Synthesis of polyhydroxysterols (V): efficient and stereospecific synthesis of 24-methylene-cholest-5-ene-3β,7α-diol and its C-7 epimer

Lü, Weigang; Zhang, Cui‐Xian; Zeng, Lang; Su, Jingyu

doi:10.1016/j.steroids.2004.09.010

Cited by 17 publications

(19 citation statements)

References 12 publications

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“…Compound 10 was obtained as a colorless solid and, based on MS, IR, 1D, and 2D NMR data, identified as 24-methylenecholesterol (10). 1,3,[49][50][51][52] Comparison of the 1 H NMR data of 10 with those reported by Su et al 52 for a synthetic sample (Table S11 †) and of the 13 C NMR shift values with those reported for a sample isolated from Litophyton viridis 51 (Table S12 †) confirmed the assignment. 24-Methylenecholesterol (10) has been found in various soft corals, for example, Capnella imbricata, 53 Litophyton viridis, 51 Sinularia flexibilis, 54 Sinularia maxima, 55 and Sinularia vander-landi.…”

Section: Capnella Fungiformissupporting

confidence: 55%

Isolation and structure elucidation of natural products of three soft corals and a sponge from the coast of Madagascar

et al. 2017

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We investigated the three soft corals Sarcophyton stellatum, Capnella fungiformis and Lobophytum crassum and the sponge Pseudoceratina arabica, which have been collected at the coast of Madagascar. In addition to previously known marine natural products, S. stellatum provided the new (+)-enantiomer of the cembranoid (1E,3E,11E)-7,8-epoxycembra-1,3,11,15-tetraene (2). Capnella fungiformis afforded three new natural products, ethyl 5-[(1E,5Z)-2,6-dimethylocta-1,5,7-trienyl]furan-3-carboxylate (6), ethyl 5-[(1E,5E)-2,6-dimethylocta-1,5,7-trienyl]furan-3-carboxylate (7) and the diepoxyguaiane sesquiterpene oxyfungiformin (9a). The extracts of all three soft corals exhibited moderate activities against the malarial parasite Plasmodium falciparum. Extracts of the sponge Pseudoceratina arabica proved to be very active against a series of Gram-positive and Gram-negative bacteria.

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Section: Capnella Fungiformissupporting

confidence: 55%

Isolation and structure elucidation of natural products of three soft corals and a sponge from the coast of Madagascar

et al. 2017

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“…The structure of the converted products of cholesterol was characterized, products 1 and 2 were 7-b-hydroxycholesterol and 7-oxocholesterol, respectively. This determination also agreed with the data found in the literature [20,21]. These products are the same as the products obtained by Dan Fan [22] 16 Cuiping Pang et al Optimal conditions for strain cultivation and 16,17-alpha epoxypregnenolone transformation The optimal experiment was used to investigate the biotransformation of 16,17-alpha epoxypregnenolone by Cladosporium sp.…”

Section: Structural Identification Of the Converted Productssupporting

confidence: 87%

Biotransformation of cholesterol and 16,17‐alpha epoxypregnenolone by novel Cladosporium sp. strain IS547

Pang

Cao

Zhu

2016

J. Basic Microbiol.

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Nowadays, there are a few steroid drugs or intermediates that have been obtained via the transformation of microorganisms, and many strains of transformed steroids have not been found yet. Therefore, it is very significant to screen for the strains that have the abilities to transform steroids to produce valuable products. This study has focused on the screen and identification of strains, the structural identification of converted products, and the optimization of transformation conditions, as well as the establishment of transformation systems. A soil microbiota was screened for strain involved in the biotransformation of steroids. A new isolate IS547 is capable of converting a variety of steroids (such as cholesterol, ergosterol, hydrocortisone, progesterone, pregnenolone, and 16,17-alpha-epoxypregnenolone). Based on the 18S rDNA gene sequence comparison, the isolate IS547 has been demonstrated to be very closely related to Cladosporium sp. genus. Present paper is the first report regarding the microbial transformation by Cladosporium sp. to produce active intermediates, which include 7-hydroxy cholesterol, 20-droxyl-16α,17α-epoxypregna-4-dien-3-one, 7-ketocholesterol, and 7-droxyl-16α,17α-epoxypregna-4-dien-3,20-dione. Under the optimum conditions, the yields of product 3 and product 4 were 20.58 and 17.42%, respectively, higher than that prior to the optimization. The transformation rate increased significantly under the optimum fermentation conditions. This study describes an efficient, rapid, and inexpensive biotransformation system for the production of active pharmaceutical intermediates.

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“…Cholesterol is oxidized at allylic position using chromium trioxide and further reduced with sodium borohydride to 7-hydroxycholesterol-3-acetate. 7-Hydroxycholesterol-3-acetate esterification produces cholestrol-3,7-diacetate [11]. Choleterol-3,7-diacetate formation is also reported by using electrochemical oxidation of cholesterol [12].…”

Section: -Dehydrocholesterol Is An Important Precursor Of Vitamin Dmentioning

confidence: 99%

<b>Synthesis of 7-dehydrocholesterol through hexacarbonyl molybdenum catalyzed elimination reaction</b>

Rahman

Tian

2011

Bull. Chem. Soc. Eth.

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ABSTRACT ABSTRACT. The efficiency of hexacarbonyl molybdenum catalyzed elimination reaction of the allylic acetates has been improved by the presence of O,N-bis(trimethylsilyl) acetamide in the reaction medium. The methodology is particularly well employed for the elimination of 7-acetoxycholesterol-3-acetate(cholestrol-3,7-diacetate) for which the resulting product obtained was exclusively 5,7-homoannular diene(7-dehydrocholesterol-3-acetate). Good yield is achieved (up to 70 %) while decreasing the side products formation and reducing the costs as compared to the previously used procedures. Hexacarbonyl molybdenum elimination reaction is greatly influenced by the reaction temperature, at low as well as at high temperature low yield of the homoannular diene product is separated while at moderate conditions of temperature high products formation is observed. KEY WORDS KEY WORDS KEY WORDS

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Synthesis of polyhydroxysterols (V): efficient and stereospecific synthesis of 24-methylene-cholest-5-ene-3β,7α-diol and its C-7 epimer

Cited by 17 publications

References 12 publications

Isolation and structure elucidation of natural products of three soft corals and a sponge from the coast of Madagascar

Isolation and structure elucidation of natural products of three soft corals and a sponge from the coast of Madagascar

Biotransformation of cholesterol and 16,17‐alpha epoxypregnenolone by novel Cladosporium sp. strain IS547

<b>Synthesis of 7-dehydrocholesterol through hexacarbonyl molybdenum catalyzed elimination reaction</b>

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