Two new prenylated isoflavones from Hedysarum multijugum

Chemical investigation on the ethyl acetate extract of the roots of Hedysarum multijugum resulted in the isolation of two new prenylated isoflavonoids: 5, 7, 2′-trihydroxy-4′-methoxy-3′-(γ, γ-dimethylallyl) isoflavone (hedysarimisoflavone A, 1) and 5, 7, 2′-trihydroxy-4′-methoxy-6, 8-di-(γ, γ-dimethylallyl) isoflavone (hedysarimisoflavone B, 2). Their structures were elucidated on the basis of spectroscopic analyses, especially, ¹H and ¹³C NMR spectra in conjunction with their 2D experiments, ¹H-¹H COSY, HMQC, HMBC, and NOESY.     

NMR确定鸡血藤中1个新的降倍半萜类化合物布卢门醇A-6-O-反式-对羟基肉桂酸酯

目的:研究鸡血藤水提取物中的化学成分。方法:采用硅胶、高效液相等柱色谱方法进行分离纯化,通过化合物的核磁共振(NMR)数据鉴定其结构。结果:从鸡血藤水提取物中分离出1个降倍半萜类化合物,根据其NMR数据鉴定其化学结构为布卢门醇A-6-O-反式-对羟基肉桂酸酯。结论:布卢门醇A-6-O-反式-对羟基肉桂酸酯为1个新的化合物。     

In vitro gastrointestinal biotransformation and characterization of a Desmodium adscendens decoction: the first step in unravelling its behaviour in the human body

Objectives

The isolation and identification of the flavonoids present in a decoction of Desmodium adscendens was performed. In view of the oral use of the decoction, this work focused on the stability in gastrointestinal conditions and biotransformation by intestinal microflora in the colon of D‐pinitol, vitexin and the flavonoid fraction of the decoction, as a first step in unravelling its behaviour in the human body.

Methods

The freeze‐dried decoction was first subjected to column chromatography. Subsequently an enriched flavonoid fraction, was separated by repeated semi‐preparative high‐performance liquid chromatography (HPLC ) or by HPLC ‐SPE . The isolated compounds were elucidated by NMR . Biotransformation experiments were carried in an in vitro gastrointestinal dialysis model.

Key findings

The major flavonoids of a decoction of D. adscendens were characterized as vicenin‐2, isoschaftoside, schaftoside, 2″‐O ‐xylosylvitexin, 2″‐O ‐pentosyl‐C ‐hexosyl apigenin and a O ‐hexosyl‐C ‐hexosyl apigenin, tentatively identified as 2″‐O ‐glucosyl‐vitexin. During their passage in the gastrointestinal dialysis model, vitexin and C ‐glycosides thereof were found to be stable. Only the O ‐glycosidic bonds of O ‐glycosides of vitexin or isovitexin were hydrolysed during the colonic phase.

Conclusions

A D. adscendens decoction was found to be rich in vitexin and isovitexin glycosides from which vitexin and the C ‐glycosides thereof were found to be stable in the simulated gastrointestinal tract.

     

豆科药用植物中的抗肿瘤活性成分

豆科(Leguminosae)植物在药用植物中占据重要地位,其化学成分类型丰富多样,且具有广泛的生物活性。近年来对该科药用植物的抗肿瘤活性研究较多,目前已经发现了一些活性较好的抗肿瘤活性成分,如甘草酸、甘草次酸以及苦参碱等。其中苦参碱已经应用于临床,且效果显著。因此,对该科植物进行抗肿瘤活性物质的研究意义重大。本文旨在概述豆科药用植物中抗肿瘤活性成分研究的最新成果及进展。     

Anti-inflammatory pterocarpanoids from the roots of Pongamia pinnata

A phytochemical study on the roots of Pongamia pinnata afforded 11 pterocarpanoids, including three new compounds. The structures of the isolated compounds were determined by 1D and 2D NMR and HRESIMS data. The absolute configurations of the new compounds were assigned via analysis of the specific rotations and electronic circular dichroism (ECD) spectra. The isolates were evaluated for their inhibitory effects on nitric oxide (NO) production in LPS-stimulated BV-2 microglial cells. Six compounds exhibited inhibitory effects against NO production, and compound 5 showed the best activity with an IC₅₀ value at 12.0?μM.     

Daidzin protects PC12 cells from serum deprivation-induced apoptosis

This article examines the effect of daidzin on PC12 cell apoptosis induced by serum-free medium. PC12 cell survival was measured by MTT assay. The DNA content and percentage of apoptosis were monitored by flow cytometry and DNA fragmentation was analyzed by agarose gel electrophoresis. The results showed that serum-free (12 h) medium induced apoptosis in PC12 cells. When the cells had been treated with daidzin (0.1, 1 w M) for 12 h, the percentage of PC12 cell apoptosis was significantly decreased to 12.21 and 4.24% from 91.94% in the group with serum deprivation, and DNA fragmentation was prevented. Daidzin (0.01-10 w M) attenuated the cytotoxic effect of sodium cyanide (20 mM), glutamate (0.5 mM) and sodium nitroprusside (0.5 mM) in a manner dependent on concentration. The results suggested that daidzin prevented PC12 cell from serum free-induced apoptosis.     

In vitro biological screening of the stem of Desmodium elegans

Objective

To explore the medicinal importance of the stem of Desmodium elegans, methanolic extract, and its different solvent fractions were evaluated for brine shrimp lethality, insecticidal and phytotoxicity, antifungal, and antibacterial activities.

Methods

The methanolic extract and its solvent fractions were tested for cytotoxic, phytotoxic, insecticidal, antifungal, and antibacterial effects using our previous published protocols.

Results

The methanolic, DCM, ethyl acetate and n-butanol fractions exhibited insecticidal effect against Callosobruchus analis and Rhyzopertha dominic. The methanolic extract, n-hexane, DCM ethyl acetate and n-butanol showed 75, 85, 85, 65 and 5% phytotoxicity at the tested concentration of 500 µg/mL respectively. The solvent fractions (DCM and ethyl acetate) were effective against F. solani (10% and 20% inhibition respectively). All the tested samples were devoid of cytotoxic and antibacterial effects.

Conclusion

It was concluded that this plant can be practiced for control of weeds and insects.     

Fatty acids and other lipid composition of five Trifolium species with antioxidant activity

The contents of fatty acids and other lipids of Trifolium balansae Boiss, Trifolium stellatum Lin., Trifolium nigrescens Viv. subsp. petrisavi (Clem) Holmboe, Trifolium constantinopolitanum Ser., and Trifolium resupinatum L. var. resupinatum L. (Leguminosae) were determined by gas chromatography-mass spectrometry (GC-MS). The whole plant hexane extracts of five Trifolium species contained eight fatty acids consisting of linolenic (31.1%) and palmitic (18.9%) acids as the most abundant unsaturated and saturated fatty acids, respectively. The total unsaturation for the oils of five Trifolium species was 30.6–42.2%. In addition to fatty acids, some alkanes and phytol were also obtained. The antioxidant activity and contents of fatty acids and lipids of five Trifolium species T. balansae, T. stellatum, T. nigrescens subsp. petrisavi, T. constantinopolitanum, and T. resupinatum var. resupinatum are presented for the first time in this study.     

Kaempferia parviflora, a plant used in traditional medicine to enhance sexual performance contains large amounts of low affinity PDE5 inhibitors

Aim of the study

A number of medicinal plants are used in traditional medicine to treat erectile dysfunction. Since cyclic nucleotide PDEs inhibitors underlie several current treatments for this condition, we sought to show whether these plants might contain substantial amounts of PDE5 inhibitors.

Materials and methods

Forty one plant extracts and eight 7-methoxyflavones from Kaempferia parviflora Wall. ex Baker were screened for PDE5 and PDE6 inhibitory activities using the two-step radioactive assay. The PDE5 and PDE6 were prepared from mice lung and chicken retinas, respectively. All plant extracts were tested at 50 μg/ml whereas the pure compounds were tested at 10 μM.

Results

From forty one plant extracts tested, four showed the PDE5 inhibitory effect. The chemical constituents isolated from rhizomes of Kaempferia parviflora were further investigated on inhibitory activity against PDE5 and PDE6. The results showed that 7-methoxyflavones from this plant showed inhibition toward both enzymes. The most potent PDE5 inhibitor was 5,7-dimethoxyflavone (IC₅₀ = 10.64 ± 2.09 μM, selectivity on PDE5 over PDE6 = 3.71). Structure activity relationship showed that the methoxyl group at C-5 position of 7-methoxyflavones was necessary for PDE5 inhibition.

Conclusions

Kaempferia parviflora rhizome extract and its 7-methoxyflavone constituents had moderate inhibitory activity against PDE5. This finding provides an explanation for enhancing sexual performance in the traditional use of Kaempferia parviflora. Moreover, 5,7-dimethoxyflavones should make a useful lead compound to further develop clinically efficacious PDE5 inhibitors.     

Two new 9,10-seco-cycloartanes from the seeds of Sphaerophysa salsula

Two new 9,10-seco-cycloartanes, named sphaerophyside SC (1) and sphaerophyside SD (2), together with four known compounds (3-6), were obtained from the ethanol extract of the seeds of Sphaerophysa salsula. The structures of these compounds were elucidated on the basis of spectral and chemical evidences. Compounds 3-6 were isolated from the plant for the first time.