Taxus Wallichiana Zucc Research Articles

Absolute configuration of (2S)-4-(4-hydroxyphenyl)butan-2-ol

The title compound, C10H14O2, was isolated from the chloro­form extract of Taxus wallichiana Zucc. In the crystal, mol­ecules are linked by inter­molecular O—H⋯O hydrogen bonds, forming sheets parallel to (100). There are weak inter­molecular C—H⋯π inter­actions between the sheets.

4-Deacetylbaccatin III: A Proposed Biosynthetic Precursor of Paclitaxel from the Bark of Taxus Wallichiana

4-Deacetylbaccatin III was isolated and characterized from the bark of Taxus wallichiana Zucc. It was previously identified as an intermediate during the synthesis of paclitaxel and was proposed as a precursor for the biosynthesis of paclitaxel. Existence of 4-deacetylbaccatin III in T. wallichiana is strong evidence for the previously proposed biosynthetic pathway of paclitaxel via 4-deacetylbaccatin III.

Molecular simulations of Taxawallin I inside classical taxol binding site of β-tubulin

A new taxoid Taxawallin I (1) along with two known taxoids (2–3) were isolated from methanolic bark extract of Taxus wallichiana Zucc. Structural characterization was confirmed by mass and NMR spectral techniques. Taxawallin I exhibited significant in-vitro anticancer activity against HepG2, A498, NCI-H226 and MDR 2780AD cancer lines. Tubulin binding assay was performed to assess its tubulin binding activity. Molecular docking analysis was performed to study the potential binding mode inside the taxol binding site of β-tubulin.

USING BIOTEST TO ESTIMATE TAXOL PRODUCTION FROM CELL SUSPENSION CULTURE OF TAXUS WALLICHIANA ZUCC. IN DIFFERENT CONDITIONS OF CULTURE

Calli and cell suspension cultures were initiated from Lam Dong Yew (Taxus wallichiana Zucc.) young stem explants, on B5 medium supplemented with 2,4-D and kinetin at appropriate concentrations. Taxol content was estimated by using a root primordium biotest with hypocotyl cuttings of Phaseolus aureus Roxb. (green bean). Results showed that taxol production was influenced by different conditions of culture, such as culture time, temperature, medium osmotic pressure or methyl jasmonate... The growth of calli were inhibited if they were lighted or maintained for a long time on medium culture but taxol synthesis was stimulated. Phenylalanine (as organic precusor), methyl jasmonate (as biotic elicitor) as well as a high osmotic pressure induced taxol accumulation.

THE STUDY ON CHEMICAL CONSTITUENTS FROM THE NEEDLES OF TAXUS WALLICHIANA ZUCC. (TAXACEAE)

A new taxane-type diterpene named 10-deacetyltaxuspine F (2) together with a known compound, taxuspine F (1), were isolated from the needles of Taxus wallichiana Zucc. (Taxaceae). Their chemical structures were elucidated by using spectroscopic methods and comparision with published data.

Variation in rooting behavior of stem cuttings in relation to their origin in Taxus wallichiana Zucc.

The present study investigates optimal conditions for the vegetative propagation of Himalayan yew Taxus wallichiana Zucc., an important medicinal tree, during spring. Effect of four treatments: (a) sex of donor plant (male and female), (b) age/type of shoot (1, 2, 3 year old, long and dwarf shoots), (c) auxin treatment (IBA and NAA at 0, 0.5, 1.25, 5.0 & 50.0 mM) and (d) rooting environment (raised beds/polythene bags) on percentage rooting in stem cuttings was studied. Randomized complete block (RBD) designs were used for experimentation. Rooting ability of cuttings was significantly influenced by all these treatments. The overall rooting response was higher in long shoot cuttings taken from female tree. Age of shoot also influenced the rooting response and was highest in 1 year old long shoot cuttings of female tree. Exogenous application of auxin, α-naphthalene acetic acid (NAA) and indole-3 butyric acid (IBA), had significant positive effect on the percentage rooting. IBA significantly enhanced the rooting percentage in 1 year old long and dwarf shoots at lower doses and 2 and 3 year old long shoots from female tree at higher doses. Maximum percent rooting (90% ± 2.8) was obtained with interactive effect of 0.5 mM, NAA (22 h) × 1 year old long shoot from female tree; followed by the interactive effect of 50 mM IBA (5 s) × 3 year old long shoot from female tree (83% ± 4.1). Cuttings planted in soil: sand medium in polythene bags showed earlier rooting response (12 weeks) than cuttings planted in raised nursery beds (24 weeks). Overall, the findings of this study suggest that 0.5 mM IBA treatment is suitable for enhancing adventitious rooting in 1 year old long and dwarf shoots of male and female trees. IBA at higher doses is suitable for enhancing the rooting percentage of 2 and 3 year old long shoots from female tree. This study provides a significant lead towards the development of a simple and inexpensive technique for large scale propagation, aforestation of elite genotypes and raising of bush type plantation under ex-situ conditions.

Anticonvulsant, analgesic and antipyretic activities of Taxus wallichiana Zucc.

Taxus wallichiana Zucc. (Himalayan Yew) is often used in northern areas of Pakistan for the treatment of pyrexia, acute pains and epilepsy. We have investigated certain pharmacological activities of the methanol leaf extract against convulsion, nociception and pyrexia induced in rodents. The aim was to justify and explore its folk uses in these pathological conditions, on scientific basis. The studies were carried out using acetic acid-induced nociception and pentylenetetrazole-induced convulsions in mice, while formalin test and yeast-induced pyrexia in rats. Significant analgesic (67.77 and 74.29%) effect was found in acetic acid-induced model at doses of 100 and 200 mg/kg, i.p. respectively. Crude extract exhibited significant ( P < 0.05) inhibition of the formalin noxious stimulation on both early and late phases of pain by the extracts (100 and 200 mg/kg doses). In case of yeast-induced pyrexia model, 200 mg/kg dose showed very significant ( P < 0.01) inhibition while 50 and 100 mg/kg dose caused a significant ( P < 0.05) inhibition. Plant extract has controlled the pentylenetetrazole-induced convulsions in mice. 100 and 200 mg/kg i.p doses of the extract significantly ( P < 0.05) inhibited the mioclonus and clonus while inhibition of tonus and hind limb tonic extension (HLTE) was highly significant ( P < 0.01). The anticonvulsant activity of this plant has been reported for the first time throughout the whole genus. The observed pharmacological activities provide the scientific basis for the folkloric use of the plant in treating epilepsy, pyrexia and acute pain.

Antifungal and antibacterial activities of Taxus wallichiana Zucc

Current study was undertaken to evaluate the in vitro antifungal and antibacterial potential of methanol extract and subsequent fractions obtained after partitioning in organic solvents with variable polarity of the aerial parts of the tree Taxus wallichiana Zucc. Traditionally, this plant is often used in folk medicines in Pakistan for treating microbial infections. In order to rationalize the traditional use, methanol extracts of leaf, bark, and heartwood of Taxus wallichiana Zucc. were tested against six bacteria and six fungal strains using the Hole diffusion and macro-dilution methods. All extracts and fractions displayed significant antimicrobial effect. Only three fungal strains, Trichophyton longifusus, Microspoum canis, and Fusarium solani were susceptible to the extracts and fractions with MICs ranging from 0.08 to 200 mg/mL. In case of bacterial strains, Staphylococcus aureus, Pseudomonas aeruginosa and Salmonella typhi were susceptible to the extracts and fractions with MICs ranging from 0.08 to 200 mg/mL. Comparison results were carried out using imipinem, miconazole and amphotericin B as standard antibiotics.

Taxines from the needles of Taxus wallichiana

A taxine, 5αO-(3′-dimethylamino-3′-phenylpropionyl) taxinine M (1) together with two known compounds 7-O-acetyltaxine A (2) and 2α-acetoxy-2′β-deacetylaustrospicatine (3) were isolated from the needles of the Himalayan yew, Taxus wallichiana Zucc. Their structures were elucidated on the basis of the NMR spectral data, ESI–MS/MS analysis and chemical methods. Compounds 1 and 3 showed moderate cytotoxic activity against the lung cancer cell line A549 in vitro.

1-Hydroxybaccatin I, C32H44O14, and 2-Deacetoxydecinnamoyltaxinine J, C28H40O9

The title compounds are diterpenoids isolated from the Himalayan yew (Taxus wallichiana Zucc.). The crystal structures allow us to rationalize some peculiar features of the NMR data of the taxane 4(20)-epoxides. Conformational differences between epoxide, olefin-type and oxetane-type compounds like paclitaxel are summarized.

New oxetane-type taxanes from Taxus wallichiana Zucc.

The needles of Taxus wallichiana Zucc. gave the novel oxetane-type taxane diterpenoids 2 and 5, whose structures have been established on the basis of spectroscopic data and chemical reactions. The acidcatalysed rearrangement of 10-deacetylbaccatin III has been investigated.

14β-Hydroxy-10-deacetylbaccatin III, a new taxane from Himalayan yew (Taxus wallichiana Zucc.)

The needles of T. wallichiana Zucc. gave a new taxane, whose structure was established as 14β-hydroxy-10-deacetylbaccatin III on the basis of chemical reactions, spectroscopic data and X-ray analysis.

Selection of solvent and extraction method for determination of antimicrobial potential of Taxus wallichiana Zucc.

Antimicrobial potential of different plant parts (needle, stem and bark) of Himalayan yew (Taxus wallichiana Zucc.) has been investigated with particular reference to selection of solvents and extraction methods. Two extraction methods (maceration and soxhlet), seven solvents (methanol, ethanol, acetone, chloroform, ethyl acetate, di chloro methane and Petroleum ether), and 3 groups of microorganisms (bacteria, actinobacteria and fungi) were considered for detection of antimicrobial activity. While qualitative estimations were done using agar well diffusion method, quantitative analysis was based on dilution method. All the plant part showed significant activity against all 3 groups of microorganisms in qualitative bioassays; maximum being in case of needles. Among solvents, ethanolic extract of needles (maceration) showed highest antibacterial activity (15.33 ± 0.25 mm). Growth of actinobacteria was inhibited maximum (22.0±0.26 mm) by the methanolic extracts of needles (maceration). Ethyl acetate extract of needles (soxhlet) showed higher antifungal activity (7.84±0.21 mm). Antibacterial and antifungal activities were higher in maceration and soxhlet methods, respectively. The most affected group among the test microorganisms was bacteria which may be due to their prokaryotic organization. This was also supported by the low minimum inhibitory concentration (MIC) values. Di chloro methane and petroleum ether did not show any antifungal activity. The antimicrobial activity of various plant parts of T. wallichiana varied with respect to the solvent as well as the extraction method. The study will have implications in selection of the use of solvent and the extraction procedure in obtaining the antimicrobial metabolites from various plant parts of T. wallichiana.