Bioactive cassane diterpenoids from the seeds of Caesalpinia sappan

Three new cassane-type diterpenoids named caesalppans G-I (1–3) together with three known ones (4–6), were isolated from the methanol extract of Caesalpinia sappan seeds. Their structures were determined based on spectroscopic data. Among the isolated compounds, compound 2 displayed a moderate antimalarial activity with an IC₅₀ value of 2.4 μM, and compound 4 showed mild anti-inflammatory activity with an IC₅₀ value of 28.65 μM.     

Labdane diterpenoids from Marrubium vulgare

Phytochemical investigation of the whole plant of Marrubium vulgare L. (Lamiaceae) resulted in isolation and characterization of two new labdane diterpenoids, 12(S)-hydroxymarrubiin and 3-deoxo-15-methoxyvelutine C and 11 known compounds, marrubiin, peregrinin, thessaline D, marrubinone B, deacetylvitexilactone, verbascoside, leucosceptoside A, martynoside, anisofolin A, terniflorin, and apigenin. Structure elucidation of the isolated compounds was determined by using spectroscopic techniques and HRESIMS. 12(S)-Hydroxymarrubiin, marrubiin, peregrinin, and marrubinone B, exhibited no antimicrobial activity up to 20 μg/mL against ten strains.     

Cytotoxic abietane-type diterpenoids from twigs and leaves of Croton laevigatus

Seven new abietane-type diterpenoids, crotolaevigatones A–G (1–7), one new aromatic compound, hexyl Z-ferulate (8), along with three known diterpenoids (9–11) and one known aromatic ester, hexyl E-ferulate (12), were obtained from the twigs and leaves of Croton laevigatus. The structures of all isolated compounds were established on the basis of extensive NMR and MS spectroscopic analyses. Compounds 2 and 7 exhibited weak anti-proliferative activity against the A549 and MDA-MB-231 cancer cells, while compound 10 selectively showed significant inhibitory activity against the A549 cancer cells.     

New labdane diterpenoids from Leonurus japonicus and their anti-inflammatory activity

Two new, 16-oxo-leoheteronone A (1) and 15-methoxyleoheteronin B (2), and four known, 8,9-secohispanolone (3), galeopsin (4), hispanone (5), and leoheteronin B (6), labdane diterpenoids were isolated from the aerial parts of Leonurus japonicus. Compound 3 was isolated for the first time as a naturally occurring compound. Structures of the two compounds were determined on the basis of extensive spectroscopic techniques, including 1D, 2D NMR, and HREIMS. In addition, compounds 1–3, 5 and 6 were examined for inhibition of superoxide anion generation and elastase release, and the results suggested that compound 5 possesses anti-inflammatory activity.     

Two new neo-clerodane diterpenoids from Scutellaria barbata

Two new neo-clerodane diterpenoids, 6,7-dibenzoyloxybarbatin C (1, named barbatin D) and 6-(2-acetoxy-3-methylbutanoloxy)-7-(2-carbonyl-3-methylbutanoyloxy) barbatin C (2, named barbatin E) were Isolated from the whole plant of Scutellaria barbata D. Don. Their structures were elucidated by spectroscopic methods including extensive 1D and 2D NMR analyses. In vitro, compounds 1-2 showed cytotoxic activities against three human cancer lines, namely, HONE-4 nasopharyngeal, KB oral epidermoid carcinoma, and HT29 colorectal carcinoma cells, and with ICso values in the range of 3.5-6.7 μM.     

Cytotoxic diterpenoids from the aerial parts of Scoparia dulcis

Two formerly undescribed labdane-type diterpenoids, scoparicols C (1) and D (2), one previously unreported scopadulane-type diterpenoid 1β-hydroxydulcinodal-13-one (3), along with six known biogenetically related analogs (4−9) were separated from the aerial parts of a traditional ethnological herb, Scoparia dulcis. Spectroscopic techniques including MS NMR and ECD were employed to characterize the structures of these molecules. While the oxidation at C-1 in 3 was reported for scopadulane-type diterpenoids for the first time, compound 7 was first obtained as a natural product in the present work. The cytotoxicity of all the isolates against four tumor cell lines (MCF-7, MDA-MB231, Hela and A549) were tested, with selective compounds showing activity in the IC₅₀ range of 4.31–28.6 μM.     

Cytotoxic macrocyclic diterpenoids from Jatropha multifida

Nine new macrocyclic diterpenoids (1–9), jatromultones A-I, along with eight known analogues (10–17) were isolated from the trunks of Jatropha multifida. The structures of the new compounds, including their absolute configurations, were elucidated by combination of spectroscopic analysis, single crystal X-ray diffraction, Rh₂(OCOCF₃)₄-induced CD method, and chemical correlations. All compounds were screened for the cytotoxicity against five cancer cell lines, including one drug-resistant cell line, and seven compounds exhibited significant activity with IC₅₀ values less than 10 μM. Compound 4 with IC₅₀ values ranging from 2.69 to 6.44 μM toward all cell lines was selected for further mechanistic study, which showed that 4 could arrest cell cycle at G2/M phase and induce apoptosis. The brief structure-activity relationships (SARs) of these macrocyclic diterpenoids were also discussed.     

New tetranorlabdane diterpenoids from the fruits of Elettaria cardamomum Maton

A pair of new tetranorlabdane diterpenoid epimers, named elettarins A (1) and B (2), together with five known labdane diterpenes (3–7), were isolated from Elettaria cardamomum Maton. The structures of elettarins A and B were established based on spectroscopic data (HRESIMS, 1D/2D NMR), and ECD experimentation. All isolates were evaluated for their inhibitory activities against nitric oxide (NO) production on BV-2 microglia cells.     

Two new diterpenoids from Aleuritopteris argentea

Two new compounds were extracted and separated from the whole plant of Aleuritopteris argentea. The structures and absolute configurations of two compounds were characterized by UV, FT-IR, NMR, MS, and single-crystal X-ray diffraction. Compound 1 was determined to be 2, 17-diol (2β, 4α)-15,16-ene-beyerane diterpenoid and compound 2 to be 2,18-diol (2β, 4α)-16-ene-ent-kaurane diterpenoid, named aleuritopsis A and aleuritopsis B respectively. The cytotoxicity of two compounds against MCF-7 and SKOV3 cells were tested using the MTT method, as the results, both exhibited obvious inhibitory effect to the tumor cells.     

Confirmation of the structure of calliterpenone,a diterpene from Callicarpa macrophylla

The structure and absolute configuration of calliterpenone has been established as 3-oxo-13β-kaurane-16α,17-diol. This conclusion confirms that proposed by Ahmad and Zaman, and the formula suggested previously by Chatterjee et al. is revised.     

Three new jatrophane diterpenoids from Euphorbia peplus Linn. with activity towards autophagic flux

Three undescribed jatrophane diterpenoids, named euphpepluones P-R (1–3), were isolated from the whole plant Euphorbia peplus. The structures of these compounds were elucidated by spectroscopic methods. The absolute configuration of 1 was further assigned by X-ray crystallographic analysis. All compounds were evaluated for bioactivity towards autophagic flux by flow cytometry using HM mCherry-GFP-LC3 cells. Compounds 2 and 6 exhibited significant inhibition of autophagic flux.     

Cassane diterpenoids from stem bark of Erythrophleum suaveolens [(Guill. et Perr.), Brenan]

Phytochemical investigation of the stem bark of Erythrophleum suaveolens yielded four new cassane diterpenoids; 6α-hydroxy-cassamic acid, methyl ester, 4β-carbomethoxy-14-methyltotarol, 6α-hydroxy-nor-cassamine, and 8,9-dehydro-nor-cassamine, along with four known cassane diterpenoids. All structures were elucidated on the basis of one- and two-dimensional NMR, HRMS and ESIMS analysis.     

neo-Clerodane diterpenoids from Scutellaria barbata with cytotoxic activities

Three neo-clerodane diterpenoids, named barbatins A-C (1-3), and the neo-clerodane diterpenoid nicotinyl ester, named scutebarbatine B (4), were isolated from the whole plant of Scutellaria barbata D. Don. Their structures were elucidated by spectroscopic analyses (UV, IR, HRFAB-MS, 1D NMR and 2D NMR). In vitro, compounds 1-4 showed significant cytotoxic activities against three human cancer lines, namely, HONE-1 nasopharyngeal, KB oral epidermoid carcinoma, and HT29 colorectal carcinoma cells, with IC50 values in the range 3.5-8.1 microM.     

Cycloartane triterpenoids from Guarea macrophylla

Nine cycloartane triterpenoids, including two new derivatives 22,25-dihydroxy-cycloart-23E-en-3-one and 24-methylenecycloartane-3 beta,22-diol have been isolated from leaves of Guarea macrophylla. The structures were elucidated by interpretation of spectral data, mainly 1H and 13C NMR, including bidimensional analysis (HOMOCOSY, HMQC and HMBC).     

Norclerodane diterpenoids from rhizomes of Dioscorea bulbifera

Three norclerodane diterpenoids, diosbulbins K-M, and one analogous enolglycoside, diosbulbinoside G, together with four norclerodane diterpenoids, diosbulbins B, E, F and G, were isolated from rhizomes of Dioscorea bulbifera. Their structures were established by spectroscopic and chemical methods, including ¹H and ¹³C NMR, NOESY, HSQC, HMBC, and HRMS analyses. The relative configurations of diosbulbins K and L, and diosbulbin F were confirmed by X-ray crystallographic diffraction analysis, and the absolute stereochemistry of diosbulbin K was determined by a modified Mosher’s method. The ¹³C NMR spectroscopic data for diosbulbins E, F and G were also measured for the first time. The compounds did not show significant cytotoxic and anti-bacterial activities.     

广东紫珠中的萜类化合物及其抗炎活性

对岭南药材广东紫珠(Callicarpa kwangtungensis)地上部分进行化学成分研究,得到11个萜类化合物,分别鉴定为sambucunlin A(1)、2α-羟基羽扇豆醇(2)、swinhoeic acid(3)、3β-羟基-乌苏烷-11-烯-13β,28-内酯(4)、蔷薇酸(5)、2α,3β,6β,18β,23-pentahydroxy-olean-12-en-28-oic acid(6)、rel-5-(3S,8S-dihydroxy-1R,5S-dimethyl-7-oxa-6-oxobicyclo-oct-8-yl)-3-methyl-2Z,4E-pentadienoic acid(7)、salvionoside B(8)、齐墩果酸(9)、白桦脂酸(10)和α-香树脂醇(11)。其中,化合物1～4和6～8为首次从该属植物中分离得到。在化学成分分离基础上,进一步选择脂多糖(LPS)诱导的RAW 264.7小鼠巨噬细胞炎症模型进行萜类化合物抗炎活性测试。结果表明:化合物3和9具有显著的抗炎活性,对比结构发现,三萜类化合物(3～6、9和11)抗炎活性优于倍半萜类化合物(7和...     

New ent-kaurane and ent-pimarane diterpenoids from Siegesbeckia pubescens

Phytochemical investigation of the aerial parts of Siegesbeckia pubescens afforded two new ent-kaurane diterpenoids (1-2), together with sixteen known ent-kaurane and ent-pimarane diterpenoids (3–18). Their structures were elucidated on the basis of extensive spectroscopic methods The absolute configurations of 1–2 and 12 were determined by single-crystal X-ray diffraction analyses. All compounds were evaluated for their cytotoxic activities against two human cancer cell lines A375 and HCT-116.