Rearranged vibsane-type diterpenes from Viburnum awabuki and photochemical reaction of vibsanin B

Nine new diterpenes, neovibsanin D (1), 7-epi-neovibsanin D (2), 15-O-methylneovibsanin F (3), 14-epi-15-O-methylneovibsanin F (4), 15-O-methyl-18-oxoneovibsanin F (5), 2-O-methylneovibsanin H (6), 2-O-methylneovibsanin I (7), neovibsanin G (8), and 14-epi-neovibsanin G (9), were isolated from a methanol extract of the leaves of Viburnum awabuki. Their structures were elucidated to be uniquely rearranged vibsane-type diterpenes by spectroscopic analyses and comparison of NMR data with those of previously reported vibsane-type diterpenes. In addition, irradiation of vibsanin B (12) in methanol with a high-pressure Hg lump led to the direct formation of neovibsanins A (14) and B (15). These results gave a clue to understanding of the biogenetic interconversion of 11-membered vibsanins into neovibsanins.     

Six new tigliane diterpenoids with anti-inflammatory activity from Euphorbia kansuensis

Six new tigliane diterpenoids, euphkanoids A ? F (1–6), along with 12 known diterpenoids (7–18) were isolated from the roots of Euphorbia kansuensis, a traditional Chinese medicinal plant. Their structures were elucidated by spectroscopic analysis, ECD calculation and chemical methods. Compounds 1–3 represent the unusual examples of tigliane diterpenoids with a conjugated olefinic aldehyde moiety. 1–18 and two hydrolyzed analogues (1c and 4a) were screened for the inhibitory effects on nitric oxide (NO) production induced by lipopolysaccharide (LPS) in RAW264.7 cells. The results showed that 1–3 and 6 markedly inhibited NO production with IC₅₀ values in the range of 4.8–11.3 μM, which were more active than the positive control quercetin (IC₅₀ = 12.3 μM).     

Neurite Outgrowth-Promoting Compounds from the Petals of Paeonia lactiflora in PC12 Cells

Isorhamnetin-3-O-glucoside and astragalin, flavonol glucosides, were isolated from the petals of Paeonia lactiflora as neurite outgrowth-promoting compounds. Isoquercitrin, formed by demethylating the B ring of isorhamnetin-3-O-glucoside or by adding a hydroxyl group to the B ring of astragalin, was evaluated for neurite outgrowth-promoting activity and was compared with the activities of isorhamnetin-3-O-glucoside and astragalin. The activities of isorhamnetin, kaempferol, and quercetin, aglycones corresponding to isorhamnetin-3-O-glucoside, astragalin, and isoquercitrin, respectively, were also evaluated. Isorhamnetin-3-O-glucoside and astragalin showed much stronger neurite outgrowth-promoting activities than the activities of the other tested flavonoids. They exhibited relatively weak anti-oxidant activities and moderate AChE inhibitory activities compared to the activities of the other tested flavonoids. Isorhamnetin-3-O-glucoside and astragalin promoted morphological neurite outgrowth and the expression of neurofilaments induced by NGF in PC12 cells. Isorhamnetin-3-O-glucoside and astragalin might be candidate compounds as neural differentiation agents in peripheral nerves and functional food ingredients preventing cognitive decline.     

Two new diterpenoids from Isodon serra

From the aerial part of Isodon serra,two new ent-6,7-seco-kaurane-type diterpenoids,15α,20β-dihydroxy-6β-methoxy-6,7- seco-6,20-epoxy-1,7-olide-ent-kaur-16-ene (1) and 6α,15α-dilaydroxy-20-aldehyde-6,7-seco-6,11α-epoxy-1,7-olide-ent-kaur-16- ene (2) were isolated.Their structures were elucidated by spectroscopic means.     

Two new ent-kaurane diterpenoids from Isodon henryi

Two new ent-kaurane diterpenoids, minheryins H （1） and I （2）, were isolated from the leaves of Isodon henryi. Their structures were elucidated by means of spectroscopic analysis, including 2D NMR spectra.     

Two new 19-oxygenated ent-kaurane diterpenoids from Isodon pharicus

<正>Two new 19-oxygenated ent-kaurane diterpenoids,pharicinins D and E(1 and 2),together with an artifact,pharicinin D acetal (3) were isolated from the leaves of Isodon pharicus.Their structures were determined by 1D and 2D NMR spectroscopic analysis. All of them were evaluated for their cytotoxicity.     

6,7-seco-ent-Kaurane diterpenoids from lsodon sculponeatus and their bioactivity

One new 6,7-seco-enr-kaurane diterpenoid,sculponin T(1),was isolated from the aerial parts of Isodon sculponeatus,along with four known analogs,sculponeatin J(2),sculponeatin K(3),sculponeatin C(4),and sculponeatin Q(5).Their structures were elucidated by extensive spectroscopic analysis and by comparison with data reported in the literature.Significant cytotoxic activity was observed for compound 2 against five human tumor cell lines with IC_(50) values ranging from 1.8 μmol/L to 3.3 μmol/L,and it also inhibited NO production in LPS-stimulated RAW264.7 cells,with IC_(50) value of 3.3 μmol/L.     

Structure and Antiarhythmic Activity of 12-Acetyl-12-epinapelline, a New Diterpenoid Alkaloid from Aconitum soongoricum

The structure of the new diterpenoid alkaloid 12-acetyl-12-epinapelline that was isolated from the mother liquor of Aconitum soongoricum was established. The conformational state of ring A was analyzed. Spectral properties and data for the antiarhythmic activity were presented.     

Isolation and purification of diterpenoids from the aerial parts of Isodon excisoides target-guided by UPLC-LTQ-Orbitrap-MS

Cytotoxic diterpenoids were enriched and orientation prepared from the aerial parts of Isodon excisoides target-guided by UPLC-LTQ-Orbitrap-MS. Four diterpenoids were obtained, including a novel compound: 1α-acetoxy-7α, 14β, 20α-trihydroxy-ent-kaur-16-en-15-one (1); together with three known compounds kamebakaurin (2), lasiokaurin (3), enmenol-1-β-glucoside (4). Their structures were elucidated on the basis of spectroscopic methods in conjunction with published data for their analogues. All compounds were tested for their cytotoxic effects against five human cancer cell lines HCT-116, HepG2, A2780, NCI-H1650 and BGC-823, respectively. Compounds 1 and 2 showed obviously cytotoxic activity against the five cancer cell lines with IC₅₀ ranging from 1.06 to 3.60 μM. Compounds 3 and 4 showed selective cytotoxic activity.     

Mass spectrometry of metastable ions from lagochiline-type diterpenoids

Low-and high-resolution mass spectra and spectra of metastable ions were studied using direct analysis of daughter ions (DADI) and metastable defocusing (MD) of lagochiline-type diterpenoids. Patterns in their fragmentation were found. __________ Translated from Khimiya Prirodnykh Soedinenii, No. 1, pp. 56–60, January–February, 2007.     

A new casbane diterpene from Euphorbia pekinensis

A new casbane diterpenoid, referred to as pekinenin G, together with one cembrane diterpene and four known casbane diterpenoids were isolated from the roots of Euphorbia pekinensis. Their structures were elucidated on the basis of spectroscopic studies and comparison with related known compounds. The six compounds showed different cytotoxic activities against four human cancer cell lines.     

Cytotoxic cassane diterpenoids from the seeds of Caesalpinia sappan

Phytochemical investigation on the seeds of Caesalpinia sappan led to the isolation of five new cassanetype diterpenoids, named 11-oxo-phanginin A(1), caesalsappanins O–Q(2–4) and phanginin U(5),together with five known compounds. The structures of the new compounds were elucidated by extensive analysis of mass spectrometric and 1D and 2D NMR spectroscopic data. All the new compounds showed moderate cytotoxic effects on human breast cancer MCF-7 and human colon cancer HCT116 cell lines.     

硫（醇）代N-对甲苯基/苯基磺酰基氨基羧酸酯类化合物的合成与神经营养活性

根据官能团的组合,设计合成了硫（醇）代N-对甲苯基/苯基磺酰基氨基羧酸酯类化合物,这些化合物的结构¹H NMR, ¹³C NMR, MS 和 HRMS证实,初步的实验结果表明：在10μg/mL浓度下,化合物4a, 4b, 4d, 5c, 5d, 5g, 6b和 6d显示对PC12细胞缺氧损伤具有显著的保护作用,化合物4c, 5b和 6c显示对PC12细胞缺氧损伤具有一定的保护作用;在5μg/mL浓度下,4d和 6d显示对PC12细胞缺氧损伤具有一定的保护作用;初步的实验也表明：在10μg/mL浓度下,4c, 5a, 5c, 5d, 5e和 6b显示对PC12细胞具有一定的促分化作用。     

Dichotellides A-E, five new iodine-containing briarane type diterpenoids from Dichotella gemmacea

Five new briarane type diterpenoids, dichotellides A−E (1−5), were isolated from the South China Sea gorgonian Dichotella gemmacea together with four known analogues (6−9). Compounds 1−5 represent the first examples of iodine-containing briarane type diterpenoids from nature. The structures of these diterpenoids were elucidated by spectroscopic analysis, including 1D, 2D-NMR, and HRESIMS, and the absolute configuration of 1 was further confirmed by single crystal X-ray diffraction analysis. All the isolates were evaluated for cytotoxicity activity against four human tumor cell lines, and only 3 exhibited marginal activity against SW1990 (human pancreatic cancer).     

Influence of surface energy distribution on neuritogenesis

PC12 cells are a useful model to study neuronal differentiation, as they can undergo terminal differentiation, typically when treated with nerve growth factor (NGF). In this study we investigated the influence of surface energy distribution on PC12 cell differentiation, by atomic force microscopy (AFM) and immunofluorescence. Glass surfaces were modified by chemisorption: an aminosilane, n-[3-(trimethoxysilyl)propyl]ethylendiamine (C₈H₂₂N₂O₃Si; EDA), was grafted by polycondensation. AFM analysis of substrate topography showed the presence of aggregates suggesting that the adsorption is heterogeneous, and generates local gradients in energy of adhesion. PC12 cells cultured on these modified glass surfaces developed neurites in absence of NGF treatment. In contrast, PC12 cells did not grow neurites when cultured in the absence of NGF on a relatively smooth surface such as poly-l-lysine substrate, where amine distribution is rather homogeneous. These results suggest that surface energy distribution, through cell–substrate interactions, triggers mechanisms that will drive PC12 cells to differentiate and to initiate neuritogenesis. We were able to create a controlled physical nano-structuration with local variations in surface energy that allowed the study of these parameters on neuritogenesis.     

灯盏乙素苷元4’-N-取代氨甲基苯甲酸酯的合成及体外抗氧化活性研究

为合成具有较强神经细胞氧化损伤保护作用的灯盏乙素苷元衍生物.以灯盏乙素苷元与N-取代氨甲基苯甲酸为原料,在偶联剂N,N＇-二环己基碳酰亚胺(DCC)/4-N,N-二甲基吡啶(DMAP)的作用下制备了6种灯盏乙素苷元4′-N-取代氨甲基苯甲酸酯衍生物6a～6f,所合成的化合物均经过1H NMR,ESI-MS以及HRMS分...     

Eight new diterpenoids from soft coral Cespitularia hypotentaculata

Chemical investigation of the soft coral Cespitularia hypotentaculata resulted in the isolation of eight new diterpenes, cespihypotins E-L (1-8). The new metabolites comprise of six verticillene-type diterpenes, one cespitularane derivative, and one derivative with 14-membered lactone ring. The structures were determined through detailed spectroscopic analyses, especially high resolution ESIMS and 2D NMR techniques. The relative stereochemistry was deduced from NOESY spectrum and application of Mosher's ester technique. Immunomodulatory and antiviral activities of 1-8 were tested and evaluated. The biogenetic pathways for 1-8 were also proposed.     

Relationship between Neuroprotective Effects and Structure of Procyanidins

This study evaluated the relationship between the neuroprotective effects of procyanidins and their structural characteristics. In vitro, a rat pheochromocytoma cell line (PC12) was exposed to the grape seed-derived procyanidin monomers: catechin (C), epicatechin (EC), and epicatechin gallate (ECG); the procyanidin dimers: procyanidin B1 (B1), procyanidin B2 (B2), procyanidin B3 (B3), procyanidin B4 (B4), procyanidin B1-3-O-gallate (B1-G), and procyanidin B2-3-O-gallate (B2-G); and the procyanidin trimers: procyanidin C1 (C1) and N-acetyl-l-cysteine (NAC) for 24 h. Cells were then incubated with 200 μM H₂O₂ for 24 h. In vivo, zebrafish larvae (AB strain) 3 days post-fertilization were incubated with NAC or procyanidins (C, EC, ECG, B1, B2, B3, B4, B1-G, B2-G, C1) in 300 µM H₂O₂ for 4 days. Different grape seed procyanidins increased the survival of PC12 cells challenged with H₂O₂, improved the movement behavior disorder of zebrafish caused by H₂O₂, inhibited the increase of ROS and MDA and the decrease of GSH-Px, CAT, and SOD activities, and up-regulated the Nrf2/ARE pathway. The neuroprotective effects of the procyanidin trimer C1 treatment group were greater than the other treatment groups. These results suggest that the neuroprotective effect of procyanidins is positively correlated with their degree of polymerization.