Taxodistines A and B, abietane-type diterpenes from Taxodium distichum

Two new abietane-type diterpenes, taxodistines A (1) and B (2), have been isolated by the guidance of inhibitory effect of tubulin polymerization from the fruits of Taxodium distichum and the structures were elucidated by using 2D NMR data. Taxodistine B (2) showed inhibition of tubulin polymerization.     

Pahangensin A and B,two new antibacterial diterpenes from the rhizomes of Alpinia pahangensis Ridley

The rhizomes of Alpinia pahangensis Ridley yielded a new bis-labdanic diterpene for which the name pahangensin A (1) was proposed along with a new labdane diterpene, pahangensin B (2). Their structures were elucidated by spectroscopic methods including, 1D and 2D NMR techniques and LCMS-IT-TOF analysis. Pahangensin A (1) was found to be an antibacterial agent against Staphylococcus aureus, Bacillus cereus and Bacillus subtilis with MIC values less than 100 μg/mL, respectively. Pahangensin B (2) exhibited antibacterial activity (MIC <100 μg/mL) against B. cereus.     

Trochelioid A and B,new cembranoid diterpenes from the Red Sea soft coral Sarcophyton trocheliophorum

Chemical investigations of the soft coral Sarcophyton trocheliophorum, has led to the isolation of six cembranoids, two of which are new, Trochelioid A (1) and B (2), and one, 16-oxosarcophytonin E (3) isolated from nature for the first time. Additionally, two have been isolated from S. trocheliophorum for the first time (4 and 6). Structures were elucidated by employing extensive NMR and HR-FAB-MS experimentation.     

Two new alkaloids and active anti-hepatitis B virus constituents from Hypserpa nitida

Two new alkaloids, hypserpanines A and B (1, 11), together with eleven known compounds, phenolbetain (2), acutumine (3), acutumidine (4), dechloroacutumine (5), dauricumine (6), dauricumidine (7), pronuciferine (8), glaziovine (9), S-reticuline (10), magnoflorine (12) and laurifoline(13), were isolated from Hypserpa nitida Miers. (Menispermaceae) and chemically elucidated through spectral analyses. All the isolated alkaloids were evaluated for their anti-HBV activities in vitro using the HBV transfected Hep G2.2.15 cell line. The most active compound, dauricumidine (7), exhibited an IC(50) value of 0.450 mM (SI=4.13) on hepatitis B virus (HBV) surface antigen (HBsAg) secretion of the Hep G2.2.15 cell line.     

Three new cassane-type furanoditerpenes from the seed of Vietnamese Caesalpinia bonducella

Three new cassane-type furanoditerpenes, bonducellpin H (1), bonducellpin I (2), and 7-acetoxycaesalpinin P (3), together with seven known compounds (4–10) have been isolated from the MeOH extract of the seed kernels of Caesalpinia bonducella from Vietnam. The structures of these compounds were elucidated by using spectroscopic techniques.     

Four new diterpenes from Sideritis serrata

Four new diterpenes have been isolated from Sideritis serata: lagascol (4, ent-8,5-friedopimar-5-ene-15S,16-diol), tobarrol (8, ent-15-beyerene-12α,17-diol), benuol (12, ent-15-beyerene-7α,17-diol) and serradiol (18, ent-16R-atis-13-ene-16,17-diol). The previously known diterpenes lagascatriol (1, ent-8,5-friedopimar-5-ene-11β,15S,16-triol), jativatriol (2, ent-15-beyerene-1β,12α,17-triol), conchitriol (3, ent-15-beyerene-7α,12α,17-triol) and sideritol (17, ent-16R-atis-13-ene-1β,16,17-triol) have also been obtained from the same source.     

Three new labdane diterpenes from Loxocalyx urticifolius

Three new labdane diterpenes, namely loxocalyxin D (1), loxocalyxin E (2) and 13-epiloxocalyxin E (3), were isolated from the whole plants of Loxocalyx urticifolius Hemsl. Their structures were elucidated by extensive spectral analysis and chemical methods. The absolute configuration of loxocalyxin D (1) was confirmed by X-ray crystallographic analysis. The cytotoxic activities of the isolated labdane diterpenes were evaluated against the four human cancer cell lines A549, HepG2, HL-60 and MCF-7. 13-epiloxocalyxin E (3) exhibited selective cytotoxicity against A549 and MCF-7 with the IC₅₀ values of 22.4 and 47.3 μM, respectively.     

Three new diterpenes and two new sesquiterpenoids from the endophytic fungus Trichoderma koningiopsis A729

Three new diterpenes koninginols A-C (1–3) and two new sesquiterpenoids 11-hydroxy-15-drimeneoic acid (4), koninginol D (5), together with twelve known compounds (6–17) were isolated from the endophytic fungus Trichoderma koningiopsis A729 derived from Morinda officinalis. Their structures were fully assigned with the aid of extensive spectroscopic analysis and reported data from the previous literatures. Koninginols A and B were disclosed as intriguing diterpene alkaloids, whereas the koninginol C was disclosed as one of the two examples of harziandione diterpene. All the isolates were evaluated for their antitumor activity, and compounds 1–2, 4–6, 11–13, 16–17 were evaluated for their antibacterial activity, wherein the new compounds 1 and 2 exhibited significant antibacterial activity against Bacillus subtilis with MIC values of 10 and 2 μg/mL, respectively.     

Verbenacine and salvinine: two new diterpenes from Salvia verbenaca

Two new diterpenes namely verbenacine (1) and salvinine (2) have been isolated from the aerial parts of Salvia verbenaca. Their structures have been elucidated on the basis of chemical and spectral data as 3alpha-hydroxy-19-carboxykaur-15-ene and 19-hydroxy-12,14-dioxo labda-15,17-diene.     

Erythrofordins D and E,two new cassaine-type diterpenes from Erythrophleum suaveolens

Two new cassaine-type diterpenoids, namely erythrofordins D (1) and E (2), sourced from a Cameroon collection of Erythrophleum suaveolens were isolated and assessed for anti-tumor activity. In the NCI-60 cancer cell assay, erythrofordins D (1) and E (2) were found to be cytotoxic in the low micro molar ranges with a mean GI₅₀ value of 2.45 and 0.71?µM, mean TGI value of 9.77 and 2.29?µM, and a mean LC₅₀ of 26.92 and 11.48?µM for 1 and 2 respectively. Using the COMPARE algorithm, the new compounds were found to have similar NCI-60 response profiles to the known cardiac glycosides hyrcanoside and strophanthin. In addition, in an assay examining the viability and contractile function in human cardiomyocytes derived from induced pluripotent stem-cells, erythrofordins showed cardiotoxicity effects at concentrations as low as 0.03?µg/mL.     

Schizonellin A and B,new glycolipids from Schizonella melanogramma

Two new glycolipids, schizonellin A and B, were isolated from cultures of the smut fungus Schizonella melanogramma. Their structures were elucidated by chemical degradation and spectroscopic methods. The schizonellins are active against Gram-positive bacteria, as well as against some Gram-negative bacteria and some fungi. DNA-, RNA- and protein-syntheses in Ehrlich carcinoma ascitic cells are inhibited simultaneously after addition of the schizonellins. Strong haemolytic action on bovine erythrocytes was observed.     

Cespitulactones A and B, new diterpenoids from Cespitularia taeniata

Two new diterpenoids, designated cespitulactones A (1) and B (2), were isolated from a sample of the soft coral Cespitularia taeniata collected in Taiwan. Compound 1 possesses a novel structure with a bond cleavage between C-10 and C-11, and having a 14-membered lactone ring junction between C-10 and C-12. Their structures were elucidated on the basis of extensive spectroscopic analysis and chemical derivatization. The isolated compounds were also evaluated for cytotoxicity toward human cancer cell lines.     

Sesquiterpenes,guaianolides and diterpenes from Stevia myriadenia

The investigation of Stevia myriadenia afforded in addition to known compounds a new clerodane and a labdane derivative, two guaianolides, a bisabolene and a germacrene derivative. The structures were elucidated by spectroscopic methods. The chemotaxonomic situation is discussed briefly.     

Four new cassane diterpenes from the seeds of Caesalpinia minax

In our survey on the chemical composition of traditional Chinese medicines to further elucidate their chemical substances for the treatment of diseases, we investigated the chemical constituents of the seeds of plants Caesalpinia minax. The investigation led to the isolation and identification of four new cassane diterpenes, caesalpines A–D (1–4). Their structures were elucidated on the basis of extensive 1D and 2D NMR (COSY, HMQC, HMBC, and NOESY) and mass (ESIMS and HR-ESIMS) spectroscopic data analyses. The phytochemical results imply that cassane diterpenes are maybe regarded as the characteristic constituents of C. minax.     

Three new cassane diterpenes from the seeds of Caesalpinia sappan

Three new cassane furanoditerpenes, phanginins N–P (1–3), together with four known ones were isolated from the seeds of Caesalpinia sappan. Their structures were elucidated on the basis of spectroscopic analysis including HRESIMS, 1D and 2D NMR techniques. Evaluation of all the compounds for cytotoxicity against three human cancer cell lines (HepG-2, MCF-7 and HCT-8) showed insignificant results (IC₅₀ > 10 μM).     

Two new cytotoxic diterpenes from the rhizomes of Hedychium spicatum

Phytochemical investigation of CHCl₃ extract of the rhizomes of Hedychium spicatum led to the isolation of two new labdane-type diterpenes, compounds 1 and 2 along with five known compounds (3–7). Their structures were established on the basis of NMR (1D and 2D) and mass spectroscopic analysis. In addition, all the isolates were tested for their cytotoxicity against the Colo-205 (Colo-cancer), A-431 (skin cancer), MCF-7 (breast cancer), A-549 (lung cancer) and Chinese hamster ovary cells (CHO). Two new compounds 1 and 2 were shown good cytotoxic activity.     

Zoapatanolide A and B,two new heliangolides from Montanoa tomentosa

The re-investigation of Montanoa tomentosa afforded, in addition to known diterpenoids of the kaurene class, two new sesquiterpene lactones, zoapatanolide A and B, of the heliangolide type.     

Deltoidin A and B,two new germacrolides from Eupatorium deltoideum

Investigation of E. deltoideum provided two new germacrolide-type sesquiterpene lactones, deltoidin A and B, besides the known guaianolide ligustrin, and diterpenes and triterpenes.     

Two new cytotoxic labdane diterpenes from the rhizomes of Hedychium coronarium

The phytochemical investigation of the hexane extract of the Hedychium coronarium led to the isolation and identification of two new labdane diterpenes (1 and 2) along with 10 known metabolites (3-12). The structures of the new compounds were established on the basis of spectroscopic data analysis (1D and 2D NMR and MS). Cytotoxic activities of the isolates were studied against the A-549 (lung cancer), SK-N-SH (human neuroblastoma), MCF-7 (breast cancer) and HeLa (cervical cancer) cell lines.