Diterpenes from Mikania species

The investigation of four further Mikania species afforded several diterpenes, four geranylgeraniol derivatives and three kaurane epoxides. The structures were elucidated by spectroscopic methods and a few chemical transformations.     

Diterpenes from Palafoxia texana

The investigation of Palafoxia texana afforded in addition to the known compound jesromotetrol two new rosene derivatives: 3β-acetoxy-jesromotetrol and 3β,19-diacetoxy-jesromotetrol. The structures were determined by spectroscopic methods and chemical transformations.     

Diterpenes from Laennecia sophiifolia

From the aerial parts of Laennecia sophiifolia (Kunth) G.L. Nesom, a neo-clerodane and an acyclic furano diterpene were isolated, along with four known compounds, 2beta-hydroxyhardwickiic acid, hawtriwaic acid, apigenin, and beta-sitosterol. Their structures were established as 12-epi-bacchotricuneatin A and (2E,6E)-9-(3-furyl)-6-methyl-2-(4-methylpent-3-enyl)-nona-2,6-dienoic acid, by analysis of spectral evidence. The absolute structure of 12-epi-bacchotricuneatin A was determined by a circular dichroism spectral comparison with that of bacchotricuneatin A.     

Diterpenes from Koanophyllon species

The investigation of two Koanophyllon species afforded, in addition to known compounds, several new diterpenes, two new geranylgeraniol derivatives and four diterpenes, most probably closely related to clerodanes; their structures, however, could not be deduced with certainty. The chemotaxonomic situation of this genus is discussed briefly.     

Diterpenes from Ballota species

Hispanolone was isolated from Ballota andreuzziana; B. pseudodictamnus contains ballonigrin, 18-hydroxyballonigrin, marrubenol, and the flavone 7, 4′-di-O-methylapigenin.     

Diterpenes from Araucaria bidwilli

Eight diterpent acids of the labdane or clerodane type were obtained from the oleoresin of Araucaria bidwilli and characterized as their methyl esters.     

Diterpenes from Stevia monardaefolia

An investigation of Stevia monardaefolia resulted in the isolation of two new labdane type diterpenes, 6α-angeloyloxy nidorellol and 6α-angeloy     

Diterpenes from euphorbia seguieriana

An extract of the whole plant of Euphorbia seguieriana afforded a known and three new diterpene lactones of the abietane type, seven myrsinanes and a tetracarbocyclic diterpene related to myrsinane. The structures were elucidated by means of high field NMR spectroscopy.     

Diterpenes derived from clerodanes from Pulicaria angustifolia

The investigation of Pulicaria angustifolia afforded, in addition to known triterpenes and caryophyllene epoxide, four methyl esters of diterpenes, all derived from clerodane. Three of them are derivatives of seco-nidoresedic acid. The structures were elucidated by spectroscopic methods.     

Three Antinematodal Diterpenes from Euphorbia kansui

Three compounds, 20-O-acetyl-[3-O-(2′E,4′Z)-decadienoyl]-ingenol (1), 20-O-acetyl-[5-O-(2′E,4′Z)-decadienoyl]-ingenol (2) and 3-O-(2′E,4′Z)-decadienoylingenol (3), were isolated from Euphorbia kansui under the bioassay-guided method. Each compound showed the same antinematodal activity against the nematode, Bursaphelenchus xylophilus, at a minimum effective dose (MED) of 5 μg/cotton ball.     

Diterpenes from Croton salutaris

The twigs of Croton salutaris afforded three new acyclic diterpenes and a new tricyclic diterpene as well as a known compound, sonderianol. The structures of three acyclic diterpenes [(10E)-3,12-dihydroxy-3,7,11,15-tetramethyl-1,10,14-hexadecatrien-5,13-dione, (6E,10E)-3,12-dihydroxy-3,7,11,15-tetramethyl-1,6,10,14-hexadecatetraen-5,13-dione and (6Z,10E)-3,12-dihydroxy-3,7,11,15-tetramethyl-1,6,10,14-hexadecatetraen-5,13-dione] and a tricyclic diterpene [12-hydroxy-13-methylpodocarpa-9,11,13-trien-3-one] were determined by spectral methods.     

Diterpenes and tetranorditerpenes from Acritopappus species

The investigation of four Acritopappus species afforded twenty-three new diterpenes of the labdane or kolavane type and three tetranorditerpenes as well as two new benzofuran derivatives and a hydroxybicyclogermacrene. The structures were elucidated by spectroscopic methods and by some chemical transformations. Though the absolute configuration were not established in all cases, most probably all diterpenes were ent-labdanes or kolavanes (clerodanes). The chemotaxonomic importance of this investigation is discussed briefly.     

Diterpenes and sesquiterpenes from Osteospermum species

The investigation of several Osteospermum species afforded in addition to known compounds three diterpenes from the rare cassane type, two further sandaracopimarene derivatives, two 6-desoxyglucosides of cubebol and 13-hydroxycaryophyllene, respectively, an isomer of 7-hydroxycalamenene, two p-hydroxyacetophenone derivatives derived from toxol, a thymol derivative and the palmitates of lupeol, taraxasterol and 3β,20-dihydroxydammarene. The structures were elucidated by spectroscopic methods. The chemotaxonomy of the genus is discussed briefly.     

Diterpenes from Dictyota dichotoma

Two new and two known diterpenes were isolated from Dictyota dichotoma. The structures of the new diterpenes were elucidated from spectral and X-ra     

Diterpenes from Salvia mellifera

Two new aromatic diterpenes have been obtained from the aerial part of Salvia mellifera and their structures identified, on the basis of spectral data and chemical correlations, as 11,12,20-trihydroxy-abieta-8,11,13-triene and 11,12,16-trihydroxy- abieta-8,11,13-trien-20-al. The known diterpenes, carnosic acid, carnosol, rosmanol, isorosmanol, galdosol, rosmadial, 9 (10 → 20)-abeo-abieta-8,11,13-triene-10β,11,12-triol (demethylsalvicanol)and salvicanol were also isolated from the same source. The absolute configuration of salvicanol was established by X-ray diffraction analysis of its 11-p-bromobenzoate derivative.     

滇姜花二萜成分的抗肿瘤活性研究

对滇姜花粗提物、滇姜花素A(1)和姜花酮(2)进行了动物体内抗肿瘤活性测试,结果表明它们均能显著性抑制小鼠体内移植性肿瘤H22的生长,其中滇姜花素A对小鼠H22肿瘤生长抑制率达54.27%,作用最强。体外抗肿瘤实验发现,滇姜花素C(3)对体外培养的人类乳腺癌细胞株MDA-MB-231具有较强的细胞毒作用,并具有明显的剂量效应关系。