Saponin-rich fraction from Agave sisalana: effect against malignant astrocytic cells and its chemical characterisation by ESI-MS/MS

Astrocytic tumour cells derived from human (GL-15) and rat (C6) gliomas, as well as non-tumoural astrocytic cells, were exposed to the saponin-rich fraction (SF) from Agave sisalana waste and the cytotoxic effects were evaluated. Cytotoxicity assays revealed a reduction of cell viability that was more intensive in glioma than in non-tumoural cells. The SF induced morphological changes in C6 cells. They were characterised by cytoplasmic vacuole formation associated with increase in the formation of acidic lysosomes. The SF was subjected to purification on Sephadex LH-20, which characterised three probable steroidal saponins (sisalins) by electrospray ionisation mass spectrometry multistage (ESI-MSⁿ). Sisalins from sisal may be responsible for the cytotoxicity, which involves cytoplasmatic vacuole formation and selective action for glioma cells.     

Optimization of Extraction or Purification Process of Multiple Components from Natural Products: Entropy Weight Method Combined with Plackett–Burman Design and Central Composite Design

In this paper, the optimization of the extraction/purification process of multiple components was performed by the entropy weight method (EWM) combined with Plackett–Burman design (PBD) and central composite design (CCD). We took the macroporous resin purification of Astragalus saponins as an example to discuss the practicability of this method. Firstly, the weight of each component was given by EWM and the sum of the product between the componential content and its weight was defined as the comprehensive score, which was taken as the evaluation index. Then, the single factor method was adopted for determining the value range of each factor. PBD was applied for screening the significant factors. Important variables were further optimized by CCD to determine the optimal process parameters. After the combination of EWM, PBD and CCD, the resulting optimal purification conditions were as follows: pH value of 6.0, the extraction solvent concentration of 0.15 g/mL, and the ethanol volume fraction of 75%. Under the optimal conditions, the practical comprehensive score of recoveries of saponins was close to the predicted value (n = 3). Therefore, the present study provided a convenient and efficient method for extraction and purification optimization technology of multiple components from natural products.     

Triterpenoid Saponins from Vaccaria segetalis

Four novel triterpenoid saponins, Vaccariside B‐E (1–4), were isolated from the seeds of Vaccaria segetalis and their structures were elucidated as 3‐O‐β‐D‐galactopyranosyl‐(1–2)‐β‐D‐glucuronopyranosyl quillaic add 28‐O‐β‐D‐xylopyranosyl‐(1–3)‐α‐L rhamno‐pyranosyl‐(1–2)‐[α‐L‐arabinofura‐nosyl‐(1–3)]‐4‐O‐acetyl‐β‐D)‐fucopyranoside (1), 3‐O‐β‐D‐galactopyranosyl ‐ (1–2) ?3‐O‐acetyl‐β‐D ‐ glucuronopyranosyl quillaic acid 28‐O‐β‐D‐xylopyranosyl‐(1–3)‐α‐L‐rhamnopyra‐nosyl‐(1–2)‐[α‐L‐arabinofuranosyl‐(1–3)]‐4‐O‐acetyl‐β‐D‐fucopyranoside (2), 3‐O‐β‐D‐galactopyranosyl‐(1–2)‐β‐D‐glucuronopyranosyl quillaic add 28‐O‐α‐L‐arabinopyranosyl‐(1–3)‐α‐L‐rhamnopyranosyl‐(1–2)‐[α‐L‐arabinofuranosyl‐(1–3)]‐4‐O‐acetyl‐β‐D‐fucopyranoside (3), 3‐O‐β‐D‐galacto‐pyranosyl‐(1–2)‐[β‐D‐xytopyranosyl‐(1–3)]‐β‐D‐glucurono‐pyranosyl quillaic add 28‐O‐β‐D‐xylopyranosyl‐(1–3)‐α‐L‐rhamnopyranosyl‐(1–2)‐[α‐L‐arabinofuranosyl‐(1–3)]‐4‐O‐acetyl‐β‐D‐fucopyranoside (4), respectively.     

新18,19-裂乌索酸型三萜皂甙的NMR研究

用二维NMR技术（HMBC和NOESY）研究了从药用冬青属植物满树星中分离出的一新18,19-裂乌索酸型三萜皂甙-满树星甙I（aculeoside I）, 确定了该化合物的碳骨架结构.     

Synthesis of an Ursolic Acid Saponin with N-Acetylglucosamine-containing Trisaccharide Residue

The focus of this work is the synthesis of an ursolic acid saponin with an N-acetylglucosamine-containingtrisaccharide residue.Therefore,ursolic acid 3-yl α-L-arabinopyranosyl-(1→2)-α-L-arabinopyranosyl-(1→6)-2-acetamido-2-deoxy-β-D-glucopyranoside(1)was concisely synthesized in convergent synthesis with 48.0% overallyield.The structure of saponin 1 was confirmed by ~1H NMR,~(13)C NMR and mass spectra.     

Hemolytic and cytotoxic activity of dammarane-type triterpenoids

The relationship between chemical structure and hemolytic and cytotoxic activity was studied for dammarane-type triterpenoids isolated from leaves of various Betula species. It was shown that an acyclic sidechain (betulafolienetriol and betulafolienetetraol) imparted significantly higher hemolytic and cytotoxic activity than a cyclic sidechain. The activity of epoxydammaranetriol with an 11α-OH group was slightly higher than that of epoxydammaranetriol with a 12β-OH group. The activity of C-3 epimeric epoxydammaranetriols and-tetraols with a 12β-OH group was independent of the configuration of the C-3 hydroxyl. Epoxydammaranetriols with an 11α-OH group and epoxydammaranediols with a 3α-OH group were more active than those with a 3β-OH group. The effect of the most active compounds on the microviscosity of tumor-cell membranes was determined. __________ Translated from Khimiya Prirodnykh Soedinenii, No. 1, pp. 61–63, January–February, 2007.     

A New Triterpenoid Saponin: Se-saponin A

In continuation of our studies on the constituents of Clerodendrum serratum var.amplexghlium Moldenke'-"', a new triterpenoid saponin, sc-saponin A (l), was isolated.To the best of our knowledge, it is the second instance oftriterpenoid saponin from theClerodendrum genus. This paper deals with the structural elucidation of the newcompound.Se-saponin A (l) an amorphous powder, gave positive Liebermann-Burchardreaction. It was deduced to have a molecular formula of C58H,,O,, by high resoluti…     

两种天然齐墩果酸皂苷的合成

3-O-[β-D-Glucopyranosyl-（1→3）-α-L-arabinopyranosyl]-oleanolic acid-28-O-[β-D-glucopyranosyl] ester 1 was synthesized concisely by a convergent strategy. Using stepwise fashion for the synthesis of saponin 2, 3-O-{[β-D-glucopyranosyl-（1→2）]-[α-L-arabinopyranosyl-（1→3）]-α-L-arabinopyranosyl）-oleanolic acid-28-O-（β- D-glucopyranosyl） ester, an abnormal phenomenon, that the terminal arabinosyl residue took the ^1C4 conformation instead of typical ^4C1 form, was observed. Deprotection or heating could not resume the normal conformation, which resulted in the product of 2＇ not 2.     

三七粗提液中皂甙与多糖泡沫分离的研究

测定了三七皂甙溶液的表面张力 ,考察了溶液 p H值、氮气流速、进料浓度等因素对泡沫分离的影响。实验结果表明 ,在 p H 7.0 0 ,进料浓度 2 .43× 1 0 2 μg· m L- 1(以人参皂甙 Rg1作参照 ,以下皂甙浓度均与此类同 ) ,三七皂甙的表面张力为 5 .93× 1 0 - 2 N· m- 1;氮气流速 1 5 m L· min- 1及进料体积 8.0 m L时 ,对三七粗提液进行泡沫分离 ,泡沫相三七皂甙收得率为 73.6%,液相三七多糖收得率为 87.5 %。本法具有简便、有效、无污染的优点     

孕甾-5,20-二烯-3β-醇-3-O-β-D-吡喃木糖苷的合成

以妊娠双烯醇酮醋酸酯为起始原料, 经过6步反应以15.0%的总收率, 首次合成了孕甾-5,20-二烯-3β-醇-3-O-β-D-吡喃木糖苷. 关键反应为选择性还原α,β-不饱和酮, 夏皮罗反应, Koenig-Knorr 反应.