A new abietane diterpenoid from Isodon inflexus

A new ent-abietane diterpenoid, 3α,6β-dihydroxy-7,17-dioxo-ent-abieta-15(16)-ene (1), and three known ent-kaurane diterpenids, kamebacetal A (2), kamebakaurin (3), and excisanin A (4), and a known triterpenoid, ursolic acid (5), were isolated from the aerial parts of Isodon inflexus. Their chemical structures were determined by extensive analysis of spectroscopic data including 1D-and 2D-NMR experiments. All isolates (1–5) were evaluated for their potential to inhibit LPS-induced nitric oxide production in RAW264.7 cells. Of these, compounds 1–4 inhibited the production of NO with IC₅₀ values ranging from 1.0 to 26.5 μM.     

A new isopimarane-type diterpene and a new natural atisane-type diterpene from Excoecaria agallocha

From the woods of Excoecaria agallocha, a new isopimarane-type diterpene, 3α,11β-dihydroxy-ent-isopimara-8(14),15-dien-2-one (1) and a new natural atisane-type diterpene, 16β-hydroxy-ent-atisan-3-one (2) were isolated together with three known compounds, ribenone (3), ent-labda-8(17),13E-diene-3β,15-diol (4), and ent-3β-hydroxybeyer-15-ene-2,12-dione (5). Their structures were determined by spectral data and x-ray crystallography evidence.     

A new <Emphasis Type="Italic">ent</Emphasis>-kaurane type diterpenoid glycoside from <Emphasis Type="Italic">Inula japonica</Emphasis> Thunb.

A new ent-kaurane type diterpenoid glycoside, 17-O-β-D-glucopyranosyl-16α-ent-kauran-19-oic acid (1), together with 17-hydroxy-16α-ent-kauran-19-oic acid (2), 16α,17-dihydroxyl-ent-kauran-19-oic acid (3), and 16α-hydroxy-17-acetoxy-ent-kauran-19-oic acid (4) were isolated from the aerial parts of Inula japonica Thunb. The structure of 1 was determined mainly by use of 1D and 2D NMR spectroscopic techniques including HSQC, ¹H-¹H COSY, HMBC, and NOESY. In addition, 4 exhibited significant inhibitory activity on NO production in LPS-stimulated RAW264.7 cells with IC₅₀ value of 14.3 μg/mL.     

Three new diterpenoids from Aralia dumetorum

Three new diterpenoids, dumetoranes A (1) and B (2), melanocane B (3), together with four known ones including melanocane A (4), ent-15S,16-dihydroxypimar-8(14)-en-19-oic acid (5), ent-pimara-8(14),15-diene-19-oic acid (6), and ent-pimara-8(14),15-diene-19-ol (7) were obtained from the ethanol extract of the roots of Aralia dumetorum. Their structure elucidation was achieved by the methods of spectroscopic HRMS, IR, NMR, and by comparison with literature. The cytotoxicities of compounds 1–3 and 5 were assayed by in vitro MTT methods.     

Cholinesterase and BACE1 inhibitory diterpenoids from <Emphasis Type="Italic">Aralia cordata</Emphasis>

Fourteen diterpenes were isolated from the n-hexane fraction of the roots of Aralia cordata (syn. = A. continentalis). Through spectroscopy, the chemical structures were determined as: ent-pimara-8(14),15-diene-19-oic acid (1); ent-kaur-16-en-19-oic-acid (2); 18-nor-ent-pimara-8(14),15-diene-4β-ol (3); 18-nor-ent-kaur-16-ene-4β-ol (4); ent-pimara-8(14),15-diene-19-ol (5); 7α-hydroxy-ent-pimara-8(14),15-diene-19-oic acid (6); 7β-hydroxy-ent-pimara-8(14),15-diene-19-oic acid (7); ent-pimar-15-en-8α,19-diol (8); 7-oxo-ent-pimara-8(14),15-diene-19-oic acid (9); 16α-hydroxy-17-isovaleroyloxy-ent-kauran-19-oic acid (10); 17-hydroxy-ent-kaur-15-en-19-oic acid (11); 15α,16α-epoxy-17-hydroxy-ent-kauran-19-oic acid (12); 16α,17-dihydroxy-ent-kauran-19-oic acid (13); and 16α-methoxy-17-hydroxy-ent-kauran-19-oic acid (14). Compounds 4, 5, 8, 12, and 14 were first isolated from this plant. The anti-Alzheimer and antioxidant effects of ent-pimarane-type diterpenes 1, 3, 5, 8, and 9, as well as ent-kaurane-type diterpenes 2, 4, and 10∼13, were evaluated via β-site amyloid precursor protein cleaving enzyme 1 (BACE1), acetylcholinesterase (AChE), butyrylcholinesterase (BChE), peroxynitrite (ONOO⁻), and nitric oxide (NO·) assays. Of the compounds tested, 8 exerted the most effective BChE inhibition with an IC₅₀ value of 7.58 μM, followed by 3, 13, 11, 2, and 10. Compounds 9∼11 exhibited good BACE1 inhibitory activities with IC₅₀ values of 18.58∼24.10 μM. However, 11 showed marginal AChE inhibitory effect, and all compounds tested showed no scavenging activities on ONOO⁻ and NO· at a concentration of 100 μM.     

Chemical constituents of Isodon nervosus and their cytotoxicity

Two new ent-kaurane diterpenoids, 6,20,15α-trihydroxy-6,7-seco-1α,7-olide-ent-kaur-16-ene (1) and 7β,12α-dihydroxy-6β,15β-diacetoxy-7α,20-epoxy-ent-kaur-2,16-dien-1-one (2), together with the six known compounds, were isolated from the aerial part of Isodon nervosus. The structures of the new compounds were determined by spectral methods (1D, 2D NMR, and MS). Six compounds were assayed for their cytotoxicity against HL60, SMMC-7721, and HeLa human cell lines. Compounds 5, 7, and 8 showed significant cytotoxicity.     

Terpenoids from the tuber of Cremastra appendiculata

Two new terpenoids including a cadinane sesquiterpene (1), and an ent-kaurane diterpene diglycoside (2), together with a known triterpene containing 32 carbons (3), have been isolated from the ethanolic extract of Cremastra appendiculata. Their structures were established by the spectroscopic methods including the IR, MS, 1D-, and 2D-NMR experiments as ( ? )-cadin-4,10(15)-dien-11-oic acid (1), ( ? )-ent-12β-hydroxykaur-16-en-19-oic acid, 19-O-β-d-xylopyranosyl-(1 → 6)-O-β-d-glucopyranoside (2), and (+)-24,24-dimethyl-25,32-cyclo-5α-lanosta-9(11)-en-3β-ol (3). Compounds 1–3 were evaluated against several human cancer cell lines. Compound 3 showed in vitro-selective cytotoxicity against human breast cancer cell lines (MCF-7) with an IC₅₀ of 3.18 μM, but 1 and 2 were inactive (IC₅₀>10 μg/ml).     

Cytotoxic ent-kaurane diterpenoids from Isodon macrophyllus

Two new ent-kaurane diterpenoids, dayecrystals D–E (1–2), together with nine known compounds, isojaponin A (3), rabdosin A (4), lushanrubescensin J (5), wikstroemioidin B (6), maoyecrystal C (7), rabdosin B (8), isodonal (9), shikokianin (10), and effusanin A (11), were isolated from the leaves of Isodon macrophyllus. The structures of the new compounds were elucidated using 1D and 2D NMR spectroscopy. The ¹³C-NMR spectral data of compound 4 are reported for the first time. All of the compounds were tested for their cytotoxicities against DU145 and LoVo human tumor cells. Compounds 4, 10, and 11 showed inhibitory effects on DU145 cells with IC₅₀ values 5.90, 4.24, and 3.16 μM, and LoVo cells with IC₅₀ values 14.20, 17.55, and 3.02 μM, respectively.     

Two new cytotoxic ent-clerodane diterpenoids from Scutellaria barbata

Two new ent-clerodane diterpenoids have been isolated from Scutellaria barbata, and their structures were established by detailed spectroscopic analyses as (13R)-6α,7β-dihydroxy-8β,13-epoxy-11β-nicotinyloxy-ent-clerodan-3-en-15,16-olide (scutelinquanine D, 1) and (11E)-6α-acetoxy-7β,8β-dihydroxy-ent-clerodan-3,11,13-trien-15,16-olide (6-acetoxybarbatin C, 2). In vitro, the isolated two new compounds showed significant cytotoxic activities against three human cancer cell lines (HONE-1 nasopharyngeal, KB oral epidermoid carcinoma, and HT29 colorectal carcinoma cells), and gave IC₅₀ values in the range of 2.5–6.6 μM.     

Microbial transformation of deoxyandrographolide by Fusarium graminearum AS 3.4598

Biotransformation of deoxyandrographolide (1) by Fusarium graminearum AS 3.4598 was investigated in this paper. And five transformed products of 1 by F. graminearum AS 3.4598 were obtained. Their chemical structures were characterized as 3-oxo-8α,17β-epoxy-14-deoxyandrographolide (2), 3-oxo-14-deoxyandrographolide (3), 3-oxo-17,19-dihydroxyl-8,13-ent-labdadien-15,16-olide (4), 1β-hydroxyl-14-deoxyandrographolide (5), and 7β-hydroxyl-14-deoxyandrographolide (6) by spectral methods including 2D NMR. Among them, products 2, 4, and 5 are new.     

Two new diterpenoid dimers,fritillebinide D and E,from bulbs of Fritillaria ebeiensis

Two new ent-kaurane diterpenoid dimers, fritillebinide D (1) and fritillebinide E (2), were isolated from bulbs of Fritillaria ebeiensis G.D. Yu et G.Q. Ji. Their structures have been determined to be ent-3g -acetoxy-kauran-16g , 17-acetal ent-3g -acetoxy-16g -kauran-17(R)-aldehyde (1) and ent-3g -acetoxy-kauran-16g ,17-acetal ent-3g -acetoxy-16g -kauran-17(S)-aldehyde (2) by means of spectral analysis.     

Six new diterpenoids from Croton laevigatus

Abstract

Six new ent-labdane-type diterpeniods (1?6), along with one known compound, were identified from the twigs and leaves of Croton laevigatus. Their structures were elucidated on the basis of extensive spectroscopic interpretation. Compounds 2 and 7 showed inhibitory activity against protein tyrosine phosphatase 1B (PTP1B) with IC₅₀ values of 4.11 and 8.33 μg/ml, respectively.     

Two new ent-kaurane diterpenes from the stems of Eurya chinensis

Abstract

Two new ent-kaurane diterpenes (1–2), together with five known analogs, were isolated from the stems of Eurya chinensis. The structures of new compounds were established by extensive analysis of mass spectrometric and 1D and 2D NMR spectroscopic data. Compound 3 exhibited noticeable anti-inflammatory activity as denoted by inhibiting LPS-induced nitric oxide (NO) production in RAW264.7 cells with an IC₅₀ value of 7.82 μM. Compound 4 showed potent cytotoxic activity against human cancer cell lines NCI-H46, HepG2 and SW480 with IC₅₀ values ranging from 7.45 to 8.54 μM.     

Chemical constituents of the Annona glabra fruit and their cytotoxic activity

Abstract

Context: Traditional Chinese medicines have attracted increasing interest as potential sources of novel drugs with a wide range of biological and pharmacological activities. Annona glabra Linn (Annonaceae) is used in traditional medicine as an anticancer drug. Phytochemical investigation of this plant led to the isolation of acetogenins, ent-kauranes, peptides, and alkaloids. In addition, compounds exhibited anticancer, anti-HIV-reserve, and antimalaria.

Objective: Isolation, structure determination, and cytotoxic activity evaluation of compounds from the methanol extract from A. glabra fruits.

Materials and methods: Using chromatographic methods to isolate compounds from the A. glabra methanol extract. The cytotoxic activity of compounds was evaluated by a 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide (MTT) assay. In addition, compounds which showed significant cytotoxic activity were chosen for further study apoptosis characteristics.

Results: One new, (2E,4E,1′R,3′S,5′R,6′S)-dihydrophaseic acid 1,3′-di-O-β-d-glucopyranoside, and eight known compounds, (2E,4E,1′R,3′S,5′R,6′S)-dihydrophaseic acid 3′-O-β-d-glucopyranoside (2), icariside D₂ (3), icariside D₂ 6′-O-β-d-xylopyranoside (4), 3,4-dimethoxyphenyl O-β-d-glucopyranoside (5), 3,4-dihydroxybenzoic acid (6), blumenol A (7), cucumegastigmane I (8), and icariside B₁ (9), were isolated from the fruits of A. glabra. Icariside D₂ (3) was found to show significant cytotoxic activity on the HL-60 cell line with the IC₅₀ value of 9.0?±?1.0?µM and did not show cytotoxic activity on the Hel-299 normal cell line. The further test indicated that compound 3 induced apoptosis via alteration of expression of apoptosis-related proteins and decreased phosphorylation of AKT in HL-60 cells.

Discussion and conclusion: The results suggested that the constituents from A. glabra may contain effective compounds which can be used as anticancer agents.     

Ceramides and cerebrosides from the marine bryozoan Bugula neritina inhabiting South China Sea

From the marine bryozoan Bugula neritina inhabiting South China Sea, a new ceramide named (2S,3R,4E)-2-(14′-methyl-pentadecanoylamino)-4-octadecene-l,3-diol (1) and a new cerebroside named 1-O-(β-d-glucopyranosyl)-(2S,3R,4E)-2-(heptadecanoylamino)-4-octadecene-l,3-diol (6), together with one known ceramide (2) and three known cerebrosides (3, 4, and 5), were isolated. Their structures were deduced by extensive spectral analysis and chemical evidences. Compound 1 is branched with a methyl [–CH(CH₃)₂] in the fatty acid moiety, which is a rare structural feature among ceramides. Compound 6 is a new cerebroside with 17 carbons in the fatty acid moiety, while 5 is a new natural product which was isolated from a natural origin for the first time.     

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.     

Four new diterpenoids from Salvia fulgens Cav.

Four new diterpenoids, salvifulgenolide (1), trans-1,2-dihydrosalvifaricin (2), ent-19- O-acetoxy-15,16-epoxy-3,13(16),14-clerodatrien-6,18-diol (3) and ent-19-acetoxy-15,16-epoxy-6-hydroxy-3,13(16),14-clerodatrien-18-al (4) along with two known diterpenoids, 10-hydroxybacchotricuneatin A (5) and dehydrokerlin (6) were isolated from the aerial parts of Salvia fulgens Cav. (Labiatae). The structures were established by spectroscopic methods, including the X-ray analysis of salvifulgenolide and trans-1,2-dihydrosalvifaricin.     

A new norlupane triterpene from the leaves of <Emphasis Type="Italic">Acanthopanax koreanum</Emphasis> increases the differentiation of osteoblastic MC3T3-e1 cells

A new norlupane-triterpene, 3α,11α-dihydroxy-20,23-dioxo-30-norlupane-28-oic acid (1), and four known compounds; 3α,11α-dihydroxy-23-oxo-lup-20(29)-en-28-oic acid (2), 3α,11α-dihydroxylup-20(29)-en-28-oic acid (3), ent-kaur-16-en-19-oic acid (4), and betulabuside B (5) were isolated from the methanolic extract of the leaves of Acanthopanax koreanum. Their chemical structures were elucidated by mass, 1D- and 2D-NMR spectroscopy. To investigate the bioactivities of these compounds, their effects on the differentiation of osteoblastic MC3T3-E1 cells were tested. Compounds 3 and 4 significantly increased osteoblastic cell growth and differentiation as assessed by the MTT assay and collagen content, respectively (p < 0.05). Compounds 1 and 5 significantly increased the growth of MC3T3-E1 cells and caused a significant elevation of osteoblastic cell differentiation as assessed by the alkaline phosphatase activity. These results suggest that the compounds isolated from A.koreanum leaves have a direct stimulatory effect on bone formation in vitro and may contribute to the prevention for osteoporosis.     

Structures of Two Diterpenoid Dimers from Bulbs of Fritillaria ebeiensis

Abstract

A new ent-kaurane diterpenoid dimer, fritillebinide C (1) together with one known diterpenoid dimer fritillebinide B (2) were isolated from the bulbs of Fritillaria ebeiensis G.D. Yu et G.Q. Ji. Compound 1 has been determined to be ent-3β-acetoxy-kauran-16β, 17-acetal entβ-kauran-17(S)-aldehyde (1) by means of spectral analysis and chemical evidence.     

A new triterpenoid from <Emphasis Type="Italic">Panax ginseng</Emphasis> exhibits cytotoxicity through p53 and the caspase signaling pathway in the HepG2 cell line

A new triterpenoid, 20(R),22(ξ),24(S)-dammar-25(26)-ene-3β,6α,12β,20,22,24-hexanol (1), and three known triterpenoids, β-D-glucopyranoside,(3β,12β)-12,20-dihydroxydammar-24-en-3-yl,6-acetate (2), 20(R)-ginsenoside Rg₃ (3), and 20(R)-ginsenoside Rh₂ (4), were isolated from the leaves of Panax ginseng. Their structures were determined by chemical analysis and spectral methods (IR, 1D and 2D NMR, HR-ESI-MS). Compounds 1–4 were exhibited various degrees of cytotoxicity in the human hepatoma cell line, HepG2. Compound 1 had the highest cytotoxic potency, with an IC₅₀ value of 20.1 μM, by stimulating p53-mediated cell cycle arrest at the G1 to S phase transition, leading to apoptosis via activation of the caspase signaling pathway.