CS270776B1 - 2cZ, 3β-Oihydroxy-178- (3'-methyl) -butyryloxy-7-oxa-B-homo-5α -androstane-6-one - Google Patents

Abstract

The solution relates to a new compound, 2=6, 3 ’4-dihydroxy-170-(3_^methyl)-butyryloxy- -7-oxa-8-homo-5o6 -androstan-6-one, which affects plant growth in a similar manner to the plant hormone brassinolide, and a method for preparing this compound.

Description

The present invention relates to a novel compound, 2,3cZ-dihydroxy-17β- (3-methyl) -butyryloxy-7-oxa-β-homo-5α-androstan-6-one, which has brassinolide activity, characterized in that affects the growth of plants, and the method of its preparation.

In 1979 / Grove M.D. et al .: Nature (London) 281, 216 (1979).] The plant hormone brassinolide was isolated, which causes cell division and elongation, thus affecting plant growth. The accessibility of brassinolide by insulation from natural material is very difficult because it occurs in very low concentrations. For example, in Rapeseed Pollen / Grove M.D. et al., Nature (London) 281, 216 (1979). Biol. Chem. 47, 655 (1983). (0.005 ppm, in Chinese cabbage) [Morishita T. et al .: Phytochemistry 22, 1051 (1983).] 0.000003 ppm and the like. The accessibility of brassinolide and its analogue by synthesis is also very difficult due to the complexity of the synthetic procedures and the low yields of notices, for example: Abe et al .: Agr. Biol. Chem. 46, 2609 (1982), Fung S. et al .: 0. Amer. Chem. Soc. 102, 6580 (1980), Inshiguro M. et al .: J, Chem. Soc., Chem. Commun. 1980, 962, Thompson M.J. et al .: Steroids £ 8, 567 (1981), Aburatani M. et al .: Agr. Biol. Chem. 50, 3043 (1986.), for a summary see, for example: Adam G. et al .: Zeitschrift fur Chemie 27, 41 (1987), Czechoslovak Patent No. 252,605 and the like. None of the synthetically prepared compounds has had two properties at the same time that are important for its practical applicability: easy availability and high efficacy. The condition of easy accessibility is met by our compound 2o, 3o, 170-trihydroxy-5-androstan-6-one, which we described in Cs. No. 252,605. This compound shows significant activity in the bean internode test, but even at high concentrations it does not achieve the typical brassinolide cleavage activity2. internode. Thus, it is desirable to obtain a compound that is easy to prepare and has high potency.

During a study of the synthesis and efficacy of a brassinolide analog, we unexpectedly found that the 2α, 3β-dihydroxy-170- (methyl) -butyryloxy) -7-oxa-β-homo-5β-androstan-6-one of formula I

shows typical brassinolide activity in the second bean internode test / ^- Mitchell JW et al .: Methods of Studying Plant Hormones and Growth Regulating Substances, Agriculture Handbook No. 336, p. 26, U.S. Government Printing Office, Washington DC, 1968.J, which is a test used to determine brassinolide efficacy.

The present invention relates to 2 ', 3Z-dihydroxy-17G- (3-methyl) -butyryloxy-7-oxa-β-homo-5'-4-androstan-6-one of the above formula I, which affects plant growth, and a process for the preparation of this compound by reacting a compound of formula II

(II),

CS 270776 B1 in which R ¹ and R ² represent, independently of one another, a suitable protecting group which can be selectively removed from the molecule in addition to 170- (3-methyl-D-butyryloxy), preferably R 1 and R 2 represent CH 2 CO- or R together with R represents group

CH, v.

3) O, CH 2 by the action of an acidic medium, for example dilute hydrochloric acid, or an alkaline medium, for example by the action of an alkali metal carbonate, such as sodium carbonate or potassium carbonate, is converted into a compound of the above formula I.

The efficacy of a compound of the above formula I according to the invention on plant growth is compared with that of epibrassinolide, a compound which is close in activity to natural brassinolide. It is clear from the data obtained that the compound of formula I, despite its much simpler structure compared to epibrassinolide, shows considerable brassinolide activity. At an applied amount of 10 ⁷ mol, there is even a typically brassinolide effect - the second internode of the test plant is split.

The following examples are intended to illustrate the invention in more detail, but are not intended to limit the scope of the invention.

Example 1

Preparation of 2,4,3-dihydroxy-170- (3-methyl) -butyryloxy-7-oxa-8-homo-5Z-androstan-6-one from 1-2 compounds of formula II wherein R ¹ R means a CH 2 CO- group.

To a solution of 2 ', 3', 4-diacetoxy-17β- (3'-methyl) -butyryloxy-7-oxy-.beta.-homo-5-androstan-6-one (220 mg) in methanol (14 ml) was added a solution of potassium carbonate (127 mg) in water (1.3 ml). The mixture was allowed to stand for thirty minutes at room temperature. Then, the reaction mixture was poured into chloroform, the chloroform layer was washed with water, separated, dried over sodium sulfate, and the solvent was distilled off under reduced pressure. 195 mg of residue are thus obtained, which, after purification by chromatography on a column of silica gel (200 g, elution with a 1: 1 mixture of chloroform and ether), gives 141 mg of the non-crystallising diol given in the title of this example. IR spectrum (carbon tetrachloride): 3445 (hydroxyl groups), 1737, 1728, 1712, 11-9 (170-ester), 172Θ, 1712, 1297 (lactone) cm- ¹ . Mass spectrum (m / z): 422 (M ⁺ ), 404, 377, 355. ¹ H NMR Spectrum: 0.82 s, 3H (H-18), 0.92 s, 3H (H-19), , 95 d, 6H (170-ester methyl groups), 3.42 to 4.18 m, 2H (H-2B and H-30), 4.05 br d, 2H (0 = 5 Hz, H-7a) , 4.61 m, 1 Η (« _1/2 = 19 Hz, H-17Z). For C ₂₄ H ₃₈ 0 ₆ (422.5) calculated: 68.22% C, 9.06% H, found: 67.99% C, 9.01% H.

Example 2

Preparation of 2α-1,3 '(-dihydroxy-17β- (3-methyl) -butyryloxy-7-oxa-β-homo-5α-androstan-6-one from a compound of formula II, wherein R and R together they represent the group CH, __ ·, C. '

A 0.1 mL solution of 2d, -isopropylidenedioxy-17β- (3-methyl) -butyryloxy-7-oxa-β-homo-5,6-androstan-6-one (110 mg) in methanol (10 mL) was added. 37¾ hydrochloric acid. After standing at room temperature for 90 minutes, 10 ml of benzene and 5 ml of ethanol are added and the whole is distilled off under reduced pressure to dryness. G9 g of oily 2- (3,4-dihydroxy-17β- (3-methyl) -butyryloxy-7-oxa-.beta.-homo-5H- -androstan-6-one are obtained, the spectroscopic properties of which (IR) ( ¹ H NMR) were identical to that prepared in Example 1.

Example 3

Test 2 ^ o, 3 «^ - dihydroxy-17 (3-methyl) butyryloxy-7-oxa-B-homo-5 <K / - _{T and an} nprQ _6_ _orll j _{at the} second internode of beans

Bean seeds (Phaseolus. Vulgaris, - var. Pinto) are planted in pots (diameter 7.0 cm) containing vermiculite and Hoagland's solution (half concentration, pH 5.7). The plants are grown in a greenhouse at 23-27 ° C with 6,000 lux lighting for 16 hours a day. Various

CS 270776 B1 amounts (in moles) of test compound in 2 [mu] l of lanolin are applied to groups B of 7-day-old plants with a second internode 2 mm long. Lanolin alone is applied to control plants. The method of application is described in the literature / Mitchell J. W. et al .: Methods of Studying Plant Hormones and Growth Regulating Substances, Agriculture Handbook No. 336, pp. 26.05 Government Printing Office, Washington 0. 0., 1968). The evaluation is performed on the fifth day after application. In the evaluation, the length of the second internode of the test and control plants is measured. The difference between these lengths is used as a measure of the potency of these compounds. In the case of maximum efficiency, the internode is amplified or even split.

Test results of 2,3-dihydroxy-170- (3'-methyl) -butyryloxy-7-oxa-β-homo-5H-androstan-6-one (compound of formula I) and its comparison with epibrassinolide [( 22R, 23R, 24R) 2a, 3, 22, 23-tetrahydroxy-24-methyl-β-homo-7-oxa-5,4-cholestan-6-one 7 are listed in Table I.

Table I

Test results

The applied dose of 2.10 moles' ⁷ 10 ^-7 1O ^'B ΙΟ' ⁹ ΙΟ ^'10 ID of' ¹¹ ID ^-12 elongation of the second internode given the applied dose (mm): bean at a compound of formula I epibrassinolide 12.2 13.6 ⁺ 6.5 4.2 3.6 - - 20.7 ⁺ 24.9 26.8 2.6 19.6 0.6 13.3

+ The 2nd internode of the tested plants was split

Claims (3)

OBJECT OF THE INVENTION 1. 2-6,3-Dihydroxy-170- (3-methyl) -butyryloxy-7-oxa-β-homo-5α <<-androstan-6-one of formula I__ HIM 2. A process for the preparation of a compound of formula II R ^X O R ² O ° '' --- r ° XCO Χ / ^ γΧ ^ (I), nf ⁰ I, characterized in that the compound of general formula 1 ------ --1 ^c0 (II), «r CS 270776 Bl Wherein R and R are, independently of one another, a selectively removable protecting group, are converted into a compound of formula I by the action of an alkaline or acidic medium. 3. The process according to item 2, characterized in that R and R individually represent an acetyl group or together a CH 2 group.