Antifouling Activity of Simple Synthetic Diterpenoids against Larvae of the Barnacle Balanus albicostatus Pilsbry

Five new pimarane diterpenoids 1-5 were synthesized using ent-8(14)-pimarene-15R,16-diol as starting material. The structures were elucidated by means of extensive NMR and MS analysis. The antifouling activity against larval settlement of the barnacle Balanus albicostatus were evaluated using capsaicin as a positive control. Compounds 1-3 and 5 showed more potent antifouling activity than capsaicin. Compound 5, which exhibited almost the same antifouling activity as starting material, showed better stability than starting material. These compounds all showed antifouling activity in a non-toxic way against larval settlement of the barnacle B. albicostatus. Analysis of structure-activity relationships (SAR) demonstrated that the substituents on the C-15 and C-16 position of pimarane diterpenoid were responsible for the antifouling activity.Program for National Key Technology RD [2007BAB26B03]; Scientific and Technological Key Projects of Fujian Province [2009N0038]; Scientific and Technological Projects of Xiamen City [3502Z20102010]; Marine Science Foundation for Young Scientist of State Oceanic Administration [2010131

Characterization of Terpenoids from the Root of Ceriops tagal with Antifouling Activity

One new dimeric diterpenoid, 8(14)-enyl-pimar-2′(3′)-en-4′(18′)-en-15′(16′)-endolabr- 16,15,2′,3′-oxoan-16-one (1) and five known terpenoids: Tagalsin C (2), Tagalsin I (3), lup-20(29)-ene-3β,28-diol (4), 3-oxolup-20(29)-en-28-oic acid (5) and 28-hydroxylup- 20(29)-en-3-one (6) were isolated from the roots of the mangrove plant Ceriops tagal. Their structures and relative stereochemistry were elucidated by means of extensive NMR, IR and MS analysis. The antifouling activity against larval settlement of the barnacle Balanus albicostatus were evaluated using capsaicin as a positive control. All these terpenoids exhibited antifouling activity against cyprid larvae of the barnacle without significant toxicity. The structure-activity relationship results demonstrated that the order of antifouling activity was diterpenoid (Compound 2) > triterpenoid (Compounds 4, 5 and 6) > dimeric diterpenoid (Compounds 1 and 3). The functional groups on the C-28 position of lupane triterpenoid significantly affect the antifouling activity. The diterpenoid dimmer with two identical diterpenoid subunits might display more potent antifouling activity than one with two different diterpenoid subunits. The stability test showed that Compounds 2, 4, 5 and 6 remained stable over 2-month exposure under filtered seawater

Diisopropyl [(4-methoxybenzamido)(p-tolyl)methyl]phosphonate

The asymmetric unit of the title compound, C22H30NO5P, contains two independent molecules in which the dihedral angles between the benzene rings are 82.0 (2) and 78.4 (2)°. In the crystal, each molecule forms an inversion dimer via a pair of N—H...O(=P) hydrogen bonds

Detection of 2-Deoxyglucose by Pre-column Derivation Reversed Phase High Performance Liquid Chromatography

A method was developed for the determination of 2-deoxyglucose(2-DG) by reversed phase high performance liquid chromatography (RP-HPLC) after pre-column derivated with p-aminobenzoic ethyl ester (ABEE). The results showed that the optimum derivation conditions were as follows: reaction temperature was 85 degrees C, reaction time was 1.5 h and molar ratio of derivative reagent (ABEE) to monosaccharide (2-DG/Glu) was 25:1. The derivative was analyzed on a Hypersil ODS 2 (250 mmx4.6 mm, 5 mu m) column with a mixture of acetonitrile to 0.02% trifluoroacetic acid (TFA) (2:80, V/V) as the mobile phase, at the flow rate of 1.0 mL/min and the detection wavelength at 307 nm. This method has a good linearity at the concentration from 1 mg/L to 700 mg/L (r=0.9999). The limit of detection was 100 mu g/L while the quantitative limit was 450 mu g/L. The average recovery of 2-DG was 101.7% and the relative standard deviation (RSD) was 0.7%. The inter-day and intra-day precision were both less than 0.7%, This method is of high sensitivity, precision and repetition, indicating that it is suitable for precise quantitative determination of 2-DG

Separation of d4T-P-N-PheOMe Diastereoisomers by Supercritical Fluid Chromatography

The separation of d4T-P-N-PheOMe diastereoisomers has been carried out by supercritical fluid chromatography on Hypersil ODS2 column (250 mm x 4.6 mm, 5 mu m). Supercritical CO2 modified with methanol, ethanol and 2-propanol were used as mobile phase. The influence of type and concentration of alcohol modifier, back pressure and column temperature on retention factor, diastereoselectivity and resolution were comprehensively studied. Among methanol, ethanol and 2-propanol, the methanol was proved to be the most favorable modifier, and 7% (V/V) of methanol was the preferred concentration at which d4T-P-N-PheOMe diastereoisomers could be separated with a resolution of 3.35. The optimal separation conditions were 7% (V/V) methanol as modifier, 2.0 mL min(-1) of flow rate for mobile phase, 308.15 K of column temperature, 15 MPa of back pressure. The d4T-P-N-PheOMe was separated baselinely in the running time of 15 min under these optimal conditions.National Natural Science Foundation of China [21075103, 20972130

Antifouling Activity of Simple Synthetic Diterpenoids against Larvae of the Barnacle Balanus albicostatus Pilsbry

Five new pimarane diterpenoids 1-5 were synthesized using ent-8(14)-pimarene-15R,16-diol as starting material. The structures were elucidated by means of extensive NMR and MS analysis. The antifouling activity against larval settlement of the barnacle Balanus albicostatus were evaluated using capsaicin as a positive control. Compounds 1-3 and 5 showed more potent antifouling activity than capsaicin. Compound 5, which exhibited almost the same antifouling activity as starting material, showed better stability than starting material. These compounds all showed antifouling activity in a non-toxic way against larval settlement of the barnacle B. albicostatus. Analysis of structure-activity relationships (SAR) demonstrated that the substituents on the C-15 and C-16 position of pimarane diterpenoid were responsible for the antifouling activity

Synthesis and crystal structure of diisopropyl hydroxy(4-methoxyphenyl)methylphosphonate

The title compound, C14H23O5P, was synthesized by the reaction of 4-methoxybenzaldehyde and diisopropyl phosphite. Its structure was determined with X-ray crystallographic, NMR, MS, and elemental analysis (EA) techniques. The crystal belongs to monoclinic, space group P2(1/n) with the following crystallographic parameters: a = 10.529 (2) angstrom, b = 8.424 (2) angstrom, c = 19.448 (4) angstrom, alpha = 90 degrees, beta = 105.2 (3)degrees, gamma = 90 degrees, mu = 0.180 mm(-1), V = 1664.1 (6) angstrom(3), Z = 4, Dx = 1.207 mg/mm(3), F (000) = 648, T = 293 (2) K, 2.00 degrees 2 sigma (I). Crystal packing is stabilized by interatomic hydrogen bond interactions between the doubly bonded phosphoryl O atom and the hydroxyl H atom which link the molecules into chains along the [011] plane of the unit cell.Foundation of Science and Technology Project of China [2006 DFA43030]; National Natural Science Foundation of China [20572061