Aporphine alkaloids,clerodane diterpenes,and other constituents from Tinospora cordifolia

Phytochemical investigation of the methanol extract of Tinospora cordifolia aerial parts led to the isolation of four new and seven known compounds. The structures of two new aporphine alkaloids, N-formylasimilobine 2-O-β-d-glucopyranosyl-(1 → 2)-β-d-glucopyranoside (tinoscorside A, 1) and N-acetylasimilobine 2-O-β-d-glucopyranosyl-(1 → 2)-β-d-glucopyranoside (tinoscorside B, 2), a new clerodane diterpene, tinoscorside C (3), and a new phenylpropanoid, sinapyl 4-O-β-d-apiofuranosyl-(1 → 6)-O-β-d-glucopyranoside (tinoscorside D, 6) were determined by extensive spectroscopic methods including FTICR-MS and 1D and 2D NMR.     

~(13)C-核磁共振谱在鉴定天然产物结构中的应用

本文参考有关文献资料,结合应用核磁共振~(13)C 谱鉴定两个四环二萜类化合物结构的工作,对一些天然化合物,如具有含氧基团的环己烷体系的化合物中,由于其含氧基团的取代情况不同而引起其核磁共振~(13)C 谱各相关碳信号呈现出的规律性变化,进行了较详细的讨论。     

Pseudopterosin Biosynthesis: Aromatization of the Diterpene Cyclase Product,Elisabethatriene

Putative precursors in pseudopterosin biosynthesis, the hydrocarbons isoelisabethatriene (10) and erogorgiaene (11), have been identified from an extract of Pseudopterogorgia elisabethae collected in the Florida Keys. Biosynthetic experiments designed to test the utilization of these compounds in pseudopterosin production revealed that erogorgiaene is transformed to pseudopterosins A–D. Together with our previous data, it is now apparent that early steps in pseudopterosin biosynthesis involve the cyclization of geranylgeranyl diphosphate to elisabethatriene followed by the dehydrogenation and aromatization to erogorgiaene.     

Cembranoid, Steroid, and Sesquiterpenoid Derivatives from the South China Sea Soft Coral Sinularia numerosa

Two new cembranoids, namely, sinumerolides A and B （1 and 2）, one new steroid, 7fl-hydroxygorgosterol （7）, along with four known cembranoid derivatives （3-6）, four known steroids （8-11）, and four known...     

Six New Diterpene Glycosides from the Soft Coral Lemnalia bournei

A chemical study on the extracts of soft coral Lemnalia bournei resulted in the isolation and identification of six new bicyclic diterpene glycosides including three new lemnaboursides E–G (1–3), and three new lemnadiolboursides A–C (4–6), along with three known lemnaboursides (7–9). Their structures were elucidated by detailed spectroscopic analysis, ECD analysis, chemical methods, and comparison with the literature data. Lemnadiolboursides A–C (4–6) contained a lemnal-1(10)-ene-7,12-diol moiety compared with the lemnaboursides. All these compounds were evaluated for antibacterial activity; cell growth inhibition of A549, Hela, HepG2, and CCRF-CEM cancer cell lines; and inhibition of LPS-induced NO production in RAW264.7 macrophages. The results indicated that compounds 1, 2, and 4–6 exhibited antibacterial activity against Staphylococcus aureus and Bacillus subtilis (MIC 4–16 μg/mL); compounds 1–9 displayed low cytotoxicity on the CCRF-CEM cell lines (IC₅₀ 10.44–27.40 µM); and compounds 1, 2, and 5 showed weak inhibition against LPS-induced NO production (IC₅₀ 21.56–28.06 μM).     

Lathyrane diterpenes from Euphorbia prolifera and their inhibitory activities on LPS-induced NO production

A new lathyrane diterpene (1), an unreported spectroscopic data lathyrane diterpenene (2), and two known analaogues (3 and 4) have been isolated from Euphorbia prolifera. Their structures were elucidated as (12E,2S,3S,4R,5R,6S,9S,11S,15R)-3-butyryloxy-5,15-diacetoxy-6,17-epoxylathyra- 12-en-14-one (1), (12E,2S,3S,4R,5R,6S,9S,11S,15R)-3-propionyloxy-5,15-diacetoxy-6,17- epoxylathyra-12-en-14-one (2), (12E,2S,3S,4R,5R,6S,9S,11S,15R)-3-benzoyloxy-5,15-diacetoxy -6,17-epoxylathyra-12-en-14-one (3), and 15-O-acetyl-17-hydroxyjolkinol (4) by spectroscopic methods (IR, ESIMS, HR-ESIMS, NMR, and X-ray crystallography). The inhibitory activities on LPS-induced NO production of these diterpenes were evaluated and compounds 1, 3 and 4 showed inhibitory effects.     

海松酸型树脂酸生物活性及应用研究进展

海松酸型树脂酸是松香树脂酸的重要组成成分,其C-13位上同时拥有一个甲基和一个乙烯基,是一类结构特殊的树脂酸.几个海松酸型异构体大多具有抗菌、抗炎、抗微生物、杀虫、降胆固醇、抗癌等生物活性.近年来国内外学者在海松酸型树脂酸或者其代表性单体化合物异海松酸的生物活性及其应用方面展开了较广泛和深入的研究,尤其是在农药和医药等方面的研究应用不断取得进展,作为树脂酸的一个重要类型,具有较好的发展趋势和开发应用前景.     

A new abietane diterpene from Glyptostrobus pensilis

A new abietane diterpene, glypensin A (1) and four known compounds, 12-acetoxy-ent-labda-8(17), 13E-dien-15-oic acid (2), quercetin 3-O-α-L-arabinofuranoside (3), quercetin 3-O-β-D-galactopyranoside (4), β-sitosterol (5) were isolated from the branches and leaves of Glyptostrobus pensilis (Staut.) Koch. Their structures were determined by MS, 1D- and 2D-NMR means. Compound 1 showed cytotoxicity on human chronic myeloid leukemia cell line K562 (IC₅₀ = 21.2 μM).     

13-Epi-9-deacetoxyxenicin,a Cytotoxic Diterpene from the Soft Coral Asterospicularia laurae (Alcyonacea)

An investigation of the soft coral Asterospicularia laurae collected on the Great Barrier Reef, Australia, afforded the cytotoxic diterpene 13-epi-9-deacetoxyxenicin (1) in addition to the known metabolites 13-epi-9-deacetylxenicin (2) and gorgosterol. 13-Epi-9-deacetoxyxenicin readily underwent an autoxidation reaction in solution to afford a single product, the hydroperoxide 3. Structures, stereochemistry, and NMR assignments were established by high resolution NMR spectroscopy and by comparison with published data for known compounds.