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The methanolic extract of the seeds of Arctium lappa was found to show inhibitory activity against prostate cancer cell lines. Bioactivity-guided fractionation of a 95% ethanol extract from the seeds of A. lappa led to the isolation of seven compounds: β-sitosterol (1), daucosterol (2), lappaol C (3), lappaol A (4), and arctignan E (5), lappaol F (6), and arctiin (7). Their structures were elucidated by UV, IR, MS, and NMR data, as well as by comparison with those of the literature. Compounds 3–7 were studied for their cytotoxicity using a prostate cancer cell line. Compounds 3, 4, and 6 showed activity against the LNCaP prostate cancer cell line with IC50 values of 8, 16, and 40 µg/mL, respectively.

The alcohol extract or Rhodiola rosea has been shown to cause 42 ± 3.2% inhibition of acetylcholine esterase (AChE) when tested at 10 g/L. This AChE inhibition provides a physiological explanation for the reported mental and memory enhancing properties of Rhodiola rosea extracts. Active guided fractionation indicated a multitude of components which are responsible for this plants AChE inhibition. Two flavonoid glycosides (gossypetin-7-O-L-rhamnopyranoside and rhodioflavonoside) were isolated and shown to cause 58 ± 15% and 38 ± 4% AChE inhibition respectively when tested at 5 g/L. In view of this new enzymatic activity and previous clinical work indicating memory and mental enhancing properties with no indication of toxicity, this plant needs to be researched for its potential at treating memory impairing disorders such as Alzheimer’s disease.

One hundred methanol plant extracts were screened for antibiotic activity against Mycobacterium tuberculosis and Mycobacterium avium. Nineteen extracts exhibited some activity against M. tuberculosis and 16 extracts showed some activity against M. avium. Thirteen of these 19 active extracts were traditionally used by First Nations peoples to treat tuberculosis. Extracts made from Heracleum maximum (Umbelliferae) roots, Moneses uniflora (Ericaceae), aerial parts, and Oplopanax horridus (Araliaceae) inner bark completely inhibited the growth of both organisms at a concentration equivalent to 20 mg dried plant material/disc. Extracts of Alnus rubra (Betulaceae) bark and catkins, Empetrum nigrum (Empetraceae) branches, Glehnia littoralis (Umbelliferae) roots, and Lomatium dissectum (Umbelliferae) roots completely inhibited the growth of both M. tuberculosis and M. avium at a concentration equivalent to 100 mg dried plant material/disc.

The discovery of porphyric insecticides was a direct fallout of the discovery and development of photodynamic herbicides. Tetrapyrrole-dependent photodynamic herbicides are compounds that force green plants to accumulate undesirable amounts of metabolic intermediates of the chlorophyll and heme metabolic pathways, namely, tetrapyrroles. In light, the accumulated tetrapyrroles photosensitize the formation of singlet oxygen that kills treated plants by oxidation of their cellular membranes. Demonstration of the potential for tetrapyrrole accumulation in insects was achieved by spraying T. ni larvae with δ-aminolevulinic acid (ALA) and 2,2-dipyridyl (Dpy). Treated larvae were placed overnight in darkness at 28°C in order to allow for tetrapyrrole accumulation. Extraction of treated, dark-incubated larvae with ammoniacal acetone, followed by spectrofluorometric examination of the larval extract, revealed the accumulation of massive amounts of protoporphyrin IX (Proto). A high degree of correlation wa...

The methanol extract of the bark of Alnus rubra showed antimicrobial activity against Gram-positive and Gram-negative bacteria. Diarylheptanoid and its glycoside (oregonin) were identified as the two constituents responsible for this activity.

Phytoplankton catabolism of L-phenylalanine and L-tyrosine was investigated with axenic cultures of the marine haptophyte Isochrysis galbana and the marine diatom Navicula incerta. Metabolic conversion and 14C-tracer studies indicated that phenylalanine is catabolized through pbenylpyruvate, phenylacetate, mandelate, benzoylformate and benzoate to p-hydroxybenzoate and its m-bromo derivative as major end-products, with marginal formation of CO2 from aromatic-ring degradation. Tyrosine is similarly metabolized through the corresponding p-hydroxylated derivatives to p-hydroxybenzoate. The side chains of these amino acids are degraded stepwise and each C1-fragment was identified as CO2. Cinnamate or p-coumarate were not detected as intermediates, nor could the ammonia-lyases for phenylalanine and tyrosine be demonstrated. However, externally supplied cinnamic acids were metabolized via hydracrylate intermediates to the corresponding benzoic acids. It was concluded that the phytoplankters catabolize ...

Ozonolysis of an A.B-ring functionalized derivative of phytosterols found in the deodorizer distillate of canola oil gave the desired aldehyde 5, Canola oil thus provides a readily available and inexpensive source of a key intermediate 5 which is frequently employed in steroidal syntheses.