Neocaryachine, a New Pavine Alkaloid from Cryptocarya chinensis, and NMR Spectral Properties of Related Alkaloids

Abstract

Cryptocarya chinensis. Its structure was established by spectral analysis including nOe and 2D nmr techniques. 13C-nmr assignments of the related pavine alkaloids (-)-caryachine [2], (-)eschscholtzine [3], (+)-eschscholtzidine [4], and their corresponding N-metho iodides 6 and 7 were also made by using 1 and (-)-caryachine N-metho perchlorate [5] as model compounds.Cryptocarya chinensis Hemsl. (Lauraceae) is a perennial plant widely distributed in forests on lowlands of altitude 500-1000 m in Taiwan and in southeastern China (1). Past studies on the alkaloidal constituents of this species have revealed that it is a good source for pavine alkaloids (2-4). So far, three tertiary pavine alkaloids, namely (-)caryachine [2}, (-)-eschscholtzine [3], and (+ )-eschscholtzidine [4], and a quaternary pavine, (-)-caryachine N-metho perchlorate [5], have been isolated from this species.Here we report the isolation and characterization of an additional new pavine alkaloid, neocaryachine [1], from the stem bark of this plant.

(−)-Neocaryachine, an Antiproliferative Pavine Alkaloid from Cryptocarya laevigata, Induces DNA Double-Strand Breaks

“…The crude extract of N025183 (9.8 g), provided by the NCI, was partitioned between EtOAc and water. The EtOAc extract was separated by silica gel column chromatography and preparative TLC techniques to give six known pavine alkaloids, (−)-neocaryachine ( 1 ), (−)-isocaryachine ( 2 ), (−)-crychine ( 3 ), (−)-eschscholtzine- N -oxide ( 4 ), , (−)-norargemonine ( 5 ), , and (−)-bisnorargemonine ( 6 ), , as well as a phenanthroindolizidine alkaloid and (−)-13aα-antofine together with their biosynthetic intermediates, (+)- N -demethylphyllocaryptine, (+)-cinnamolaurine, − (+)- N -methylcoculaurine, and (−)-reticuline. , The structures of all isolated compounds were identified based on various NMR spectroscopic and HRMS data analyses, and their spectroscopic data agreed with published values. We evaluated five ( 1 – 5 ) of the six pavine alkaloids isolated from C. laevigata for antiproliferative activity against five human tumor cell lines, A549 (lung carcinoma), MDA-MB-231 (triple-negative breast cancer), MCF-7 (breast cancer), KB (originally isolated from epidermoid carcinoma of the nasopharynx), and vincristine-resistant KB-subline KB-VIN showing multidrug resistance (MDR) phenotype with overexpression of P-glycoprotein (P-gp) (Table ).…”

“…The EtOAc extract was separated by silica gel column chromatography and preparative TLC techniques to give six known pavine alkaloids, (−)-neocaryachine ( 1 ), 28 (−)-isocaryachine ( 2 ), 29 (−)-crychine ( 3 ), 30 (−)-eschscholtzine- N -oxide ( 4 ), 31,32 (−)-norargemonine ( 5 ), 33,34 and (−)-bisnorargemonine ( 6 ), 33,35 as well as a phenanthroindolizidine alkaloid and (−)-13aα-antofine 36 together with their biosynthetic intermediates, (+)- N -demethylphyllocaryptine, 37 (+)-cinnamolaurine, 38−40 (+)- N -methylcoculaurine, 41 and (−)-reticuline. 39,40 The structures of all isolated compounds were identified based on various NMR spectroscopic and HRMS data analyses, and their spectroscopic data agreed with published values.…”

Spiro[3.5]nonenyl Meroterpenoid Lactones, Cryptolaevilactones G–L, an Ionone Derivative, and Total Synthesis of Cryptolaevilactone M from Cryptocarya laevigata

“…Although the biosynthetic pathway is not clear, their spiro[3.5]­nonene moiety is probably biosynthesized through hetero [2 + 2] cycloaddition of a monoterpene, β-phellandrene, and a polyketide δ-lactone containing a double bond. Our continuing research has now furnished six new spiro[3.5]­nonenyl meroterpenoid lactones ( 1 – 6 ), a new linear lactone ( 7 ), and an ionone derivative ( 8 ) with a 3,4- syn -diol functionality (Figure ), together with eight known compounds, caryophyllene oxide, (−)-boscialin, (−)-13aα-antofine, (−)-crychine, N - trans -feruloyl 3′- O -methyldopamine, epicatechin, quercitrin, and lutein. , …”

Quaternary Alkaloids from Litsea cubeba and Cryptocarya konishii

“…were assigned by correlation with a model compound, juziphine [6], which is the corresponding tertiary base of 3 (9), and with the quaternary effect on 13C nmr deduced from pavine alkaloids (10). These assigned data are listed in Table 1.…”