著者
松田 彰 小尾 紀行 宮坂 貞
出版者
The Pharmaceutical Society of Japan
雑誌
Chemical and Pharmaceutical Bulletin (ISSN:00092363)
巻号頁・発行日
vol.33, no.6, pp.2575-2578, 1985-06-25 (Released:2008-03-31)
参考文献数
21
被引用文献数
13 18

Reaction of 2', 3', 5'-tri-O-benzoyluridine (3) with 1-methylimidazole in the presence of phosphoryl chloride in acetonitrile afforded 3-methyl-1-imidazolium intermediate (4), from which a variety of 4-substituted pyrimidin-2 (1H)-one ribosides (5-12) were obtained in a one-pot manner by nucleophilic substitutions under mild conditions. Application of this method to 2'-deoxyriboside of several pyrimidines (13a, b, c) is also described.
著者
沢田 誠吾 野方 健一郎 古田 富雄 横倉 輝男 宮坂 貞
出版者
公益社団法人日本薬学会
雑誌
Chemical & pharmaceutical bulletin (ISSN:00092363)
巻号頁・発行日
vol.39, no.10, pp.2574-2580, 1991-10-25

A radical substitution reaction of 20(S)-camptothecin (1) with methanol furnished 7-hydroxymethylcamptothecin (2). Reaction of 1 with primary alcohols higher than methanol gave 7-alkylcamptothecins (4), of which alkyl groups were one carbon less than the alcohols used and also 7-hydroxyalkylcamptothecins (5). For the preparation of 7-alkylcamptothecin (4), aldehydes were used as a radical source and several alkylated derivatives were synthesized. 7-Acyloxymethyl derivatives (6), 7-carbaldehyde (7), iminomethyl derivatives (10), acid (11), esters (12) and amides (13) were synthesized starting from 2. 7-Ethyl-(4b) and 7-propylcamptothecin (4c), acyloxymethyl compounds 6a, 6c and ethyl ester (12b) exhibited higher antitumor activity than 1 against L1210 in mice.
著者
八重樫 隆 野方 健一郎 沢田 誠吾 古田 富雄 横倉 輝男 宮坂 貞
出版者
公益社団法人日本薬学会
雑誌
Chemical & pharmaceutical bulletin (ISSN:00092363)
巻号頁・発行日
vol.40, no.1, pp.131-135, 1992-01-25

Water-soluble derivatives having the lactone ring intact were synthesized starting from 7-ethyl-10-hydroxycamptothecin (1). Glycosides (2) of the phenolic hydroxyl group of 1 were obtained by reaction with acetylated α-bromosugars in acetone or aqueous acetone in the presence of potassium carbonate, followed by deprotection.Phosphates (3) were prepared by reaction of 1 with phosphoryl chloride in pyridine or with dibenzylchlorophosphoridate.Sulfates (4) were obtained by reaction of 1 with sulfur trioxide-pyridine complex in the presence of a tertiary amine.The organic ammonium salts of monophosphate (3p) and sulfates (4a and 4b) showed significant activity against L1210 in vivo.
著者
沢田 誠吾 八重樫 隆 古田 富雄 横倉 輝男 宮坂 貞
出版者
公益社団法人日本薬学会
雑誌
Chemical & pharmaceutical bulletin (ISSN:00092363)
巻号頁・発行日
vol.41, no.2, pp.310-313, 1993-02-15

7-Ethylcamptothecin (1d), a model which does not have any site on the A-ring for further modification was converted into water-soluble derivatives by opening the E-ring lactone. 1d was heated in N, N-dimethylenediamine to yield amide 2a, and this was then acylated to furnish 3a-q, which were soluble in water as their HCl salts. The propionyl (3b), butyryl (3c) and methylthiopropionyl (3h) derivatives showed higher activity than the sodium salt of 1d. The acyl group makes the derivatives more lipophilic, and ease of hydrolysis of amide 2a to 1d is thought to be necessary for significant activity.
著者
沢田 誠吾 野方 健一郎 古田 富雄 横倉 輝男 宮坂 貞
出版者
公益社団法人 日本薬学会
雑誌
CHEMICAL & PHARMACEUTICAL BULLETIN (ISSN:00092363)
巻号頁・発行日
vol.39, no.10, pp.2574-2580, 1991
被引用文献数
56

A radical substitution reaction of 20(S)-camptothecin (1) with methanol furnished 7-hydroxymethylcamptothecin (2). Reaction of 1 with primary alcohols higher than methanol gave 7-alkylcamptothecins (4), of which alkyl groups were one carbon less than the alcohols used and also 7-hydroxyalkylcamptothecins (5). For the preparation of 7-alkylcamptothecin (4), aldehydes were used as a radical source and several alkylated derivatives were synthesized. 7-Acyloxymethyl derivatives (6), 7-carbaldehyde (7), iminomethyl derivatives (10), acid (11), esters (12) and amides (13) were synthesized starting from 2. 7-Ethyl-(4b) and 7-propylcamptothecin (4c), acyloxymethyl compounds 6a, 6c and ethyl ester (12b) exhibited higher antitumor activity than 1 against L1210 in mice.
著者
沢田 誠吾 松岡 俊一 野方 健一郎 永田 洋 古田 富雄 横倉 輝男 宮坂 貞
出版者
公益社団法人 日本薬学会
雑誌
CHEMICAL & PHARMACEUTICAL BULLETIN (ISSN:00092363)
巻号頁・発行日
vol.39, no.12, pp.3183-3188, 1991
被引用文献数
57

20(S)-Camptothecin derivatives having nitro, amino, chloro, bromo, hydroxyl and methoxyl groups in the A-ring were synthesized. B-Ring hydrogenated camptothecin (2a) was converted into 10-hydroxycamptothecin (6e) by treatment with lead tetraacetate in trifluoroacetic acid. 10-Substituted derivatives (6) were obtained by a photoreaction of N-oxides (9). The cytotoxicity o the A-ring modified camptothecins was evaluated against KB cells in vitro and leukemia L1210 in mice. 7-Ethyl-10-hydroxycamptothecin (6i) was identified as a potential derivative for further modification.
著者
沢田 誠吾 岡島 悟 相山 律男 野方 健一郎 古田 富雄 横倉 輝雄 杉野 栄一 山口 健太郎 宮坂 貞
出版者
公益社団法人日本薬学会
雑誌
Chem. Pharm. Bull. (ISSN:00092363)
巻号頁・発行日
vol.39, pp.1446-1454, 1991
被引用文献数
9

Nevel 36 derivatives (6), bonding the phenolic hydroxyl group of 7-ethyl-10-hydroxycamptothecin (4) with diamines through a monocarbamate linkage, were synthesized and their antitumor activity was evaluated in vivo. The derivatives were soluble in water as their HC1 salts wiht the E lactone ring intact and exhibited significant antitumor activity. One of the derivatives, 6-27 showed excellent activity against L1210 leukemia and other murine tumors.The structure of its hydrochloride trihydrate (CPT-11) was determined by spectroscopic and crystallographic methods.
著者
八重樫 隆 沢田 誠吾 永田 洋 古田 富雄 横倉 輝男 宮坂 貞
出版者
公益社団法人 日本薬学会
雑誌
CHEMICAL & PHARMACEUTICAL BULLETIN (ISSN:00092363)
巻号頁・発行日
vol.42, no.12, pp.2518-2525, 1994
被引用文献数
42

Twenty-six novel A-ring-modified 7-ethylcamptothecins (6) were synthesized by Friedlander's condensation of the chiral tricyclic ketone (5) with aminopropiophenones (4). The compounds substituted with fluorine at the 11 position showed strong cytotoxicity to KB and L1210 cells. The 11-fluoro derivatives also exhibited strong inhibitory activity on DNA topoisomerase I. Nine compounds 6 with four to ten times stronger cytotoxicity than that of camptothecin were selected and converted into water-soluble 17-O-acyl amide derivatives (8). Compounds 8e (10-Me, O-COCH<SUB>2</SUB>CH<SUB>2</SUB>SCH<SUB>3</SUB>) and 8f (11-F, O-COC<SUB>2</SUB>H<SUB>5</SUB>) showed activity towards Meth A in mice that was comparable to that of CPT-11, at lower doses than CPT-11.
著者
八重樫 隆 沢田 誠吾 永田 洋 古田 富雄 横倉 輝男 宮坂 貞
出版者
公益社団法人日本薬学会
雑誌
Chemical & pharmaceutical bulletin (ISSN:00092363)
巻号頁・発行日
vol.42, no.12, pp.2518-2525, 1994-12-15

Twenty-six novel A-ring-modified 7-ethylcamptothecins (6) were synthesized by Friedlander's condensation of the chiral tricyclic ketone (5) with aminopropiophenones (4). The compounds substituted with fluorine at the 11 position showed strong cytotoxicity to KB and L1210 cells. The 11-fluoro derivatives also exhibited strong inhibitory activity on DNA topoisomerase I. Nine compounds 6 with four to ten times stronger cytotoxicity than that of camptothecin were selected and converted into water-soluble 17-O-acyl amide derivatives (8). Compounds 8e (10-Me, O-COCH_2CH_2SCH_3) and 8f (11-F, O-COC_2H_5) showed activity towards Meth A in mice that was comparable to that of CPT-11,at lower doses than CPT-11.
著者
田中 博道 早川 弘之 宮坂 貞
出版者
The Society of Synthetic Organic Chemistry, Japan
雑誌
有機合成化学協会誌 (ISSN:00379980)
巻号頁・発行日
vol.49, no.12, pp.1142-1155, 1991-12-01 (Released:2009-11-16)
参考文献数
63
被引用文献数
2 6

Lithiation of nucleosides has been shown to be a highly general method for chemical modification of the base moiety. A wide range of substitutions can be accomplished simply by using different electrophiles in the reaction with the respective lithiated species.In the case of uridine, the protecting group of the sugar hydroxyl groups appeared to be an important determinant of the efficiency and regiochemical outcome of the lithiation. Regiospecific abstraction of H-6 in uracil moiety with LDA takes place only when 2'- and 3'-hydroxyl groups are simultaneously protected with an alkylidene group, e.g. isopropylidene group. Subsequent reaction with a variety of electrophiles furnishes 6-substituted derivatives, which are difficult to synthesize by any other methods.As an application of the C-6 lithiation with LDA, a series of 6-iodo and 6-phenylthio acyclouridines were synthesized. Among these derivatives, 1- [(2-hydroxyethoxy) methyl] -6-phenylthiothymine (HEPT) was found to be a new lead for anti-HIV agents. The activity of HEPT is highly specific to HIV-1 : other viruses, including HIV-2, are totally non-susceptible to HEPT. Further synthetic study improved the activity to a greater extent. In terms of excellent activity, low toxicity, and effectiveness against AZT-resistant HIV-1, these HEPT analogues constitute promising candidates for AIDS chemotherapy.