Hatching stimulant

Eco-Chemical Control of the Potato Cyst Nematode by a Hatching Stimulator from Solanaceae Plants... 

The eggs hatch in spring imder suitable temperature and moisture conditions and additional host plant diffusates. Without host plant diffusate, J2s do not hatch in the soil for 20 years. Therefore, the substances that stimulate the hatching are considered to be effectively utilized for controlling J2s in the farm field, since the hatched J2s in the absence of host plant are to be starved. In view of this, we have searched for hatching stimulators produced by the host plants of cyst nematodes, aiming at utilizing them for potential available nematicides. 

Classification of Cyst Nematodes and Research History to Elucidate the Naturally Occurring Hatching Stimulants... 

The secretion of hatching stimulants for PCN from the potato root was first observed by Baunacke in 1922 [1]. Todd s group attempted the isolation of hatching... 

Figure 1. Chemical structures of hatching stimulants toward cyst nematodes.

After an intensive effort to isolate the hatching factors from host plant roots or their diffusates, Masamune s group hrst established the structure of hatching stimulant to SCN, glycinoeclepin A, in 1982, which was active at a concentration of as low as 10 g/niL (Figure 1) [5-8]. Subsequently, solanoeclepin A was reported as the stimulant to PCN by Mulder et al. in 1992 [9]. This compound was isolated from the hydroponic culture medium of tomato and active at 10 g/mL in an aqueous solution. In spite of their ultra-high activity, neither of these compounds has been commercialized as nematicides because of their limited solubility in water. Besides, recent research reveals that the reality of chemical hatching control is not that simple. 

Involvement of Multiple Factors in Hatching Stimulation for Cyst Nematodes... 

Figure 2. Hatching stimulating activity of the freeze-dried potato root diffusate (FD-PRD) and the effect of addition of freshly prepared PRD at the concentration of 10 g/mL.

On the other hand, the residue after the concentration by rotary evaporator was separated on normal phase gel adsorbents HP-20, Sephadex LH-20, and Toyopearl HW-40, to give 3 mg of a hatching stimulator. This material was active at 10 " g/mL. The activity of this stimulant was increased more than 100-fold by SylA and SylB. Syll had a striking synergistic activity, enhancing the hatching activity ca. 100,000-fold. 

Based on NMR spectra, the hatching stimulator is tentatively concluded to be a triterpene glycoside, whereas SylA and IB are both presumed to diesters, and Syll to be a monoester. Detailed structure analyses are in progress. 

Hatching Stimulator, Hatching Synergist, Potato Cyst Nematode, Globodera rostochiensis, Heterodera glycines. Tomato Root Diffusate... 

Constit. of Phaseolus vulgaris roots. Hatching stimulant of nematode eggs. Mp 135-137. ... 

Glycinoeclepin A (Scheme 10) was isolated from the dried root of the kidney bean [136,137]. It is a potent hatch-stimulating agent of the soybean cyst nematode, a devastating pest of host plants including soybean, kidney bean, and adzuki [138]. Four total syntheses of these compounds have been presented. In the first approach of Murai et al. [139,140] (Scheme 10), the key synthetic intermediate is the 7-oxanorbomane derivative 73 derived from 2,2-dimethylcyclohexa-l,3-dione via baker s yeast reduction into aldol 69. After protection as an ethoxyethyl ether. 

Asymmetrical reduction of some bridged bicyclic p-diketones 58, 60, 62, and 64 yielded ketols 59 [26], 61 [74], 63 [74], and 65 [74], respectively, as shown in Fig. 28. The hydroxy ketones 5 and 59 were the building blocks for the synthesis of glycinoeclepin A (Fig. 29), a degraded triterpenoid with remarkable hatch-stimulating activity against the... 

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