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A glycosphingolipid and glycerol 1,3-distearate-2-oleate from holothuria vagabunda

(4E,BE)-N-13'-methyl-tetradecanoyl-1-O-beta-D-glucopyranosyl4-sphingodiene and glycerol 1,3-distearate-2-oleate have been isolated from the methanol extract of the sea cucumber Holothuria vagabunda, which collected from Ha Long sea, Vietnam. Their chemical structures were established on the basis of extensive 1D, 2D NMR, EI-MS spectroscopic data and GC-MS.

Isolating a compound N-[3-(4-metoxiphenyl)-1-oxopropyl]pirol of piper longun Linn leaves

From n-hexane extract of piper longum Linn leaves a compound N-[3-(4-metoxiphenyl)-1 oxopropyl]pirol has been isolated and identified by IR, NMR, M8 spectrum. N-[3-(4-methoxiphenyl)-1-oxopropyl]pirol is a new compound and first reported from this plant.

Isolation and identification on some chemical components of croton tiglium L. and croton tonkinens seeds

We have isolated and identified components of Croton tiglium L. and Croton tonkinens is grain the first time in Vietnam. The compounds were isolated: beta-sitosterol, beta-sitosterol-3-0-beta-D-glucopiranoside and alpha-amyrin acetate. The idenfication of these compounds was investigated by modern physical methods like 1H-NMR, 13C-NMR and MS spectroscopies.

Study on characteristics of the conversional zinc phosphate coating by manganese

Structure, morphology and corrosion protection property of the phosphate conversion coating modified by manganese were studied using mass methods, polarisation resistance (Rp, X-ray diffraction (XRD), scanning electronic microscopy (SEM) and salt-spray test. The results show that the phosphate coating has a uniform thickness and it covers the metal surface completely. The composition of the layer was estimated to be (Zn,Mn,Fe)3(PO4)2-4H2O, in which a large amount of Mn, Fe was replaced by Zn. The thickness of modified phosphate layer ranges, but the polarisation resistance is high due to small size of pores on the coating. As a result, the corrosion protection ability of modified phosphate layer is 2-3 times higher than convertional zinc phosphate coating.

Study on multigand complexing of Bi(III) with 4-(2-pyridilazo)-resorcinol (PAR) and acetic acid in water solution by the photometric method

Study on multiligand complexing of Bi(III) with 4-(2-pyridilazo)- resorcinol (PAR) and acetic acid in water solution by the photometric method is resulted in: 1. Optimal conditions for multiligand complexing of PAR-Bi(lII)-CH3COO system are defined; 2. The component of complex compound PAR-Bi(lII)-CH3COO in the two pH ranges are defined.

Synthesizing and biological activities of some derivatives of hydantoin

By the condensation of aromatic aldehydes (5-nitrofurfural and m- nitrobenzal-dehyde) with hydantoin, the derivatives I and VI were obtained. The compounds I, VI underwent Mannich reaction and gave 8 Mannich base derivatives (II-V, VII-X). The structures of synthesized compounds have been characterized by IR, UV, 1H-NMR, 13C-NMR and mass spectroscopy. Ten obtained compounds were tested for biological activities such as antibacterial, antifungal and anticancer. Compound I and its Mannich base derivatives showed high biological activitives.

Synthesizing some derivatives of nitrodiphenylamine

We synthesized some polymers containing radicals of nitrodiphenylamine, which may be used as polymeric ultraviolet light and thermal stabilizers.