Hasubanan Type Alkaloids from <i>Stephania </i><i>l</i><i>onga</i>

Thirteen new hasubanan type alkaloids, stephalonines A−I (1−9), norprostephabyssine (15), isoprostephabyssine (16), isolonganone (18), and isostephaboline (21), as well as nine known ones, were isolated from the whole plants of Stephania longa, a well-known traditional Chinese medicine. Their structures were elucidated on the basis of spectroscopic data and chemical methods

Two Novel Alkaloids with a Unique Fused Hexacyclic Skeleton from <i>Daphniphyllum </i><i>s</i><i>ubverticillatum</i>

Two novel major alkaloids, deoxycalyciphylline B (1) and deoxyisocalyciphylline B (2) with a unique fused hexacyclic skeleton, together with a quite recently reported alkaloid calyciphylline B (3), were isolated from the stem of Daphniphyllum subverticillatum. Their structures were established by spectral methods and chemical evidence, especially 2D NMR techniques. The structure of 1 was further confirmed by a single-crystal X-ray diffraction determination

First Diamino <i>Daphniphyllum</i> Alkaloid, Daphnipaxinin, with an Unprecedented Heterohexacyclic Skeleton from <i>Daphniphyllum </i><i>p</i><i>axianum</i>

The first diamino Daphniphyllum alkaloid, daphnipaxinin (1), with an unprecedented hexacyclic fused skeleton, along with a known alkaloid, daphnicyclidin A (2), was isolated from the stem of Daphniphyllum paxianum Rosenth. The structure and absolute stereochemistry of 1 were established by spectral methods, especially two-dimensional NMR techniques and CD analysis

Alkaloids from the Twigs of <i>Daphniphyllum calycinum</i>

Twelve new alkaloids, caldaphnidines G−R (1−12), along with 24 known ones, were isolated from the twigs of Daphniphyllum calycinum. Their structures were elucidated by spectroscopic methods, especially two-dimensional NMR techniques

Paxdaphnidines A and B, Novel Penta- and Tetracyclic Alkaloids from <i>Daphniphyllum </i><i>p</i><i>axianum</i>

Two novel alkaloids, paxdaphnidine A (1) with a unique pentacyclic skeleton and paxdaphnidine B (2) with an uncommon tetracyclic skeleton, were isolated from the stems and leaves of Daphniphyllum paxianum. Their structures were established by spectral methods, especially two-dimensional NMR techniques (1H−1H COSY, HSQC, HMBC, and NOESY)

Tetranortriterpenoids from <i>Cipadessa baccifera</i>

Five new mexicanolide-type tetranortriterpenoids, tigloylseneganolide A (1), 2‘R-methylbutanoylproceranolide (2), 2‘S-methylbutanoylproceranolide (3), 2‘R-cipadesin A (4), and 2‘R-cipadesin (6), as well as the known 2‘S-epimers of 4 and 6 (5 and 7), together with six other known limonoids, were isolated from the seeds of Cipadessa baccifera. The structures of these compounds were elucidated on the basis of spectroscopic analyses and chemical methods. 1H NMR-based conformational analysis was applied to establish the absolute configuration of the sterically hindered 2-methylbutanoyl in three epimeric pairs (2−7). A general rule for the determination of the absolute configurations of 2R- and 2S-methylbutanoyl groups at C-3 of a limonoid in a mixture is proposed

Novel Diterpenoids and Diterpenoid Glycosides from <i>Siegesbeckia </i><i>o</i><i>rientalis</i>

Eight new ent-pimarane diterpenoids and diterpenoid glycosides, namely, ent-12α,16-epoxy-2β,15α,19-trihydroxypimar-8-ene (1), ent-12α,16-epoxy-2β,15α,19-trihydroxypimar-8(14)-ene (2), ent-2α,15,16,19-tetrahydroxypimar-8(14)-ene (3), ent-15-oxo-2β,16,19-trihydroxypimar-8(14)-ene (4), ent-2-oxo-15,16-dihydroxypimar-8(14)-en-16-O-β-glucopyranoside (5), ent-2-oxo-15,16,19-trihydroxypimar-8(14)-ene (6), ent-2-oxo-3β,15,16-trihydroxypimar-8(14)-en-3-O-β-glucopyranoside (7), and ent-2β,15,16,19-tetrahydroxypimar-8(14)-en-19-O-β-glucopyranoside (9), together with seven known diterpenes (8, 10−15) were isolated from Siegesbeckia orientalis. Compounds 1 and 2 are novel ent-pimarane diterpenoids with an unprecedented 12α,16-epoxy group. Their structures were established by spectral methods, especially 1D and 2D NMR spectral methods

Terpenoid Indole Alkaloids from <i>Winchia </i><i>c</i><i>alophylla</i>

Three new indole alkaloids, N(4)-demethyl-12-methoxyalstogustine (1), 17-carboxyl-N(4)-methylechitamidine chloride (2), and 17-carboxyl-12-methoxy-N(4)-methylechitamidine chloride (3), along with 15 known alkaloids, were isolated from the ethanolic extract of the stem bark of Winchia calophylla. The structures of 1−3 were elucidated on the basis of spectroscopic means and chemical methods. The determination of relative configurations at C-19 and C-20 for 1−3 was aided by 13C NMR spectroscopic data. The absolute configurations of alkaloids 1−3 were determined by direct comparison of their CD spectra with those of known alkaloids. All the alkaloids were tested in cytotoxic assays against P-388 and A-549 tumor cell lines, and only two of them showed weak activity against the A-549 cell line

Limonoids and Triterpenoids from <i>Khaya senegalensis</i>

Seven new limonoids (1−7), named khayalenoids C−I, three new triterpenoids (8−10), named senegalenes A−C, and eight known limonoids have been isolated from stems of Khaya senegalensis. The structures of these compounds were elucidated on the basis of spectroscopic analyses

Daphniyunnines A−E, Alkaloids from <i>Daphniphyllum yunnanense</i>

The first chemical study on the stems and leaves of Daphniphyllum yunnanense led to the isolation of five new alkaloids, daphniyunnines A−E (1−5). Daphniyunnines B−E (2−5) are four unusual C-22 nor-Daphniphyllum alkaloids. The structures of these alkaloids were characterized by spectroscopic methods, especially 2D NMR techniques. A single-crystal X-ray diffraction analysis was used to confirm the structure of 1. Daphniyunnine D (4) showed cytotoxicity against two tumor cell lines, P-388 and A-549, with IC50 values of 3.0 and 0.6 μM, respectively