Influence of harvesting strategy on nutrient supply and production of dairy cows consuming diets based on grass and red clover silage

The main objective of this thesis was to elucidate the effects of regrowth grass silage and red clover silage on nutrient supply and milk production of dairy cows as compared with primary growth grass silages. In the first experiment (publication I), two primary growth and four regrowth grass silages were harvested at two stages of growth. These six silages were fed to 24 lactating dairy cows with two levels of concentrate allowance. Silage intake and energy corrected milk yield (ECM) responses, and the range in these response variables between the diets, were smaller when regrowth silages rather than primary growth silages were fed. Milk production of dairy cows reflected the intake of metabolizable energy (ME), and no differences in the ME utilization were found between the diets based on silages harvested from primary growth and regrowth. The ECM response to increased concentrate allowance was, on average, greater when regrowth rather than primary growth silages were fed. In the second experiment (publication II), two silages from primary growth and two from regrowth used in I were fed to rumen cannulated lactating dairy cows. Cows consumed less feed dry matter (DM), energy and protein, and produced less milk, when fed diets based on regrowth silages rather than primary growth silages. Lower milk production responses of regrowth grass silage diets were mainly due to the lower silage DM intake, and could not be accounted for by differences in energy or protein utilization. Regrowth grass silage intake was not limited due to neutral detergent fibre (NDF) digestion or rumen fill or passage kinetics. However, lower intake may be at least partly attributable to plant diseases such as leaf spot infections, dead deteriorating material or abundance of weeds, which are all higher in regrowth compared with primary growth, and increase with advancing regrowth. In the third experiment (publications III and IV), red clover silages and grass silages harvested at two stages of growth, and a mixed diet of red clover and grass silages, were fed to five rumen cannulated lactating dairy cows. In spite of the lower average ME intake for red clover diets, the ECM production remained unchanged suggesting more efficient utilisation of ME for red clover diets compared with grass diets. Intake of N, and omasal canal flows of total non-ammonia N (NAN), microbial and non-microbial NAN were higher for red clover than for grass silage diets, but were not affected by forage maturity. Delaying the harvest tended to decrease DM intake of grass silage and increase that of red clover silage. The digestion rate of potentially digestible NDF was faster for red clover diets than for grass silage diets. Delaying the harvest decreased the digestion rate for grass but increased it for red clover silage diets. The low intake of early-cut red clover silage could not be explained by silage digestibility, fermentation quality, or rumen fill but was most likely related to the nutritionally suboptimal diet composition because inclusion of moderate quality grass silage in mixed diet increased silage DM intake. Despite the higher total amino acid supply of cows fed red clover versus grass silage diets, further milk production responses on red clover diets were possibly compromised by an inadequate supply of methionine as evidenced by lower methionine concentration in the amino acid profile of omasal digesta and plasma. Increasing the maturity of ensiled red clover does not seem to affect silage DM intake as consistently as that of grasses. The efficiency of N utilization for milk protein synthesis was lower for red clover diets than for grass diets. It was negatively related to diet crude protein concentration similarly to grass silage diets.

Nitrogen dynamics of organic farming in a crop rotation based on red clover (Trifolium pratense) leys

In agricultural systems which rely on organic sources of nitrogen (N), of which the primary source is biological N fixation (BNF), it is extremely important to use N as efficiently as possible with minimal losses to the environment. The amount of N through BNF should be maximised and the availability of the residual N after legumes should be synchronised to the subsequent plant needs in the crop rotation. Six field experiments in three locations in Finland were conducted in 1994-2006 to determine the productivity and amount of BNF in red clover-grass leys of different ages. The residual effects of the leys for subsequent cereals as well as the N leaching risk were studied by field measurements and by simulation using the CoupModel. N use efficiency (NUE) and N balances were also calculated. The yields of red clover-grass leys were highest in the two-year-old leys (6 700 kg ha-1) under study, but the differences between 2- and 3-year old leys were not high in most cases. BNF (90 kg ha-1 in harvested biomass) correlated strongly with red clover dry matter yield, as the proportion of red clover N derived from the atmosphere (> 85%) was high in our conditions of organically farmed field with low soil mineral N. A red clover content of over 40% in dry matter is targeted to avoid negative N-balances and to gain N for the subsequent crop. Surprisingly, the leys had no significant effect on the yields and N uptake of the two subsequent cereals (winter rye or spring wheat, followed by spring oats). On the other hand, yield and C:N of leys, as well as BNF-N and total-N incorporated into the soil influenced on subsequent cereal yields. NUE of cereals from incorporated ley crop residues was rather high, varying from 30% to 80% (mean 48%). The mineral N content of soil in the profile of 0-90 cm was low, mainly 15-30 kg ha-1. Simulation of N dynamics by CoupModel functioned satisfactorily and is considered a useful tool to estimate N flows in cropping systems relying on organic N sources. Understanding the long-term influence of cultivation history and soil properties on N dynamics remains to be a challenge to further research.

Death in the Bolivian High Plateau : Burials and Tiwanaku Society

My Ph.D. dissertation presents a multi-disciplinary analysis of the mortuary practices of the Tiwanaku culture of the Bolivian high plateau, situated at an altitude of c. 3800 m above sea level. The Tiwanaku State (c. AD 500-1150) was one of the most important pre-Inca civilisations of the South Central Andes. The book begins with a brief introductory chapter. In chapter 2 I discuss methodological and theoretical developments in archaeological mortuary studies from the late 1960s until the turn of the millennium. I am especially interested in the issue how archaeological burial data can be used to draw inferences on the social structure of prehistoric societies. Chapter 3 deals with the early historic sources written in the 16th and 17th centuries, following the Spanish Conquest of the Incas. In particular, I review information on how the Incas manifested status differences between and within social classes and what kinds of burial treatments they applied. In chapter 4 I compare the Inca case with 20th century ethnographic data on the Aymara Indians of the Bolivian high plateau. Even if Christianity has affected virtually every level of Aymara religion, surprisingly many traditional features can still be observed in present day Aymara mortuary ceremonies. The archaeological part of my book begins with chapter 5, which is an introduction into Tiwanaku archaeology. In the next chapter, I present an overview of previously reported Tiwanaku cemeteries and burials. Chapter 7 deals with my own excavations at the Late Tiwanaku/early post-Tiwanaku cemetery site of Tiraska, located on the south-eastern shore of Lake Titicaca. During the 1998, 2002, and 2003 field seasons, a total of 32 burials were investigated at Tiraska. The great majority of these were subterranean stone-lined tombs, each containing the skeletal remains of 1 individual and 1-2 ceramic vessels. Nine burials have been radiocarbon dated, the dates in question indicating that the cemetery was in use from the 10th until the 13th century AD. In chapter 8 I point out that considerable regional and/or ethnic differences can be noted between studied Tiwanaku cemetery sites. Because of the mentioned differences, and a general lack of securely dated burial contexts, I feel that at present we can do no better than to classify most studied Tiwanaku burials into three broad categories: (1) elite and/or priests, (2) "commoners", and (3) sacrificial victims and/or slaves and/or prisoners of war. On the basis of such indicators as monumental architecture and occupational specialisation we would expect to find considerable status-related differences in tomb size, grave goods, etc. among the Tiwanaku. Interestingly, however, such variation is rather modest, and the Tiwanaku seem to have been a lot less interested in expending considerable labour and resources in burial facilities than their pre-Columbian contemporaries of many parts of the Central Andes.

Kansallisvaltion teräsmiehestä valtakunnan sovittelijaksi : Poliisikulttuurin psykohistorialliset solmukohdat 1930-1997

From Steely Nation-State Superman to Conciliator of Economical Global Empire – A Psychohistory of Finnish Police Culture 1930-1997 My study concerns the way police culture has changed within the societal changes in Finnish society between 1930 and 1997. The method of my study was psycho-historical and post-structural analysis. The research was conducted by examining the psycho-historical plateaus traceable within Finnish police culture. I made a social diagnosis of the autopoietic relationship between the power-holders of Finnish society and the police (at various levels of hierarchical organization). According to police researcher John P. Crank, police culture should be understood as the cognitive processes behind the actions of the police. Among these processes are the values, beliefs, rituals, customs and advice which standardize their work and the common sense of policemen. According to Crank, police culture is defined by a mindset which thinks, judges and acts according to its evaluations filtered by its own preliminary comprehension. Police culture consists of all the unsaid assumptions of being a policeman, the organizational structures of police, official policies, unofficial ways of behaviour, forms of arrest, procedures of practice and different kinds of training habits, attitudes towards suspects and citizens, and also possible corruption. Police culture channels its members’ feelings and emotions. Crank says that police culture can be seen in how policemen express their feelings. He advises police researchers to ask themselves how it feels to be a member of the police. Ethos has been described as a communal frame for thought that guides one’s actions. According to sociologist Martti Grönfors, the Finnish mentality of the Protestant ethic is accentuated among Finnish policemen. The concept of ethos expresses very well the self-made mentality as an ethical tension which prevails in police work between communal belonging and individual freedom of choice. However, it is significant that it is a matter of the quality of relationships, and that the relationship is always tied to the context of the cultural history of dealing with one’s anxiety. According to criminologist Clifford Shearing, the values of police culture act as subterranean processes of the maintenance of social power in society. Policemen have been called microcosmic mediators, or street corner politicians. Robert Reiner argues that at the level of self-comprehension, policemen disparage the dimension of politics in their work. Reiner points out that all relationships which hold a dimension of power are political. Police culture has also been called a canteen culture. This idea expresses the day-to-day basis of the mentality of taking care of business which policing produces as a necessity for dealing with everyday hardships. According to police researcher Timo Korander, this figurative expression embodies the nature of police culture as a crew culture which is partly hidden from police chiefs who are at a different level. This multitude of standpoints depicts the diversity of police cultures. According to Reiner, one should not see police culture as one monolithic whole; instead one should assess it as the interplay of individuals negotiating with their environment and societal power networks. The cases analyzed formed different plateaus of study. The first plateau was the so-called ‘Rovaniemi arson’ case in the summer of 1930. The second plateau consisted of the examinations of alleged police assaults towards the Communists during the Finnish Continuation War of 1941 to 1944 and the threats that societal change after the war posed to Finnish Society. The third plateau was thematic. Here I investigated how using force towards police clients has changed culturally from the 1930s to the 1980s. The fourth plateau concerned with the material produced by the Security Police detectives traced the interaction between Soviet KGB agents and Finnish politicians during the long 1970s. The fifth plateau of larger changes in Finnish police culture then occurred during the 1980s as an aftermath of the former decade. The last, sixth plateau of changing relationships between policing and the national logic of action can be seen in the murder of two policemen in the autumn of 1997. My study shows that police culture has transformed from a “stone cold” steely fixed identity towards a more relational identity that tries to solve problems by negotiating with clients instead of using excessive force. However, in this process of change there is a traceable paradox in Finnish policing and police culture. On the one hand, policemen have, at the practical level, constructed their policing identity by protecting their inner self in their organizational role at work against the projections of anger and fear in society. On the other hand, however, they have had to safeguard themselves at the emotional level against the predominance of this same organizational role. Because of this dilemma they must simultaneously construct both a distance from their own role as police officers and the role of the police itself. This makes the task of policing susceptible to the political pressures of society. In an era of globalization, and after the heyday of the welfare state, this can produce heightened challenges for Finnish police culture.

Agronomic challenges for organic crop husbandry

With respect to resource management and environmental impact, organic farming offers rationales for agricultural sustainability. However, agronomic productivity is usually higher with conventional farming. This work aimed at investigating two factors of major importance for the agronomic productivity of organic crop husbandry, nitrogen (N) supply through symbiotic N fixation (SNF) and weed occurrence. Perennial red clover-grass leys and spring cereal crops subjected to regular agricultural practices were studied on 34 organic farms located in the southern and the north-western coastal regions of Finland. Herbage growth, clover content as a proportion of the ley and extent of SNF in perennial leys, and the occurrence of weed species and weed-crop competition in spring cereal stands were related to climate conditions, soil properties, and management measures. The herbage accumulated from the first and the second cut of one- and two-year-old leys averaged 7.5 t DM ha-1 (SD ± 1.7 t DM ha-1); the clover content averaged 43.9% (SD ± 18.8%). Along with the clover content, herbage production decreased with ley age. Radiation use efficiency (RUE) correlated positively with clover proportion but despite low clover contents, three-year-old leys were still productive with regard to RUE. SNF in the accumulated annual growth of one- and two-year-old leys averaged 247.5 kg N ha-1 yr-1 (SD ± 114.4 kg N ha-1 yr-1). It was supposed that if red clover-grass leys constituted 40% of the rotation, then the mean N supply by SNF would be able to sustain two or three succeeding cereal crops (green manure and forage ley, respectively), yielding 3.0 to 4.0 t grain ha-1. Being a function of clover biomass, the SNF increased from the first to the second cut and thereafter declined with ley age. Coefficients of variation of clover contents (and SNF) between and within fields were around 50%, which was about twice as high as those of herbage production. The lower were the clover contents, the higher were the within-field variations of clover as a proportion of the ley. Low clover contents in one-year-old leys and increasing variability with ley age suggested that red clover growth was limited by poor establishment and poor overwintering. The proportions of clover in leys were lower and their variability was higher in the northwest than in the south. Soil properties, primarily texture and structure, had a major impact on clover proportion and herbage production, which largely explained regional differences in ley growth. Within-field variability of soil properties can be amended through site-specific measures, including drainage, liming, and applications of organic manures and mineral fertilizers. Overwintering and the persistence of leys can be improved by the choice of winter-hardy varieties, careful establishment and the appropriate harvest regime. Mean grain yields of spring cereal crops amounted to 3.2 t ha-1 in the south and 3.6 t ha-1 in the northwest. At 570 and 565 m-2 for the south and northwest respectively, mean weed densities did not differ between the regions, whereas the respective mean weed biomass of 697 and 1594 kg dry weight ha-1, respectively did differ. Weed abundance varied remarkably between single fields. The number of weed species was higher in the south than in the northwest. For example, Fumaria officinalis and Lamium spp. were found only in the south. Frequencies and abundances of Lapsana communis, Myosotis arvensis, Polygonum aviculare, Tripleurospermum inodorum, and Vicia spp. were higher in the south, whereas those of Elymus repens, Persicaria spp. and Spergula arvensis were higher in the northwest. The number of years since conversion to organic farming, i.e. long-term management, was one of the variables that explained the abundance of single weed species. E. repens was the weed species whose biomass increased most with the duration of organic farming. Another significant variable was crop biomass, which was affected by short-term management. The presence of different weed species was related to the duration of organic farming and to low crop yield. This finding demonstrated that it was not the organic farming regime per se, which resulted in high weed infestation and low yielding crops, but failures in the understanding and the management of organic farming systems. Successful weed control relies on farm- and field-specific long- and short-term management approaches. The agronomic productivity of ley and spring cereal crops managed by full-time farmers with an interest in organic farming was on the same level as of the mean for conventional farming. Given the many options for further improvements of the agronomic performance of organic arable systems, organic farming offers foundations for the development of sustainable agriculture. The main threat to the sustainability of farming in Finland, both conventional and organic, is the spatial separation of crop production and animal husbandry by region, along with the simplification of associated crop rotations.

Undersowing in a northern climate: effects on spring cereal yield and risk of nitrate leaching

Disadvantages of invariable cereal cropping, concern of nutrient leaching and prices of nitrogen (N) fertilizer have all increased during last decades. An undersown crop, which grows together with a main crop and after harvest, could mitigate all those questions. The aim of this study was to develop undersowing in Finnish conditions, so that it suits for spring cereal farming as well as possible and enhances taking care of soil and environment, especially when control of N is concerned. In total, 17 plant species were undersown in spring cereals during the field experiments between 1991-1999 at four sites in South and Central Finland, but after selection, eight of them were studied more thoroughly. Two legumes, one grass species and one mixture of them were included in long-term trials in order to study annually repeated undersowing. Further, simultaneous broadcasting of seeds instead of separate undersowing was studied. Grain yield response and the capacity of the undersown crop to absorb soil N or fix N from atmosphere, and the release of N were of greatest interest. Seeding rates of undersown crops and N fertilization rates during annually repeated undersowing were also studied. Italian ryegrass (Lolium multiflorum Lam., IR) absorbed soil nitrate N (NO3-N) most efficiently in autumn and timothy (Phleum pratense L.) in spring. The capacity of other grass species to absorb N was low, or it was insufficient considering the negative effect on grain yield. Red clover (Trifolium pratense L.) and white clover (Trifolium repens L.) suited well in annually repeated undersowing, supplying fixed N for cereals without markedly increased risk of N leaching. Autumn oriented growth rhythm of the studied legumes was optimal for undersowing, whereas the growth rhythm of grasses was less suited but varied between species. A model of adaptive undersowing system was outlined in order to emphasize allocation of measures according needs. After defining the goal of undersowing, many decisions are to be done. When diminishing N leaching is primarily sought, a mixture of IR and timothy is advantageous. Clovers suit for replacing N fertilization, as the positive residual effect is greater than the negative effect caused by competition. A mixture of legume and non legume is a good choice when increased diversity is the main target. Seeding rate is an efficient means for adjusting competition and N effects. Broadcasting with soil covering equipment can be used to establish an undersown crop. In addition, timing and method of cover crop termination have an important role in the outcome. Continuous observing of the system is needed as for instance conditions significantly affect growth of undersown crop and on the other hand N release from crop residues may increase in long run.

Biological Control of Oilseed Rape Pests with Entomopathogenic Nematodes

Biological control techniques attract increasing attention as one of the sustainable alternatives to pesticide use in integrated pest management programs. In order to develop sustainable pest management methods for arable crops based on entomopathogenic nematodes (EPN), their efficacy and persistence needed to be investigated, and an economically feasible delivery system had to be developed. In this study, first a survey of entomopathogens was conducted, and a system approach was tested, using the oilseed Brassica (OSB) growing system (OSB, spring wheat, and red clover) as a model. The system approach aimed at determining the potential of Steinernema feltiae (Filipjev) for the control of OSB pests, developing OSB rotation schemes that support EPN persistence, and investigating the impact of the selected biotic and abiotic factors on efficacy and persistence of EPN. This study employed abductive logic (which employs constant interplay between the theory and empirical observation), quantitative methods, and a case study on OSB. Laboratory and field experiments were carried out, and two types of pathogen surveys. A horizontal survey included OSB fields across Estonia, Germany, Poland, Sweden and the UK, while a vertical survey included sampling from two sets of differently managed experimental fields during three years. A new approach was introduced for measuring occurrence, where the prevalence and relative intensity of entomopathogens, biotic agents, and unidentified insect antagonists were determined. The effect of dose, timing, and the application method on S. feltiae in the control of pests in OSB, and the potential of a controlled release delivery system (CRS) were evaluated in the field. Studies on the impact of selected biotic and abiotc factors (Brassica plant, bait insects, developmental stages of Meligethes aeneus Fab., Isaria fumosorosea Wize (Ifr), and organic and synthetic fertilizers) on the efficacy of S. feltiae were conducted in the laboratory. Persistence of S. feltiae in the OSB growing system, and the effect of dose, timing, and the application method, was assessed in the field as part of the efficacy experiments. The impact of selected biotic and abiotic factors on S. feltiae persistence was assessed in laboratory experiments. The pathogen survey showed that the occurrence of entomopathogens is low in the OSB growing system, and that a management system causing less disturbance (ICM) to the soil increases the relative intensity of insect parasitic nematodes and other insect antagonists. A longer study period is required to show any possible impact of ICM on the relative intensity of entomopathogenic fungi, or on the prevalence of entomopathogens. Two different measures of the occurrence yielded different results: the relative intensity revealed the difference between the two different crop management methods, while prevalence did not. The highest efficacy of S. feltiae was achieved by using a low dose and targeting all stages of M. aeneus. When only the larval stage was targeted, the application method and dose had no significant effect. The CRS decreased the pest abundance significantly more than the surface application method. S. feltiae persisted in the OSB fields in Finland for several months, but did not survive the winter. The strain survived for 7 months when it was applied in autumn in Germany, but its populations declined rapidly after winter. The examined biotic and abiotic factors had variable impacts on S. feltiae efficacy and persistence. The two measures, prevalence and relative intensity of entomopathogens, gave valuable information for their use in biocontrol programs. The recommended biocontrol strategy for OSB growing in Finland is inundation and seasonal inoculation of EPN. The impact of some biotic and abiotic factors on S. feltiae efficacy and persistence is significant, and can be used to improve the efficacy of EPN. The CRS is a novel alternative for EPN application, and should also be considered for use on other crops. Keywords: Biological control, inundation, inoculation, conservation, formulation, slow release method, crop rotation, Entomopathogenic nematodes, Steinernema feltiae, oilseed rape pests, Meligethes aeneus, Phyllotreta spp., occurrence, prevalence, intensity, efficacy, persistence, field, Isaria fumosorosea, biotic factors, abiotic factors, interaction, impact, insect stages, integrated crop management, standard (conventional) crop management

Identification of Isoflavonoid Metabolites in Humans

Epidemiological studies have associated high soy intake with a lowered risk for certain hormone-dependent diseases, such as breast and prostate cancers, osteoporosis, and cardiovascular disease. Soy is a rich source of isoflavones, diphenolic plant compounds that have been shown to possess several biological activities. Soy is not part of the traditional Western diet, but many dietary supplements are commercially available in order to provide the proposed beneficial health effects of isoflavones without changing the original diet. These supplements are usually manufactured from extracts of soy or red clover, which is another important source of isoflavones. However, until recently, detailed studies of the metabolism of these compounds in humans have been lacking. The aim of this study was to identify urinary metabolites of isoflavones originating from soy or red clover using gas chromatography - mass spectrometry (GC-MS). To examine metabolism, soy and red clover supplementation studies with human volunteers were carried out. In addition, the metabolism of isoflavones was investigated in vitro by identification of metabolites formed during a 24-h fermentation of pure isoflavones with a human fecal inoculum. Qualitative methods for identification and analysis of isoflavone metabolites in urine and fecal fermentation samples by GC-MS were developed. Moreover, a detailed investigation of fragmentation of isoflavonoids in electron ionization mass spectrometry (EIMS) was carried out by means of synthetic reference compounds and deuterated trimethylsilyl derivatives. After isoflavone supplementation, 18 new metabolites of isoflavones were identified in human urine samples. The most abundant urinary metabolites of soy isoflavones daidzein, genistein, and glycitein were found to be the reduced metabolites, i.e. analogous isoflavanones, a-methyldeoxybenzoins, and isoflavans. Metabolites having additional hydroxyl and/or methoxy substituents, or their reduced analogs, were also identified. The main metabolites of red clover isoflavones formononetin and biochanin A were identified as daidzein and genistein. In addition, reduced and hydroxylated metabolites of formononetin and biochanin A were identified; however, they occurred at much lower levels in urine samples than daidzein or genistein or their reduced metabolites. The results of this study show that the metabolism of isoflavones is diverse. More studies are needed to determine whether the new isoflavonoid metabolites identified here have biological activities that contribute to the proposed beneficial effects of isoflavones on human health. Another task is to develop validated quantitative methods to determine the actual levels of isoflavones and their metabolites in biological matrices in order to assess the role of isoflavones in prevention of chronic diseases.

Studies on Stone Age Housepits in Fennoscandia (4000 - 2000 cal BC) : Changes in ground plan, site location and degree of sedentism

Housepits have a remarkably short research history as compared to Fennoscandian archaeological research on the Stone Age in general. The current understanding of the numbers and the distribution of Stone Age housepits in the Nordic countries has, for the most part, been shaped by archaeological studies carried out over the last twenty to thirty years. The main subjects of this research are Neolithic housepits, which are archaeological remains of semi-subterranean pithouses. This dissertation consists of five peer-reviewed articles and a synthesis paper. The articles deal with the development of housepits as seen in the data gathered from Finland (the Lake Saimaa area and south-eastern Finland) and Russia (the Karelian Isthmus). This synthesis expands the discussion of the changes observed in the Papers to include Fennoscandian housepit research as a whole. Certain changes in the size, shape, environmental location, and clustering of housepits extended into various cultures and ecological zones in northern Fennoscandia. Previously, the evolution of housepits has been interpreted to have been caused by the adaptation of Neolithic societies to prevailing environmental circumstances or to re-organization following contacts with the agrarian Corded Ware/Battle Axe Cultures spreading to North. This dissertation argues for two waves of change in the pithouse building tradition. Both waves brought with them certain changes in the pithouses themselves and in the practices of locating the dwellings in the environment/landscape. The changes in housepits do not go hand in hand with other changes in material culture, nor are the changes restricted to certain ecological environments. Based on current information, it appears that the changes relate primarily to the spread of new concepts of housing and possibly to new technology, as opposed to representing merely a local response to environmental factors. This development commenced already before the birth of the Corded Ware/Battle Axe Cultures. Therefore, the changes are argued to have resulted from the spreading of new ideas through the same networks that actively distributed commodities, exotic goods, and raw materials over vast areas between the southern Baltic Sea, the north-west Russian forest zone, and Fennoscandia.

Synthesis of Reduced Metabolites of Isoflavonoids, and their Enantiomeric Forms

Isoflavonoids are naturally occurring plant derived biochemicals, which act as phytoalexins. Isoflavonoids are of interest due to their estrogenic and other potential physiological properties, particularly in mammals that typically consume isoflavonoid rich nutrients such as soy and red clover. The literature review of this thesis mainly focuses on the reduced metabolites of hydroxy and/or methoxy substituted isoflavones with four groups: isoflavan-4-ols, isoflav-3-enes, isoflavans and α-methyldeoxybenzoins (1,2-diarylpropan-1-ones), which are all reduced metabolites of food derived isoflavones in mammals. Related isoflavan-4-ones are briefly discussed. Results of an extensive survey of the literature concerning the synthesis of polyhydroxy- or methoxysubstituted isoflavonoids and especially asymmetric approaches are discussed. The experimental section describes new synthetic methods to prepare polyphenolic reduced isoflavonoid structures such as isoflav-3-enes, isoflavan-4-ones, cis- and trans-isoflavan-4-ols, 1,2-diarylpropan-1-ones and isoflavans by various hydride reagents and hydrogenations. The specific reactivity differences of various hydride reagents toward isoflavonoids are discussed. The first enantioselective synthesis of natural (S)-(-)-equol and the opposite enantiomer (R)-(+)-equol is also described by the asymmetric iridium PHOX catalysed hydrogenation of isoflav-3-enes. Both of these equol enantiomers are found to possess biological activity in mammals due to estrogen receptor binding activity. The natural enantiomer prefers estrogen receptor β and the R-enantiomer prefers the estrogen receptor α. Also the precursor, isoflav-3-ene, is found to possess positive biological effects on mammals. In connection with the synthetic work, the (S)-(-)-equol was discovered from serum of ewes after isoflavone rich red clover feeding. The chiral HPLC method was developed to identify natural equol enantiomer for the first time in this species. The first synthesis of natural isoflavonoid (R)-(-)-angolensin and its enantiomer (S)-(+)-angolensin is desribed by the use of recyclable chiral auxiliaries (chiral pseudoephedrines). The method offers a general approach also to other natural polyphenolic 1,2-diarylpropan-1-ones and to further study isoflavonoid metabolism in human and other mammals. The absolute configurations of these new chiral isoflavonoid metabolites were determined by X-ray spectroscopy. Also thorough NMR and MS analysis of synthesised structures are presented.