Biologically active phenols from Saussurea medusa

Sixteen phenolic compounds were isolated from the polar fraction of Saussurea medusa and were structurally elucidated by chemical evidences and spectral methods. These compounds include two new lignan glucosides, namely medusasides A (1) and B (2), and fourteen known phenolic compounds (3-16). One major compound, apigenin 7-O-[alpha-L-rhamnopyranosyl-(1-->6)-beta-D-glucopyranoside] (6) showed remarkable activity to attenuate the scopolamine induced memory deficit of mice. Compound 6 and another major one, quercetin (8) also exhibited moderate cell protecting activities against hydrogen peroxide (H(2)O(2)) induced PC12 cell damage.

Songorine, a diterpenoid alkaloid of the genus Aconitum, is a novel GABA(A) receptor antagonist in rat brain

Songorine, a diterpenoid alkaloid isolated from the genus Aconitum, was recently found to enhance the excitatory synaptic transmission in rat hippocampus. The mechanism underlying the effects was examined in the present study. The alkaloid at 0.1-300 microM inhibited the specific binding of [(3)H]muscimol to Triton-treated synaptic membranes of rat brain in a concentration-dependent manner (IC(50)=7.06 microM; 95% confidence limits: 3.28-10.84 microM). Scatchard analysis and Lineweaver-Burk double reciprocal plot of [(3)H]muscimol saturation binding data indicate a non-competitive inhibition of the alkaloid on the gamma-aminobutyric acid(A) (GABA(A)) receptor. In acutely dissociated rat hippocampal neurons the alkaloid did not elicit current response, but markedly inhibited the GABA-induced inward current (IC(50)=19.6 microM). The results suggest that songorine is a novel non-competitive antagonist at the GABA(A) receptor in rat brain.

Five new diterpenoids from Pseudolarix kaempferi

Five new diterpenoids, pseudolaric acids F (1), G (2), and H (3), 2',3'-dihydroxy-1'-propoxypseudolarate B (4), and 6'-O-acetylpseudolaric acid B O-beta-D-glucopyranoside (5), along with nine known diterpenoids, pseudolaric acids A, B, and C(1), deacetylpseudolaric acid C(2), deacetylpseudolaric acid A, methyl pseudolarate A, methyl pseudolarate B, pseudolaric acid A-O-beta-D-glucopyranoside, and pseudolaric acid B-O-beta-D-glucopyranoside, were isolated from the root bark of Pseudolarix kaempferi. Their structures and stereochemistry were elucidated mainly by spectral data, especially 2D NMR techniques.

Triterpene saponins from Craniotome furcata

Three saponins, craniosaponin A (1) and buddlejasaponins Ia (2) and I (3) were isolated from the n-butanol soluble fraction of Craniotome furcata for the first time. Among them, craniosaponin A (1) was identified to be a new compound. The structure of craniosaponin A was assigned mainly by spectral methods. A preliminary assay in vitro was applied to evaluate their cytotoxicity against several tumor cell-lines.

Two novel cytotoxic and antimicrobial triterpenoids from Pseudolarix kaempferi

Two novel antimicrobial and cytotoxic triterpenoids, isopseudolarifuroic acids A (1) and B (2), were isolated from the bark of Pseudolarix kaempferi. The structural elucidation of two novel compounds was carried out mainly by spectroscopic methods, and also by computer modeling. Compounds 1 and 2 exhibited significant cytotoxic activities against several tumor cell lines. Compound 1 also showed most potent antimicrobial activities against both Gram-positive and Gram-negative bacteria.

Novel ceramides from the fungus Lactarium volemus

Two novel ceramides, lactariamides A (N-2'-hydroxytetracosanoyl-2-amino-3,4-epoxyoctadecan-1-ol (1)) and B ((4E,8E)-N-2'-hydroxyoctadecanoyl-2-amino-9-methyl-4,8-octadecadine-1,3-diol (2)), were isolated from the fungus Lactarium volemus, together with a known compound, cerebroside D (3). Their structures were determined on the basis of chemical evidence and spectral methods.

Sterols from the fungus Lactarium volemus

Seven ergostane-type sterols and two mono-glucosides were isolated from the ethyl acetate soluble fraction of Lactarium rolemus. Three are previously unknown, i.e. 3-O-beta-D-glucopyranosyl-22E,24R-5alpha,8alpha-epidioxyergosta-6,22-diene, 3-O-beta-D-glucopyranosyl-22E,24R-5beta,8beta-epidioxyergosta-6,22-diene and 22E,24R-ergosta-7,22-diene-3beta,5alpha,6beta,9alpha-tetraol. The structural elucidation of these compounds was mainly achieved by spectroscopic methods.

[The development of mouse bioreactor expressing human tissue plasminogen activator (tPA) in mammary gland by transfecting spermatozoa in testicular duct]

The most established methods for development of transgenic animals are the microinjection of DNA into the fertilized eggs, but it is still a procedure of certain complexity and high cost. Therefore, the idea of using sperm as a vehicle to carry exogenous DNA into eggs is very attractive, and there have been some successful reports. Though the methods are rather simple they sometimes have low reproducibility. To improve the technique we transinfected the spermatozoa in testicular duct, not in vitro, to produce mice which expressed human tissue plasminogen activator (tPA) in mammary gland. The results demonstrated that: (1) 5 transinfected mice mated 10 female mice in 10 days after operation, (2) 79 founders were developed and 42 survived, (3) using PCR to detect foreign DNA integrated into the genome of founders, 7 out of 42 founders were positive (16.67%), (4) The expression level of tPA was 48-80 ng/ml in the milk of 5 PCR positive founders and (5) the foreign DNA integrated into the genome was detected in 2 out of 4 1st offspring by PCR technique.

Diterpenoids from isodon eriocalyx

Three new diterpenoids, eriocalyxins C-E (1-3), were isolated from Isodon eriocalyx. Their structures were elucidated as 6beta-hydroxy-15beta-acetoxy-3alpha,20-epoxy-16beta, 17-epoxy-ent-kaur-1,7-dione (1), 1alpha,7beta-dihydroxy-6beta, 15beta-diacetoxy-7,20-epoxy-ent-kaur-16-ene (2), and 15beta-acetoxy-1,6-dioxo-6,7-seco-ent-kaur-2,16-dien-7,20-olide (3), respectively, by means of spectroscopic methods, including one- and two-dimensional NMR techniques.

[Expression and regulation of milk protein gene in mammalia]

On the basis of introducing the structures and relations of evolution in milk protein genes, the factors involved in gene expression including cis-acting elements, trans-acting factors as well as induction of hormones were discussed. Finally the applicable prospect of mammary gland as a bioreactor was estimated.