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.     

Diterpenoids from Isodon enanderianus

Four ent-kauranoids, 6-epiangustifolin and enanderinanins F-H, as well as 11 known ent-kaurane diterpenoids, macrocalin B, xerophilusin A, trichorabdal A, trichorabdal B, effusin, angustifolin, longikaurin D, longikaurin F, enanderinanin B, xerophilusin G and shikokianin were isolated from the aerial parts of Isodon enanderianus. The new diterpenoids were identified as 6-epiangustifolin (11alpha-hydroxy-6alpha-methoxy-6,19-epoxy-6,7-seco-ent-kaur-16-en-15-one-7,20-olide), enanderinanin F (19-acetoxy-6,20:6,11beta-diepoxy-6,7-seco-ent-kaur-16-en-15-one-1beta,7-olide), enanderinanin G (1beta,6beta,7beta-trihydroxy-19-acetoxy-16beta-methoxymethyl-7alpha,20-epoxy-ent-kaur-15-one) and enanderinanin H (6beta,7beta,14beta-trihydroxy-1alpha,11beta-acetonide-7alpha,20-epoxy-ent-kaur-16-en-15-one), respectively, on the basis of spectral data, especially by 2D NMR techniques. 6-Epiangustifolin showed significant cytotoxic activity against K562 cell.     

Cytotoxic 7,20-epoxy ent-kauranoids from Isodon xerophilus

Four 7,20-epoxy ent-kaurane diterpenoids, xerophilusins G (1) and I-K (2-4), were isolated from the leaves of Isodon xerophilus, along with four known ones, enanderianin C (5), rosthorin A (6), longikaurin B (7), and rabdoternin D (8). Their structures were determined primarily using NMR spectroscopic techniques. The structure and stereochemistry of 3 were confirmed by X-ray crystallography. Compounds 4 and 7 exhibited broad cytotoxicity against four kinds of human tumor cells (K562, HL-60, HCT, and MKN-28 cells) in the range of 2.23-15.35 and 0.30-8.61 microg/ml, respectively.     

New clerodane diterpenoids from the aerial parts of Pulicaria wightiana

Two new ent-clerodane-type diterpenoids, compounds 1 and 2, were isolated from the aerial parts of Pulicaria wightiana, together with three known constituents. Their structures were established based on spectroscopic data, and their antibacterial activities were evaluated (Table 2).     

Coumarin and terpenoids from Perezia alamani var. oolepis

Isoparvifolinone (2a), 8-hydroxypereflorine (3a) and diperezone (5) and the known sesquiterpenes cyperene and parvifoline (1a) were isolated from the roots of Perezia alamani var. oolepis. The structures of the new compounds were deduced from spectral data and tested by chemical correlation. Thus diperezone (5) was identical to the dimerization product of perezone (4a), isoparvifolinone (2a) was partially synthesized from parvifoline (1a) and 8-hydroxypereflorine (3a) was converted into the known 8-methoxypereflorine (3b).     

New neoclerodane diterpenoids isolated from the leaves of Salvia divinorum and their binding affinities for human kappa opioid receptors

Bioactivity-guided fractionation of the leaves of Salvia divinorum has resulted in the isolation of three new neoclerodane diterpenoids: divinatorin D (1), divinatorin E (2), and salvinorin G (3), together with 10 known terpenoids, divinatorin C (4), hardwickiic acid (5), salvinorin-A (6), -B (7), -C (8), -D (9), -E (10), and -F (11), presqualene alcohol (12), and (E)-phytol (13). The structures of these three new compounds were characterized by spectroscopic methods. All these compounds were evaluated for their binding affinities to the human kappa opioid receptors. In comparison with divinatorin D (1), divinatorin E (2), and salvinorin G (3), salvinorin A (6) is still the most potent kappa agonist.     

20-Nor-abietane and rearranged abietane diterpenoids from the root of Salvia argentea

From the root of Salvia argentea three new abietane diterpenoids, 1R-hydroxymiltirone, arucadiol and 1-keto-aethiopinone, have been isolated, together with the previously known diterpenes isopimara-8(9),15-diene, salvipisone, ferruginol and aethiopinone. The structures of the new compounds were established by spectroscopic means.     

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).     

Four New Kaurane Diterpenoids from the Chinese Liverwort Jungermannia comata Nees

In our continuing program to find new bioactive compounds from the Chinese liverworts, four new kaurane‐type diterpenoids, (6β)‐kaur‐16‐ene‐6,9‐diol ( 1 ), (6β,12β)‐kaur‐16‐ene‐6,9,12‐triol ( 2 ), (6β)‐kaur‐16‐ene‐5,6,9‐triol ( 3 ), and kaur‐16‐ene‐9,19‐diol ( 4 ), have been isolated from the Chinese liverwort Jungermannia comata Nees . Five known kaurane‐type diterpenoids ( 5  –  9 ) and four known trachylobane‐type diterpenoids ( 10  –  13 ) were also obtained. The structures of the new compounds were established unequivocally on the basis of spectroscopic data. The absolute configuration of compound 1 was established by comparing experimental and calculated electronic circular dichroism spectra.     

New diterpenoids and the bioactivity of Erythrophleum fordii

A phytochemical investigation of the leaves of Erythrophleum fordii Oliv. has led to the isolation of three new cassaine-type diterpenoids, erythrofordin A (1), erythrofordin B (2) and erythrofordin C (3), as well as a norcassaine diterpenoid with a novel skeleton, norerythrofordin A (4), and 27 known compounds (5-31). The structures of 1-4 were elucidated on the basis of spectroscopic analysis. Selected compounds from this plant were examined for anti-inflammatory activity. Taraxerol (16) displayed potent NO-reducing activity in microglial cells, and gallic acid (27) exhibited excellent DPPH radical-scavenging effects.     

Bioactive briarane diterpenoids from the South China Sea gorgonian Dichotella gemmacea

Six new briarane diterpenoids, gemmacolides T-Y (1-6), were isolated together with three known analogs, juncenolide J (7), praelolide (8), and junceellolide C (9), from the South China Sea gorgonian Dichotella gemmacea. The structures of the new compounds were elucidated by detailed spectroscopic analysis and comparison with reported data. The absolute configuration was suggested based on biosynthetic considerations. In an in vitro bioassay, compounds 3 and 6 showed potent growth inhibition towards tumor cell lines of A549 and MG63, being stronger than the positive control of adriamycin. These compounds also exhibited weak antimicrobial activity against the bacterium Escherichia coli and the fungi Microbotryum violaceum and Septoria tritici.     

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.     

Acyclic precursors of the uterotonic oxepane diterpenoids of ‘zoapatle’ (Montanoa tomentosa)

Chemical analysis of Montanoa tomentosa yielded, in addition to the known biologically active oxepane diterpenoids zoapatanol, tomentol and tomexanthol, three new uterotonic acyclic diterpenoids, which are considered the precursors of the oxepane derivatives mentioned above. The structures of the new compounds were established by spectroscopic methods.     

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.     

Oxepane diterpenoids sesquiterpene lactones from ‘zoapatle’ (montanoa tomentosa), a mexican plant with oxytocic activity

Investigation of the ‘tea’ prepared from the leaves of ‘zoapatle’ (Montanoa tomentosa), resulted in the isolation of the known biologically active oxepane diterpenoids zoapatanol and montanol, the known sesquiterpene lactones zoapatanolide A, C and D as well as two new biologically active oxepane diterpenoids and a new sesquiterpene lactone. The structures of the new compounds were established by spectroscopic methods.     

Sesquiterpenes from Perezia carpholepis

The previously unknown curcuquinol monoisovalerate and the known sesquiterpenes cyperene, cyperone, parvifoline, perezone, and α- and β-pipitzol were found in the roots of Perezia carpholepis. The structure of the new sesquiterpene was deduced from spectral data and by transformation into curcuquinone. Parvifoline and its derived acetate, previously thought to be oily materials, were characterized as crystalline compounds.     

New 4,5‐seco‐20(10→5)‐abeo‐Abietane Diterpenoids with Anti‐Inflammatory Activity from Isodon lophanthoides var. graciliflorus (Benth.) H.Hara

Three new 4,5‐seco‐20(10→5)‐abeo‐abietane diterpenoids, 16‐hydroxysalvilenone ( 1 ), 15‐hydroxysalprionin ( 2 ), and 11β,15‐dihydroxysalprionin‐12‐one ( 3 ), and nine known abietane diterpenoids, 4 – 12 , along with one known sempervirane diterpenoid, hispidanol A ( 13 ), were isolated from the aerial parts of Isodon lophanthoides var. graciliflorus. The structures of compounds 1 – 3 were determined on the basis of spectroscopic methods including extensive analysis of NMR and mass spectroscopic data. All diterpenoids were tested for their TNF‐α inhibitory effects on LPS‐induced RAW264.7 cells. Compound 9 (16‐acetoxyhorminone) was the most potent with an IC₅₀ value of 3.97±0.70 μm .     

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 New Prenylated Indole Diterpenoids from Tolypocladium sp. and Their Antimicrobial Activities

Two new prenylated indole diterpenoids, tolypocladins K and L ( 1 and 2 ), together with a known analog terpendole L ( 3 ), were isolated from the solid fermentation culture of a mine soil‐derived fungus Tolypocladium sp. XL115. Their structures and relative configurations were determined by comprehensive spectroscopic data analysis, as well as by comparison of their NMR data with those related known compounds. Compound 3 exhibited remarkable antibacterial activity against Micrococcus luteus with an MIC value of 6.25 μg/mL, and compounds 1 and 3 displayed moderate antifungal activity selectively against tested strains with MIC values of 25–50 μg/mL.     

Ceriopsins F and G,diterpenoids from Ceriops decandra

Chemical examination of the ethyl acetate solubles of the CH(3)OH:CH(2)Cl(2) (1:1) extract of the roots of Ceriops decandra collected from Kauvery estuary resulted in the isolation of two more diterpenoids, ceriopsins F and G (1-2) and five known compounds, ent-13-hydroxy-16-kauren-19-oic acid (steviol, 3), methyl ent-16beta,17-dihydroxy-9(11)-kauren-19-oate (4), ent-16beta,17-dihydroxy-9(11)-kauren-19-oic acid (5), ent-16-oxobeyeran-19-oic acid (isosteviol, 6), 8,15R-epoxypimaran-16-ol (7). The structures of the new diterpenoids were elucidated by a study of their physical and spectral data as methyl ent-13,17-epoxy-16-hydroxykauran-19-oate (1) and ent-16-oxobeyeran-19-al (2).