Diterpenes from the Roots of Oryza sativa L. and Their Inhibition Activity on NO Production in LPS‐Stimulated RAW264.7 Macrophages

Two new pimarane diterpenoids, momilactone D ( 3 ) and momilactone E ( 5 ), along with three known diterpenoids, momilactone A ( 1 ), sandaracopimaradien‐3‐one ( 2 ), and oryzalexin A ( 4 ) were isolated from Oryza sativa roots. The chemical structures of the compounds were determined by spectroscopic data analysis. The isolated diterpenoids were evaluated for their ability to inhibit NO production and iNOS mRNA and protein expression in LPS‐stimulated RAW264.7 macrophages. Compound 4 showed strong inhibition activity on NO production, and compounds 1 and 4 decreased the expression of iNOS mRNA and protein levels.     

Clerodane diterpenoids from Pulicaria wightiana

Five clerodane diterpenoids have been isolated from the aerial parts of Pulicaria wightiana along with 3'5,6-trihydroxy-3,4',7-trimethoxyflavone and 2-methyl-5-hydroxy-chroman-4-one. The structures and stereochemistry of the compounds were established from spectral (mainly 1D and 2D NMR) studies. The last two compounds were not reported earlier from this plant. The antibacterial activity of the diterpenoids were studied.     

Diterpenoids from Euphorbia paralias.

Two segatane diterpenoids containing a bicyclic [4,3,1] ring system were isolated, together with 11 known diterpenoids, four segetanes, five jatrophanes and two paralianes, from the aerial parts of Euphorbia paralias. The structures of the new compounds were established by spectroscopic means, including by 2D NMR and CD spectroscopic analyses. The antifeedant and antiviral activities of the isolated compounds are also described.     

Cytotoxic ent-kauranoids from Isodon parvifolius

Three new ent-kaurane diterpenoids, parvifoline Z (1), parvifoline AA (2), and parvifoline AB (3), together with 14 known compounds, were isolated from the leaves of Isodon parvifolius. The structures of the new compounds were elucidated by 1D- and 2D-NMR spectroscopy and mass spectrometry, and by comparison with known compounds. These three new diterpenoids included three types of ent-kauranoids, namely, C(20)-non-oxygenated-ent-kauranoid, 7,20-cyclo-ent-kauranoid and 6,7-seco-ent-kauranoid-7,20-olide. Compounds 1 and 2 exhibited significant cytotoxicities against A549, HT-29, and K562 cell lines.     

Kaurane and abietane diterpenoids from Tripterygium doianum (Celastraceae)

Extraction of Tripterygium doianum (Celastraceae) afforded five new diterpenoids and 11 known diterpenoids belonging to the ent-kaurane and abietane families. Their structures were established based on spectroscopic studies. The isolated compounds showed moderate cytotoxicity against human tumor cell assays.     

New bioactive macrocyclic diterpenoids from Jatropha multifida

Two new macrocyclic diterpenoids, multifidanol (1) and multifidenol (2) along with several known compounds have been isolated from the stem of Jatropha multifida. The structures of the new compounds were established from the extensive studies of their 1D and 2D NMR spectra. The cytotoxic and antimicrobial activities of these two constituents were examined.     

Highly Oxygenated Labdane Diterpenoids from Stevia rebaudiana and Their Anti-Atherosclerosis Activities

Five unknown labdane diterpenoids Stevelins A–E ( 1–5 ), three known labdane diterpenoids ( 6–8 ) and three labdane norditerpenoids ( 9–11 ) were isolated from the Stevia rebaudiana. The structures were determined primarily via NMR spectroscopic data and HR-ESI-MS experiments. X-ray crystallography using CuK_α radiation was used to determine the absolute configurations of 1 , and the absolute configurations of 2–5 were deduced by electronic circular dichroism (ECD) calculations. The potential anti-atherosclerosis activities of all compounds were evaluated by measuring their inhibitory effects on the macrophage foam cell formation. As a result, most isolated compounds could significantly inhibit oxidized low-density lipoprotein (ox-LDL)-induced macrophage foam cell formation, which suggests that these compounds may be promising candidates in the treatment for atherosclerosis.     

Diterpenoids from Pinus massoniana resin and their cytotoxicity against A431 and A549 cells

Five diterpenoids and 14 known diterpenoids were isolated from the petroleum ether extract of Pinus massoniana resin. Their structures were elucidated by spectroscopic data interpretation. The cytotoxic activities of these compounds were evaluated using the MTT method. The results showed that three of the less polar diterpenoids had strong cytotoxicity against A431 and A549 cancer cells, whereas those of high polarity had none.     

Methylenebissantin: a rare methylene-bridged bisflavonoid from Dodonaea viscosa which inhibits Plasmodium falciparum enoyl-ACP reductase

A new methylene-bridged bisflavonoid, methylenebissantin (1), and nine known compounds, including flavonoids (2-5), diterpenoids (6 and 7), and phenol derivatives (8-10) were isolated from the aerial parts of Dodonaea viscosa Jacq. The structure elucidation was based on spectroscopic data analyses. The isolated compounds were evaluated for the inhibition of Plasmodium falciparum enoyl-ACP reductase (PfENR). Methylenebissantin (1) exhibited a moderate inhibition (IC(50) 91.13 μM) against PfENR.     

Two novel diterpenoids, erinacines H and I from the mycelia of Hericium erinaceum

Novel diterpenoids, erinacines H (1) and I (3), were isolated from the cultured mycelia of Hericium erinaceum. The structures of the compounds were determined by interpretation of the spectral data. Erinacine H showed stimulating activity of nerve growth factor (NGF)-synthesis.     

甘肃产蓝萼香茶菜二萜化学成分研究

对甘肃天水小陇山产蓝萼香茶菜进行二萜化学成分研究。采用硅胶柱色谱法分离纯化,通过薄层色谱及波谱法进行结构鉴定,SRB法分别对分离化合物进行了体外细胞毒活性测试。共鉴定出5个二萜化合物,它们分别为:1α,6,11β,15β-四乙酰基-6,7-断裂-7,20-内酯-对映-贝壳杉-16-烯(1α,6,11β,15β-tetraacetoy-6,7-seco-7,20-olide-ent-kaur-16-en,Ⅰ),6β,11α-二羟基-6,7-断裂-6,20-环氧-1α,7-内酯-对映-贝壳杉-16-烯-15-酮(6β,11α-di-hydroxy-6,7-seco-6,20-epoxy-1α,7-olide-ent-kaur-16-en-15-one,Ⅱ),6β,7β,14β-三羟基-1α-乙酰氧基-7α,20-环氧-对映-贝壳杉-16烯-15-酮(6β,7β,14β-trihydroxy-1α-acetoxy-7α,20-epoxy-ent-kaur-16-en-15-one,Ⅲ),6β,11α,15α-三羟基-6,7-断裂-6,20-环氧-1α,7-内酯-对映-贝壳杉-16-烯(6β,11α,15α-trihydroxy-6,7-seco-6,20-epoxy-1α,7-olide-ent-kaur-16-en,Ⅳ),1α,6β,7β,14β-四羟基-7α,20-环氧-对映-贝壳杉-16-烯-15-酮(1α,6β,7β,14β-tetrahydroxy-7α-20-ep-oxy-ent-kaur-16-en-15-one,Ⅴ)。化合物Ⅲ、Ⅳ、Ⅴ均为首次从该植物中分离得到,并且以上5个二萜化合物对人肝癌细胞株Bel-7402和人卵巢癌细胞株HO-8910均显示了良好的细胞毒活性。     

ent-Rosane and abietane diterpenoids as cancer chemopreventive agents

Two ent-rosane- (cuzcol, 1 and 6-dehydroxycuzcol, 2) and a abietatriene- (salvadoriol, 3) type diterpenoids have been isolated from Maytenus cuzcoina and Crossopetalum uragoga, respectively, along with five known diterpene compounds (4-8). Their stereostructures have been elucidated on the basis of spectroscopic analysis, including 1D and 2D NMR techniques, and computational data. The absolute configuration of cuzcol was determined by application of Riguera ester procedure. This is the first instance of isolation of ent-rosane diterpenoids from species of the Celastraceae. The isolated diterpenes were found to be potent anti-tumour-promoter agents, and carnosol (7) also showed a remarkable chemopreventive effect in an in vivo two-stage carcinogenesis model.     

Novel antibacterial diterpenoids from Larix chinensis Beissn

Two novel labdane-type diterpenoids, butanedioic acid mono[(13S)-13-hydroxylabda-8(17),14-dien-19-yl] ester (1) and butanedioic acid bis[(13S)-13-hydroxylabda-8(17),14-dien-19-yl] ester (2), along with the eleven known diterpenoids 3-13 and three other known compounds, were isolated from the bark of Larix chinensis. Their structures were elucidated both spectroscopically and chemically. The major diterpenoids 1-9, 11, and 13, as well as the very abundant phenolic compound 16, were subjected to antibacterial and cytotoxic bioassays. Compounds 7 and 9 showed remarkable in vitro inhibition of Staphylococcus aureus and S. epidermidis (MIC = 37-73 microM).     

Isolation and characterization of two new diterpenoids from Stachys parviflora: Antidiarrheal potential in mice

Two new diterpenoids trivially named Stachysrosane (1) and Stachysrosane (2) have been isolated from the ethyl acetate soluble fraction of Stachys parviflora. The structure elucidation of isolated diterpenoids were based on one-(1D) and two-dimensional (2D)-NMR techniques including correlation spectroscopy (COSY), heteronuclear multiple quantum coherence (HMQC), heteronuclear multiple bond correlation (HMBC), and nuclear Overhauser effect spectroscopy (NOESY). The isolated diterpenoids 1 and 2 caused marked attenuation of castor oil induced diarrhea in dose dependent manner with 100% and 70% protection at 45 mg/kg p.o. respectively. It can be concluded with confidence that both the isolated compounds could be useful antidiarrheal agents; however, detailed studies will be needed.     

Two Novel Diterpenoids,Erinacines H and I from the Mycelia of Hericium erinaceum

Novel diterpenoids, erinacines H (1) and I (3), were isolated from the cultured mycelia of Hericium erinaceum. The structures of the compounds were determined by interpretation of the spectral data. Erinacine H showed stimulating activity of nerve growth factor (NGF)-synthesis.     

New Diterpenoids from Andrographis paniculata （Burm. f.） Nees

To investigate diterpenoids from the aerial parts of Andrographis paniculata （Burm. f.） Nees, three new ent-labdane diterpenoids, namely 19-norandrographolides A-C （compounds 1-3）, were isolated from the ethanolic extract of A. paniculata. Their structures were established by HRESIMS and NMR spectral data in combination with X-ray crystallographic analysis.     

Novel rearranged abietane diterpenoids from the roots of Salvia sahendica

Two naphthoquinone diterpenoids, 1 and 2, one tricyclic, and one tetracyclic rearranged abietane ('4,5-seco-10,5-friedo-abietane') diterpenoids, 3 and 4, respectively, together with horminone (5) have been isolated from the roots of Salvia sahendica. Compounds 2 and 3 are new, and the 13C-NMR assignment for compound 4 was modified using ' Heteronuclear Multiple-Bond Correlation' (HMBC) spectroscopic data. The structures of the compounds have been established by using different spectral data including 1D- and 2D-NMR, IR, UV, and MS. The elemental composition for the major peaks of 3 and 4 were determined by ' High-Resolution Electron Impact Mass Spectrometry' (HR-EI-MS). The relative configurations of the new compounds were determined by 1H-NMR and 'Rotating-Frame NOES' (ROESY) spectroscopy. Compounds 1, 2, and 5 showed antifungal activities when tested on Blakeslea trispora. Lapachol, a prelynated naphthoquinone, was used as a positive control. The biological activities of the related naphthoquinones and abietane diterpenoids were discussed.     

ent-Pimarane derivatives from Dysoxylum hainanense

Four ent-pimarene diterpenoids. ent-18-acetoxy-8(14)-pimarene-15S, 16-diol, ent-18-acetoxy-16-hydroxy-8(14)-pimaren-15-one, ent-16,18-dihydroxy-8(14)-pimaren-15-one and ent-19-nor-4,16,18-trihydroxy-8(14)-pimaren-15-one, together with three known damarane triterpenoids, richenoic acid, eichleriainic acid and shoreic acid were isolated from the bark of Dysoxyhum hainanense Merr. Their structures were elucidated on the basis of spectroscopic techniques. The absolute configurations of four diterpenoids were assigned as ent-pimarene type by chemical transformation and by co-occurrence in the plant as well as by negative optical rotations for four compounds.     

Cytotoxic and antimalarial constituents from the roots of Eurycoma longifolia

Sixty-five compounds were isolated from the roots of Eurycoma longifolia and characterized by comprehensive analyses of their 1D and 2D NMR, and mass spectral data. Among these isolates, four quassinoid diterpenoids were reported from natural sources for the first time, namely eurycomalide A (1), eurycomalide B (2), 13beta, 21-dihydroxyeurycomanol (3), and 5alpha, 14beta, 15beta-trihydroxyklaineanone (4). Screening of cytotoxicity, anti-HIV and antimalarial activity of these isolated compounds was also furnished by in vitro assays. Compounds 12, 13, 17, 18, 36, 38, 59, and 62 demonstrated strong cytotoxicity toward human lung cancer (A-549) cell lines, however, 12, 13, 17, 38, 57, 58, and 59 exhibited strong cytoxicity toward human breast cancer (MCF-7) cell lines. Compounds 57 and 58 displayed potent antimalarial activity against the resistant Plasmodium falciparum. The thorough studies on the stereochemistry of the different quassinoid diterpenoids provide a clear reference to the scientists who are interested on this field.     

Neo-clerodane diterpenoids from Teucrium lanigerum

From the aerial part of Teucrium lanigerum, six new neo-clerodane diterpenoids, 7,8-dehydroeriocephalin, teulanigeral, teulanigin, 20-epi-teulanigin, teulanigerin and teulanigeridin, have been isolated. The first of these, 7,8-dehydroeriocephalin, is a natural substance, whereas the other compounds were isolated as their acetyl derivatives after acetylation of an inseparable mixture of natural diterpenoids. The structures of these substances were established mainly by spectroscopic means and, in the case of 7,8-dehydroeriocephalin, by partial synthesis from eriocephalin.