Structural determination of diterpenes from Daphne genkwa by NMR spectroscopy

Five daphnane type diterpenes have been isolated from the chloroform soluble fraction of Daphne genkwa. The structure of the new compound (1) was assigned as 5beta-hydroxyresiniferonol-6alpha,7alpha-epoxy-12beta-acetoxy-9,13,14-ortho-2E-decenoate by extensive NMR studies.     

A new highly oxygenated daphnane diterpene esters from the flower buds of Daphne genkwa

The phytochemical investigation of the flower buds of Daphne genkwa yielded eight highly oxygenated daphnane-type diterpene esters, including a new one, genkwanine N 20-palmitate (1) and seven known ones (2–8). The molecular structures of the isolated compounds were elucidated on the basis of extensive spectroscopic analysis, including UV, IR, NMR, and MS, and comparison with literature data. Furthermore, compound 1 showed potential cytotoxic activity in vitro, against A549 and Hep G2 tumour cell lines.     

芫花中芫花素的提取工艺与杀虫试验

芫花 (ＤａｐｈｎｅｇｅｎｋｗａＳｉｅｂ.ｅｔＺｕｃｃ.)属于瑞香科植物[1] ,芫花的浸取液对棉蛉虫、稻螟虫、菜青虫、班蝥等害虫具有较好的杀虫效果 ,且对人畜无害 ,是一种理想的无公害农药[2 ] 。为了提高药效 ,更好地开发这种无公害农药 ,本文对芫花中杀虫有效成分的提取工艺与杀虫效果进行了初步研究。1　实验部分1 1　试剂和仪器苯 ,氯仿和 95 %的乙醇均为分析纯 ;岛津ＵＶ -2 40型紫外可见分光光度仪 ;ＦＴ -80ＡＮＭＲ仪。1 2　实验方法芫花枝条干粉 1 5 0 0ｇ,加水 1 0 .0 0Ｌ煮沸 1 2小时 ,煮沸过程中陆续补加少量水分。将煮沸…     

芫花花蕾中的两个新二萜

瑞香烷型二萜类化合物具有良好的抗肿瘤生理活性.为了进一步研究该类抗肿瘤活性成分,对富含瑞香烷型二萜的芫花花蕾进行化学成分研究,从中分离得到一个巴豆烷型二萜1和两个瑞香烷型二萜原酸酯2和3.应用多种波谱学方法（1H NMR,13C NMR,HSQC,HMBC,NOESY,ESI-MS,HR-ESI-MS等）,确定了3个化...     

Daphnane‐Type Diterpenoids from the Flower Buds of Daphne genkwa

Three new daphnane‐type diterpenoids, genkwanines M–O ( 1 – 3 , resp.), together with seven known daphnane‐type diterpenoids, genkwanines D and H, genkwaine F, genkwadaphnine, yuanhuatine, yuanhuafine, and yuanhuapine ( 4 – 10 , resp.), were isolated from the flower buds of Daphne genkwa during a phytochemical investigation. The structures of the new compounds were elucidated on the basis of spectroscopic analyses, especially 2D‐NMR spectra (HSQC, HMBC, and NOESY).     

A simple and efficient protocol for large‐scale preparation of three flavonoids from the flower of Daphne genkwa by combination of macroporous resin and counter‐current chromatography

In this paper, macroporous resin column chromatography and counter‐current chromatography (CCC) were applied for large‐scale preparative separation of three flavonoids from the flower of Daphne genkwa, a famous Chinese medicinal herb. Nine kinds of resins were investigated by adsorption and desorption tests and D101 macroporous resin was selected for the first cleaning‐up, in which 40% aqueous ethanol was used to remove the undesired constituents and 90% aqueous ethanol was used to elute the targets. The crude extract after the first step was directly subjected to the preparative CCC purification using the solvent system composed of n‐hexane–ethyl acetate–methanol–water (4:5:4:5, v/v). The compounds apigemin (823 mg), 3‐hydroxyl‐genkwanin (842 mg) and genkwanin (998 mg) with the purities of 98.79, 97.71 and 93.53%, respectively, determined by HPLC were produced from 3‐g crude extract only in one CCC run. Their chemical structures were identified by MS, UV and the standards.     

A new coumarin glycoside from Daphne giraldii

A new coumarin glycoside was isolated from the ethanol extract of the barks of stem of Daphne giraldii Nitsche. Its structure was defined as daphnetin 8-O-b-D-glucopyranosyl-(1→6)-b-D-glucopyranoside on the basis of spectral evidences.     

Relationship between the UPLC‐Q‐TOF‐MS fingerprinted constituents from Daphne genkwa and their anti‐inflammatory,anti‐oxidant activities

Daphne genkwa Sieb.et Zucc. is a well‐known medicinal plant. This study was designed to apply the ultra‐high performance liquid chromatography system to establish a quality control method for D. genkwa. Data revealed that there were 15 common peaks in 10 batches of D. genkwa Sieb. Et Zucc. (Thymelaeaceae) from different provinces of China. On this basis, the fingerprint chromatogram was established to provide references for quality control. Afterwards, the chemical constitutions of these common peaks were analyzed using the UPLC‐Q‐TOF‐MS system and nine of them were identified. In addition, LPS‐stimulated RAW264.7 murine macrophages and DPPH assay were used to study the anti‐inflammatory and anti‐oxidation effects of D. genkwa . Then the fingerprint–efficacy relationships between UPLC fingerprints and pharmacodynamic data were studied with canonical correlation analysis. Analysis results indicated that the anti‐inflammatory and anti‐oxidation effects differed among the 10 D. genkwa samples owing to their inherent differences of chemical compositions. Taken together, this research established a fingerprint–efficacy relationship model of D. genkwa plant by combining the UPLC analytic technique and pharmacological research, which provided references for the detection of the principal components of traditional Chinese medicine on bioactivity.     

Simultaneous determination of three flavonoids and one coumarin by LC–MS/MS: Application to a comparative pharmacokinetic study in normal and arthritic rats after oral administration of Daphne genkwa extract

A selective and sensitive liquid chromatography–tandem mass spectrometry method was developed and validated for investigating the pharmacokinetics of umbelliferone, apigenin, genkwanin and hydroxygenkwanin after oral administration of Daphne genkwa extract. Plasma samples were treated by protein precipitation with acetonitrile. Analytes were detected by triple‐quadrupole MS/MS with an ESI source in negative selection reaction monitoring mode. The transitions of m/z 161 → 133 for umbelliferone, m/z 269 → 117 for apigenin, m/z 283 → 268 for genkwanin and m/z 299 → 284 for hydroxygenkwanin were confirmed for quantification. Chromatographic separation was conducted using an Eclipse XDB‐C₁₈ column, and the applied isocratic elution program allowed for simultaneous determination of the four analytes for a total run time of 2.5 min. The linearity was validated over the plasma concentration ranges of 1.421–1421 ng/mL for umbelliferone, 0.845–845 ng/mL for apigenin, 1.025–1025 ng/mL for genkwanin and 0.845–845 ng/mL for hydroxygenkwanin. The extraction recovery rate was >82.7% for each analyte. No apparent matrix effect was observed during the bioanalysis. After full validation, the proposed method was successfully applied to compare the pharmacokinetics of these analytes between normal and arthritic rats.     

A New Compound from Daphne giraldii Nitsche

Daphne giraldii Nitsche (Thymelaeaceae) is widely distributed in Shanxi, Gansu, Sichuan and Ningxia provinces of China. According to the modern research, it showed the activity against inflammatory, pain, cancer and so on1. Herein we report the identifica…     

Five New Biflavonoids from Daphne aurantiaca

Five new biflavonoids, 1 – 5 , were isolated from the stem bark of Daphne aurantiaca. The structures were elucidated as 2,2″‐bisteppogenin ( 1 ), 2,2″‐bisteppogenin 7‐O‐β‐glucopyranoside ( 2 ), 2′′′‐dehydroxy‐2,2″‐bisteppogenin ( 3 ), 2′′′‐dehydroxy‐2,2″‐bisteppogenin 7‐O‐β‐glucopyranoside ( 4 ), and 7‐methoxyneochamaejasmin B ( 5 ) on the basis of spectral analyses.     

Salvinicins A and B, new neoclerodane diterpenes from Salvia divinorum

[reaction: see text] Two new neoclerodane diterpenes, salvinicins A (4) and B (5), were isolated from the dried leaves of Salvia divinorum. The structures of these compounds were elucidated by spectroscopic techniques, including (1)H and (13)C NMR, NOESY, HMQC, and HMBC. The absolute stereochemistry of these compounds was assigned on the basis of single-crystal X-ray crystallographic analysis of salvinicin A (4) and a 3,4-dichlorobenzoate derivative of salvinorin B.     

Phytochemistry and Pharmacological Activities of the Diterpenoids from the Genus Daphne

There are abundant natural diterpenoids in the plants of the genus Daphne from the Thymelaeaceae family, featuring a 5/7/6-tricyclic ring system and usually with an orthoester group. So far, a total of 135 diterpenoids has been isolated from the species of the genus Daphne, which could be further classified into three main types according to the substitution pattern of ring A and oxygen-containing functions at ring B. A variety of studies have demonstrated that these compounds exert a wide range of bioactivities both in vitro and in vivo including anticancer, anti-inflammatory, anti-HIV, antifertility, neurotrophic, and cholesterol-lowering effects, which is reviewed herein. Meanwhile, the fascinating structure–activity relationship is also concluded in this review in the hope of providing an easy access to available information for the synthesis and optimization of efficient drugs.     

Bicunningines A and B, two new dimeric diterpenes from Cunninghamia lanceolata

Two unprecedented dimeric diterpenoids, with a 2,3-dihydrofuran ring fusing an abietane and a 4,5-seco-abietane diterpene, were isolated from Cunninghamia lanceolata. Their structures were elucidated by spectroscopic measurements, and their absolute configurations were determined by quantum chemical TDDFT ECD calculations, chemical transformations, and Mosher's method. The Mosher method carried out with MPA and MTPA esters of the sterically hindered sec-hydroxyl group gave contradictory results, while MPA afforded the correct absolute configuration.     

Five new ent-kaurane diterpenes from Annona squamosa L. pericarps

Abstract

In the present study, five new ent-kaurane diterpenes including 4α-hydroxy-17,19-dinor-ent-kaurane-16-one (1), 4β-hydroxy-16β-H-18-nor-ent-kaurane-17-oic acid (2), 4β,17-dihydroxy-16α-acetoxy-18-nor-ent-kaurane (3), Annosquamosin Z (4) and 16α-H-ent-kaurane-17,18-dioic acid, 17-methy ester (5) were isolated from Annona squamosa L. pericarp. The compounds were also evaluated for their cytotoxic activities against SMMC-7721 and HepG2 cell lines, among which compound 3 exhibited potent cytotoxicity with IC₅₀ value of less than 20?μM.     

Melidianolic acid A and B, new antimalarial acyclic diterpenes from Aphanamixis grandifolia

Two new acyclic diterpenes, melidianolic acids A (1) and B (2), have been isolated from the bark of Aphanamixis grandifolia. Their structures were elucidated on the basis of spectroscopic and chemical methods. Melidianolic acids A (1) and B (2) showed antimalarial activity against Plasmodium falciparum 3D7 with IC50 of 6.1 and 7.3 microg/mL, respectively.     

Two new abietane diterpenes huperphlegmarins A and B from Huperzia phlegmaria

Two new abietane diterpenes, huperphlegmarin A–B (1–2), were isolated from the aerial parts of Huperzia phlegmaria (L.) Rothm. (Lycopodiaceae), in addition to five known compounds including lycoxanthol (3), 21β-hydroxyserrat-14-en-3β-yl acetate (4), 21α-hydroxyserrat-14-en-3β-yl acetate (5), 21α-hydroxyserrat-14-en-3β-ol (6), and fawcettidine (7). Their structures were determined by the combination analyses of spectroscopy, including 1D-, 2D-NMR, HRESIMS, CD and comparison with the reported data in the literature. Huperphlegmarin B (2) presented the rare 1,11-epoxy group in the molecule. Compounds 3, 4, 5 and 6 were performed for AChE inhibitory activity and compound 3 showed the inhibitory activity against AChE with IC₅₀ of 465.6 μg/mL.     

Kitungolides A, B, and C, new diterpenes from a soft coral of a new genus

Three novel compounds, designated kitungolides A (1), B (2), and C (3), were isolated from a soft coral of a new genus collected at Kitungamwe, Kenya. The three new compounds are of a unique heterotricyclic skeleton. The structures and relative stereochemistry of the compounds were elucidated by interpretation of MS, COSY, HMQC, HMBC, and NOESY experiments. [structure: see text]     

Daphnogirins A and B, two biflavones from Daphne giraldii

Two new biflavonoids, daphnogirins A (1) and B (2), were obtained from the roots of Daphne giraldii. Their structures were established on the basis of the spectral data and X-ray diffraction data of the co-crystal of 1 and 2. Daphnogrins A and B have the same configuration at C-1 and opposite configurations at C-16 and C-17. Oxygen radical scavenging assay has indicated that they are of significant antioxidative activity.