Picrasma quassioides

Picrasma quassioides (D. Don) Benn. P quassioides (D. Don) Benn. f. dasycarpa Kitag. Ku Shu (stem bark) 2.4- dichloro-6-aminopyridine, 4.5- dimethoxycanthin-6-one, 2.6- dimethoxy-p-benzo-quinone, methyl nigakinone, picrasmin, nigakihemiacetal A, nigakilactone A, nigakinone, quassin.50 Treat fever, stomachache. 

Picrasma quassioides (D. Don) Benn., P quassioides (D. Don) Benn. f. dasycarpa Kitag. 

Nelumbium nelumbo Michelia alba, M. figo Cryptotaenia japonica, C. canadensis Araucaria cunninghamii Allium victorialis Osmanthus fragrans Cinnamomum zeglanicum Zanthoxylum ailanthoides Picrasma quassioides... 

L. ovatum, L. trewianum, L. turbinatum, Lycoperiscon esculentum, Solanum nigrum Picrasma quassioides Picrasma quassioides Picrasma quassioides... 

G. confusum, G. javanum, G. luteo-album, G. multiceps, G. ramigerum, G. tranzschelii, G. uliginosum, Panax quinquefolium, Syzygium aromaticum, Ulmus campestris, U. macrocarpa, U. pumila Jatropha gospiifolia, J. curcas Alstonia scholaris Picrasma quassioides Alstonia scholaris Picrorhiza kurroa Vitex nequndo... 

This ring system is also contained in Serpenticine (294), Schoberidine (295), and Ophiorine (296) (Scheme 93). Picrasidine F (297) was identified as a hydrochloride in Picrasma quassioides and its structure was elucidated by an X-ray structure analysis (86CPB3228). Bleekerine (298) is an additional example. 3. 4. 5. 6 - T e t r a d e h y d r o 1 o n g i c a u d a t i n e (299)was identified in 1998 in Strychnos usambarensis collected from the Ivory Coast. The roots are the main ingredients of African arrow poisons. The absorption maxima were found at Amax = 204, 255, 308, and 367 nm in acidic as well as neutral solutions, thus suggesting a /1-carbolinium chromophore. A bathochromic shift was observed on deprotonation, due to the formation of a zwitterionic species (98P1263). 

Quassin is a bitter-tasting substance that can be extracted from the quassia tree (bitter tree, Picrasma quassioides Benn).156 It is said to be the most bitter substance found in nature. Quassin is used in traditional Chinese medicine. Besides quassin, modified triterpenes, the so-called quassinoid, are the principal component of the bitter taste. 

Picrasidine Q (27) has been isolated from the root wood of Picrasma quassioides (48). The IR spectrum of 27 shows a hydroxyl group, and its UV spectrum shows the typical absorption arising from the canthin-6-one chromophore. Its H-NMR spectrum shows a methoxyl group, a pair of ortho-coupled signals at H-1 and H-2, and signals of four continuous aromatic protons at H-8 through H-11. It is understood, therefore, that the hydroxyl and methoxyl substituents are located at positions 4 and 5, respectively. Methylated 27 is identical with 8 but is not identical with authentic 28. On the basis of these facts, structure 27 was determined. 

UV spectra of canthin-5,6-dione alkaloids 3 and 33, which were isolated by Ohmoto and Koike (3,48) from Picrasma quassioides, showed a characteristic absorption between 400 and 500 nm. This absorption was hypochromically shifted under acidic conditions. The UV spectrum of 3 in acidic solvents resembles that of 5-hydroxycanthin-6-one (16) (Fig. 3). This fact, that is, that 3 undergoes chemical shift in acidic solvents, indicates that the carbonyl at position 5 of the canthin-5,6-dione skeleton in 16 is protonated, producing 42a. On the basis of the above observations, Ohmoto and Koike refluxed 16 and 33 with dimethyl sulfate in acetone and synthesized 3 and 28 (Scheme 3). 

Quassinoids.—Simarolide (136) had previously been the only substance providing a structural link between limonoids and quassinoids. The related picrasin A (137) has now been isolated from Picrasma quassioides P. ailan-thoides). It was accompanied in the extract by picrasin B (138) which was converted to quassin (139) by bismuth oxide oxidation and methylation. A series of closely related quassin derivatives, nigakilactones A (140), B (141), C (142), E (143), and F (144) occur with quassin in P. ailanthoides. - The structure of amarolide has been revised to (145). Observation of a large coupling between H-9 and H-11 in the n.m.r. spectrum makes the previous... 

Until 1985, only six quassinoids possessing the C25 basic skeleton were known simarolide (209) from the bark of Simarouba amara, picrasin A (210) isolated from Picrasma quassioides, soulameolide (211) from Soulamea tomentosa, simarinolide (212) and guanepolide (213) from the root bark of the Simaba cf. orinocencis, and deacetylsimarolide (214) isolated from the fruits of Simaba moretii [1]. 

A group of carboline alkaloids, e.g., P-carboline-1-propanoic acid (a) (C,4H,2N202, Mr 240.26 needles, mp. 215 °C) from the wood of Picrasma quassioides (Simaroubaceae) and its methyl ester I. (b) (C 5H,4N202, Mr 254.29, cryst., mp. 145-146°C), from the fruit bodies of the agaric Cortinarius infrac-... 

Chen J, YanXH, Dong JH, Sang P, fang X,DiYT,etaL Tobacco mosaic virus (TMV) inhibitors from Picrasma Quassioides B m. JAgric Food Chem 2009 57(15) 6590-5. 

Atlantis dC18 (100 mm X 4.6 mm, 5 pm) Methanol-water (40 60) 255 nm, LC/MS Quassia excels, Picrasma quassioides Quassin, two isomers of neoquassin [96]... 

Yang S-P, Yue J-M (2004) Five new quassinoids from the bark of Picrasma quassioides. Helv Chim Acta 87 1591-1600... 

Scragg AH, Allan EJ (1986) Production of the triterpenoid quassin in callus and cell suspension cultures of Picrasma quassioides Bennett. Plant Cell Rep 5 356-359... 

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