Microbial deglycosylation and ketonization of ginsenosides Rg1 and Rb1 by Fusarium oxysporum

Two major ginsenosides, ginsenoside-Rg₁ (1) and ginsenoside-Rb₁ (2), were transformed by the fungus Fusarium oxysporum f. sp. Lycopersici (Z-001). 1 was converted into five metabolites, ginsenoside-F₁ (3), 6α,12β-dihydroxydammar-3-one-20(S)-O-β-d-glucopyranoside (4), 3a-oxa-3a-homo-6α,12β-dihydroxydammar-3-one-20(S)-O-β-d-glucopyranoside (5), 20(S)-protopanaxatriol (6), and 3-oxo-20(S)-protopanaxatriol (7). 2 was converted into four metabolites, ginsenoside-Rd (8), ginsenoside-F₂ (9), compound K (10), and 12β-hydroxydammar-3-one-20(S)-O-β-d-glucopyranoside (11). The structures of these metabolites were determined by the analysis of extensive spectroscopic data. Among them, 4 and 5 were two new compounds. Deglycosylation and ketonization at C-3 were recognized as the characteristic reactions of this strain.     

群海绵Agelas sp.的化学成分研究

目的 研究海绵Agelas sp.的化学成分。方法 运用乙醇提取、硅胶、Sephadex-LH₂₀色谱柱、HPLC等多种方法进行分离和纯化,根据理化性质和波谱数据进行结构鉴定。结果 分离得到9个化合物,经结构鉴定分别为4,5-二溴吡咯-2-甲酰胺（1）、4,5-二溴吡咯-2-甲酸（2）、4,5-二溴吡咯-2-甲酸甲酯（3）、N-（4,5-二溴-2-吡咯甲酰基）甘氨酸甲酯（4）、1-（4,5-二溴-2-吡咯甲酰胺基）丙酸甲酯（5）、1-（4,5-二溴-2-吡咯甲酰胺基）丙酸乙酯（6）、异吲哚-1,3-二酮（7）、2（3H）-苯并噻唑酮（8）和manzacidin C（9）。结论 化合物4~9为首次从该属海绵中分离得到,其中化合物4~6为新天然产物。     

Microbial transformation of resibufogenin by Curvularia lunata AS 3.4381

In this paper, the microbial transformation of resibufogenin (1) by Curvularia lunata AS 3.4381 was investigated, and four transformed products were isolated and characterized as 3-epi-resibufogenin (2), 12α-hydroxy-3-epi-resibufogenin (3), 12-oxo-16β-hydroxy-3-epi-resibufogenin (4), and 12β,15-epoxy-3-epi-bufalin-14,15-ene (5). Among them, 4 and 5 are new compounds, and isomerization, hydroxylation, and oxidation reactions in microbial transformation process were observed. Additionally, the cytotoxicities of transformed products (2–5) were also investigated.     

Polyphenolic compounds from the leaves of Koelreuteria paniculata Laxm

From the fresh leaves of Koelreuteria paniculata Laxm (Sapindaceae), four new compounds, named ethyl p-trigallate (1), 3"-O-galloyl-4'-O-galloyl-4-O-galloyl-gallic acid (2), ethyl p-heptagallate (3) and 3"-galloylquercitrin (4), together with 12 known compounds namely catechin (5), galloylepicatechin (6), isorhamnetin (7), kaempferol-3-O-arabinopyranoside (8), quercetin-3'-O- g -D-arabinopyranoside (9), quercitrin (10), methyl p-digallate (11), methyl m-digallate (12), p-digalloyl acid (13), m-digalloyl acid (14), hyperin (15) and kaempferol-3-O- f -L-rhamnoside (16) were isolated by extensive column chromatographic separation. Their structures were elucidated on the basis of chemical and spectroscopic methods. Compound 9 was not reported previously with pyranoside of arabinose at C-3'. Compounds 4 and 9 possessed the activity for PTK inhibition.     

Investigation of 6-O-methyl-scutellarein metabolites in rats by ultra-flow liquid chromatography/quadrupole-time-of-flight mass spectrometry

Context Scutellarin (1) has been widely used in China to treat acute cerebral infarction and paralysis induced by cerebrovascular diseases. However, scutellarin (1) has unstable metabolic characteristics.

Objective The metabolic profile of 6-O-scutellarein was studied to determine its metabolic stability in vivo.

Materials and methods In this study, a method of UFLC/Q-TOF MS was used to study the 6-O-methyl-scutellarein metabolites in rat plasma, urine, bile and faeces after oral administration of 6-O-methyl-scutellarein (3). One hour after oral administration of 6-O-methyl-scutellarein (3) (34?mg/kg), approximately 1?mL blood samples were collected in EP tubes from all groups. Bile, urine and faeces samples were collected from eight SD rats during 0–24?h after oral administration. The mass defect filtering, dynamic background subtraction and information dependent acquisition techniques were also used to identify the 6-O-methyl-scutellarein metabolites.

Results The parent compound 6-O-methyl-scutellarein (3) was found in rat urine, plasma, bile and faeces. The glucuronide conjugate of 6-O-methyl-scutellarein (M1, M2), diglucuronide conjugate of 6-O-methyl-scutellarein (M3), sulphate conjugate of 6-O-methyl-scutellarein (M4), glucuronide and sulphate conjugate of 6-O-methyl-scutellarein (M5), methylated conjugate of 6-O-methyl-scutellarein (M6) were detected in rat urine. M1, M2 and M3 were detected in rat bile. M1 was found in rat plasma and M7 was detected in faeces.

Discussion and conclusion Because the parent compound 6-O-methyl-scutellarein (3) was found in rat urine, plasma, bile and faeces, we speculate that 6-O-methyl-scutellarein (3) had good metabolic stability in vivo. This warrants further study to develop it as a promising candidate for the treatment of ischemic cerebrovascular disease.     

Antiviral phenolics from Antenoron filiforme var. neofiliforme

Abstract

Two new phenolics, 1,3-di-O-p-coumaroyl-2′,6′-di-O-acetylsucrose (1) and quercetin 3-O-β-D-apiofuranoyl-(1→2)-α-L-rhamnopyranoside (2), along with nine known compounds (3–11), were isolated from the whole plants of Antenoron filiforme var. neofiliforme. Their chemical structures were characterized on the basis of various spectroscopic techniques. This is the first report of the isolation of phenylpropanoid sucrose (1, 3–4) from the genus Antenoron. The bioassay results showed that compound 11 exhibited antiviral activity against the Coxsackie virus B3 (CVB3).     

Two pairs of phenylpropanoid enantiomers from the leaves of Eucommia ulmoides

Abstract

Two pairs of phenylpropanoid enantiomers, (+)-(7S,8S)-alatusol D (1a), (?)-(7R,8R)-alatusol D (1b), (?)-(7S,8R)-alatusol D (2a) and (+)-(7R,8S)-alatusol D (2b) were isolated from the leaves of Eucommia ulmoides Oliver. Among them, 1a and 2b were firstly obtained by chiral enantiomeric resolution. Their structures were elucidated based on extensive spectroscopic analysis and the induced CD (ICD) spectrum caused by adding Mo₂(AcO)₄ in DMSO. All compounds were tested on Hep G2 tumor cell lines. However, none of the compounds showed potential cytotoxic activity against Hep G2 in vitro.     

Bioactive spirans and other constituents from the leaves of Cannabis sativa f. sativa

In this paper, 17 compounds (1–17) were isolated from the leaves of Hemp (Cannabis sativa f. sativa). Among the isolates, two were determined to be new spirans: cannabispirketal (1), and α-cannabispiranol 4’-O-β-D-glucopyranose (2) by 1D and 2D NMR spectroscopy, LC-MS, and HRESIMS. The known compounds 7, 8, 10, 13, 15, and 16 were isolated from Hemp (C. sativa f. sativa) for the first time. Furthermore, compounds 8 and 13 were isolated from the nature for the first time. All isolated compounds were evaluated for cytotoxicity on different tissue-derived passage cancer cell lines through cell viability and apoptosis assay. Among these compounds, compounds 5, 9 and 16 exhibited a broad-spectrum antitumor effect via inhibiting cell proliferation and promoting apoptosis. These results obtained have provided valuable clues to the understanding of the cytotoxic profile for these isolated compounds from Hemp (C. sativa f. sativa).     

Antibacterial activity of <Emphasis Type="Italic">Capsicum annuum</Emphasis> extract and synthetic capsaicinoid derivatives against <Emphasis Type="Italic">Streptococcus mutans</Emphasis>

The inhibitory effects of the ethyl acetate extract and capsaicin (1) and dihydrocapsaicin (2) isolated from fruits of Capsicum annuum chili pepper type, and synthetic capsaicinoid derivatives (N-(4-hydroxyphenylethyl)decamide (3), (E)-N-(4-hydroxy-3-methoxybenzyl)-3,7-dimethylocta-2,6-dienamide (4), 4-hydroxy-3-methoxy-N-((E)-3,7-dimethylocta-2,6-dienyl)benzamide (5) and N-(4-hydroxy-3-methoxybenzyl)decamide (6) at different concentrations were evaluated against Streptococcus mutans. The minimum inhibitory concentration at which the ethyl acetate extract prevented the growth of S. mutans was 2.5 mg/mL; those of the isolated compounds 1 and 2 were 1.25 μg/mL, while 3 was 5.0 μg/mL, and 4, 5 and 6 were 2.5 μg/mL, respectively.     

Phenolic compounds from the twigs and leaves of Tara (Caesalpinia spinosa)

Two new homoisoflavans, 4′-hydroxy-7-methoxy-3-benzyl-2H-chromene (1) and 3,4-cis-di-O-3-hydroxy-7-methoxy-3-(4-hydroxybenzyl)-4-ethoxychroman (2), one new coumarin, 7-methoxy-3-(4-hydroxybenzyl)coumarin (4), together with seven known phenolic compounds, bonducellin (3), anemarcoumarin A (5), (+)-syringaresinol (6), curuilignan D (7), scopoletin (8), and p-hydroxybenzaldehyde (9), were isolated from Tara (Caesalpinia spinosa Kuntze). The structures of the new compounds were characterized from their 1D and 2D NMR spectral data. All the compounds were isolated from this plant for the first time.     

Seven new dammarane triterpenes from the floral spikes of Betula platyphylla var. japonica

Seven new dammarane-type triterpenoids, including two 20(S)-hydroxy-25-methoxy-dammar-23-enes (1 and 2), two 20(S),24(R)-epoxydammaranes (3 and 4), a cabralealactone (5), and two 20(S),25-epoxydammaranes (6 and 7), together with seven known triterpenes (8–14), were isolated from the floral spikes of Betula platyphylla var. japonica. The structures for all compounds were elucidated by the analyses of extensive spectroscopic data, as well as chemical examinations.     

Irritant and co-carcinogenic diterpene esters from the latex of Euphorbia cauducifolia L.

Ten (1–10) irritant and mild co-carcinogenic diterpene esters were isolated from the latex of Euphorbia cauducifolia L. using bioassay-guided countercurrent distribution and other chromatographic techniques. The isolated compounds were characterized on the basis of spectroscopic results and mass measurements. As an outcome, the ingenane-type esters were established with the following structures: 3-O-angeloyl-17-O-palmatoylingenol (1), 3-O-palmatoyl-5-O-angeloylingenol (2), 5-O-angeloyl-17-O-palmatoylingenol (3), 3-O-angeloyl-5-O-palmatoylingenol (4), 17-O-(2Z,4E,6Z)-2,4,6-tetradecatrienoyl-20-O-palmatoylingenol (5), 5-O-angeloyl-17-O-benzoylingenol (6), 5-O-angeloyl-17,20-diacetoxyingenol (7), 3-O-angeloyl-17-O-benzoyl-20-acetoxyingenol (8), 3-acetoxy-5-O-angeloyl-17-O-benzoylingenol (9), and 5-O-angeloyl-3,17,20-triacetoxyingenol (10). Their biological screening revealed that they are moderate irritants, and low to moderate tumor promoters compared to TPA, but hardly showed any solitary carcinogenic activity. The isolated esters represent new compounds and were not reported before from any source.     

Four new compounds from the rhizome of Aristolochia championii

Three new flavonoid glycosides (1–3) and one new aristololactam N-glycoside (4) were isolated from the rhizome of Aristolochia championii. The structures of compounds 1–4 were elucidated on the basis of their spectroscopic data and chemical evidence (UV, IR, HR-ESI-MS, 1D and 2D NMR). Their structures were determined as 8-(5-formyl-2-furanmethyl)-isorhamentin 3-O-robinobioside (1), 8-(5-methyl-2-furanoyl)-isorhamentin 3-O-robinobioside (2), 8-formylisorhamentin 3-O-robinobioside (3), and N-β-D-glucopyranosylaristololactam V (4), respectively.     

Biotransformation of resibufogenin by Actinomucor elegans

Resibufogenin (RB), a major bioactive bufadienolide, has the potential anticancer activity. In the present work, biotransformation of RB by Actinomucor elegans AS 3.2778 yielded five products, namely 3-oxo-resibufogenin (1), 3-epi-resibufogenin (2), 3-epi-12-oxo-hydroxylresibufogenin (3), 3α-acetoxy-15α-hydroxylbufalin (4), and 3-epi-12α-hydroxylresibufogenin (5), respectively. Among them, metabolites 3 and 4 are previously unreported. The chemical structures of metabolites 1–5 were fully elucidated on the basis of 2D NMR and HR-MS. The highly stereo- and regio-specific isomerization, hydroxylation, and esterification reactions were observed in the biotransformation process of RB by A. elegans. Their cytotoxicities against A549 and H1299 cells were evaluated.     

Chemical constituents of Euonymus fortunei

A new flavonol glycoside, kaempferol-3-O-β-d-(2-O-E-p-coumaroyl)-glucopyranosyl-7-O-α-l-rhamnopyranoside (1), along with eleven known compounds including five flavonol glycosides (2–6), one phenolic glycoside (7), two megastigmane glycosides (8 and 9), two triterpenoids (10 and 11) and one alditol (12), was isolated from the aerial parts of Euonymus fortunei. Their structures were determined on the basis of spectroscopic analysis and chemical evidence. Compounds 2–4, 7, 8, and 10–12 were evaluated their antimicrobial activities against Ureaplasma urealyticumin vitro, but all tested compounds have no useful activities against Ureaplasma urealyticum.     

Carbamate derivatives of felbamate as potential anticonvulsant agents

Several monocarbamate compounds derived from felbamate were synthesized and 11 target compounds (1, 4, and 6–14) were initially evaluated in mice MES and PTZ models in our laboratory. Carbamate compounds with varying substituents on the oxygen (1–4) gave anticonvulsant activity with a wide range of ED₅₀ in MES test from <20 mg/kg (2) to >300 mg/kg (4) and compounds with different groups on the nitrogen (5–14) also were quite active in the range of 15 mg/kg (14) to 170.5 mg/kg (6). This suggested that the spatial limitation in the MES model seemed flexible especially on the nitrogen end. All tested compounds showed some activity against mice scPTZ test, but none had the ED₅₀ value <50 mg/kg. Ten selected compounds (1 and 6–14) for subsequent pharmacological evaluation in NIH all gave positive mice MES activity except 8 and 9, which were unexpectedly active in rats after further evaluations. Among the compounds, 1, 8, and 9 advanced to the quantitative study and 1 and 9 provided the highest PI values, 15 and 21, respectively, in the rat oral MES test.     

Two new phthalide dimers from the rhizomes of Ligusticum chuanxiong

Two pairs of diastereoisomers, namely (3′Z)-(3S,8S,3a′S,6′R)-4,5-dehydro-3.3a′,8.6′-diligustilide (1) and (3′Z)-(3S,8R,3a′S,6′R)-4,5-dehydro-3.3a′,8.6′-diligustilide (3), chuanxiongdiolide R3 (2), and chuanxiongdiolide R1 (4), were isolated from the 95% ethanolic aqueous extract of the rhizomes of Ligusticum chuanxiong. Among these Phthalide dimers, compounds 1 and 2 were new ones. The structures of the new isolates were elucidated based on spectroscopic data analyses, and their absolute configurations were determined by comparison of experimental and calculated electronic circular dichroism spectra.     

New iridoids from the fruits of Crescentia cujete

Four new 11-nor-iridoids, 6-O-p-hydroxybenzoyl-10-deoxyeucommiol (1), 6-O-benzoyl-10-deoxyeucommiol (2), 6-O-benzoyl-dihydrocatalpolgenin (a mixture of 3 and 4), as well as two known iridoids, ningpogenin (5) and 6-O-p-hydroxybenzoylaucubin (6), were isolated from the fruits of Crescentia cujete Linn. The structures of these compounds were established on the basis of spectroscopic analysis.     

Cytotoxic and antiproliferative constituents from Dictyota ciliolata,Padina sanctae-crucis and Turbinaria tricostata

Context: The hexane extracts of Dictyota ciliolata Sonder ex Kützing (Dictyotaceae), Padina sanctae-crucis Børgesen (Dictyotaceae), and Turbinaria tricostata E.S. Barton (Sargassaceae) were found to exhibit cytotoxic and antiproliferative activities in vitro. Bioactive compounds responsible for these activities have not been studied in detail for these species and phytochemical studies are very limited.

Objective: Isolate, evaluate, and elucidate the bioactive constituents of D. ciliolata, P. sanctae-crucis, and T. tricostata.

Materials and methods: Bioassay-guided cytotoxicity fractionations using the Hep-2 cell line of the hexane extracts from these brown algae were analyzed using various chromatographic techniques. Cytotoxic and antiproliferative activities of all isolated compounds were also evaluated on a panel of cell lines (KB, Hep-2, MCF-7, and SiHa). Furthermore, their selectivity index, the ratio of cytotoxicity on normal cells to cancer cells, was evaluated using the HEK-293 cell line.

Results: Four compounds were isolated from studied species: two sterol, fucosterol (1) and 24ξ-hydroperoxy-24-vinylcholesterol (2); and two diterpenes, pachydictyol A (3) and dictyol B acetate (4). The major bioactive components of the hexane extracts of T. tricostata and P. sanctae-crucis were compounds 1 and 2 (with CC₅₀ varying around 3.1–25.6?µg/mL) on cell lines tested. Whereas compounds 1, 3, and 4 showed cytotoxic activity against cancer cell lines (CC₅₀ varying between 14.8 and 41.2?µg/mL) and were major bioactive constituents of hexane extract of D. ciliolata. Compounds 1 and 4 showed antiproliferative activity on MCF-7 (IC₅₀?=?43.3?µg/mL for compound 1 and 38.3?µg/mL for compound 2) and SiHa (IC₅₀?=?43.3?µg/mL for compound 1 and 38.3?µg/mL for compound 2) cell lines.

Conclusion: This study is the first investigation on the bioactive components of D. ciliolata, P. sanctae-crucis, and T. tricostata. Although compounds 1–3 were described previously, the pharmacological activity of compound 4 is presented here for the first time.     

New flavonoids with 2BS cell proliferation promoting effect from the seeds of <Emphasis Type="Italic">Trigonella foenum</Emphasis>-<Emphasis Type="Italic">graecum</Emphasis> L.

Ten flavonoids were isolated from the ethyl acetate-soluble fraction of the ethanolic extract of the seeds of Trigonella foenum-graecum and their structures were elucidated on the basis of spectroscopic methods to be 5,7,3′-trihydroxy-5′-methoxylisoflavone (1), biochanin A (2), formononetin (3), irilone (4), tricin (5), daidzein (6), calycosin (7), orientin-2″-O-p-trans-coumarate (8), vitexin-2″-O-p-trans-coumarate (9), and tricin-7-O-β-d-glucopyranoside (10). Compounds 1 and 8 are new flavonoids, and 8 and 9 strongly promoted 2BS cell proliferation induced by H₂O₂.