Alkaloidal Constituents of the Leaves of Stephania cepharantha Cultivated in Japan: Structure of Cephasugine, a New Morphinane Alkaloid.

Identification of structurally diverse alkaloids in Talguenea quinquinervia (gill. Et hook) by liquid chromatography/electrospray ionisation tandem mass spectroscopy and insecticidal activity

“…The split of the [M + H] + ion led to the base peak fragment ion at m/z 107.0492, 30 Da lower than of compound 5 , thus indicating the presence of only one hydroxyl group on ring C. If the OH group was at C‐11, compound 8 could be identified as norcanelilline . However, if the OH group was at C‐12, compound 8 would be coclaurine or norjuziphine . According to data in the literature, benzylisoquinoline alkaloids without an oxygen functional group at C‐11 show benzyl fragments as the most intense fragment ions, which is due to their lesser ability to stabilise the benzyl leaving group .…”

New Alkaloids and Cytotoxic Principles from Sinomenium acutum

“…The IR spectrum of 2 showed absorption bands for hydroxyl (3280 cm −1 ), ester carbonyl (1742 cm −1 ), conjugated carbonyl (1686 cm −1 ), and aryl (1602, 1571 cm −1 ) groups. The 1 H NMR spectrum of 2 revealed one N-methyl (δ H 2.95), one methoxy (δ H 3.84), five aromatic protons [δ H 6.86 (2H, s), δ H 6.92/6.70 (each 1H, d, J = 9.5 Hz), δ H 6.03 (1H, s)], and two sets of methylene protons (δ H 2.11/2.29, δ H 2.82/3.31), which resembled the signals of sinoracutine (5) [12]. In addition, an oxygenated ethyl group (at δ H 3.72/4.01, δ H 0.68) accompanied by the carbonyl signal at δ C 178.6 indicated an ethyl carboxylate group was present.…”

“…All the 1 H, 13 C NMR data of 3 are consistent with the values reported in the literature [29], except the signal of C-13 (s, δ C 41.2). Oxypalmatine (11) and 8-oxyberberine (12) belong to protoberberine-type alkaloids. The 1 H NMR spectra of 11 and 12 were similar, except for the methoxyl and dioxylmethylene groups.…”

“…[12], 8-demethoxyrunanine (7)[6], 8-demethoxycephatonene (8) [12], acutumine (9) [2], acutumidine (10) [2], (−)-8-oxoisocorypalmine (13) [13], (−)-stepholidine (14) [3], (−)-chelanthifoline (15) [14], dauriporphine (16) [15], 6-O-demethylmenisporphine (17)…”

Foodinformatics

“…In this regard, a number of authors have addressed the issue of how to estimate the diversity of a large collection of compounds [190][191][192]. Willett [193,194] and Agrafiotis [191] have presented descriptions of many aspects of diversity-related methods and procedures. An interesting discussion of the early history of the concept of molecular diversity was published in 2001 [195].…”