Cloverly formation

The last of the fat-soluble vitamins to be identified was vitamin K, found by Dam to be an anti-hemorrhagic factor for young chicks, distinct from vitamin C. Its structure was determined by Dam in collaboration with Karrer. Interest in the vitamin was intensified when it was discovered (Link, 1941) that dicoumarol, present in spoiled sweet clover, was the agent producing hypothrombinemia (giving prolonged blood-clotting time) in cattle. Since vitamin K is structurally similar to dicoumarol, the vitamin was presumptively implicated in thrombin formation. This has been fully substantiated by recent work on the role of vitamin K in the synthesis of prothrombin in the liver. 

Many plants produce coumarins coumarin itself is found in sweet clover and contributes to the smell of new-mown hay. However, if sweet clover is allowed to ferment, oxidative processes initiated by the microorganisms lead to the formation of 4-hydroxycoumarin rather than coumarin. 4-Hydroxycoumarin then reacts with formaldehyde, also produced via the microbial degradative reactions, and provides dicoumarol. 

The effects of ozone are not limited to altering metabolic pools in plant foliage they can also induce the formation of toxic compounds. Leachate was collected from fescue leaves 2 weeks following a 2 hr exposure to 590 yg/m ozone and used to irrigate clover plants (20). Top and root dry weights of ladino clover were unaffected by leachate from ozone-treated fescue leaves. However, the leachate from the ozone-exposed fescue leaves reduced the nodule number of ladino clover (Table IV). 

FIGURE 8.7 Model for the role of Rhizobium- nd xnodule formation in white clover. (Redrawn from Mathesius, U., J. Exp. Bot., 52, 419, 2001. With permission of Oxford University Press.)... 

Hutangura, P. et al.. Auxin induction is a trigger for root gall formation caused by root-knot nematodes in white clover and is associated with the activation of the flavonoid pathway, Aust. J. Plant Physiol, 26, 221, 1999. 

Mathesius U, Schlaman FIRM, Spaink PIP, Sautter C, Rolfe BG, Djordjevic MA. 1998. Auxin transport inhibition precedes root nodule formation in white clover roots and is regulated by flavonoids and derivatives of chitin oligosaccharides. Plant J 14 23-34. 

Red clover D, G, FORM, ononin, BCA, sissotrin, their glycosides Ultrasonication in MeOH-H20-Tris buffer C-18 MeOH- ammonium formate HPLC/UV (265 nm), FD (250/418 nm) or MS/APCIB UV 20-90 mg/L 98... 

Both molecules, 28 and 30, are topologically chiral the chirality of 30 was proven by H-NMR spectroscopy with the addition of KPFs and Pirkles reagent. This resulted in different chemical shifts for the hydrogen atoms of the clover-leaf knot 30 due to formation of diastereomeric complexes. 

Over 300 different plants contain either compounds with estrogenic activity or precursors for the formation of nonsteroidal estrogens. Coumestrol, equol, and zearalenone are examples of phytoestrogens that are found in legumes, tubers, and fungi that infest grains. These substances clearly act as reproductive toxins in sheep (equol in clover disease) and... 

Dicoumarol is found in spoiled sweet clover warfarin is used as a rat poison. Similar antagonists may be used clinically to reduce the probability of blood clotting in patients with a tendency to thrombus formation. Several other clotting factors also contain g-carboxyglutamate and they, too, will be affected by vitamin K antagonists. 

The distribution in soil profiles follows the general trends of soil solution circulation (Kabata-Pendias et al. 1989, Kabata-Pendias and Pendias 1991). The aim of our experiments was to examine the influence of the geological origin and the condition of soil formation on the correlation of the elements in shooting wheat (n = 550), rye in blossom (n = 485), field red clover (n = 3269) and meadow red clover in blossom... 

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