Pregnane glycosides

seco-Pregnane Glycosides from Australian Caustic Vine (Cynanchum viminale subsp. australe)

Cynanchum viminale subsp. australe, more commonly known as caustic vine, is a leafless succulent that grows in the northern arid zone of Australia. Toxicity toward livestock has been reported for this species, along with use in traditional medicine and its potential anticancer activity. Disclosed herein are novel seco-pregnane aglycones cynavimigenin A (5) and cynaviminoside A (6), together with new pregnane glycosides cynaviminoside B (7) and cynavimigenin B (8). Cynavimigenin B (8) contains an unprecedented 7-oxobicyclo[2.2.1]heptane moiety in the seco-pregnane series, likely arising from a pinacol-type rearrangement. Interestingly, these isolates displayed only limited cytotoxicity in cancer and normal human cell lines, in addition to low activity against acetylcholinesterase and Sarcoptes scabiei bioassays, suggesting that 5-8 are not associated with the reported toxicity of this plant species.

Polyoxypregnane Ester Derivatives and Lignans from Euphorbia gossypina var. coccinea Pax

From the aerial parts of Euphorbiagossypina var. coccinea Pax., eight new pregnane glycosides (euphogossypins A-H, 1-8) of the cynanforidine and deacetylmetaplexigenin aglycons, two new lignans (gossypilignans A and B, 9 and 10), and four known compounds, namely, the pregnane 12-O-benzoyldeaxcylmetaplexigenin (11), the lignan 9α-hydroxypinoresinol (12), and the flavonoids naringenin (13) and quercitrin (14) were isolated. The structure elucidation of the new compounds was carried out by a spectroscopic analysis, including HRMS, 1D (¹H, ¹³C JMOD), and 2D NMR (HSQC, ¹H-¹H COSY, HMBC, and NOESY) experiments. The obtained pregnane glycosides were substituted with acetyl and benzoyl ester moieties, and sugar chains containing thevetose, cymarose, digitoxose, and glucose monosaccharides. All of the compounds are described for the first time from E. gossypina var. coccinea. The isolated pregnanes and lignans were tested for their antiproliferative activity on HeLa cells using the MTT assay; the compounds exerted no significant effect against the tumor cells.

The binding proximity of methyl β-lilacinobioside isolated from Caralluma retrospiciens with topoisomerase II attributes apoptosis in breast cancer cell line

The alterations in somatic genomes that controls the mechanism of cell division as a main cause of cancer, and then the drug that specifically toxic to the cancer cells further complicates the process of the development of the widely effective potential anticancer drug. The side effects of the drug as well as the radiotherapy used for the treatment of cancer is severe; therefore, the search of the natural products from the sources of wild plants having anticancer potential is become immense importance today. The ethno-medicinal survey undertaken in Al-Fayfa and Wadi-E-Damad region of southern Saudi Arabia revealed that the Caralluma retrospiciens (Ehrenb.) N.E.Br. (family Apocynaceae) is being used for the treatment of cancer by the native inhabitants. The biological evaluation of anticancer potential of bioassay-guided fractionations of methanolic extract of whole plant of C. retrospiciens against human breast adenocarcinoma cell line (MCF-7) followed by characterization using spectroscopic methods confirmed the presence of methyl β-lilacinobioside, a novel active constituent reported for the first time from C. retrospiciens, is capable of inhibition of cell proliferation and induction of apoptosis in MCF-7 cells by regulating ROS mediated autophagy, and thus validated the folkloric claim. Based on a small-scale computational target screening, Topoisomerase II was identified as the potential binding target of methyl β-lilacinobioside.

The Effect of Polyphenols Isolated from Cynanchi wilfordii Radix with Anti-inflammatory, Antioxidant, and Anti-bacterial Activity

Recently, Cynanchi wilfordii Radix has gained wide use in Asian countries as a functional food effective for relieving fatigue, osteoporosis, and constipation, particularly in menopausal disorders. However, its anti-inflammatory and anti-microbial activities have not been explored in detail to date. The anti-inflammatory, antioxidant, and anti-bacterial properties of the Cynanchi wilfordii Radix extracts obtained with water, methanol, ethanol, and acetone were compared. All 4 polyphenol-containing extracts exhibited anti-inflammatory and antioxidant effects. The ethanol extract was found to elicit the most potent reduction of nitric oxide (NO), prostaglandin E₂ (PGE₂), and cytokine (IL-1β, IL-6, IL-10, and TNF-α) levels, as well as inhibit the expression of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) in a concentration-dependent manner. The evaluation of antioxidant activity also revealed the ethanol extract to have the highest free radical scavenging activity, measured as 85.3±0.4%, which is equivalent to 99.9% of the activity of α -tocopherol. In the assessment of anti-bacterial activity, only ethanol extract was found to inhibit the growth of the Bacillus species Bacillus cereus and Bacillus anthracis. These results show that polyphenols of Cynanchi wilfordii Radix have anti-inflammatory, antioxidant, and anti-bacterial properties that can be exploited and further improved for use as a supplementary functional food, in cosmetics, and for pharmaceutical purposes.

Investigation of Pharmacological Activity of Caralluma penicillata: Anti-Inflammatory Properties and Gastritis Protection against Indomethacin in Adult Guinea Pigs

Caralluma is a plant that possessing a great therapeutic potential in folk medicine in Yemen, namely, Caralluma penicillata (C. penicillata) as antiulcer. The study aims to evaluate the anti-inflammatory properties and gastritis protection activity of C. penicillata against indomethacin in adult guinea pigs. The study was divided into four parts: firstly, the optimum dose of extract as anti-inflammatory effect was determined. Secondly, the acute anti-inflammatory effect of extract were estimated. Thirdly, the repeated doses of extract against chronic inflammation was estimated. The anti-inflammatory activity of extract was compared with indomethacin as a prototype of drug against inflammation. Fourthly, the gastritis protection properties of extract with/without indomethacin were performed. The results showed that a 400 mg/kg of 10% ethanol extract produced the maximum of anti-inflammatory effect. Also, the single dose of extract was equipotent for indomethacin (10 mg/kg), but shorter in duration with regard to acute anti-inflammatory effect. In addition, the repeated doses of extract against chronic inflammation were less potent than indomethacin with regard to ulcerogenic effect. On the other hand, extract-indomethacin combination reduced the gastritis effect of indomethacin based on ulcer index and histological study.

Pregnane and pregnane glycosides from the Malagasy plant, Cynanchum aphyllum

A new 8,14-seco-pregnane type of steroid called cynaphyllogenin and its eight glycosides, cynaphyllosides A-H, were isolated from the aerial parts of Cynanchum aphyllum. The structures of these compounds were elucidated based on chemical and spectroscopic evidence.

New steroids from Solenostemma argel leaves

Two new pregnane ester glycosides, named stemmoside A (1) and stemmoside B (2) and a third new polyhydroxy pregnane, named stemmin C (3), were isolated from Solenostemma argel leaves. The structures were achieved by extensive one- and two-dimensional NMR and MS spectroscopic analysis.