15-hydroxyblennin A,a new lactarane-type sesquiterpene lactone isolated from Lactarius torminosus

15-Hydroxyblennin A, a new lactarane-type sesquiterpene lactone was isolated from Lactarius torminosus mushrooms. Through spectroscopic (IR, ¹H NMR, ¹³C NMR, MS, UV) investigation and comparison with data for other known lactaranolides its structure was deduced as 3.     

New oxandrolone derivatives by biotransformation using Rhizopus stolonifer

Structural transformation of the steroidal lactone, oxandrolone (1), by suspended-cell cultures of the plant pathogen fungus Rhizopus stolonifer, resulted in the production of three new metabolites. These metabolites were identified as 11α-hydroxyoxandrolone (2), 6α-hydroxyoxandrolone (3) and 9α-hydroxyoxandrolone (4), by different spectroscopic methods and single-crystal X-ray diffraction analysis for metabolite 2. Compounds 1 and 3 showed a significant β-glucuronidase inhibitory activity.     

Isolation and structural elucidation of novel cholestane glycosides and spirostane saponins from Polygonatum odoratum

Much attention has been paid to cholestane-type steroidal glycosides because of their importance from the perspectives of both chemical diversity and significant biological activities. A phytochemical investigation of the rhizomes of Polygonatum odoratum (Liliaceae) resulted in the isolation of three novel cholestane-type steroidal glycosides (1–3) with unique Δ^14,16-unsaturated D-ring structures as well as two novel spirostane-type steroidal saponins (4 and 5) and three known steroidal glycosides (6–8). Their structures were determined by various spectroscopic methods and chemical reactions. Steroidal saponin 7 showed significant antifungal activity against Candida albicans JCM1542 (MIC 3.1 μg/mL) and Aspergillus fumigatus JCM1738 (MIC 6.3 μg/mL).     

2,3-Dihydrowithaferin A-3β-O-sulfate,a new potential prodrug of withaferin A from aeroponically grown Withania somnifera

Preparations of the roots of the medicinal plant Withania somnifera (L.) Dunal commonly called ashwagandha have been used for millennia in the Ayurvedic medical tradition of India as a general tonic to relieve stress and enhance health, especially in the elderly. In modern times, ashwagandha has been shown to possess intriguing antiangiogenic and anticancer activity, largely attributable to the presence of the steroidal lactone withaferin A as the major constituent. When cultured using the aeroponic technique, however, this plant was found to produce a new natural product, 2,3-dihydrowithaferin A-3β-O-sulfate (1), as the predominant constituent of methanolic extracts prepared from aerial tissues. The characteristic bioactivities exhibited by 1 including inhibition of cancer cell proliferation/survival, disruption of cytoskeletal organization and induction of the cellular heat-shock response paralleled those displayed by withaferin A (2). The delayed onset of action and reduced potency of 1 in cell culture along with previous observations demonstrating the requirement of the 2(3)-double bond in withanolides for bioactivity suggested that 1 might be converted to 2 in cell culture media and this was confirmed by HPLC analysis. The abundant yield of 1 from aeroponically cultivated plants, its good aqueous solubility and spontaneous conversion to 2 under cell culture conditions, suggest that 1 could prove useful as a readily formulated prodrug of withaferin A that merits further evaluation in animal models.     

Fenugreekine,a new steroidal sapogenin-peptide ester of Trigonella foenum-graecum

A new C₂₇-steroidal sapogenin-peptide ester, fenugreekine, has been isolated from seeds of Trigonella foenum-graecum. On acid hydrolysis, it afforded diosgenin, yamogenin, (25R)-spirosta-3,5-diene, a mixture of three isomeric (2S,3R,4R-, 2S,3R,4S-, 2S,3S,4R-)-4-hydroxyisoleucine lactones, 4′-hydroxyisoleucyl-4-hydroxyisoleucine lactone, and a C₁₄-dipeptide which was partially characterized. On the basis of this chemical transformation and spectral (UV, IR, PMR, MS) evidence of fenugreekine and its transformation products, the steroidal sapogenin-peptide ester is assigned structure (1). The two dipeptides also have not been encountered before in nature or prepared synthetically. The compound shows a number of interesting pharmacological and virological activities.     

Steroidal saponins from the rhizomes of Paris delavayi

Two new steroidal saponins, padelaosides A (1) and B (2), along with two other known steroidal saponins (3 and 4) were isolated from the rhizomes of Paris delavayi. Their structures were elucidated by 1D and 2D NMR techniques, HRFTMS, physical data and chemical methods. The two different absolute configurations of fucose, assigned as l and d that were found on compounds 1 and 2, respectively, were simultaneously reported in a natural medicine for the first time.     

Helicascolide C,a new lactone from an Indonesian marine algicolous strain of Daldinia eschscholzii (Xylariaceae,Ascomycota)

From an endophytic Daldinia eschscholzii strain isolated from the agar-producing red alga Gracilaria sp. SGR-1, collected from the coast of South Sulawesi, Indonesia, a new lactone helicascolide C (1) was obtained as colourless crystals from the ethyl acetate extract together with the related structurally known compound helicascolide A (2). The structure of the new compound 1 reveals a carbonyl group replacing an alcohol group of compound 2. The structure of 1 was elucidated by X-ray diffraction and spectral analyses. Compound 1 showed fungistatic activity against the phytopathogenic fungus Cladosporium cucumerinum.     

Withanolides of Datura spp. and hybrids

A new steroidal lactone of the withanolide group has been isolated from two Datura species and three hybrids and characterized as (20R,22R-5α,12α-dihydroxy-1-oxo-6α, 7α-epoxywitha-2,24-dienolide. The distribution of six withanolides throughout section Stramonium of the genus has been investigated.     

Steroidal saponins from the rhizomes and roots of Smilax scobinicaulis

Two new spirostane-type steroidal saponins, named smilscobinosides A (1) and B (2), together with a known congener (3), have been isolated from the EtOH extract of the rhizomes and roots of Smilax scobinicaulis. The structures of the new compounds were determined by means of chemical evidence and 1D- and 2D-NMR spectroscopic analysis, FABMS and HRESIMS.     

Alkene lactones from Persea fulva (Lauraceae): Evaluation of their effects on tumor cell growth in vitro and molecular docking studies

The new alkene lactone, (3E)-5,6-dihydro-5-(hydroxymethyl)-3-docdecylidenefuran-3(4H)-one (1), named majoranolide B, and three alkene lactones known as majorenolide (2), majoranolide (3) and majorynolide (4) were obtained from the aerial parts of Persea fulva (Lauraceae). The structures were elucidated in light of extensive spectroscopic analysis, including 1D, 2D NMR (¹H, ¹³C, ¹H-¹H-COSY, HMBC and HSQC) and HR-ESI-MS. These compounds were screened for their in vitro antiproliferative activity in rat C6 glioma and astrocyte cells using MTT assay and in silico by molecular docking against targets that play a central role in controlling glioma cell cycle progression. Majoranolide (3) is the most active compound with IC₅₀ 6.69 µM against C6 glioma cells, followed by the compounds 1 (IC₅₀ 9.06 µM), 2 (IC₅₀ 12.04 µM) and 4 (IC₅₀ 41.90 µM). The alkene lactones 1–3 exhibited lower toxicity in non-tumor cells when compared to glioma cells. Molecular docking results showed that majoranolide establishes hydrogen bonds with all targets through its α,β-unsaturated-γ-lactone moiety, whereas the long-chain alkyl group binds by means of several hydrophobic bonds. In the present study, it can be concluded from the anti-proliferative activity of isolates against C6 glioma cells that lactone constituents from P. fulva could have a great potential for the control of C6 glioma cells.     

Microwave-assisted synthesis and in vitro antibacterial activity of novel steroidal thiosemicarbazone derivatives

Herein, we reported the synthesis of 16 novel steroidal thiosemicarbazone derivatives via the condensation of steroidal ketones and substituted thiosemicarbazides under solvent-free conditions using microwave irradiation. The yields obtained are in the range of 84–96% using microwave method and 46–62% using conventional method. All the synthesized compounds (7a–p) have been characterized by ¹H NMR, ESI-MS, IR and elemental analyses. All the series compounds (7a–p) were evaluated for their antibacterial activity against and the results were compared with the standard drug Amoxicillin. Some of the compounds from the series like 7c, 7o and 7p were equipotent with Amoxicillin against Pseudomonas aeruginosa. Also compound 7h was better than Amoxicillin against Staphylococcus aureus and Bacillus subtilis.     

New cytotoxic dihydrochalcone and steroidal saponins from the aerial parts of Sansevieria cylindrica Bojer ex Hook

A new dihydrochalcone, 2‘,4‘-dihydroxy-3‘-methoxy-3,4-methylenedioxy-8-hydroxymethylene dihydrochalcone 1 and two new steroidal saponins, (25S)-ruscogenin-1-O-α-l-rhamnopyranosyl-(1 → 2)-β-d-glucopyranoside 2, (25S)-ruscogenin-3-O-α-l-rhamnopyranosyl-(1 → 4)-β-d-glucopyranoside 3, together with three known steroidal saponins (25S)-ruscogenin-3-O-β-d-glucopyranoside 4, (25S)-ruscogenin-1-O-α-l-rhamnopyranosyl-(1 → 2)-[β-d-xylopyranosyl-(1 → 3)]-α-l-arabinopyranoside 5 and (25R)-26-O-β-d-glucopyranosyl-furost-5-ene-1β,3β,22α,26-tetrol-1-O-α-L-rhamnopyranosyl-(1 → 2)-[β-d-xylopyranosyl-(1 → 3)]-α-l-arabinopyranoside 6 were isolated from the aerial parts of Sansevieria cylindrica. The structures of the new compounds were established by UV, IR, EI-MS, HR-ESI–MS as well as 1D (¹H,¹³C and DEPT-135) and 2D (HSQC, HMBC and TOCSY) NMR spectral analysis. The isolated compounds 1-6 were assayed for in vitro cytotoxicities against the three human tumor cell lines HT116, MCF7 and HepG2. Compound 1 showed a moderate cytotoxicity against MCF7. Compounds 2, 3 and 6 exhibited moderate cytotoxicities against the three used cell lines and compound 5 showed marked cytotoxicities against all used cell lines.     

Steroidal saponins and homoisoflavanone from the aerial parts of Sansevieria cylindrica Bojer ex Hook.

Phytochemical study on the methanolic extract of Sansevieria cylindrica aerial parts lead to the isolation, characterization and structure elucidation of a new steroidal saponin, 1β-hydroxy-kryptogenin-1-O-α-l-rhamnopyranosyl-(1 → 2)-α-l-arabinopyranoside (1), a new homoisoflavanone, (3S)-3,7-dihydroxy-8-methoxy-3-(3′,4′-methylenedioxybenzyl) chroman-4-one (2) and the known saponin alliospiroside A (3). To the best of our knowledge, the genin 1β-hydroxy-kryptogenin is reported here for the first time. The structures of the new compounds were determined by UV, IR, EIMS, HRESIMS together with 1D (¹H and ¹³C) and 2D (HSQC and HMBC) NMR spectral analysis. The isolated compounds 1–3 were tested for their radical scavenging activity (DPPH). Compound 2 exhibited activity compared to that of ascorbic acid as a standard. The cytotoxicity of the isolated compounds and the standard doxorubicin was tested against the three human tumor cell lines HT116, MCF-7 and PC-3. The results showed that the isolated compounds were inactive.     

Resolution of biotin intermediate lactone by enzyme-catalyzed stereoselective lactonization in organic solvent

A strain of Aspergillus oryzae WZ007 producing intracellular lipase with preference for the formation of the d-biotin intermediate lactone ((3aS,6aR)-tetrahydro-1,3-dibenzylhexahydro-1H-Furo[3,4-d]imidazole-2,4-dione) 1 was screened from soil samples. The microbial cells fermented by the strain were used as biocatalysts after lyophilization, to resolve the racemic biotin intermediate lactone 1 by enantioselective lactonization in organic solvents. The enantioselective lactonization afforded optically active lactone 1 with high enantiomeric excess (e.e. ≥ 98%) and conversion ratio (c ≥ 40%) when the biotransformation was carried out in dichloromethane. The e.e. of product was up to 99% after purification by inducing crystallization in acetone and basically satisfied the industrial application. The biosynthesis has been employed to produce kilograms supplies of optically active lactone 1 with high optical purity.     

A new C21 steroidal compound from the whole herb of Pachysandra terminalis Sieb. et Zucc

A new C21 steroidal compound (1), along with 12 known compounds (2–13) were isolated from the whole herb of Pachysandra terminalis Sieb. et Zucc. Their structures were determined by extensive analysis using various spectroscopic techniques. Notably, compound 6 was reported for the first time from P. terminalis, and compounds 3–5, 7 and 9 were isolated from the family Buxaceae for the first time.     

Microbiological transformation of diosgenin by resting cells of filamentous fungus,Cunninghamella echinulata CGMCC 3.2716

Microbial transformation of the steroidal sapogenin diosgenin (1) by resting cells of the filamentous fungus, Cunninghamella echinulata CGMCC 3.2716 was studied. Four metabolites were isolated and unambiguously characterized as (25R)-spirost-5-ene-3β,7β-diol-11-one (2), (25R)-spirost-5-ene-3β,7β-diol (3), (25R)-spirost-5-ene-3β,7β,11α-triol (4), and (25R)-spirost-5-ene-3β,7β,12β-triol (5), by various spectroscopic methods (¹H, ¹³C NMR, DEPT, ¹H–¹H COSY, HMBC, HSQC and NOESY). Compound 2 is a new metabolite. The NMR data and full assignment for the known metabolites (25R)-spirost-5-ene-3β,7β-diol (3) and (25R)-spirost-5-ene-3β,7β,11α-triol (4) are described here for the first time. The biotransformation characteristics observed included were C-7β, C-11α and C-12β hydroxylations. Compounds 1–5 exhibited no significant cytotoxic activity to human glioma cell line U87.     

Steroidal alkaloid saponins and steroidal saponins from Solanum surattense

A rare 16β-H steroidal alkaloid saponin (1), an avenacoside-type saponin (2), two steroidal saponins (4, 5), one revised-structure steroidal saponin (3) and six known compounds (6-11) were isolated from aerial parts of Solanum surattense Burm. f. Their structures were established on the basis of physical data, as well as by using spectroscopic (HRESIMS, 1D and 2D NMR), and chemical analysis methods. Compounds 1 and 11 showed cytotoxicity against A549 cell line with IC₅₀ values of 20.3 and 15.7 μM, respectively.     

The withanolides of Withania somnifera chemotypes I and II

Seven steroidal lactones of the withanolide series have been isolated as minor constituents of the leaves of Withania somnifera Dun. (Solanaceae) chemotype I, along with the major component withaferin A. Structures have been assigned to the new compounds: withanolide N (17α,27-dihydroxy-1-oxo-20R,22R-witha-2,5,14,24-tetraenolide) (6a) and withanolide O (4β,17α-dihydroxy-1-oxo-20R,22R-witha-2,5,8(14),24-tetraenolide) (7a). Similarly the leaves of W. somnifera chemotype II afforded three new withanolides along with the major component withanolide D (9a) and trace amounts of withanolide G (10). The new compounds are: 27-hydroxywithanolide D(4β,20α,27-trihydroxy-1-oxo-5β,6β-epoxy-20R,22R-witha-2,24-dienolide) (11a), 14α-hydroxywithanolide D (4β,14α,20α-trihydroxy-1-oxo-5β,6β-epoxy-20R,22R-witha-2,24-dienolide) (12a) and 17α-hydroxywithanolide D (4β,17β,20α-trihydroxy-1-oxo-5β,6β-epoxy-20S,22R-witha-2,24-dienolide) (13a). Whereas all the withanolides of chemotype I are unsubstituted at C-20 (20α-H), those of chemotype II possess an OH at this position (20α-OH).     

New immunomodulatory steroidal alkaloids from Sarcococa saligna

Two new steroidal alkaloids, (20 S)-(bennzamido)-3β-(N,N-dimethyamino)-pregnane (1), and (20 S)-(bennzamido)-pregnane-3-one- (2), and two known steroidal alkaloids, pachysanaximine A (3) and 3β, 20α-diacetamido-5α-pregnane (4) were isolated from the whole plant of Sarcococca saligna. The structures of these compounds were identified with the help of spectroscopic techniques while spectra for known compounds were compared with spectra reported in literature. The immunomodulatory potential of the new compounds were found to be significant and dose dependent. Compound 1 showed inhibition of T cells proliferation at 10 μg/mL (95%), and inhibition of IL-2 production with an IC50 = 1.6 μg/mL.