Bruce M. Smallfield

Essential oils from New Zealand manuka and kanuka: Chemotaxonomy of Leptospermum

Standardized steam distillation and GC analytical methods for oils from manuka, Leptospermum scoparium, are described. These methods were used to analyse two oils from each of 15 L. scoparium populations derived from all around New Zealand, seven Australian Leptospermum populations and one population of Kunzea sinclairii. These populations were all grown from seed at a single site. Principal component analyses of the levels of 50 GC peaks in these 46 oils revealed compositional patterns. Kunzea sinclairii oils were distinguished from Leptospermum oils by higher α-pinene levels (mean 76%). Australian Leptospermum oils had significantly higher 1,8-cineole (mean 20%) and total monoterpene levels (mean 51%) than New Zealand L. scoparium oils (1,8-cineole mean 0.9%, total monoterpene mean 14%). This indicates the need for further taxonomic study of plants currently included in L. scoparium in Australia and New Zealand. There is evidence for three chemotypes of L. scoparium in New Zealand, conforming in part to morphological types: a high-pinene chemotype in the far north, a high-triketone (especially leptospermone) chemotype on the East Cape, and a type containing a complex of sesquiterpenes found over the rest of the country. An oil from the East Cape chemotype showed the strongest antimicrobial activity.

Betalains in Red and Yellow Varieties of the Andean Tuber Crop Ulluco (Ullucus tuberosus)

The betalain pigments in ulluco (Ullucus tuberosus), a tuberous crop native to the Andes, have been investigated for the first time using LC-DAD-ESI-MS-MS(2) analyses. Five red, yellow, and red-spotted accessions introduced into New Zealand as a new food crop plus two red tetraploid lines were investigated. Thirty-two different betalains were identified. Both the yellow and red tubers were rich in yellow betaxanthins, and the most prominent among the 20 identified were histidine-betaxanthin, arginine-betaxanthin and glutamine-betaxanthin. Arginine-betaxanthin has been reported to occur naturally only once before and was found in yellow ulluco but not in the red tubers. Twelve betacyanins were found in red tubers, with roughly 50% of this content being betanin/isobetanin. Betacyanin levels were up to 70 microg/g fresh weight in red tubers, but were below quantifiable levels in yellow tubers. Betaxanthin levels were up to 50 microg/g fresh weight in yellow tubers. Interference by betacyanins in measuring levels of betaxanthins by visible spectrophotometry is discussed. Low concentrations of betalains were detected in leaves, whereas stems contained total levels similar to the tubers, with dopamine-betaxanthin and betanin being the major pigments. This is the first report describing both the betacyanin and betaxanthin patterns in a plant from the Basellaceae family.

Essential oils from new zealand manuka and kanuka: Chemotaxonomy of Kunzea

Abstract A standardized analytical GC method has been used to analyse essential oils from selected Australian and New Zealand Kunzea species, grown from seed at a single site. The distillation yields and analyses are reported for oils from 26 populations of K. ericoides (kanuka) and from single populations of each of K. flavescens , K. pauciflora , K. sinclairii and x Kunzspermum hirakimata (a Kunzea x Leptospermum cross). Principal components analyses of 37 GC peaks in these oils were used to distinguish compositional patterns. Oils from K. flavescens , K. pauciflora and x Kunzspermum hirakimata had chemical compositions distinct from K. sinclairii and K. ericoides . Oils front New Zealand K. ericoides were mainly α-pinene (mean 68%), but some oils had high p -cymene contents, particularly oils from one Marlborough provenance (mean 31%). A wild population of K. ericoides var. linearis gave oils with similar composition to other K. ericoides . Two K. ericoides oils showed weak antifungal activity.

Variation in response to cold damage by populations of Cordyline australis and of some other species of Cordyline (Lomandraceae)

Abstract Winter cold damage in 1996 and 1997 was recorded for 28 populations of Cordyline australis from a wide latitudinal range in New zealand and single populations of C. banskii and C, indivisa grown in field experiments at Lincoln and Invermay New Zealand. Damage to a single plant of C. obtecta grown at Lincoln was also recorded. Cordyline banskii and C. obtecta were damaged the most by freezing. Levels of cold damage to C. australis were closely related to latitude of origin; populations from northern North Island suffered severe damage whereas those from inland southern south Island showed little damage. These relationships were clearest when the populations were exposed to the lowest grass minimum temperature of ‐9.7°C that occurred at Invermay in winter 1996. Retardation of the height growth of the populations most severely damaged in winter 1996 kept them in the frost layer in winter 1997, increasing their exposure to further damage. Variation in cold damage that related to altitude and topography of the sites of origin was also indicated. Damage to shoot apices by freezing temperatures at Invermay in 1996 induced plants of northern populations to form multiple shoots. The results suggest that there has been strong natural selection matching the cold tolerance of seedlings of C. australis populations to minimum temperature regimes at their sites of origin. The results are relevant to the sourcing of plants for restoration of native vegetation and to horticultural use of C. australis.

Sesquiterpene Lactones in Arnica montana: Helenalin and Dihydrohelenalin Chemotypes in Spain

An analytical RPLC method for sesquiterpene lactones in Arnica montana has been extended to include quantitative analyses of dihydrohelenalin esters. LC-ESI-MS-MS distinguished the isomeric helenalin and dihydrohelenalin esters. The dihydrohelenalin esters have lower response factors for UV detection than do helenalin esters, which must be taken into account for quantitative analyses. Analyses of flowers from 16 different wild populations of A. montana in Spain showed differing proportions of helenalin and dihydrohelenalin esters. For the first time a chemotype with high levels of helenalin esters (total helenalins 5.2-10.3 mg/g dry weight) is reported in Spanish A. montana. These samples were from heath lands at high altitude (1330-1460 m), whereas samples from meadows and peat bogs at lower altitudes were the expected chemotype with high levels of dihydrohelenalin esters (total dihydrohelenalins 10.9-18.2 mg/g). The phenolic compounds, both flavonoid glycosides and caffeoylquinic acids, in Spanish A. montana are reported for the first time. The levels of several of these compounds differed significantly between samples from heath lands and samples from peat bogs or meadows, with the heath land samples being most similar to central European A. montana in their phenolic composition.

Flavor, Glucosinolates, and Isothiocyanates of Nau (Cook’s Scurvy Grass, Lepidium oleraceum) and Other Rare New Zealand Lepidium Species

The traditionally consumed New Zealand native plant nau, Cooks scurvy grass, Lepidium oleraceum, has a pungent wasabi-like taste, with potential for development as a flavor ingredient. The main glucosinolate in this Brassicaceae was identified by LC-MS and NMR spectroscopy as 3-butenyl glucosinolate (gluconapin, 7-22 mg/g DM in leaves). The leaves were treated to mimic chewing, and the headspace was analyzed by solid-phase microextraction and GC-MS. This showed that 3-butenyl isothiocyanate, with a wasabi-like flavor, was produced by the endogenous myrosinase. Different postharvest treatments were used to create leaf powders as potential flavor products, which were tasted and analyzed for gluconapin and release of 3-butenyl isothiocyanate. A high drying temperature (75 °C) did not give major glucosinolate degradation, but did largely inactivate the myrosinase, resulting in no wasabi-like flavor release. Drying at 45 °C produced more pungent flavor than freeze-drying. Seven other Lepidium species endemic to New Zealand were also analyzed to determine their flavor potential and also whether glucosinolates were taxonomic markers. Six contained mostly gluconapin, but the critically endangered Lepidium banksii had a distinct composition including isopropyl glucosinolate, not detected in the other species.

Effect of growing media on the production of ginseng (Panax ginseng) in Central Otago, New Zealand

Abstract Ginseng (Panax ginseng C.A. Meyer) is a potential new crop for New Zealand. Under artificial shade, 1‐year‐old seedlings were grown in either peat‐ or soil‐based media for 4 years. At the final harvest mean root fresh weight was 55 g/plant in the peat media and 40 g/plant in the soil media. Total ginsenoside % of the 5‐year‐old roots was up to 6.9%. Macrochemical content (N, P, K, S, Mg, Ca) and trace element (Mn, Zn, Cu, Fe, B) content of roots at each harvest and of the leaves at the final harvest, were determined and compared with reported levels for P. ginseng and standards for P. quinquefolius. Botrytis cinerea was present on plant material throughout the experiment, and there was evidence of predation by the scarab larvae of Costelytra novae‐zealandica in the first year. After 4 years of growth, 45% of the plants in the soil media and 63% of plants in the peat‐based media survived.