Volume 75, Issue 1-2

A new phenolic sesquiterpene, dysoxyphenol ( 1 ), and the known sesquiterpene, 7 R ,10 S -2-hydroxycalamenene ( 2 ), were isolated from the acetone extract of Dysoxylum densiflorum seeds. The structures of these compounds were determined based on physical, Nuclear Magnetic Resonance, and mass spectral data. Both compounds were evaluated for their antibacterial and antifungal properties against seven pathogenic bacteria and two wood-rotting fungi, respectively. The results showed that both compounds have significant antibacterial properties only against Bacillus subtilis (Minimum Inhibitory Concentration 28 μM), while in the antifungal evaluation compound 1 was found to be more active than compound 2 . Therefore, compound 1 has promising antifungal properties that can be developed further for finding new antifungal agents.

6-Tuliposides A (6-PosA) and B (6-PosB) are major defensive secondary metabolites in tulip cultivars ( Tulipa gesneriana ), having an acyl group at the C-6 position of d -glucose. Although some wild tulip species produce 1,6-diacyl-glucose type of Pos (PosD and PosF), as well as 6-PosA/B, they have not yet been isolated from tulip cultivars. Here, aiming at verifying the presence of PosD and PosF in tulip cultivars, tissue extracts of 25 cultivars were analyzed by high-performance liquid chromatography (HPLC). Although no HPLC peaks for PosD nor PosF were detected in most cultivars, we found two cultivars giving a minute HPLC peak for PosD and the other two cultivars giving that for PosF. PosD and PosF were then purified from petals of cultivar ‘Orca’ and from pistils of cultivar ‘Murasakizuisho’, respectively, and their identities were verified by spectroscopic analyses. This is the first report that substantiates the presence of 1,6-diacyl-glucose type of Pos in tulip cultivars.

Peptidoglycan recognition proteins (PGRPs) are pattern recognition receptors that can recognize bacterial peptidoglycans and trigger the innate immune response of insects. Here, we identified and characterized a novel short-type Bombyx mori peptidoglycan recognition proteins short-4 (BmPGRP-S4) in a lepidopteran insect, Bombyx mori . BmPGRP-S4 exhibited a cDNA sequence length of 600 bp, encoding 199 aa with a protein molecular weight of 22 kDa. Multiple sequence alignment revealed that BmPGRP-S4 contains a conserved PGRP domain. Quantitative real-time polymerase chain reaction analysis showed that BmPGRP-S4 is highly expressed in the early developmental stages of silkworm larvae and presents tissue-specific expression in hemocytes. Interestingly, BmPGRP-S4 expression is significantly induced by bacterial infection in the midgut, fat body, and hemocytes. Furthermore, a dual luciferase reporter gene assay revealed that BmPGRP-S4 can activate the expression of the antimicrobial peptide genes lebocin , moricin , cecropin D , cecropin B , and attacin . Taken together, these results suggest that BmPGRP-S4 plays an important role in the innate immune response of silkworms.

This is the first report on the modification of a hemocyanin from Helix lucorum (HlH), a large molluscan respiratory protein, with folic acid (FA). In a two-step synthetic reaction, we prepared samples of HlH conjugated with 20 and 50 FA residues denoted as FA-HlH-1 and FA-HlH-2, respectively. Comparison of the attenuated total reflectance–Fourier transform infrared spectra in the amide I band region showed a structural rearrangement in the HlH that is due to FA conjugation. The changes in the secondary structure were more noticeable for FA-HlH-2. The thermal stability of HlH was not significantly affected by the FA modification, which is consistent with the observed structural similarities with the native protein. Preliminary cytotoxicity assays showed that FA-HlH-1 and FA-HlH-2 stimulate fibroblast proliferation when applied in concentrations of 50 and 100 μg/well. A negligible reduction of fibroblast growth was observed only for FA-HlH-1 and FA-HlH-2, exposed to 200 μg/well for 48 h. We found that FA-HlH-2 exhibits a low to moderate cytotoxic effect on two breast cancer cell lines, which express folate receptors, a hormone-dependent (MCF-7) and a hormone-independent (MDA-MB-231). FA-HlH-2 protects nontransformed cells and affects only neoplastic cells, which could be an advantage, and the protein could have potential in combination with other chemotherapeutics.

This study aimed to compare the biological activities of 35 herbal hydroethanolic extracts and select high potential extract, which showed antioxidative activity and inhibitory activities of α-glucosidase, lipase, and hyaluronidase, and to investigate the isolation, structural elucidation, and biological activities of five phenolic compounds from the selected extracts of Rosa gallica . On the basis of one-dimensional nuclear magnetic resonance together with the comparison with the literature values, the phenolic compounds were identified as methyl gallate ( 1 ), kaempferol-3- O -arabinofuranoside ( 2 ), multinoside A acetate ( 3 ), kaempferol ( 4 ), and quercetin ( 5 ), respectively. The results suggest that the extracts from R. gallica show the strongest biological activities in 35 herbal extracts and that 1 , 4 , and 5 among the five isolated compounds from rose extracts are effective in promoting antioxidative and enzymatic inhibitory activities.

The overexpression of sialic acids and sialyltransferases (STs) during malignant transformation and progression could result in the aberrant sialylation of cancer cells. Therefore, interfering the sialic acid synthesis might be an effective pathway in cancer therapy. In this study, we assessed that the antitumor inhibitors of 20( S )-ginsenosides Rg3, 20( R )-ginsenosides Rg3, 20( S )-ginsenosides Rh2, and 20( R )-ginsenosides Rh2 could block the sialoglycans in liver cancer cells HepG2. The results showed that these four compounds could inhibit the expressions of the total and free sialic acid at different levels in HepG2, respectively; also, it showed dose dependence. In addition, the results of the enzyme-linked immunosorbent assay showed that the above four compounds can inhibit the expression of STs significantly. We also found that these compounds could mediate the block of sialylation of α2,3- and α2,6-linked sialic acids in HepG2 cells by flow cytometry. Meanwhile, the results of the molecular docking investigation showed that these compounds showed strong interaction with ST6GalI and ST3GalI. These results verified that the ginsenosides have a powerful inhibiting aberrant sialylation, and it laid a theoretical foundation for further research on the investigation of ginsenosides as the target inhibitors on STs.

The leaves of Garcinia epunctata Stapf have furnished two new phenolic glucosides, epunctosides A and B, along with 13 known secondary metabolites identified as lanceoloside A, betulinic acid, lupeol, stigmasterol, β-sitosterol, β-sitosterol-3-O-β- d -glucopyranoside, stigmasterol-3-O-β- d -glucopyranoside, luteolin-7-O-glucoside, quercitin-7-O-glucoside, amentoflavone, robustaflavone, 4′-O-methyl-amentoflavone and 4′-O-methyl-robustaflavone. All structures were established from chemical and spectroscopic evidence including 1D and 2D NMR data as well as by comparing the obtained spectroscopic data with literature. This is the first report of the presence of phenolic glucosides in the genus Garcinia .