Cloning, functional expression, and characterization of the raffinose oligosaccharide chain elongation enzyme, galactan:galactan galactosyltransferase, from common bugle leaves. (1/9)

Galactan:galactan galactosyltransferase (GGT) is a unique enzyme of the raffinose family oligosaccharide (RFO) biosynthetic pathway. It catalyzes the chain elongation of RFOs without using galactinol (alpha-galactosyl-myoinositol) by simply transferring a terminal alpha-galactosyl residue from one RFO molecule to another one. Here, we report the cloning and functional expression of a cDNA encoding GGT from leaves of the common bugle (Ajuga reptans), a winter-hardy long-chain RFO-storing Lamiaceae. The cDNA comprises an open reading frame of 1215 bp. Expression in tobacco (Nicotiana plumbaginifolia) protoplasts resulted in a functional recombinant protein, which showed GGT activity like the previously described purified, native GGT enzyme. At the amino acid level, GGT shows high homologies (>60%) to acid plant alpha-galactosidases of the family 27 of glycosylhydrolases. It is clearly distinct from the family 36 of glycosylhydrolases, which harbor galactinol-dependent raffinose and stachyose synthases as well as alkaline alpha-galactosidases. Physiological studies on the role of GGT confirmed that GGT plays a key role in RFO chain elongation and carbon storage. When excised leaves were exposed to chilling temperatures, levels of GGT transcripts, enzyme activities, and long-chain RFO concentrations increased concomitantly. On a whole-plant level, chilling temperatures induced GGT expression mainly in the roots and fully developed leaves, both known RFO storage organs of the common bugle, indicating an adaptation of the metabolism from active growth to transient storage in the cold.  (+info)

Neoclerodane diterpenoids from Ajuga taiwanensis. (2/9)

Phytochemical investigation of Ajuga taiwanensis resulted in the isolation of seven neoclerodane diterpenes, four of which ajugalide-A (1), -B (2), -C (3), and -D (4), are new and the remaining three are known diterpenes, ajugamacrin B (5), ajugapantin A (6), and ajugamarin C1 (7). Their structures were elucidated in spectral and chemical transformation studies.  (+info)

A new phytoecdysteroid from Ajuga taiwanensis. (3/9)

A new phytoecdysteroid, namely ajugalide-E (1), together with twenty five known compounds were isolated from Ajuga taiwanensis collected from Tainan, Taiwan. Their structures were determined by spectral analysis including high resolution one- and two-dimensional NMR spectroscopy.  (+info)

The C-terminal sequence from common bugle leaf galactan:galactan galactosyltransferase is a non-sequence-specific vacuolar sorting determinant. (4/9)

The Ajuga reptans L. galactan:galactan galactosyltransferase (ArGGT) is a vacuolar enzyme that synthesizes long-chain raffinose family oligosaccharides (RFOs), the major storage carbohydrates of this plant. ArGGT is structurally and functionally related to acid plant alpha-galactosidases (alpha-Gals) of the glycosylhydrolase family 27, present in the apoplast or the vacuole. Sequence comparison of acid alpha-Gals with ArGGT revealed that they all contain an N-terminal signal sequence and a highly similar core sequence. Additionally, ArGGT and some acid alpha-Gals contain C-terminal extensions with low sequence similarities to each other. Here, we show that the C-terminal pentapeptide, SLQMS, is a non-sequence-specific vacuolar sorting determinant. Analogously, we demonstrate that the C-terminal extensions of selected acid alpha-Gals from Arabidopsis, barley, and rice, are also non-sequence-specific vacuolar sorting determinants, suggesting the presence of at least one vacuolar form of acid alpha-Gal in every plant species.  (+info)

Beneficial effects of Ajuga decumbens on osteoporosis and arthritis. (5/9)

Extract of the whole plant, Ajuga decumbens (KE) has long been used in China as a medication for the relief of joint pain. Previously, we proved that KE up-regulated the synthesis of collagen in false aged model rats. In this paper we examined the effects of KE on nitric oxide (NO) production, expression of inducible nitric oxide synthase (iNOS), osteoblast and osteoclast activity. We also investigated whether KE had any anti-osteoporosis or anti-arthritic activity by using ovariectmized mice and adjuvant induced arthritic rats. KE exhibited down-regulation of differentiation into osteoclast and up-regulation of mineralization in osteoblast-like MC3T3-E1 cells in a concentration-dependent manner. NO synthesized by iNOS plays important roles in inflammatory disease and imbalance between bone resorption and bone formation caused by estrogen depletion. KE inhibited expression of iNOS which caused concentration dependent inhibition of NO production. Furthermore, KE prevented brittle bones in ovariectomized mice and swelling of the left hind ankle in adjuvant induced arthritic rats. Therefore, KE improved the balance of bone resorption and bone formation, showing anti-inflammatory effects. Consequently, KE is beneficial for sufferers of bone and joint disease.  (+info)

Antiplasmodial activity of Ajuga bracteosa against Plasmodium berghei infected BALB/c mice. (6/9)

BACKGROUND & OBJECTIVES: The present work was undertaken to evaluate antiplasmodial activity of ethanolic leaves extract of traditional medicinal plant Ajuga bracteosa in Plasmodium berghei infected BALB/c mice along with its phytochemical screening and acute toxicity test to support its traditional use as a remedy for malaria. METHODS: Plant extract (ethanolic) 250, 500, 750 mg/kg/day was evaluated in the early and established infection along with repository activity in P. berghei infected BALB/c mice through suppressive, curative and preventive test. The phytochemical screening was carried out by employing standard procedures. The acute toxicity was checked through limit test. RESULTS: The ethanolic leaves extract of A. bracteosa (250, 500 and 750 mg/kg/day) demonstrated a dose-dependent chemosuppression during early and in established infections, along with significant (P<0.05) repository activity. At a concentration of 750 mg/kg/day maximum 77.7 per cent chemosuppression during early infection and 68.8 per cent chemosuppression in repository activity were found. This dose enhanced significant mean survival period up to 27.4 +/- 0.46 days in established infection. ELEAB was found to be safe up to 5 g/kg weight when administrated orally in the female BALB/c mice, which is upper limit for oral administration of the test material to rodents. ED(50) of ELEAB was 300 mg/kg body weight of mice. INTERPRETATION & CONCLUSION: ELEAB inhibited parasitaemia and enhanced mean survival time in a dose- dependent manner upto 750 mg/kg/day dose in treated mice. Further studies need to be done to isolate and characterize active constituents of extract and to study their mechanism of action.  (+info)

Dietary effects of four phytoecdysteroids on growth and development of the Indian meal moth, Plodia interpunctella. (7/9)

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Four new iridoid glucosides from Ajuga reptans. (8/9)

Four new iridoid glucosides were isolated from the whole plant of Ajuga reptans L. (Labiatae) along with four known iridoid glucosides, one known diterpenoid glycoside, one known aliphatic alcohol glycoside, and three known ecdysteroids. Their chemical structures were determined on the basis of spectroscopic data and chemical evidence. The diterpenoid glycoside exhibited 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical and H(2)O(2) scavenging activities.  (+info)

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