Cytotoxic prenylated flavonoids from Morus alba

A phytochemical fractionation of the methanol extract of the Morus alba leaves led to the isolation of eleven flavonoids (1–11). The structure of the new 3′-geranyl-3-prenyl-2′,4′,5,7-tetrahydroxyflavone (1) was elucidated by means of spectroscopic methods. The cytotoxicity of the isolated compounds against human cervical carcinoma HeLa, human breast carcinoma MCF-7, and human hepatocarcinoma Hep3B cells was evaluated. Of note, morusin (9) was the most potent with an IC₅₀ value of 0.64 μM against HeLa cells.     

Biochanin A triglycoside from Andira inermis

A new isoflavonol triglycoside, biochanin A 7-O-β- -apiofuranosyl-(1→5)-β- -apiofuranosyl-(1→6)-β- -glucopyranoside (1), was isolated from Andira inermis roots in addition to the known compounds genistein 7-O-β- -apiofuranosyl-(1→6)-β- -glucopyranoside and lanceolarin.     

A new flavone glycoside from the seeds of Shorea robusta

A new flavonoid, 3,7-dihydroxy-8-methoxyflavone 7-O-α- -rhamnopyranosyl-(1→4)-α- -rhamnopyranosyl-(1→6)-β- -glucopyranoside (1), was isolated from the seeds of Shorea robusta.     

Two new chalcones from leaves of Morus alba L.

Two new chalcone derivatives named morachalcones B and C (1 and 2) were isolated from the leaves of Morus alba L. Their structures were elucidated by spectroscopic analysis. Morachalcones B (1) and C (2) represent two examples of chalcones having unusual furan rings which are formed by cyclization between C-α-OH and C-2-OH. Compounds 1 and 2 displayed only moderate cytotoxic activity against HCT-8 and BGC823 human cancer cell lines.     

A new ellagic acid glycoside from Paeonia delavayi

A new ellagic acid glycoside, 4'-O-methylellagic acid 4-O-beta-D-glucopyranoside (1), was isolated from the root cortex of Paeonia delavayi. The structure was elucidated on the basis of spectroscopic methods.     

A new phenolic glycoside from the roots of Lygodium japonicum

A new phenolic glycoside, 3,4-dihydroxybenzoic acid 4-O-(4'-O-methyl)-beta-D-glucopyranoside (1), was isolated from the roots of Lygodium japonicum. The structure was elucidated on the basis of spectroscopic methods.     

Andalasin A, a new stilbene dimer from Morus macroura

A new stilbene dimer, andalasin A (1), together with the known stilbene oxyresveratrol and the 2-arylbenzofuran glycoside mulberroside C, have been isolated from the wood of Morus macroura. The structure of the new compound was elucidated on the basis of spectroscopic data. Compound 1 shows weak antinematodal and moderate antifungal properties.     

A new 2-arylbenzofuran from the root bark of Chinese Morus cathayana

A new 2-arylbenzofuran, sanggenofuran B (3',5'-dihydroxy-6-methoxy-4'-prenyl-2-arylbenzofuran), from the root bark of Chinese Morus cathayana is reported.     

Chemical composition of the green alga Codium Divaricatum Holmes

A new sterol, 24-R-stigmasta-4,25-diene-3β,6β-diol (1), along with three known compounds (2–3), was isolated from the green alga Codium divaricatum Holmes, a traditional Chinese medicine, which is efficacious against cancer. All structures were determined by spectroscopic methods and comparison with related known compounds. Single-crystal X-ray crystallography allowed us to confirm the structure of 1. To our knowledge, the compound 1 is reported as the first from natural source, and compounds 2, 4 have not been isolated from green algae before.     

Inhibition of glucose intestinal absorption by kaempferol 3-O-α-rhamnoside purified from Bauhinia megalandra leaves

Glucose intestinal absorption (GIA) is one of the factors that increase glycemia. Its reduction could be an important factor in decreasing hyperglycemia in diabetic patients. It has been shown that the aqueous extract of Bauhinia megalandra leaves inhibits GIA. In the present study we identified a compound present in the extract of B. megalandra responsible for the biological effect. The methanol extract of B. megalandra leaves was fractionated using different solvents, and high-speed counter-current chromatography yielding two pure compounds identified by ¹H NMR and ¹³C NMR as kaempferol 3-O-α-rhamnoside and quercetin 3-O-α-rhamnoside. The first one increased the K_M without changes in the V_MAX of GIA. In addition it exerted an additive inhibitory effect, on GIA, when combined with phlorizin. We suggest that kaempferol 3-O-α-rhamnoside is a competitive inhibitor of intestinal SGLT1 cotransporter.     

A new diglycosyl megastigmane from Carallia brachiata

A new megastigmane diglycoside was isolated from the leaves of Carallia brachiata. The structure was determined by spectroscopic methods as 3-hydroxy-5,6-epoxy-beta-ionol -3-O-beta-apiofuranosyl-(1-->6)-beta-glucopyranoside (1). Additionally, 29 known compounds consisting of two megastigmanes, one 1,2-dithiolane derivative, seven aromatic compounds, five condensed tannins, 12 flavonoids, and two glyceroglycolipids were isolated and identified.     

A new chromone glycoside from Polygonum capitatum

A new chromone glycoside (1), 7-O-(6'-galloyl)-beta-D-glucopyranosyl-5-hydroxychromone was isolated from Polygonum capitatum.     

A new cytotoxic casbane diterpene from Euphorbia pekinensis

A new cytotoxic casbane diterpene, named pekinenal, was isolated from the roots of Euphorbia pekinensis. Its structure was elucidated as 5α-hydroxy-1βH,2αH-casba-3Z,7E,11E-triene-18-al by a combination of 1D- and 2D-NMR techniques and confirmed by X-ray crystallography. Pekinenal showed cytotoxic activity against all four human cancer cell lines tested.     

Alpha-glucosidase inhibitory effect of mulberry (Morus alba) leaves on Caco-2

The effects of brewing time on dry weight content and alpha-glucosidase inhibitory active component released from mulberry (Morus alba) tea were studied. Different tea products showed significant differences in inhibitory activity against both sucrase and maltase. The most effective enzyme inhibition was observed when 3 to 5 min brewing time was applied in tea preparation. In a Caco-2 cell culture experiment the tea reduced the liberated glucose contents in both apical and basal sides of the cell monolayers. It can be concluded that hot water extract of mulberry leaves does have inhibitory effect against alpha-glucosidases, sucrase and maltase enzymes, and has a potential to be consumed as antidiabetic herb tea.     

Neolignans and flavonoids from the root bark of Illicium henryi

Two new neolignans (1 and 2) were isolated from the root bark of Illicium henryi, along with four known neolignans and seven known flavonoids (3–13). Their structures were elucidated on the basis of spectroscopic and chemical methods. The absolute configurations of compounds 1 and 2 were determined by the CD spectrum.     

A new coumarin glycoside from the husks of Xanthoceras sorbifolia

From the husks of Xanthoceras sorbifolia, a new coumarin glycoside, isofraxetin-6-O-beta-D-glucopyranoside (1), was isolated. The structure was established on the basis of spectroscopic methods.     

A new flavone glycoside from the fruits of Luffa cylindrica

The methyl ester of diosmetin 7-O-beta-D-glucuronide (1) was isolated from the fruits of Luffa cylindrica. Its structure was determined by spectroscopic methods.     

A new chlorosesquiterpene lactone from Ambrosia maritima

A new chloro-pseudoguaianolide-type sesquiterpene lactone, 11β-hydroxy-13-chloro-11,13-dihydrohymenin (1), was isolated from the Egyptian medicinal plant Ambrosia maritima. The structure was determined by spectroscopic methods, particularly high-resolution ¹H, ¹³C-NMR and 2D ¹H–¹H and ¹H–¹³C COSY NMR analysis.     

Benzofuran from seeds of Styrax officinalis

A new benzofuran was isolated from seeds of Styrax officinalis and has been identified as 5-[3"-(2-methylbutanoyloxy) propyl]-7-methoxy-2-(3',4'-dimethoxyphenyl) benzofuran (1) by means of spectroscopic analysis.     

Cyclisation of farnesyl pyrophosphate into sesquiterpenoids in ginger rhizomes (Zingiber officinale)

The atomic ratios (¹⁴C/³H) obtained in ar-curcumene, α-zingiberene, β-bisabolene obtained from the essential oil of rhizomes of Zingiber officinale which were fed with [2-¹⁴C, 2-³H₂], [2-¹⁴C, 4R-³H₁] and [2-¹⁴C, 5-³H₂]mevalonic acid and [1-³H₂]farnesylpyrophosphate (FPP) revealed that (a) (2E,6E)-isomer of FPP is isomerised to (2Z,6E)-isomer without loss of epimeric hydrogen that means without a redox process; (b) (2Z,6E)-FPP is cyclised to bisabolyl cation which is the penultimate precursor of α-zingiberene, ar-curcumene and β-bisabolene; and (c) two 1,2-hydrogen shifts take place during the formation of α-zingiberene whereas one 1,2 shift has been observed during the formation of ar-curcumene.