A diterpenoid from Elaeoselinum foetidum

A new diterpene acid has been isolated from the roots of Elaeoselinum foetidum. Its structure was established as ent-7α-senecioxy-15α-hydroxy-atis-16-en-19-oic acid by ¹H NMR and ¹³C NMR spectroscopic studies of its methyl ester derivative and confirmed by correlation with a margotianin derivative.     

Oxidized kaurene derivatives from leaves of Solidago missouriensis and S. Rigida

Oxidized kaurene derivatives were isolated from the leaves of Solidago missouriensis and S. rigida and identified as kauran-16β-ol, kaur-16-en-19-oic acid and 7β-hydroxykaur-16-en-19-oic acid. The structure of the latter compound was determined by X-ray crystallographic analysis of its methyl ester.     

A diterpenoid of the atis-16-ene class from Elaeoselinum foetidum

A new diterpenoid has been isolated from the root of Elaeoselinum foetidum. Its structure was established as ent-15α-senecioxy-atis-16-en-19-oic acid mainly by ¹H NMR ¹³C NMR spectroscopic studies of its methyl ester derivative.     

Sapogenins from Guaiacum officinale

Acid hydrolysis of the saponins from the stem bark of Guaiacum officinale yielded the new sapogenin 3β,20η-dihydroxy-30-norolean-12-en-28-oic acid and the artifacts 3β-hydroxy-30-norolean-12,19-dien-28-oic acid and its methyl ester. Larreagenin, sitosterol and oleanolic acid were also isolated.     

Kolavane and kaurane diterpenes from the stem bark of Xylopia aethiopica

The stem bark of Xylopia aethiopica has yielded four diterpenes, two of them novel. Three of the diterpenes were identified as (?)-kaur-16-en-19-oic acid and its 7-oxo and 7β-hydroxy derivatives. The fourth was the novel kolavane derivative 2-oxo-kolav-3,13-dien-15-oic acid, a type of compound not previously recorded in the Annonaceae.     

Minor diterpenoid glycosides from the leaves of Stevia rebaudiana

From the commercial extract of the leaves of Stevia rebaudiana, three new diterpenoid glycosides were isolated besides eight known steviol glycosides including stevioside, rebaudiosides A–F and dulcoside A. The structures of the three compounds were identified as 13-[(2-O-β-d-glucopyranosyl-β-d-glucopyranosyl) oxy]-kaur-16-en-18-oic acid-(6-O-β-d-xylopyranosyl-β-d-glucopyranosyl) ester (1), 13-[(2-O-β-d-glucopyranosyl-β-d-glucopyranosyl) oxy]-17-hydroxy-kaur-15-en-18-oic acid β-d-glucopyranosyl ester (2), and 13-[(2-O-β-d-glucopyranosyl-β-d-glucopyranosyl) oxy]-17-oxo-kaur-15-en-18-oic acid β-d-glucopyranosyl ester (3) on the basis of extensive NMR and MS spectral studies. Another known diterpenoid glycoside, 13-[(2-O-β-d-glucopyranosyl-β-d-glucopyranosyl) oxy]-kaur-15-en-18-oic acid β-d-glucopyranosyl ester (4) was also isolated and its complete NMR spectral assignments were made on the basis of COSY, HSQC and HMBC spectral data.     

Ent-kauren-19-oic acid derivatives from the stem bark of Croton pseudopulchellus Pax

Two new ent-kauren-19-oic acid derivatives, ent-14S*-hydroxykaur-16-en-19-oic acid and ent-14S*,17-dihydroxykaur-15-en-19-oic acid together with eleven known compounds ent-kaur-16-en-19-oic acid, ent-kaur-16-en-19-al, ent-12β-hydroxykaur-16-en-19-oic acid, ent-12β-acetoxykaur-16-en-19-oic acid, 8R,13R-epoxylabd-14-ene, eudesm-4(15)-ene-1β,6α-diol, (?)-7-epivaleran-4-one, germacra-4(15), 5E,10(14)-trien-9β-ol, acetyl aleuritolic acid, β-amyrin, and stigmasterol were isolated from the stem bark of Croton pseudopulchellus (Euphorbiaceae). Structures were determined using spectroscopic techniques. Ent-14S*-hydroxykaur-16-en-19-oic acid, ent-kaur-16-en-19-oic acid, ent-12β-hydroxykaur-16-en-19-oic acid, ent-12β-acetoxykaur-16-en-19-oic acid and 8R,13R-epoxylabd-14-ene were tested for their effects on Semliki Forest virus replication and for cytotoxicity against human liver tumour cells (Huh-7 strain) but were found to be inactive. Ent-kaur-16-en-19-oic acid, the major constituent, showed weak activity against the Plasmodium falciparum (CQS) D10 strain.     

Two triterpenes from Davidsonia pruriens

Two new triterpenoids, methyl 3-oxo-bauer-7-en-28-oate and 3β-hydroxy-bauer-7-en-28-oic acid, were isolated from the stem bark of Davidsonia pruriens and their structures were established by chemical and spectroscopic means.     

3β-hydroxy-21β-e-cinnamoyloxyolean-12-en-28-oic acid,a triterpenoid from enterolobium contorstisiliquum

The triterpenes 3β-hydroxy-21β-E-cinnamoyloxyolean-12-en-20-oic acid, 3β,21β-dihydroxyolean-12-en-28-oic acid (machaerinic acid) and its lactone (3β-hydroxyolean-12-en-21β→28-lactone) were isolated from the fruits of Enterolobium contorstisiliquum. Methyl and ethyl esters of 3β,21β-dihydroxyolean-12-en-oic acid were isolated and characterized as artifacts. The structures of these triterpenes have been established by a study of their chemical and spectroscopic (IR, MS and NMR) data.     

Synthesis of homoursodeoxycholic acid and [11,12-3H]homoursodeoxycholic acid

Homoursodeoxycholic acid and [11,12-³H]homoursodeoxycholic acid were synthesized from ursodeoxycholic acid and homocholic acid, respectively. Ursodeoxycholic acid (Ia) was converted to 3α,7β-diformoxy-5β-cholan-24-oic acid (Ib) using formic acid. Reaction of the diformoxy derivative (Ib) with thionyl chloride yielded the acid chloride (II) which was treated with diazomethane to produce 3α,7β-diformoxy-25-diazo-25-homo-5β-cholan-24-one (III). Homoursodeoxycholic acid (IV) was formed from the diazoketone (III) by means of the Wolff rearrangement of the Arndt-Eistert synthesis.N-Bromosuccinimide oxidation of homocholic acid (V), which was prepared from cholic acid by the same procedure described above, afforded 3α,12α-dihydroxy-7-oxo-25-homo-5β-cholan-25-oic acid (VI). Reduction of the 7-ketohomodeoxycholic acid (VI) with sodium in 1-propanol gave 3α,7β,12α-trihydroxy-25-homo-5β-cholan-25-oic acid (VII). The methyl ester of 7-epihomocholic acid (VII) was partially acetylated to give methyl 3α,7β-diacetoxy-12α-hydroxy-25-homo-5β-cholan-25-oate (VIII) using a mixture of acetic anhydride, pyridine and benzene. Dehydration of the diacetoxy derivative (VIII) with phosphorus oxychloride yielded methyl 3α,7β-diacetoxy-25-homo-5β-chol-11-en-25-oate (IX). Reduction of the unsaturated ester (IX) with tritium gas in the presence of platinum oxide catalyst followed by alkaline hydrolysis gave [11,12-³H]homoursodeoxycholic acid.     

A kolavane derivative from Liatris scariosa

A new kolavane derivative, 18-acetoxy-kolav-3-en-15-oic acid, has been isolated from Liatris scariosa.     

水麻的化学成分研究(英文)

从水麻(Debregeasia orientalis C J Chen)地上部分的95%乙醇提取物中首次分离到18个化合物,应用波谱方法或与已知品对照的手段鉴定它们为棕榈酸 (1)、正二十烷酸 (2)、正二十烷酸甲酯 (3)、β-谷甾醇 (4)、Monogynol A (5)、白桦酸 (6)、Hederagenin (7)、β-胡萝卜甙 (8)、18αH-20(29)-烯-3-酮-乌苏烷 (9)、3,4-开环-20(29)-烯-乌苏烷-3-酸 (10)、Pomolic acid (11)、表儿茶素 (12)、儿茶素 (13)、槲皮素 (14)、槲皮素-3-O-β-D-吡喃葡萄糖苷 (15)、紫丁香苷 (16)、紫丁香酚苷 (17)和山萘酚-3-O-β-D-芦丁糖苷 (18).     

Bioactive constituents of Helianthus tuberosus (Jerusalem artichoke)

In a cytotoxicity-guided study using the MCF-7 human breast cancer cell line, nine known compounds, ent-17-oxokaur-15(16)-en-19-oic acid (1), ent-17-hydroxykaur-15(16)-en-19-oic acid (2), ent-15β-hydroxykaur-16(17)-en-19-oic acid methyl ester (3), ent-15-nor-14-oxolabda-8(17),12E-dien-18-oic acid (4), 4,15-isoatriplicolide angelate (5), 4,15-isoatriplicolide methylacrylate (6), (+)-pinoresinol (7), (?)-loliolide (8), and vanillin (9) were isolated from the chloroform-soluble subfraction of a methanol extract of the whole plant of Helianthus tuberosus collected in Ohio, USA. This is the first time that diterpenes have been isolated and identified from this economically important plant. The bioactivities of all isolates were evaluated using the MCF-7 human breast cancer cell line as well as a soybean isoflavonoid defense activation bioassay. The results showed that two germacrane-type sesquiterpene lactones, 5 and 6, are cytotoxic agents. While compounds 2, 3, 5 and 6 blocked isoflavone accumulation in the soybean, the norisoprenoid (?)-loliolide (8) was somewhat stimulatory of these defense metabolites.     

野桂花化学成分研究

从野桂花（Osmanthus yunnanensis）地上部分95％乙醇提取物中首次分离得到18个化合物,应用波谱方法及与已知品对照的手段鉴定它们为：E-阿魏酸二十烷基酯（1）、β-谷甾醇（2）、羽扇豆醇（3）、齐墩果酸（4）、7-oxo-β—sitosterol（5）、乙酰齐墩果酸（6）、（6＇-O－palmitoyl）－sitosterol-3-O-β—D—glucoside（7）、rotundioic acid（8）、地榆糖甙II（9）、3β-hydroxy－27-p－（E）－eoumaroyloxyolean－12－en-28－oicacid（10）、3β—laydroxy-27-p－（Z）－coumaroyloxy－olean－12－en-28-oicacid（11）、hycandinic acid ester（12）、绿原酸丁酯（13）、4,5-二咖啡酰奎尼酸丁酯（14）、28-O-β-D—glueopyranosyl rottmdioic acid（16）以及三个半萜类化合物：4,5-dihydroxyprenyl caffeate（15）、4-（6-O-caffeoyl -β-D—glucopyranosyloxy）-5-hydroxyprenyl caffeate（17）、4-β-D—glucopyranosyloxy5-hydroxyprenyl caffeate（18）。     

Chemotaxonomic implications of the absence of sesquiterpene lactones in Grazielia multifida (DC.) R.M.King & H.Rob. (Asteraceae)

The phytochemical investigation of Grazielia multifida aerial parts yielded eight compounds, including four ent-kaurenic acid diterpenes derivatives, 15-tiglinoyloxy-ent-kaur-16-en-19-oic acid (1), 15-hydroxy-ent-kaur-16-en-19-oic acid (2), 17-hydroxy-ent-kaur-15-en-19-oic acid (3) and 15-isovaleroyloxy-ent-kaur-16-en-19-oic acid (4), one amino acid, tryptophan (5), and three flavonoids, eupafolin (6), guaijaverin (7) and quercitrin (8). The structures of the isolated compounds were established based on analysis of their spectroscopic data and comparison with literature. All the compounds were isolated from this species for the first time. The chemotaxonomic significance of the absence of sesquiterpene lactones in G. multifida has also been summarized.     

Ent-kaurane derivatives from the root cortex of yacon and other three Smallanthus species (Heliantheae,Asteraceae)

The metabolites produced by the secretory canals of the root cortex from four Smallanthus species belonging to the yacon group were identified as ent-kaurane-type diterpenes. The dichloromethane root cortex extracts of the four species were treated with diazomethane and analyzed comparatively by GC–MS using a simple and rapid procedure which is very sensitive and reproducible permitting detection of minor components. In all cases, ent-16-kauren-19-oic acid (kaurenoic acid) methyl ester was the main component, differences being observed only in the minor components. The minor components identified were grandiflorenic acid methyl ester, ent-16-kauren-19-al, 16α,17-epoxy-15α-angeloyloxy-kauran-19-oic acid methyl ester and several O-acyl derivatives at C-15 or C-18 of kaurenoic acid. One of the minor components, 18-isobutyroyloxy-ent-kaur-16-en-19-oic acid is a new kaurenoic acid derivative. Grandiflorenic acid and 15-α-angeloyloxy-16,17-α-epoxy-ent-16-kauren-19-oic acid were present only in Smallanthus sonchifolius and Smallanthus siegesbeckius which showed very similar GC traces. The different GC profile of RC diterpenes from Smallanthus connatus and Smallanthus macroscyphus supports the view that they are different taxa. Some chemotaxonomic aspects of the genus Smallanthus and the subtribe Milleriinae are briefly discussed.     

Tirucallane triterpenes from the roots of Ozoroa insignis

Eight tirucallane triterpenes, methyl 3alpha,24S-dihydroxytirucalla-8,25-dien-21-oate (2), methyl 3alpha-hydroxy-24-oxotirucalla-8,25-dien-21-oate (3), methyl 3alpha-hydroxy-25,26,27-trinor-24-oxotirucall-8-en-21-oate (4), 3alpha,25-dihydroxy-24-(2-hydroxyethyl)-tirucall-8-en-21-oic acid (5), 3alpha,24S,25-trihydroxytirucall-8-en-21-oic acid (6), 3alpha,24R,25-trihydroxytirucall-8-en-21-oic acid (7), 3alpha,25-dihydroxytirucall-8-en-21-oic acid (8), and methyl 3alpha,25-dihydroxytirucall-8-en-21-oate (9), together with alpha-elemolic acid methyl ester (1), were isolated from the roots of Ozoroa insignis. Their structures were elucidated on the basis of spectroscopic evidence.     

Structure of terminic acid,a dihydroxytriterpene carboxylic acid from Terminalia arjuna

The structure of terminic acid, a new dihydroxytriterpene carboxylic acid isolated from the roots of Terminalia arjuna, has been established as 3β, 13β-dihydroxylup-20(29)-en-28-oic acid by a study of its chemical reactions and spectroscopic data. Terminic acid and its derivatives were found to undergo skeletal rearrangement under protonic conditions to yield oleanene lactone.     

Plectranthoic acid,acetylplectranthoic acid and plectranthadiol,three triterpenoids from Plectranthus rugosus

Sitosterol and three new pentacyclic triterpenoids, plectranthoic acid, acetylplectranthoic acid and plectranthadiol, have been isolated from leaves of P. rugosus. From spectroscopic evidence and chemical behaviour the structure of plectranthoic acid was established as (19S)-3α-hydroxy-18α-urs-12-en-29β-oic acid and acetylplectranthoic acid is the 3α-acetyl derivative of this compound. Plectranthadiol is (19S)- 3α-hydroxy-18α-urs-12-en-29β-ol.     

Further triterpenoids and 13C NMR spectra of oleanane derivatives from Phytolacca acinosa

In addition to five known triterpenoids, namely acinosolic acid, phytolaccagenin, phytolaccagenic acid, esculentic acid and jaligonic acid, three new oleanane derivatives, designated as phytolaccagenin A, acinosolic acid A and acinosolic acid B, have been isolated and characterized from the defatted berries of Phytolacca acinosa. The new compounds have been identified as 3β-acetoxy-3β-methyloleanate-12-en-2β,23α-diol-28β-oic acid, 3β-acetoxy-28β-methyloleanate-12-en-2β-ol-30β-oic acid and 2β-acetoxy-28β-methyloleanate-12-en-3β-ol-30β-oic acid, respectively.