Cryptobuchanosides A-G: seven previously undescribed triterpene glycosides from Cryptolepis buchananii R.Br. ex Roem. and Schult. with nitric oxide production inhibition activity.

In this study, nine triterpene glycosides including seven previously undescribed compounds (1-7), were isolated from leaves of Cryptolepis buchananii R.Br. ex Roem. and Schult. using various chromatographic methods. The chemical structures of the compounds were elucidated to be 3-O-ß-D-glucopyranosyl-(1 → 6)-ß-D-glucopyranosyluncargenin C 28-O-α-L-rhamnopyranosyl-(1 → 2)-ß-D-glucopyranosyl ester (1), 3-O-ß-D-glucopyranosyl-(1 → 2)-ß-D-glucopyranosyluncargenin C 28-O-α-L-rhamnopyranosyl-(1 → 2)-ß-D-glucopyranosyl ester (2), 3-O-ß-D-glucopyranosyl-(1 → 2)-ß-D-glucopyranosyluncargenin C 28-O-ß-D-glucopyranosyl-(1 → 4)-α-L-rhamnopyranosyl-(1 → 2)-ß-D-glucopyranosyl ester (3), 3-O-ß-D-glucopyranosyl-(1 → 2)-ß-D-glucopyranosylhederagenin 28-O-α-L-rhamnopyranosyl-(1 → 2)-ß-D-glucopyranosyl ester (4), 3-O-ß-D-glucopyranosylarjunolic acid 28-O-α-L-rhamnopyranosyl-(1 → 2)-ß-D-glucopyranosyl ester (5), 3-O-ß-D-glucopyranosyl-(1 → 2)-ß- D-glucopyranosyl-6ß,23-dihydroxyursolic acid 28-O-α-L-rhamnopyranosyl-(1 → 2)-ß-D-glucopyranosyl ester (6), 3-O-ß-D-glucopyranosyl-6ß,23-dihydroxyursolic acid 28-O-α-L-rhamnopyranosyl-(1 → 2)-ß-D-glucopyranosyl ester (7), asiatic acid 28-O-α-L-rhamnopyranosyl-(1 → 2)-ß-D-glucopyranosyl ester (8), and 3-O-ß-D-glucopyranosylasiatic acid 28-O-α-L-rhamnopyranosyl-(1 → 2)-ß-D-glucopyranosyl ester (9), through infrared, high-resolution electrospray ionization mass spectrometry, one- and two-dimensional nuclear magnetic resonance spectral analyses. The isolates inhibited nitric oxide production in lipopolysaccharide-activated RAW 264.7 cells, with half-maximal inhibitory concentration (IC50) values of 18.8-58.5 µM, compared to the positive control compound, dexamethasone, which exhibited an IC50 of 14.1 µM.

The complete plastome genome sequence of Cynanchum otophyllum (Asclepiadaceae), a unique medicinal species in China.

Cynanchum otophyllum Schneid is an important medicinal plant in China. In this paper, the chloroplast genome of C. otophyllum was sequenced based on high-throughput technology, and the chloroplast genome structure characteristics and phylogenetic relationship of C. otophyllum were analyzed. The results showed the complete plastome genome size of C. otophyllumis 160,874bp, including one small single copy (SSC, 19,851bp) and one large single copy (LSC, 92,009bp) regions isolated by a pair of inverted repeat regions (IRs, 24,507bp). The whole plastome genome including 84 protein encoding genes, 8 rRNA and 37 tRNA. Based on the phylogenetic topologies, C. otophyllum shows close association with additional Gomphocarpus and Asclepias genus. This study contributes to an enhanced understanding of the genetic information of C. otophyllum and provides a theoretical basis for the development of molecular markers and phylogeographic of the species, as well as for constructing the phylogenetic tree of Asclepiadaceae.

C21 steroids from the roots of Marsdenia tenacissima.

A phytochemical investigation of the dichloromethane soluble fraction of the ethanolic extract obtained from the roots of Marsdenia tenacissima led to the discovery of the sixteen undescribed pregnane C21 steroids (1-16) and isolation of eleven known C21 steroidal analogues (17-27). Their chemical structures were elucidated by one- and two-dimensional nuclear magnetic resonance spectroscopy and, high resolution-electrospray ionization mass spectrometry and their absolute configurations were determined using electronic circular dichroism or single-crystal X-ray diffraction. The in vitro anti-proliferative effects of 1-16 were evaluated against HepG2 (human hepatocellular cancer), A549 (lung cancer), and MCF-7 (human breast cancer) cell lines. Even though some of them showed moderate cytotoxic activities, marsectohexol derivative 12 exhibited significant cytotoxicity against A549 cells with an IC50 value of 5.2 µM.

Nine New Pregnane Glycosides from the Cultivated Medicinal Plant Marsdenia tenacissima.

The ethnobotanical plant Marsdenia tenacissima has been used for hundreds of years for Dai people in Yunnan Province, China. Previously, chemical investigations on this plant have revealed that pregnane glycosides were the main biological constituents. Nine new pregnane glycosides, marsdeosides A-I (1-9), were isolated from cultivated dried stems of the medicinal plant Marsdenia tenacissima in this study. The structures were analyzed by extensive spectroscopic analysis, including 1D, 2D NMR, HRESIMS, and IR spectroscopic analysis. The absolute configurations of the sugar moieties were identified by comparing the Rf values and specific optical rotations with those of the commercially available standard samples and the data reported in the literature. Marsdeosides A (1) featured an unusual 8,14-seco-pregnane skeleton. Compounds 1, 8, and 9 showed activity against nitric oxide production in lipopolysaccharide-activated macrophage RAW264.7, with IC50 values of 37.5, 38.8, and 42.8 µM (L-NMMA was used as a positive control, IC50 39.3 µM), respectively. This study puts the knowledge of the chemical profile of the botanical plant M. tenacissima one step forward and, thereby, promotes the sustainable utilization of the resources of traditional folk medicinal plants.

Undescribed meleagrin alkaloids from the endophytic fungus Penicillium commune.

Six undescribed meleagrin analogues, isomeleagrin, meleagrin F, meleagrin G, methylmeleagrin G, isomethylmeleagrin G and meleagrin H, were isolated from the endophytic fungus Penicillium commune, which was obtained from the fresh leaves of a toxic medicinal plant, Tylophora ovata. The structures of these analogues were elucidated through extensive spectroscopic data analysis, and their absolute configurations were characterized by calculated electronic circular dichroism (ECD). Structurally, meleagrin F features an undescribed skeleton with an aniline moiety, which is linked to meleagrin through a C-C bond at C8-C26. Connecting N19-C3' through the C-N bond in meleagrin G, methylmeleagrin G, isomethylmeleagrin G and meleagrin H was rare for amino acid condensation. The cytotoxicity activity of these undescribed compounds was evaluated, and isomeleagrin exhibited a selective cytotoxicity activity against HGC27 cells with an IC50 value of 2.01 µM.

Isolation of a new steroid from phytochemical investigation on Caralluma lasiantha.

A new steroid (acylated C21 pregnane steroid) was isolated from chloroform extract in phytochemical screening of Caralluma lasiantha. The isolated compound is found to be 3ß-hydroxy-14ß-(6'- carboxyphenyl)propionyloxypregn-5-en-20-one based on spectroscopic studies (IR, 1H NMR, 13C NMR, DEPT, COSY, HSQC, HMBC and ESI-MS). The isolated new steroid was tested against four bacterial strains and the activity was related to the structure of the molecule.

The complete chloroplast genome sequence of medicinal plant: Cynanchum thesioides (Asclepiadaceae).

Cynanchum thesioides is a medicinal plant. The complete chloroplast genome sequence of is 158,547 bp in length, contains 131 complete genes, including 85 protein-coding genes (85 PCGs), 8 ribosomal RNA genes (8 rRNAs), and 37 tRNA genes (37 tRNAs). The overall AT content of cp DNA is 62.1%, the corresponding values of the LSC, SSC, and IR regions are 63.7, 67.7, and 56.5%. Phylogenetic tree shows that C. thesioides was identified as the most divergent among the sequenced species of Cynanchum used.

Perisomalien A, a new cytotoxic scalarane sesterterpene from the fruits of Periploca somaliensis.

The CHCl3 fraction of MeOH extract of Periploca somaliensis (family Asclepiadaceae) fruits afforded a new scalarane sesterterpene, namely perisomalien A (1), along with lupeol acetate (2), ß-amyrin (3), cycloart-23Z-ene-3ß,25-diol (4), and ß-sitosterol-3-O-ß-D-glucopyranoside (5). Their chemical structures were established by various spectroscopic analyses, in addition to comparison with the formerly reported data. Moreover, the cytotoxic activity of these metabolites was assessed towards MCF-7, HepG2, and HCT-116 tumour cell lines using sulforhodamine B (SRB) assay. Compound 4 showed the most potent cytotoxic profile with IC50 9.0 µM towards MCF-7, compared to doxorubicin (IC50 0.18 µM). Also, 1 and 4 possessed the most potent effect towards HepG2 with IC50s 26.7 and 25.9 µM, respectively. In addition, all tested compounds showed cytotoxic effects with IC50 values ranging from 19.9 to 39.3 µM against HCT-116.

Hepatoprotective steroids from roots of Cynanchum otophyllum.

Seven undescribed C21 steroids, namely cynanchin A-G, together with thirteen known analogues, were isolated from the roots of cynanchum otophyllum. Their structures were elucidated by 1D, 2D NMR and MS spectra, as well as chemical methods. Meanwhile, all of isolates were tested for their anti-hepatic fibrosis activity. Among them, compounds 4-6, 10-12 and 14-17 showed moderate or significant inhibitory effects for the proliferation of hepatic stellate cells (HSCs) induced by transforming growth factor-ß1 (TGF-ß1) in vitro.

Pregnane glycosides from the bark of Marsdenia cundurango and their cytotoxic activity.

Seven new pregnane glycosides (1-7) and eight known compounds (8-15) were isolated from the bark of Marsdenia cundurango (Asclepiadaceae). The structures of 1-7 were determined by spectroscopic analysis, including two-dimension NMR spectroscopy, chemical transformations, and chromatographic analysis of the hydrolyzed products. The isolated compounds 1-15 were evaluated for their cytotoxic activity against HL-60 human leukemia cells, A549 human lung adenocarcinoma cells, and TIG-3 normal human lung cells, including apoptosis-inducing activity of a representative pregnane glycoside in HL-60 cells.

Melanogenesis inhibitory pregnane glycosides from Cynanchum atratum.

Bioassay-guided fractionation of the methanolic extract from the roots of Cynanchum atratum has resulted in the isolation of three new pregnane glycosides (1-3) along with four known compounds (4-7). Their structures were identified by analysis of the spectroscopic data including extensive 2D NMR. All of the isolates were evaluated for their potential to inhibit the melanin production in α-melanocyte stimulating hormone (α-MSH)-activated B16 melanoma cells. Of these, compounds 4-7 dose-dependently inhibited the melanin production with the IC50 values ranging from 4 µM to 33 µM.

Discrimination of different geographic varieties of Gymnema sylvestre, an anti-sweet plant used for the treatment of type 2 diabetes.

Gymnema sylvestre (Retz.) R.Br. ex Sm. (Asclepiadaceae) is a well-known Ayurvedic anti-sweet plant for the treatment of type 2 diabetes mellitus. Although it was previously proposed that G. sylvestre exhibits chemical variation based on geography, most research on G. sylvestre has used material originating from India. Morphological and anatomical descriptions, ITS1-5.8S-ITS2 DNA sequencing, and acid hydrolysis analyses showed that G. sylvestre samples from Vietnam are distinguishable from those of Indian origin and thus suggest a dissimilarity among G. sylvestre samples with different geographic distributions. An LC-MS-guided strategy targeting 3ß-glucuronide oleane-triterpenes in the Vietnamese G. sylvestre variety led to the isolation of four known compounds and nine previously undescribed compounds, named gymnemosides ND1-ND9. None of the isolated compounds were reported in the Indian sample, further supporting the geo-diversity of G. sylvestre. Three compounds, gymnemosides ND7-9, exerted significant stimulatory effects on the uptake of 2-NBDG in 3T3-L1 adipocyte cells and thus have potential as lead molecules for anti-diabetes agents.

New 8,12;8,20-diepoxy-8,14-secopregnane hexa- and hepta-glycosides from the roots of Asclepias tuberosa.

Previously, phytochemical investigation of the roots of Asclepias tuberosa (Asclepiadaceae) led to the isolation of some 8,12;8,20-diepoxy-8,14-secopregnane tri-, tetra-, and penta-glycosides. An additional eight new minor 8,12;8,20-diepoxy-8,14-secopregnane glycosides were afforded in the recent investigation of this plant. These glycosides consisted of six or seven 2,6-dideoxy-hexopyranoses together with the aglycone, tuberogenin. The structures of each of these compounds were established using NMR, mass spectroscopic analysis and chemical evidence. As 8,12;8,20-diepoxy-8,14-secopregnane-type glycosides were observed only in A. tuberosa, these compounds were considered to be characteristic phytochemicals of this plant.

C21 steroid derivatives from the Dai herbal medicine Dai-Bai-Jie, the dried roots of Marsdenia tenacissima, and their screening for anti-HIV activity.

Twenty-three new C21 steroidal glycosides, marstenacissides C1-C10 (1-10), D1-D7 (11-17) and E1-E6 (18-23), and four new C21 steroids, 11α,12ß-O-ditigloyl-tenacigenin C (24), 11α-O-benzoyl-12ß-O-tigloyl-tenacigenin C (25), 11α-O-tigloyl-12ß-O-benzoyl-tenacigenin C (26) and 11α-O-tigloyl-12ß-O-benzoyl-marsdenin (27), were isolated from the Dai herbal medicine Dai-Bai-Jie, derived from the roots of Marsdenia tenacissima. The chemical structures of all compounds were established by spectroscopic techniques, including high-resolution mass spectrometry and NMR spectroscopy, as well as by comparison with reported spectral data. The anti-HIV activities of these compounds were screened, and the compounds obtained displayed inhibitory effects against HIV-1 with inhibition rates of 36.4-81.3% at 30 µM.

Molecular identification of Cynanchum auriculatum and its closely related species based on ITS2 sequence / 中草药

Objective To identify Cynanchum auriculatum and its closely related species using the ITS2 barcode. Methods A total of 54 samples of C. auriculatum and its related species were collected. Genomic DNAs were extracted from these samples. The ITS2 sequences of these samples were amplified and bidirectional sequenced by PCR. The obtained sequences were submitted to the Gen Bank and the ITS2 sequences of 47 samples belonging to 15 species were downloaded from the GenBank, and ITS2 sequences were annotated by ITS2 database. A total of 101 ITS2 sequences were aligned and the intraspecific and interspecific distances were calculated using the MEGA 5.0. Identification analyses were performed using the similarity search method and nearest distance method, and were presented intuitively by constructing neighbor-joining (NJ) tree. Results The length of all ITS2 sequences of C. auriculatum was 249 bp, which was a haplotype and was close to Cynanchum. There was a significant difference between the interspecific and intraspecific genetic distances of the ITS2 sequences. The NJ tree showed that C. auriculatum obviously differed from its closely related species, which showed high monophyly. According to the secondary structure of ITS2, it was also possible to distinguish between C. auriculatumi and Asclepiadaceae related species. Conclusion As a DNA barcode, ITS2 sequences can stably and accurately distinguish C. auriculatum from its closely related species and also provide a new technique to ensure the clinical safety in utilization of Chinese materia medica.

Cytotoxic activities of Telectadium dongnaiense and its constituents by inhibition of the Wnt/ß-catenin signaling pathway.

BACKGROUND: Wnt/ß-catenin signaling pathway is a potential target for the treatment of human colon cancer. Thus, the inhibitory effects of various plant extracts on cell proliferation and Wnt signal transduction were evaluated to discover a Wnt signaling inhibitor. PURPOSE: The present study aimed to investigate the cytotoxicity involved in Wnt pathway of the MeOH extract from Telectadium dongnaiense bark (TDB) and to identify its bioactive constituents by bioassay-guided fractionation. METHODS: The sulforhodamine B-based proliferation assay and the ß-catenin/TCF-responsive reporter gene assay were employed as screening systems. The isolation and identification of compounds were elucidated on the basis of spectroscopic methods. Inhibitory effects on the expression levels of Wnt target genes were determined by real-time PCR and western blotting. RESULTS: The extract of TDB most strongly inhibited cell proliferation and TOPflash activity (IC50 = 1.5 and 2.0 µg/ml), which was correlated with its inhibitory effects on the expression of Wnt target genes. Three major compounds were isolated from bioactive fractions and were identified as 1,4-dicaffeoylquinic acid (1), quercetin 3-rutinoside (2), and periplocin (3). Only compound 3 showed anti-proliferative activity (IC50 = 0.06 µM) and exhibited Wnt signaling inhibitory effects in HCT116 colon cancer cells. CONCLUSIONS: This study contributes to understanding the cytotoxic properties of TDB extract and its constituents and provides a potent strategy for its further application.

Sugar-free pregnane-type steroids from the roots of Cynanchum stauntonii.

Two new sugar-free 14,15-secopregnane-type steroids, 14-O-methyl-3-epi-hirundigenin (1) and 2-deoxyamplexicogenin A (2), along with two known sugar-free pregnane-type steroids, were isolated from the 95% ethanol extract of the roots of Cynanchum stauntonii. The structures of the new compounds were characterized on the basis of extensive spectroscopic analyses, mainly 1D and 2D NMR methods, albeit the MS experiments did not display the molecular ion peaks. Compound 2 was the aglycones of stauntosides J and K, etc., previously isolated from C. stauntonii. The isolation and identification of the new compounds graced the structural diversity of pregnane-type steroids from C. stauntonii.

Paniculatumoside G, a new C21 steroidal glycoside from Cynanchum paniculatum

ABSTRACT A new C21 steroidal glycoside, paniculatumoside G, together with neocynapanogenin C isolated for the first time from the natural source and two known compounds were isolated and characterized from the roots and rhizomes of Cynanchum paniculatum (Bunge) Kitag. ex H.Hara, Apocynaceae, a commonly used Traditional Chinese Medicine. On the basis of spectroscopic analysis, including HR-ESI-MS, 1D and 2D NMR spectral data, the structure of the new C21 steroidal glycoside was elucidated as neocynapanogenin H 3-O-β-D-oleandropyranoside.

Isolation and identification of two novel compounds from Marsdenia roylei and their quantum chemical calculations.

Two new compounds 1 (Methyl 26-di-deoxy-6-methyl-ß-D-allohexopyranoside) and 3 (3, 11, 12, 20 tetra-O-acetyl-pregn-5-ene-14ß-ol) have been isolated from the chloroform-soluble extract of the whole plant of Marsdenia roylei (family: Asclepiadaceae) and their structures were determined by 1D, 2D NMR and ESI-MS as well as by chemical modification. We have calculated the molecular geometries, local reactivity descriptors by the density functional theory with B3LYP functional with basis set 6-311G+(d,2p) of 1, 3 and 4 (deacylated 3). The 1H and 13C NMR chemical shifts of 1, 3 and 4 were calculated using Gauge-Including Atomic Orbital approach and these values are correlated with the experimental observations.

Recent advances in phytochemistry and pharmacology of C21 steroid constituents from Cynanchum plants.

Cynanchum is one of the most important genera in Asclepiadaceae family, which has long been known for its therapeutic effects. In this genus, 16 species are of high medicinal value. The extracts of the root and/or rhizome parts have been applied in traditional Chinese medicines (TCM) for the prevention and treatment of various illnesses for centuries. C21 steroids, as the typical constituents of Cynanchum species, possess a variety of structures and pharmacological activities. This review summarizes the comprehensive information on phytochemistry and pharmacology of C21 steroid constituents from Cynanchum plants, based on reports published between 2007 and 2015. Our aim is to provide a rationale for their therapeutic application, and to discuss the future trends in research and development of these compounds. A total of 172 newly identified compounds are reviewed according to their structural classifications. Their in vitro and in vivo pharmacological studies are also reviewed and discussed, focusing on antitumor, antidepressant, antifungal, antitaging, Na(+)/K(+)-ATPase inhibitory, appetite suppressing and antiviral activities. Future research efforts should concentrate on in vitro and in vivo biological studies and structure activity relationship of various C21 steroid constituents.