Molecular cloning and expression of AmCDPK from mangrove Avicennia marina under elevated temperature

Considered as an essential calcium sensor, the calcium-dependent protein kinase (CDPK) family plays a critical part in terrestrial plants’ responses to both biotic and abiotic stresses. In the study, Avicennia marina was proved to have better heat tolerance than other species. A CDPK gene was cloned from mangrove species A. marina using RACE-PCR and designated as AmCDPK. By predicting and analyzing its properties, structures and expression patterns, we found that the amino acid sequence, containing a kinase domain and four EF-hand Ca²⁺-binding sites, shared high identity with Handroanthus impetiginosus and Sesamum indicum. Quantitative real-time PCR data analysis suggested that AmCDPK demonstrated significant up-regulation under heat stress. It is likely that AmCDPK is a versatile gene involved in various stresses, including dehydration, cold, light, defense and ABA stress responses by analyzing cis-elements. It is the first time that CDPKs from mangroves have been cloned and our results brought evidence to the effect of AmCDPK on heat stress, which is particularly important under the background of global warming.

     

Rearranged abietane diterpenoids from Clerodendrum mandarinorum

Five new abietane derivatives which have a commonly rearranged abietane skeleton contained a 17(15 → 16),18(4 → 3)-diabeo-abietane framework, mandarones D-H, were isolated from the stem of Clerodendrum mandarinorum Diels (Verbenaceae). The structures were characterized as (16S)-12,16-epoxy-11-hydroxy-17(15 → 16),18(4 → 3)-diabeo-abieta-3,5,8,11,13-pentaene-7-one (mandarone D, 1), 12,16-epoxy-11,14-dihydroxy-17(15 → 16),18(4 → 3)-diabeo-abieta-3,5,8,11,13,15-hexaene-7-one (mandarone E, 2), 12,16-epoxy-6,11,14-trihydroxy-17(15 → 16),18(4 → 3)-diabeo-abieta-3,5,8,11,13,15-hexaene-7-one (mandarone F, 3), 12,16-epoxy-11,14-dihydroxy-6-methoxy-17(15 → 16),18(4 → 3)-diabeo-abieta-3,5,8,11,13,15-hexaene-2,7-dione (mandarone G, 4) and 12,16-epoxy-11,14-dihydroxy-17(15 → 16),18(4 → 3)-diabeo-abieta-3,5,8,11,13,15-hexaene-1,7-dione (mandarone H, 5) respectively, mainly based on the spectral analysis and by comparison with those of closely related compounds.     

Two new abietane diterpenoids from Salvia yunnanensis

Two new abietane diterpenoids, yunnannin A and danshenol C, were isolated from Salvia yunnanensis together with ten known diterpenoids, danshenol A, przewalskin, tanshinone IIA, tanshinone I, crypotanshinone, 1,2-dihydrotanshinone, tanshinlactone, 5,6-dehydrosugiol, 12-hydroxy-6,7-seco-8,11,3-abietatriene-6,7-dial and phytol. Their structures were established based on spectroscopic data, chemical reactions and comparison with literature data. Compounds were tested for their antitumor activity in T-24, QGY, K562, Me180 and BIU87 cell lines. Compound showed inhibited growth of K562 (IC50=0.53 microg/mL), T-24 (IC50=7.94 microg/mL), QGY (IC50=4.65 microg/mL) and Me180 (IC50=6.89 microg/mL) cell lines while compound was inactive. Compound showed moderate inhibitory activity on QGY (IC50=16.75 microg/mL) and Me180 (IC50=5.84 microg/mL) cells.     

Cytotoxic abietane and kaurane diterpenoids from Celastrus orbiculatus

Journal of Natural Medicines - Celastrus orbiculatus is a medicinal plant belonging to the Celastraceae family. In this survey on the secondary metabolites of plants for obtaining antitumor...     

Two new rearranged abietane diterpenoids from tropical Isodon coetsa

Two new rearranged abietane diterpenoids, sincoetsin A (1) and sincoetsin B (2), were isolated from the aerial part of Isodon coetsa (Buth-Ham ex D.Don) Hara collected in Singapore, and their structures were determined by spectroscopic methods, especially 2D NMR techniques.     

Two new rearranged abietane diterpenoids from tropical Isodon coetsa

Two new rearranged abietane diterpenoids, sincoetsin A (1) and sincoetsin B (2), were isolated from the aerial part of Isodon coetsa (Buth-Ham ex D.Don) Hara collected in Singapore, and their structures were determined by spectroscopic methods, especially 2D NMR techniques.     

Salt tolerance and exclusion in the mangrove plant Avicennia marina in relation to root apoplastic barriers

Ecotoxicology - Salt tolerance and the possible functions of suberization on salt exclusion and secretion were examined in a dominant mangrove plant, Avicennia marina. The results showed that low...     

Proline metabolism and molecular cloning of AmP5CS in the mangrove Avicennia marina under heat stress

Ecotoxicology - Proline is one of the most important compatible osmolyte in cells, which accumulates in response to various stresses, including salt, water deficit, heavy metal, pathogen infection...     

Antiproliferative effects of abietane diterpenoids isolated from Hyptis martiusii Benth (Labiatae)

Two abietane diterpenes were isolated from a hexane extract of Hyptis martiusii roots and identified as carnasol 11,14-dihidroxy-8,11,13-abietatrien-7-one. These compounds were tested for their antiproliferative effects on tumor cell lines using 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide and on the sea urchin egg development. Both compounds displayed cytotoxic activity against tumor cell lines, but only carnasol was able to inhibit the sea urchin egg cleavages.     

Three new pimaren diterpenoids from marine mangrove plant, Bruguiera gymnorrhiza

Three new pimaren diterpenoids, ent-8(14)-pimarene-15R, 16-diol (1), ent-8(14)-pimarene-1alpha,15R,16-triol (2), and (5R, 9S, 10R, 13S, 15S)-ent-8(14)-pimarene-1-oxo-15R,16-diol (3), along with three known diterpenoids (4-6) have been isolated from the stem of mangrove plant Bruguiera gymnorrhiza. The structures of compounds 1-3 were determined by extensive spectroscopic (2D NMR, MS, IR, and CD) analysis, and 3 and 5 showed moderate cytotoxic activities against L-929 and K562, respectively.     

New diterpenoids from Sapium discolor

Abstract

Chemical fractionation of the ethanolic extract generated from the twigs and leaves of Sapium discolor led to the isolation and identification of four new macrocyclic diterpenoids including three members of the rare casbane family, sapidisins A-C (1–3), and an analog of the cembrane class, sapidisin D (4), a new 3,4-seco ent-kaurane diterpenoid (5), and 18 known phenolic compounds. Their structures were elucidated by comprehensive spectroscopic analyses especially 1D NMR ¹H-¹H couplings and 2D NMR ROESY data. The discovery of 1–4 from S. discolor provides a clue for further study on the biogenetic evolution of the widely existent tigliane-type diterpenoids in the Sapium species.     

New diterpenoids from Semiaquilegia adoxoides

Two new ent-kaurane-type diterpenoids, E-semiaquilegin (1) and Z-semiaquilegin (2), together with eight known compounds (3-10) were isolated from the dried roots of Semiaquilegia adoxoides (DC.) Makino. The structures of compounds 1 and 2 were elucidated mainly by 2D NMR techniques including 1H-1H COSY, HSQC, HMBC, NOESY as 16alpha-hydroxy-ent-kaurane-17,20-di-(3,4-dihydroxy-E-cinnamoyl) ester and its (Z)-isomer.     

New diterpenoids from Semiaquilegia adoxoides

Two new ent-kaurane-type diterpenoids, E-semiaquilegin (1) and Z-semiaquilegin (2), together with eight known compounds (3–10) were isolated from the dried roots of Semiaquilegia adoxoides (DC.) Makino. The structures of compounds 1 and 2 were elucidated mainly by 2D NMR techniques including ¹H–¹H COSY, HSQC, HMBC, NOESY as 16α-hydroxy-ent-kaurane-17,20-di-(3,4-dihydroxy-E-cinnamoyl) ester and its (Z)-isomer.     

Isolation,structure elucidation,and induction of hepatoma cell apoptosis of abietane diterpenoids from Abies faxoniana

Two new abietane diterpenoids (1–2) and 13 known compounds (3–15) were characterized from the branches and leaves of Abies faxoniana. The chemical structures of the new diterpenoids (1–2) were determined through the analysis of various 1D/2D NMR techniques. Compound 3 is 151,617-trinor-abietane diterpenoid conjugated with a three-membered epoxide ring. The isolated diterpenoids were tested for their cytotoxicities. Among them, compound 3 exhibited the strongest antiproliferative effect against human hepatoma cell SMMC7721 with an IC₅₀ value of 12.5 μM. To elucidate the preliminary mechanism responsible for compound 3-induced inhibition of cell proliferation, we investigated the effects of compound 3 on apoptosis, cell cycle progression, and reactive oxygen species generation in SMMC7721 cells. The results showed that compound 3 induced cell apoptosis and excessive ROS production, but did not change the cell cycle distribution in SMMC7721 cells.     

New macrocyclic diterpenoids from Euphorbia esula

The structures of two new macrocyclic jatrophane diterpenoid esters from the whole herb of Euphorbia esula, were established as 11,14-epoxy-3beta,5alpha,7beta,8alpha,9alpha,15beta-hexaacetoxy-12-oxo-13alphaH-jatropha-6(17)-ene (1) and 1alpha,3beta-diacetoxy-5alpha,7beta-dibenzoyloxy-9,14-dioxo-11beta,12alpha-epoxy-2alpha,8alpha,15beta-trihydroxy-13betaH-jatropha-6(17)-ene (2) by a combination of 1D- and 2D-NMR techniques as well as UV, IR and mass spectral data. Bioassay evaluation of all isolates against the human tumor cell lines (B16, KB, SMMC and BGC) indicated that ester 2 was cytotoxic to B16 with the IC50 value being 1.81 microg/ml. In addition, the irritant activity assay indicated that both diterpenoids were inactive (ID(24)50 > 100 microg/ear).     

New halimane diterpenoids from Croton oblongifolius

Three new halimane-type diterpenoids, crotohalimaneic acid ( 1), crotohalimoneic acid ( 2) and 12-benzoyloxycrotohalimaneic acid ( 3), were isolated from the stem bark of Croton oblongifolius Roxb. Their structures were established on the basis of spectroscopic and X-ray analysis. Compounds 1 and 2 showed non-specific strong cytotoxicity against a panel of human tumor cell lines; whereas 3 was inactive.     

New cytotoxic bis-labdanic diterpenoids from Alpinia calcarata

Two novel bis-labdanic diterpenoids named calcaratarin D and calcaratarin E were isolated from the rhizomes of Alpinia calcarata. Their structures were elucidated as a pair of stereoisomers on the basis of the spectral evidence. 2D NMR techniques including (1)H- (1)H COSY, HMQC, HMBC, NOESY spectra and HRFABMS were extensively applied to establish the structures. The two bis-labdanic diterpenoids showed cytotoxic activity against human KB cells in vitro.     

New diterpenoids from the aerial parts of Salvia candelabrum

The new diterpenoids, candesalvoquinone, 12- O-methylcandesalvone B, candesalvone B methyl ester with the 3,4-secoabietane skeleton, and candelabroquinone with the abietane skeleton were isolated from the aerial parts of Salvia candelabrum, together with the known compound candelabrone. The structures were established by mass spectroscopy and advanced two-dimensional NMR methods, including 1H-NMR, JMOD, 1H- 1H COSY, HSQC, HMBC and NOESY experiments.