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In this work, the β-galactosidase from Enterobacter cloacae B5 (BgaB5) exhibited excellent transglycosylation activity toward tyrosol ( p -hydroxyphenethyl alcohol) when using lactose as the glycosyl donor, generating a series of tyrosol glycosides with potential pharmacological properties. The effects of substrate concentration, temperature, pH, and reaction time on the transglycosylation reaction catalyzed by the enzyme BgaB5 were studied in detail. Three tyrosol derivatives were produced in a total high yield of 50.0% when incubating the enzyme with 250 mM tyrosol and 1000 mM lactose (pH 7.5) at 50 °C for 5 min. These derivatives were subsequently purified by column chromatography and preparative thin-layer chromatography. MS analysis of the purified compounds suggested one monogalactoside ( M r 300) and two digalactoside derivatives ( M r 462). The following NMR analysis further identified them to be p -hydroxyphenethyl β-D-galactopyranoside, p -hydroxyphenethyl β-D- galactopyranosyl-(1 → 3′)-β-D-galactopyranoside, and p -hydroxyphenethyl β-D- galactopyranosyl-(1 → 6′)-β-D-galactopyranoside, respectively. The yield of the tyrosol monogalactoside which was known to possess potent bioactivities reached 39.4%, higher than other enzymatic yields reported so far. The two digalactosides, which were expected to have potential applications for novel drug screening and discovery, were artificially obtained with 10.6% yield for the first time.

Seven antialgal compounds ( 1 – 7 ) were successfully isolated from the red alga Gracilaria lemaneiformis through a combination of silica gel column chromatography and repeated preparative thin-layer chromatography. On the basis of the spectral data, the compounds were identified as gossonorol ( 1 ), 7,10-epoxy-ar-bisabol-11-ol ( 2 ), glycerol monopalmitate ( 3 ), stigmasterol ( 4 ), 15-hydroxymethyl-2, 6, 10, 18, 22, 26, 30-heptamethyl-14-methylene-17-hentriacontene ( 5 ), 4-hydroxyphenethyl alcohol ( 6 ), and margaric acid ( 7 ). These seven compounds were isolated from G. lemaneiformis for the first time, while the compounds 4 , 6 , and 7 were isolated from marine macroalgae for the first time. Furthermore, a quantitative relationship between the inhibition of algal growth and the concentration of each antialgal compound was determined and important parameters for future practical HAB control, e.g., EC 50-96h , were also obtained. The results indicated that isolated compounds 1–7 possess selective antialgal activity against the growth of several red tide microalgae (including Amphidinium carterae , Heterosigma akashiwo , Karenia mikimitoi , Phaeocystis globsa , Prorocentrum donghaiense , and Skeletonema costatum ). Their antialgal activity against test red tide microalgae has not been previously reported. Furthermore, the EC 50-96h of one or more of the compounds towards the tested red microalgae was not only significantly less than 10 μg/mL but also was smaller than that of the characteristic antialgal agent potassium dichromate. The study demonstrates that compounds 1–7 possess significant application potential as antialgal agents against several harmful red tide microalgae.

To develop a new antiviral preparation from a microbial source, the halophilic bacterium Bacillus pumilus E303035 was isolated from a soil sample collected at Qarhan Salt Lake in Qinghai, China. The inhibitory activity of an ethyl acetate extract of its fermentation broth was higher than that of an n-butanol extract. After isolation and purification, 9 compounds were obtained: cyclo(L-Leu-L-Pro) ( 1 ), cyclo(L-Pro-L-Tyr) ( 2 ), Brevianamide F ( 3 ), 2-(3-Indolyl) ethanol ( 4 ), N-[2-(1H-indol-3-yl) ethyl] acetamide ( 5 ), 3, 3-di(1H-indol-3-yl)propane-1,2-diol ( 6 ), Lincomycin B ( 7 ), dibutylphthalate ( 8 ), and p-hydroxyphenethyl alcohol ( 9 ). Compounds 1 , 5 , and 9 showed inhibitory activities against potato virus Y (PVY). Compounds 1 , 4 , and 9 had significant inhibitory activity against genes HC - pro , P3 , and Nib , compound 5 against gene P3 , and compounds 1 and 4 against NIa . Compounds 1 , 4 , 5 , and 9 had significant inhibitory activity against genes VPg and 6K1 . Active compounds 1 , 5 , and 9 had various effects on the expression of viral genes related to pathogenesis. Expression of genes cullin and XTH was up-regulated and CP was down-regulated, compared to the positive control. In conclusion, compounds 1 , 5 , and 9 might be considered as potential antiviral agents for future development.

Isolation of phenolic compounds from water boiled with Hizikia fusiformis and purificartrion of the extracts from solvent fractions was achieved using column chromatography. The simple phenolic compound, 4-hydroxyphenethyl alcohol (4-HPEA) with an elemental composition C8H10O2 was identified on the basis of spectroscopic data. The whitening effects of 4-HPEA, inhibitory activity against mushroom tyrosinase, and inhibitory activity against melanin production in B16 melanoma cells were evaluated using an in vitro assay system. The whitening effect of 4-HPEA was also measured using a colorimeter and visual assessment of UVB induced hyperpigmentation of brown guinea pig skin. Topical application of 4-HPEA promoted depigmentation of UVB-induced hyperpigmented spots. 4-HPEA has a potential for use as a safe and effective ingredient for whitening in cosmetic and medical applications.