aerial structures and anthraquinones in roots. Immature in vitro-cultured plantlets of Streptocarpus dunnii and S.× hybridus ‘Ruby’ (Gesneriaceae) excrete orange-red metabolites into their growth media (‘artificial’ rhizosphere). Our objectives were to: (i) extract and identify excreted...

Taxus is a genus of trees and shrubs with high value in horticulture and medicine as a source of the anticancer drug paclitaxel. The taxonomy of the group is complex due to the lack of diagnostic morphological characters and the high degree of similarity among species. Taxus has a wide global geographic distribution and some taxonomists recognize o...

Streptocarpus dunnii Hook.f. (Gesneriaceae) grows wild in South Africa in rocky terrain and at high altitude. It possesses unique patterns of growth, is acaulescent, unifoliate and monocarpic and produces unique naphthoquinones. Morphological examinations of Streptocarpus species have tended to concentrate on germination, cotyledon anatomy and deve...

Ethnopharmacological relevance: Danggui (Chinese Angelica root; Dong quai; Angelica sinensis (Oliv.) Diels.) is a traditional Chinese herbal remedy with a long history of use in China, Korea and Japan. Even today it is still one of the herbs most commonly used by Traditional Chinese Medicine (TCM) practitioners in China, as well as Europe. It is m...

This review analyzes the more recent publications concerning the distribution, chemistry, and bioactivities of naphthoquinones (NQs) in higher plants. These highly reactive molecules have a diverse distribution in nature being isolated from bacteria, algae, fungi, lichens, insects, and higher plants, where they mostly occur in Eudicots. Over 200 sp...

Two new furanonaphthoquinones, (3R)-7-methoxy-α-dunnione (5) and (3R)-6-hydroxy-7-methoxy-α-dunnione (6), along with the known (3R)-dunnione (1), (3R)-α-dunnione (2), (3R)-7-hydroxy-α-dunnione (3), and 1-hydroxy-2-methylanthraquinone (4), were isolated from in vitro cultures of Streptocarpus dunnii. The structures of compounds 5 and 6 were establis...

An in vitro T-cell migration assay has been established that can be used to study the effects of compounds on the development of T-cell polarisation with HuT-78 T lymphocytes. This assay indicates the ability of compounds tested to inhibit the inflammatory response by decreasing LFA-1-mediated T-cell motility. The effect of a series of naturally oc...

Representatives from Papaver, Roemeria, Stylomecon and Meconopsis were studied to elucidate phylogenetic relationships between Papaver and these closely allied genera. Two molecular data sets were used individually and combined and included sequences from the internally transcribed spacer region (ITS) of 18S-26S nuclear ribosomal DNA and the trnL i...

Cultures of Alternaria chrysanthemic are known to produce the alpha-pyrones radicinin {1} and radicinol {2}. During the course of a study to monitor the ability of A. chrysanthemi cultures to biotransform foreign substrates it was observed that the addition of foreign substrates stimulated the production of a third alpha-pyrone. This compound was i...

A suspension culture of Papaw bracteatum was developed, which initially yielded high levels (>2.55% of dry wt) of the benzophenanthridine alkaloid dihydrosanguinarine [1]. This productivity has been lost on repeated subculture. In an attempt to improve alkaloid yields modifications in the concentrations of various minor constituents present in the...

To allow more accurate identification of Taxus species, a number of morphological and chemical characteristics of needles and seeds were examined. Macro- and microscopical foliar characteristics of Taxus baccata, T. canadensis, T. celebica, T. cuspidata, T. × hunnewelliana and T. × media were examined. All mean needle lengths fell within the recogn...

The biotransformation of a series of aliphatic and aromatic ketones by five cultures of photosynthetic microalgae is reported. The test substrates include the monoterpenoid ketones carvone and menthone and a series of aromatic ketones related to and including acetophenone. All of the test organisms show some degree of specificity and stereoselectiv...

Amplified fragment length polymorphism (AFLP) markers were employed to deteet genetic variation among species of Papever (section Oxytona) and assess genetic fidelity between in vitro cell lines of Papaver bracteatum and mature plants derived from the propagation of their callus cultures. Regenerated plants exhibited morphological and phytochemical...

In vitro cultured carnivorous plants were grown on a hormone-free medium. They produced the following naphthoquinones: Dionaea muscipula (plumbagin: 5.3%), Drosera rotundifolia (7-methyljuglone: 0.6%), D. binata (plumbagin: 1.4%), and D. capensis (7-methyljuglone: 0.5%). A red, slow-growing suspension culture of D. muscipula was maintained in a mod...

Leontopodium alpinum Cass. (Compositae; Inuleae), commonly known as the European edelweiss, is a plant indigenous to the alpine regions of Europe, traditionally growing on limestone formations at altitudes up to 3140 m. Although the plant has medicinal properties and the flower is a well-known touristic emblem of alpine countries, few researchers h...

The morphological similarities of most Taxus species (Yews) questions the correct identification of many samples of plant material. To determine if real differences exist, authenticated samples were collected from the same Arboretum, at the same time of year. Needles from six Taxus species and 25 varieties of a single species ( T. baccata ) were ex...

The concentrations of paclitaxel, 10-deacetylbaccatin III (10-DAB III), basic taxoids (= "total alkaloids", TA), taxine B and isotaxine B (= "taxines B", TBS) in the dried needles of 127 trees belonging to 30 Taxus cultivars and species were determined by HPLC. Neutral and basic taxoid contents varied in individual trees within species as well as a...

Seasonal variations of taxoid constituents were determined in shoots of European Yew collected from two locations. The first samples originated from a male Taxus baccata tree growing in Gif, France. The second samples were obtained from genetically identical female Irish Yew trees (T. baccata var. fastigiata), of the same age and growing at one sit...

The isolation of (S)-(−)-2,3-dihydro-2,6-dimethyl-4H-benzopyran-4-one (1) from the essential oil produced by natural roots and also from genetically transformed (“hairy”) root cultures of Leontopodium alpinum is described. This is the first reported natural occurrence of 1. Structural assignments were made on the basis of spectroscopic data and by...

Suspension cultures were developed from in vitro cultured plants of Drosera capensis L. (Cape Sundew). A novel cold biphasic extraction procedure using pet. ether:water [5:1] allowed the extraction of a naphthoquinone, confirmed as 7-methyljuglone. Dried shoots yielded 0.50% and roots 0.17%. Suspension cultures were grown in media formulated with v...

The average annual taxol content of shoots with dark green needles from Irish Yew (Taxus baccata var. fastigiata) was found to be 0.0075%. Maximum levels were recorded in April (0.010%) and minimum in February. Golden-leaved ("aurea") varieties contained only traces of taxol. Shoot growth took place mainly between May and July.

The formation of 5 hairy root lines of Leontopodium alpinum was induced by infection of sterile plants with Agrobacterium rhizogenes. The transformed roots were grown as batch cultures in a phytohormone-free modified Murashige & Skoog medium. A time-course experiment with the most productive line showed that a culture period of 6 weeks was optimum...

The genus Taraxacum (family Compositae) is found widely distributed over all five continents, though concentrated in the warmer temperate zone of the northern hemisphere. Plants belonging to this genus grow in many habitats and show considerable diversity in morphological features. For taxonomists, Taraxacum presents many problems, and different ta...

Papaver bracteatum Lindley [Papaveraceae, section Oxytona Bernh (= Macrantha Fedde)], commonly known as the Giant Scarlet Poppy, is a robust perennial plant with unbranched flower stalks (70–120 cm), bearing erect bracteate buds expanding into conspicuous flowers having six purplish crimson petals, each usually with a black blotch longer than broad...

Dandelion (Taraxacum officinale Weber) was evaluated for diuretic activity. Extracts and purified fractions isolated from autumn-collected roots were examined using saline - loaded mice. No significant increases in urine volume and sodium excretion were produced by any extracts. Dandelion leaves and roots collected from different locations in Irela...

The genus Leontopodium (Compositae; Inulae; Gnaphaliinae sensu amplo) consists of between 30 and 40 species (Handel-Mazzetti 1927) found growing in mountainous areas of Japan (Nishikawa 1985), Asia (Hartmann 1972; Yoroshilov 1979; Shmetova and Shcherbova 1982; Khokhryakov 1983; Lee et al. 1985; Park et al. 1987; Khatoon and Ali 1988) and Europe (Su...

A suspension culture of T. officinale (dandelion) was developed and maintained on modified Gamborg's B5 and Murashige and Skoog's media. Volatile metabolites, which collectively had an 'apple-like' odour, were released into the head-space air above the cultures. Analysis by GC-MS indicated the presence of acetic acid butyl ester, 2-methyl-l-propano...

Suspension cultures of Papaver bracteatum biotransform the acyclic monoterpene, linalyl acetate, into linalool, geraniol and the monocyclic alcohol, α-terpineol. Total metabolism of linalyl acetate occurs within eight days of substrate addition, with 40% of the substrate being transformed within the first 36 hr. No regiospecific hydroxylation of th...

Cell suspension cultures of Leontopodium alpinum were established in a modified Murashige and Sköog medium. The cultures were found to produce sitosterol and high concentrations of chlorogenic acid and 3,4-di-O-caffeoylquinic acid. Leaves and roots of Edelweiss plants obtained through micropropagation were also found to contain small amounts of the...

Growth and alkaloid production were studied in callus and cell suspension cultures derived from seeds of three strains of Papaver bracteatum. Traces of oxysanguinarine and sanguinarine were identified in the cultures. Dihydrosanguinarine was the major alkaloid produced by all cell cultures and its crystalline intracellular accumulation was observed...

Three types of administration sets for intravenous fluids currently used in the Republic of Ireland were examined. They were found to differ in almost all aspects of construction. Some of these differences affected their performance when attached to three types of plastic intravenous fluid containers frequently used in hospitals.Braun sets were the...

The plant growth régulant chlorocholine chloride (CCC), in concentrations ranging from 50 to 16,000 ppm was applied as a soil drench to young Black Peppermint (Mentha piperita) plants. Treatment effects (i. e. reductions in height and leaf size, enhancement of leaf colour (and with 16,000 ppm) toxicity symptoms) were evident within one week .Growth...