نتایج جستجو برای: labdan diterpenoid

تعداد نتایج: 1007  

2009
Huan Wang Kai-Bei Yu Li-Sheng Ding Xiao-Duo Luo Xiao-Feng Zhang

The title compound, C(20)H(30)O(2), is an ent-atisane diterpenoid which was isolated from the roots of Euphorbia kansuensis. The mol-ecule contains five six-membered rings, among which three six-membered rings of the bicyclo-[2.2.2]octane unit adopt boat conformations and two cyclo-hexane rings adopt chair conformations. In the crystal structure, mol-ecules are connected by inter-molecular O-H⋯...

Journal: :Molecules 2009
Qi-Cheng Wu Yu-Ping Tang An-Wei Ding Fen-Qiang You Li Zhang Jin-Ao Duan

Euphorbia species are widely distributed plants, many of which are used in folk medicine. Over the past twenty years, they have received considerable phytochemical and biological attention. Their diterpenoid constituents, especially those with abietane, tigliane, ingenane skeletons, are thought to be the main toxicant and bioactive factors. In this work, the utility of (13)C-NMR spectroscopy fo...

2016
Farrokh Eghtesadi Mahdi Moridi Farimani Nourallah Hazeri Jafar Valizadeh

BACKGROUND The genus Salvia is a rich source of structurally diverse terpenoids. Different species of the Salvia have been used in folk medicine of Iran and therefore attracted the attention of researchers for exploring their chemical constituents. In a project directed at structurally interesting bioactive metabolites from Iranian Lamiaceae, we studied Salvia rhytidea. RESULTS Fractionation ...

2003
Ana Letícia A. Dantas Ligia Maria M. Valente Angelo C. Pinto

The Velloziaceae is a family of tropical plants occurring in South America and Africa. The Brazilian species occur in the subtropical regions, especially in the states of Minas Gerais, Bahia, Goiás, Mato Grosso, Rio de Janeiro and Santa Catarina. These plants grow in a characteristic ecosystem fully exposed on mountainsides in rocky or sandy soils. Plants of the family Velloziaceae in spite of ...

Journal: :Journal of environmental science and health. Part C, Environmental carcinogenesis & ecotoxicology reviews 2014
M A Turabekova B F Rasulev F N Dzhakhangirov A A Toropov D Leszczynska J Leszczynski

The duration of anesthesia (related to protein binding of a drug) and the onset time (determined by the pKa) are important characteristics in assessment of local anesthetic agents. They are known to be affected by a number of factors. Early studies of antiarrhythmic diterpenoid alkaloids from plants Aconitum and Delphinium suggested that they possess local anesthetic activity due to their abili...

2017
Takeyoshi SuGiyAMA

A newly reErranged 2(3.20)abeotaxane diterpenoid with a unique 6/1016 skeleton was isolated from the bark of the Chillese yew, Taxus mairei. The structure was established as being 7fi,13(M-diacetoxy-2or,5a,10fi-trihydrexy-9keto-2(3 -20)abeotaxane on the basis of 1-D and 2-D N"M data. The relative stereochemistry was defined from the results of a NOESY experiment. This is the first reported isol...

Journal: :Molecules 2012
Ching-Hsiao Cheng Hsu-Ming Chung Tsong-Long Hwang Mei-Chin Lu Zhi-Hong Wen Yueh-Hsiung Kuo Wei-Hsien Wang Ping-Jyun Sung

A new clerodane-type diterpenoid, echinoclerodane A (1), was isolated from a Formosan gorgonian coral Echinomuricea sp. The structure of 1 was elucidated by spectroscopic methods. Echinoclerodane A (1) is the first clerodane-type compound obtained from the marine organisms belonging to the phylum Cnidaria. Echinoclerodane A (1) exhibited moderate cytotoxicity toward MOLT-4, HL-60, DLD-1 and LoV...

2010
Junqing Chen Xiaoming Zha

The title compound, C(24)H(37)BrO(3), is a tetra-cyclic diterpenoid with a beyerane skeleton, synthesized by esterification of isosteviol. It comprises a fused four-ring system A/B/C/D. Rings A and B have a chair conformation, whereas ring C is an unsymmetrical distorted chair; the remaining five-membered ring D adopts an envelope conformation. The stereochemistry of the A/B and B/C ring juncti...

Journal: :Molecules 2013
Yong-Xi Song Shi-Ping Liu Zhao Jin Jian-Fei Qin Zhi-Yuan Jiang

A rapid resolution liquid chromatography/time-of-flight tandem mass spectrometry (RRLC-TOF/MS) method was developed for qualitative and quantitative analysis of the major chemical constituents in Andrographis paniculata. Fifteen compounds, including flavonoids and diterpenoid lactones, were unambiguously or tentatively identified in 10 min by comparing their retention times and accurate masses ...

Journal: :Planta medica 1997
M Hezari R Croteau

The novel diterpenoid taxol (paclitaxel) is now well-established as a potent chemotherapeutic agent. Total synthesis of the drug is not commercially feasible and, in the foreseeable future, the supply of taxol and its synthetically useful progenitors must rely on biological methods of production. The first three steps of taxol biosynthesis have been defined and the responsible enzymes described...

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