Prenylated anthranoids from Psorospermum species

The chemical composition of the root extracts of two Psorospermum sp. from the Ivory Coast is reported. Together with previously known compounds, acetylvismione F and 2-geranylemodin anthrone were isolated from P. corymbiferum, and vismione G from P. glaberrimum. Geranyl substitution is confirmed to be a typical feature of this genus.     

Plagiochilines C,D, E and F,four novel secoaromadendrane-type sesquiterpene hemiacetals from Plagiochila asplenioides and Plagiochila semidecurrens

Four novel secoaromadendrane-type sesquiterpene hemiacetals, plagiochilines C, D, E and F, together with the previously known (?)-bicyclogermacrene, have been isolated from the liverwort, Plagiochila asplenioides and their structures have been spectroscopically elucidated. From Plagiochila semidecurrens plagiochilines A and C have been obtained along with (?)-bicyclogermacrene and its related sesquiterpene hydrocarbons.     

Globulixanthones C,D and E: three prenylated xanthones with antimicrobial properties from the root bark of Symphonia globulifera

Two prenylated xanthone derivatives, named globulixanthones C and D and one bis-xanthone, designated globulixanthone E, have been isolated from the root bark of Symphonia globulifera. The structures of these compounds were elucidated by a detailed spectroscopic analysis. They have been shown to exhibit in vitro significant antimicrobial activity against a range of micro-organisms.     

Chlorohyssopifolin C,D, E and vahlenin,four new sesquiterpene lactones from Centaurea hyssopifolia

On the basis of chemical and spectroscopic evidence, structures are assigned to four new sesquiterpene lactones: chlorohyssopifolin C, D and E (guaiano     

Nine isoflavones from Tephrosia maxima

The isolation and characterisation of nine closely related 3′,4′-disubstituted isoflavones from the aerial parts and roots of Tephrosia maxima     

Leishmania mexicana and Leishmania tropica: Cross immunity in C57BL/6 mice

Leishmania mexicana and Leishmania tropica infection were comparatively studied in C57BL/6 mice. Infection with 10⁴ amastigotes of L. mexicana was followed by the appearance of a single lesion which ulcerated in 8 weeks and healed in 24 weeks. Mice infected with 10⁴ amastigotes of L. tropica developed less severe lesions which healed in 18 weeks. In both cases healing was accompanied by a delayed hypersensitivity response and an in vitro lymphocyte reactivity to leishmanial antigens. Mice recovered from a primary infection with L. mexicana or L. tropica were resistant to both homologous and heterologous challenge. In vitro and in vivo immunological tests indicated that L. mexicana and L. tropica share antigenic determinants which are involved in cell-mediated immune responses to these parasites.     

Albizosides D and E, two new cytotoxic triterpene saponins from Albizia chinensis

Two oleanane-type triterpene saponins, named albizosides D and E (1 and 2), together with a known compound, Julibroside J₈ (3), were isolated from the stem bark of Albizia chinensis. The structures of compounds 1 and 2 were established by 1D, 2D NMR experiments, and chemical methods, and they showed moderate cytotoxic activity against a small panel of human tumor cell lines.     

6-Methoxyflavonoids from Brickellia californica

Two new and eleven known 6-methoxyflavonoids were identified in leaf tissue of Brickellia californica. The new flavonols are eupatin 3-SO₃ Ca_1/2 and patuletin 3-SO₃K. The known compounds include the flavones hispidulin and eupafolin and their respective 7- and 4′-monomethyl ethers and the flavonols; spinacetin, eupatin, patuletin 3-glucoside and 3-galactoside, and eupatolitin 3-galactoside.     

Major xanthones from Garcinia quadrifaria and Garcinia staudtii stem barks

The stem bark of Garcinia quadrifaria has yielded the novel xanthone 1, 3, 5-trihydroxy-4, 8-di(3,3-dimethylallyl)xanthone and the biflavonoids O-methylfukugetin and morelloflavone. The seeds contained the biflavonoids but not the xanthone. G. staudtii stem bark gave rheediaxanthone-A and the polyisoprenylated benzophenone xanthochymol. .     

Applanoxidic acids A, B, C and D, biologically active tetracyclic triterpenes from Ganoderma applanatum

Four novel polyoxygenated lanostanoid triterpenes, named applanoxidic acids A, B, C, and D, have been isolated from an Indonesian tropical fungus, Ganoderma applanatum. Their structures were determined by spectrocopic and chemical methods. Biological activity as an anti-tumour promoter was observed for these components.     

New physalins from Physalis angulata and Physalis lancifolia. Structure and reactions of physalins D,I, G and K

The structures of physalins I, G and K are established respectively as 5,6-dihydro-5α-methoxy-6β-hydroxy, 4,5-dehydro-5,6-dihydro-4β-hydroxy and 5,6-dihydro-4α,5α-epoxy-6α-hydroxy derivatives of physalin B. The chemistry of physalin D, and the synthesis of physalins D and I from physalin F and physalin K from physalin G are described.     

拟南芥2-甲基-6-叶绿基-1,4-苯醌甲基转移酶启动子的分离及表达特性分析

维生素E是一类人体必需的脂溶性抗氧化剂, 具有重要的生理功能。2-甲基-6-叶绿基-1,4-苯醌甲基转移酶(MPBQ MT)是天然维生素E合成途径中的关键酶之一, 催化MPBQ甲基化, 生成DMPBQ。从拟南芥分离了MPBQ MT基因1018bp的启动子序列, 构建了含该启动子和GUS报告基因的植物表达载体, 通过农杆菌介导转化拟南芥, 获得了转基因植株。GUS组织化学染色结果表明, 在MPBQ MT启动子驱动下, 报告基因GUS在拟南芥的茎、叶、花萼、雄蕊、种荚均有表达, 且在茎、叶、种荚中表达量较高, 而在根、花瓣和种子中则没有观察到GUS基因的表达, 表明MPBQ MT基因可能仅在拟南芥幼嫩茎、叶、种荚等绿色组织中特异性高表达。     

Cytokinins: Synthesis of 2-, 8-, and 2,8-substituted 6-(3-methyl-2-butenylamino)purines and their relative activities in promoting cell growth

We have synthesized 2- and 8-monosubstituted and 2,8-disubstituted derivatives of the cytokinin 6-(3-methyl-2-butenylamino)purine (N⁶-isopentenyladenine) and have shown the dependence of growth-promoting activity in the tobacco bioassay upon the position, number, and type of substituent. The representative substituent groups were MeS, Me, MeSO₂, C₆H₅CH₂S, HS and Cl. The 8-methyl derivative was exceptional in being more active than the unsubstituted parent compound. In general, substitution in the 8-position decreases activity less than substitution in the 2-position, with the exception of the electron-attracting methylsulfonyl. Substitution in both the 2- and 8-positions lowers the activity more than substitution at either single position on the adenine nucleus, with the exception of the 2,8-dimethyl derivative. The chloro and methylthio derivatives show activity in the same range as the methyl derivatives, and the mercapto compounds, which exist mainly as CS tautomers, show somewhat less activity than the corresponding methylthio compounds. Bulky (C₆H₅CH₂S and MeSO₂) and strongly electron-attracting (MeSO₂) substituents cause relatively great reduction in cytokinin activity.     

D:b-friedoolean-5-ene-3β,29-diol,an angular methyl oxygenated d: b-friedooleanene from elaeodendron balae

A new dioxygenated D: B-friedooleanene from Elaeodendron balae root bark was shown to be D:B–friedoolean-5-ene-3β,29-diol by relating it to 29-oxygenated D:A-friedooleanane. This is the first report of angular methyl oxygenation in the D: B-friedooleananes.     

′6β-propanoyloxy-3α-tigloyloxytropane,a new alkaloid from Datura innoxia

A new alkaloid, shown by spectroscopic and degradative means to be 6β-propanoyloxy-3α-tigloyloxytropane has been isolated from Datura innoxia r     

Brain Diurnal Levels of Adenosine 3', 5' Cyclic Monophasphate in C57 Bl/6 and Balb/C Mice

Adenosine 3', 5'-cyclic monophosphate (cAMP) was measured in whole brain of two inbred strains of mice (BALB/C and C57 BL/6) submitted to a lighting schedule consisting of 12 hr light (0700-1900) and 12 hr darkness (1900-0700). Different mean levels of cAMP were found in each strain. Furthermore, statistical analysis of diurnal brain cAMP fluctuations showed different nycthemeral rhythms in both strains. BALB/C was mainly characterized by the presence of very significant 0600 and 0800 harmonics and C57 BL/6 by an orthophase around 1700 hr.

Because both strains were studied under the same experimental conditions of light, temperature and food availability, these factors cannot account for the observed differences, which were thus tentatively interpreted in terms of genetic regulatory processes.     

Teuchamaedrin C,a neo-clerodane diterpenoid from Teucrium chamaedrys

A new neo-clerodane diterpenoid, teuchamaedrin C, has been isolated from the aerial parts of Teucrium chamaedrys. Its structure, (12S,18S)-15,16-epoxy-neo-clerodane-13(16)14-dien-19,20-olide-18,6β-hemiacetal, was established by spectroscopic and chemical means. In addition, the previously known diterpenoids 6α-hydroxyteuscordin and dihydroteugin were isolated from the same source.     

Hallmarks of HPV carcinogenesis: The role of E6, E7 and E5 oncoproteins in cellular malignancy

Human papillomavirus (HPV) is the most common sexually transmitted infectious agent worldwide, being also responsible for 5% of all human cancers. The integration and hypermethylation mechanisms of the HPV viral genome promote the unbalanced expression of the E6, E7 and E5 oncoproteins, which are crucial factors for the carcinogenic cascade in HPV-induced cancers. This review highlights the action of E6, E7 and E5 over key regulatory targets, promoting all known hallmarks of cancer. Both well-characterized and novel targets of these HPV oncoproteins are described, detailing their mechanisms of action. Finally, this review approaches the possibility of targeting E6, E7 and E5 for therapeutic applications in the context of cancer.