80483-89-2

Usage

Uses

Used in Plant Biology Research:
22(S),23(S)-Homobrassinolide is used as a brassinosteroid supplement for studying its effects on various aspects of plant growth and development. It is utilized to investigate its impact on DNA methylation, callus growth, and regeneration in barley, as well as its influence on cell elongation in Arabidopsis thaliana.
Used in Plant Growth and Development Studies:
This brassinosteroid is employed to study its effects on cell division, root germination, and the antioxidant system enzymes in barley. These studies aim to understand the underlying mechanisms of its growth-promoting and anti-stress properties, which can potentially be harnessed to improve crop yields and resilience.
Used in Agriculture:
As a new class of steroidal phytohormones, 22(S),23(S)-Homobrassinolide is used in agriculture for its high growth-promoting and anti-stress activity. It can potentially enhance crop productivity and improve plants' ability to withstand various environmental stresses, making it a valuable tool for sustainable agriculture practices.

Biochem/physiol Actions

22(S),23(S)-Homobrassinolide is a brassinosteroid. It might play a role in the control of plant embryogenesis.

InChI:InChI=1/C29H50O6/c1-7-18(14(2)3)25(32)24(31)15(4)28-23-22(20-13-17(30)10-11-19(20)16(5)35-28)27(34)26(33)21-9-8-12-29(21,23)6/h14-16,18-28,31-34H,7-13H2,1-6H3/t15?,16-,18-,19+,20?,21?,22?,23?,24-,25-,26+,27-,28-,29-/m0/s1

Synthetic route

(22E,24S)-B-homo-7-oxa-5α-stigmasta-2,22-dien-6-one (99647-00-4) → (22S,23S)-28-homobrassinolide (80483-89-2)

Conditions	Yield
With osmium(VIII) oxide; sulfuric acid; sodium sulfite 1.) pyridine, room temp. 30h, 2.) 45 - 50 deg C, 0.5h;	95%

(2α,3α,22S,23S)-tetraacetoxy-B-homo-7-oxastigmastan-6-one (80483-88-1) → (22S,23S)-28-homobrassinolide (80483-89-2)

Conditions	Yield
Stage #1: (2α,3α,22S,23S)-tetraacetoxy-B-homo-7-oxastigmastan-6-one With potassium carbonate In methanol for 4h; Heating; Stage #2: With hydrogenchloride In methanol for 1h; Heating;	84%
With sodium hydroxide In methanol; water for 1h; Heating;	70%
Yield given;
With hydrogenchloride; potassium carbonate 1.) MeOH, reflux, 4 h, 2.) 90 deg C, 30 min; Yield given. Multistep reaction;

(2R,3S,22S,23S)-2,3;22,23,-di-isopropylidenedioxy-B-homo-7-oxa-5α-stigmastan 6-one (110556-61-1) → (22S,23S)-28-homobrassinolide (80483-89-2)

Conditions	Yield
With hydrogenchloride In methanol for 1h; Heating; Yield given;

(22E)-stigmasta-2,22-dien-6-one (74174-45-1) → (22S,23S)-28-homobrassinolide (80483-89-2)

Conditions

Yield

Multi-step reaction with 8 steps 1: 1.) lithium di-isopropylamide, 2.) triethylamine / 1.) THF, -78 deg C, 1 h; 2.) -78 deg C, 15 min; rt, 1 h. 2: 1.) osmium tetraoxide; 2.) hydrogen sulphide / 1.) pyridine, 70 h; 2.) MeOH-CH2Cl2, 7 h. 3: toluene-p-sulphonic acid / CH2Cl2 / 2 h / 0 °C 4: periodic acid dihydrate / diethyl ether / 1.) 0 deg C, 1 h; 2.) rt, 3 h. 5: diethyl ether / 0 °C 6: sodium borohydride / diethyl ether; methanol; propan-2-ol / 0.5 h / 0 °C 7: toluene / 0.17 h / Heating 8: HCl / methanol / 1 h / Heating View Scheme

(22E,24S)-3β-bromo-5α-stigmasta-22-en-6-one (92804-65-4) → (22S,23S)-28-homobrassinolide (80483-89-2)

Conditions	Yield
Multi-step reaction with 3 steps 1: 37 percent / Br2 / CHCl3 2: 54 percent / lithium carbonate / dimethylformamide / 1 h / Heating 3: 95 percent / 1.) osmium tetroxide, 2.)sodium sulfite, sulfuric acid / 1.) pyridine, room temp. 30h, 2.) 45 - 50 deg C, 0.5h View Scheme

3β,22R,23S-tribromo-24S-ethyl-5α-cholestan-6-one (99646-98-7) → (22S,23S)-28-homobrassinolide (80483-89-2)

Conditions	Yield
Multi-step reaction with 2 steps 1: 54 percent / lithium carbonate / dimethylformamide / 1 h / Heating 2: 95 percent / 1.) osmium tetroxide, 2.)sodium sulfite, sulfuric acid / 1.) pyridine, room temp. 30h, 2.) 45 - 50 deg C, 0.5h View Scheme

6-trimethylsiloxy-5α-stigmasta-2,6,22-triene (110556-55-3) → (22S,23S)-28-homobrassinolide (80483-89-2)

Conditions

Yield

Multi-step reaction with 7 steps 1: 1.) osmium tetraoxide; 2.) hydrogen sulphide / 1.) pyridine, 70 h; 2.) MeOH-CH2Cl2, 7 h. 2: toluene-p-sulphonic acid / CH2Cl2 / 2 h / 0 °C 3: periodic acid dihydrate / diethyl ether / 1.) 0 deg C, 1 h; 2.) rt, 3 h. 4: diethyl ether / 0 °C 5: sodium borohydride / diethyl ether; methanol; propan-2-ol / 0.5 h / 0 °C 6: toluene / 0.17 h / Heating 7: HCl / methanol / 1 h / Heating View Scheme

(2R,3S,7S,22S,23S)-2,3,7,22,23-pentahydroxy-5α-stigmastan-6-one (110556-56-4) → (22S,23S)-28-homobrassinolide (80483-89-2)

Conditions	Yield
Multi-step reaction with 6 steps 1: toluene-p-sulphonic acid / CH2Cl2 / 2 h / 0 °C 2: periodic acid dihydrate / diethyl ether / 1.) 0 deg C, 1 h; 2.) rt, 3 h. 3: diethyl ether / 0 °C 4: sodium borohydride / diethyl ether; methanol; propan-2-ol / 0.5 h / 0 °C 5: toluene / 0.17 h / Heating 6: HCl / methanol / 1 h / Heating View Scheme

(2R,3S,7S,22S,23S)-7-hydroxy-2,3;22,23-di-isopropylidenedioxy-5α-stigmastan-6-one (110556-57-5) → (22S,23S)-28-homobrassinolide (80483-89-2)

Conditions	Yield
Multi-step reaction with 5 steps 1: periodic acid dihydrate / diethyl ether / 1.) 0 deg C, 1 h; 2.) rt, 3 h. 2: diethyl ether / 0 °C 3: sodium borohydride / diethyl ether; methanol; propan-2-ol / 0.5 h / 0 °C 4: toluene / 0.17 h / Heating 5: HCl / methanol / 1 h / Heating View Scheme

methyl (2R,3S,22S,23S)-7-hydroxy-2,3;22,23-di-isopropylidene-dioxy-6,7-seco-5α-stigmastan-6-oate (110556-60-0) → (22S,23S)-28-homobrassinolide (80483-89-2)

Conditions	Yield
Multi-step reaction with 2 steps 1: toluene / 0.17 h / Heating 2: HCl / methanol / 1 h / Heating View Scheme

(2R,3S,22S,23S)-2,3;22,23-di-isopropylidenedioxy-7-oxo-6,7-seco-5α-stigmastan-6-oic acid (110556-58-6) → (22S,23S)-28-homobrassinolide (80483-89-2)

Conditions	Yield
Multi-step reaction with 4 steps 1: diethyl ether / 0 °C 2: sodium borohydride / diethyl ether; methanol; propan-2-ol / 0.5 h / 0 °C 3: toluene / 0.17 h / Heating 4: HCl / methanol / 1 h / Heating View Scheme

methyl (2R,3S,22S,23S)-2,3;22,23-di-isopropylidenedioxy-7-oxo-6,7-seco-5α-stigmastan-6-oate (110556-59-7) → (22S,23S)-28-homobrassinolide (80483-89-2)

Conditions	Yield
Multi-step reaction with 3 steps 1: sodium borohydride / diethyl ether; methanol; propan-2-ol / 0.5 h / 0 °C 2: toluene / 0.17 h / Heating 3: HCl / methanol / 1 h / Heating View Scheme

C29H48O4 → (22S,23S)-28-homobrassinolide (80483-89-2)

Conditions	Yield
With osmium(VIII) oxide

Upstream product

• 99647-00-4 (22E,24S)-B-homo-7-oxa-5α-stigmasta-2,22-dien-6-one 
• 110556-61-1 (2R,3S,22S,23S)-2,3;22,23,-di-isopropylidenedioxy-B-homo-7-oxa-5α-stigmastan 6-one 
• 80483-88-1 (2α,3α,22S,23S)-tetraacetoxy-B-homo-7-oxastigmastan-6-one 
• 74174-45-1 (22E)-stigmasta-2,22-dien-6-one 
• 92804-65-4 (22E,24S)-3β-bromo-5α-stigmasta-22-en-6-one 
• 99646-98-7 3β,22R,23S-tribromo-24S-ethyl-5α-cholestan-6-one 
• 110556-55-3 6-trimethylsiloxy-5α-stigmasta-2,6,22-triene 
• 110556-56-4 (2R,3S,7S,22S,23S)-2,3,7,22,23-pentahydroxy-5α-stigmastan-6-one 
• 110556-57-5 (2R,3S,7S,22S,23S)-7-hydroxy-2,3;22,23-di-isopropylidenedioxy-5α-stigmastan-6-one 
• 110556-60-0 methyl (2R,3S,22S,23S)-7-hydroxy-2,3;22,23-di-isopropylidene-dioxy-6,7-seco-5α-stigmastan-6-oate 
• 110556-58-6 (2R,3S,22S,23S)-2,3;22,23-di-isopropylidenedioxy-7-oxo-6,7-seco-5α-stigmastan-6-oic acid 
• 110556-59-7 methyl (2R,3S,22S,23S)-2,3;22,23-di-isopropylidenedioxy-7-oxo-6,7-seco-5α-stigmastan-6-oate 
• 74174-48-4 Acetic acid (1S,3aS,3bS,6aS,8S,9R,10aR,10bS,12aS)-8-acetoxy-1-((1S,2S,3S,4S)-2,3-diacetoxy-4-ethyl-1,5-dimethyl-hexyl)-10a,12a-dimethyl-6-oxo-hexadecahydro-5-oxa-benzo[3,4]cyclohepta[1,2-e]inden-9-yl ester 
• 74174-48-4 Acetic acid (1S,3aS,3bS,6aS,8S,9R,10aR,10bS,12aS)-8-acetoxy-1-((1S,2R,3R,4S)-2,3-diacetoxy-4-ethyl-1,5-dimethyl-hexyl)-10a,12a-dimethyl-6-oxo-hexadecahydro-5-oxa-benzo[3,4]cyclohepta[1,2-e]inden-9-yl ester 

Relevant academic research and scientific papers

Toxicity of (22R,23R)-22,23-dihydroxystigmastane derivatives to cultured cancer cells

Toxicity of eight 22,23-dihydroxystigmastane derivatives (four pairs of (22R,23R)- and (22S,23S)-isomers differing in steroid backbone structure) to human breast carcinoma MCF-7 cells was compared. For every pair of structurally related compounds, (22R,23

New route for the synthesis of (22S,23S)-28-homobrassinolide

A new and highly efficient synthesis of (22S,23S)-28-homobrassinolide (3) has been achieved. (2α,3α,22S,23S)-Tetrahydroxy-5α-stigmastan-6-one (4), a key intermediate for the synthesis of 3, and (2α,3α)-dihydroxy-5α-stigmast-22-en-6-one (6), a versatile intermediate for the synthesis of 3, and several naturally occurring brassinosteroids have been obtained in excellent yield from stigmasta-2,(22E)-dien-6-one (5) by catalytic RuO4 hydroxylation. Sodium perborate, a cheap and large-scale industrial chemical is used for Baeyer-Villiger oxidation of B-ring ketone 9 to its lactone 10.

SYNTHESIS OF 22S,23S-BRASSINOSTEROIDS BASED ON STIGMASTEROL

The analogs of 29C-brassinosteroids based on stigmasterol , i.e., 22S,23S-homocastasterone and 22S,23S-homobrassinolide, were synthesized.Electrophilic additions at the Δ22-bond, hydroxylation with osmium tetroxide, and epoxidation followed by conversion of the epoxide into the diol were used for the construction of the 22S,23S-diol grouping.

Synthesis of (2R,3S,22S,23S)-2,3,22,23-Tetrahydroxy-B-homo-7-aza-5α-stigmastan-6-one, an Aza-analogue of Homobrassinolide

(2R,3S,22S,23S)-2,3,22,23-Tetrahydroxy-B-homo-7-aza-5α-stigmastan-6-one, an aza-analogue of homobrassinolide, has been synthesized starting with 5α-stigmasta-2,22-dien-6-one.Osmylation of the trimethylsilyl enol ether of this dienone afforded (2R,3S,7S,22S,23S)-2,3,7,22,23-pentahydroxy-5α-stigmastan-6-one, which by oxidation of the acyloin group, after protection of the glycolic systems, afforded (by esterification) an aldehydo ester, which is the key intermediate for the production of the final compound by reductive amination.

Synthesis of (22R,23R)-28-Homobrassinolide

(22R,23R)-28-Homobrassinolide (18), an analog of brassinolide (1), was synthesized from stigmasterol (3).Keywords - brassinolide; plant growth-promoting substance; active analogs of brassinolide; structure-activity relationship; stigmasterol; plant hormones; Baeyer-Villiger oxidation

SYNTHESIS OF (22S,23S)-HOMOBRASSINOLIDE AND BRASSINOLIDE FROM STIGMASTEROL

(22S, 23S)-Homobrassinolide (2α, 3α, 22S, 23S-tetrahydroxy-24S-ethyl-B-homo-7-oxa-5α-cholestan-6-one) and brassinolide (2α, 3α, 22R, 23R-tetrahydroxy-24S-methyl-B-homo-7-oxa-5α-cholestan-6-one) were synthesized from stigmasterol and shown to promote plant growth.

Synthesis and Plant Growth-promoting Activity of Brassinolide Analogues

The analogues of brassinolide, 15, 19-23 and 30, were synthezised via key intermediate 5 from stigmasterol.Compound 15 which has the same functional groups as brassinolide on rings A and B showed one tenth of the activity of brassinolide in the lamina inclination test on rice seedlings.However, other analogues with modified ring A were poorly active, and an analogue with modified ring B, 6-oxa-ketone 30, showed only one hundredth of the activity of its 7-oxa-ketone isomer, 29, suggesting that the 2α,3α-dihydroxy-7-oxa-6-ketone moiety is one of the requisites fro the biological activity.