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Two new monoterpenoid indole alkaloids, (2 R, 7 R, 16 R, 20 R, 21S)-12-hydroxypleiocarpine (1) and (2S, 7 R, 16S, 20 R, 21S)-N-methoxycarbonyl-11,12-methylenedioxy-Δ14,15-kopsinaline (2), along wit...

A phytochemical investigation on the 90% ethanol aqueous extract of the aerial part of Kopsia arborea led to the isolation of three new monoterpenoid indole alkaloids, kopsiarborines A–C (1–3). The...

The tryptamine-derived polycyclic bridged bioactive indole alkaloids subincanadines A-G were isolated in 2002 by Ohsaki and coworkers from the bark of the Brazilian medicinal plant Aspidosperma subincanum. Kobayashi proposed that subincanadines D-F could be biosynthetically resulting from stemmadenine via two different pathways and, furthermore, that the subincanadines A-C could be biogenetically resulting from subincanadines D and E. Kam and coworkers, in their focused efforts, isolated five indole alkaloids from Malaysian Kopsia arborea species, namely valparicine, apparicine, arboridinine, arborisidine, and arbornamine in combination with subincanadine E. On the basis of structural features, it has been proposed and proved in some examples that subincanadine E is a biogenetic precursor of these five different bioactive indole alkaloids bearing complex structural architectures. All important information on isolation, characterization, bioactivity, probable biogenetic pathways, and more specifically racemic and enantioselective total synthesis of subincanadine alkaloids and their biogenetic congeners are summarized in the present chapter. Special importance is given to the total synthesis and the synthetic strategies intended therein, comprising a set of main reactions.

The first asymmetric total synthesis of andranginine (1) via an asymmetric Morita-Baylis-Hillman reaction and a diastereoselective intramolecular Diels-Alder reaction has revealed that natural andranginine (1) isolated from Kopsia arborea existed as a scalemic mixture and contained predominantly the (16R,21S) form rather than the (16S,21R) form.

Three new bisindole alkaloids, arbolodinines A−C, comprising aspidofractinine-aspidofractinine, aspidofractinine-strychnan, and kopsine-strychnan alkaloids, respectively, were isolated from the stem bark extract of the Malayan Kopsia arborea. The structures of the alkaloids were elucidated based on analysis of the spectroscopic data while the absolute configurations were established based on experimental and calculated ECD data. Arbolodinine A is characterized by the union of two aspidofractinine halves with rare and unusual branching from C-5′ of an iminium/carboxylate zwitterion of one aspidofractinine half to the olefinic C-14 of the other aspidofractinine half, while arbolodinines B and C represent first examples of aspidofractinine-strychnan and kopsine-strychnan bisindoles, respectively. Arbolodinine B displayed pronounced cytotoxic effects against an array of human cancer cell lines, including KB, vincristine-resistant KB, PC-3, HCT 116, HT-29, MDA-MB-231, MCF7 and A549 cells with IC50 values ranging from 1.3 to 9.6 μM.

Two new indole alkaloids having unusual skeletons were isolated from Yunnan Kopsia arborea. Kopsiyunnanine L has a novel 2,3,4,5-tetrahydro-1H-benzazepine skeleton rearranged from a Strychnos-type monoterpenoid indole alkaloid. Kopsiyunnanine M is a new type of bisindole alkaloid consisting of two Strychnos-type alkaloids.

A new monoterpenoid indole alkaloid, kopsiyunnanine K, was isolated from Kopsia arborea. Its intriguing rearranged structure and absolute configuration, which were inferred from spectral data and a possible biosynthetic pathway, were determined on the basis of a 13-step asymmetric total synthesis.

Two new monoterpene indole alkaloids, characterized by previously unencountered natural product skeletons, viz., arborisidine (1), incorporating indolizidine and cyclohexanone moieties fused to an indole unit, and arbornamine (2), incorporating an unprecedented 6/5/6/5/6 "arbornane" skeleton (distinct from the eburnan or tacaman skeleton), were isolated from a Malayan Kopsia arborea. The structures of the alkaloids were determined based on analysis of the NMR and MS data. Possible biogenetic pathways to these alkaloids from a common pericine precursor (3) are presented.

The plant always associates with microbes for its life, includes the endophytes. Aim of this study is to examine the effect of endophytic fungi on Kopsia (Kopsia arborea) seed germination and seedling growth. Here, we used endophytic fungus from forest pathology laboratory, namely Phomopsis sp1, Phomopsis sp2, and Helminthosporium sp. All endophytic fungi were combined with liquid fertilizer to assess Kopsia seedling growth. The results showed that the Kopsia seed germinations, which treated with endophytic fungi have a higher value than the control. The endophytic fungi Phomopsis sp1 and Helminthosporium sp could increase the number of leaves without adding liquid fertilizer, while the Phomopsis sp2 needed liquid fertilizer for it. The NPA and the IMB values of the Kopsia seedlings are 0.71-1.71, and 0.18-0.33 strongly indicates the readiness of Kopsia seedlings to plant in the field, respectively.

Two new monoterpene indole alkaloids, characterized by previously unencountered natural product skeletons, viz., arborisidine (1), incorporating indolizidine and cyclohexanone moieties fused to an indole unit, and arbornamine (2), incorporating an unprecedented 6/5/6/5/6 “arbornane” skeleton (distinct from the eburnan or tacaman skeleton), were isolated from a Malayan Kopsia arborea. The structures of the alkaloids were determined based on analysis of the NMR and MS data. Possible biogenetic pathways to these alkaloids from a common pericine precursor (3) are presented.

A new pyridone-containing Strychnos alkaloid named kopsiyunnanine-I was found in the aerial part of Yunnan Kopsia arborea Blume. The structure of the new alkaloid was elucidated by chemical conversion from strychnine.

Two novel indole alkaloids having unusual skeletons were isolated from the aerial part of Yunnan Kopsia arborea. Kopsiyunnanine A (1) is a new class of bisindole alkaloid composed of vallesiachotamine (modified Corynanthe-type) and Aspidospermatan-type alkaloids. Kopsiyunnanine B (2) is a new Corynanthe-type oxindole alkaloid rearranged by D ring rotation.

Two new indole alkaloids, 12-methoxykopsine (6) and danuphylline B (7), were obtained from the leaf extract of the Malayan Kopsia species, K. arborea, and their structures established by spectroscopic analysis. An electrochemically-mediated partial synthesis of the ring-opened alkaloid, danuphylline B from the hexacyclic alkaloid, methyl N(1)-de(methoxycarbonyl)chanofruticosinate was carried out.

Six alkaloids belonging to the methyl chanofruticosinate group, viz., prunifolines A-F, in addition to six other known methyl chanofruticosinate alkaloids, were isolated from the leaf extract of Kopsia arborea. The structures were determined using NMR and MS analysis and comparison with known related compounds.

Nine new indole alkaloids, rhazinoline (1), 19(S)-methoxytubotaiwine (2), 19(R)-methoxytubotaiwine (3), kopsamidine A (4), kopsamidine B (5), kopsinidine A (6), kopsinidine B (7), paucidactine C (8), and pericine N-oxide (9), in addition to several recently reported novel indoles and 34 other known ones, were obtained from the stem-bark extract of the Malayan Kopsia arborea. The structures were determined using NMR and MS analysis. Valparicine (12) showed pronounced cytotoxic effects against KB and Jurkat cells (IC(50) 13.0 and 0.91 microM, respectively).

Two new indole alkaloids, kopsiyunnanines J1 and J2, were isolated from Yunnan Kopsia arborea, and their structures were determined by spectroscopic analyses. Kopsiyunnanines J1 and J2 are unprecedented Strychnos-type indole alkaloids having an additional C1 unit in the secologanin moiety of the molecule.

Antioxidant activity of Purnajiwa (Kopsia arborea Blume.) fruit has been investigated.The fruit was extracted by various solvents such as n-hexane, ethyl acetate, and ethanol. The aim of the research is to define a class of compounds and antioxidant activity. The compounds test was conducted by the phytochemical method. The results showed that the purnajiwa fruit extract is classified as secondary metabolites of flavonoids, saponins, tannins, alkaloids, and steroids. The antioxidant activity was tested by DPPH method and the amount of antioxidant activity was characterized by IC50 values. The result indicated that the antioxidant activity (IC50) for n-hexane, ethyl acetate, and ethanol solvents is 3524.05 ppm, 316.09 ppm, and 154.89 ppm respectively.Keywords: Purnajiwa Fruit, Antioxidant, DPPH, Phytochemicals

A new pentacyclic indole alkaloid, kopsiyunnanine E, was isolated from Yunnan Kopsia arborea, and its structure, which was inferred from spectroscopic data, was established by a 16-step asymmetric total synthesis that proved that the natural alkaloid was not enantiomerically pure.

A pair of unusual regioisomeric tetracyclic indoles of the corynantheine-type, arboricine and arboricinine were obtained from the Malayan Kopsia arborea. The structures were established by spectroscopic analysis and a possible biogenetic link between the alkaloids is presented.

Two new indole alkaloids, kopsiyunnanines G (1) and H (2), possessing the Aspidosperma skeleton were isolated from the aerial part of Yunnan Kopsia arborea BLUME (Apocynaceae). Their structures and stereochemistry were elucidated by means of MS and 2D NMR analyses.

Two new indole alkaloids, kopsiyunnanines G (1) and H (2), possessing the Aspidosperma skeleton were isolated from the aerial part of Yunnan Kopsia arborea BLUME (Apocynaceae). Their structures and stereochemistry were elucidated by means of MS and 2D NMR analyses.

Five new alkaloids, including three 19,20-epoxytubotaiwine stereoisomers, viz. kopsiyunnanines F1 (1), F2 (2), and F3 (3), (Z)-isocondylocarpine (4), and (Z)-isocondylocarpine N-oxide (5), along with five known tubotaiwine-type indole alkaloids were isolated from the aerial part of Yunnan Kopsia arborea Blume (Apocynaceae). Their structures including absolute configurations were elucidated by spectroscopic and chemical means.

Three new rhazinilam-derived alkaloids, kopsiyunnanines C1, C2, and C3, and a new quebrachamine-type alkaloid, kopsiyunnanine D, which possess an unusual methoxymethyl or ethoxymethyl function, were isolated from the aerial parts of Yunnan Kopsia arborea. This is the first report of the presence of these functions in natural alkaloids. The structures and absolute configurations of the alkaloids were determined by spectroscopic methods and confirmed by semisynthesis.

A new indole alkaloid, arbophylline, possessing a novel heptacyclic cage skeleton, and incorporating an acetal function, was obtained from the Malayan Kopsia arborea. The structure was established by spectroscopic analysis and a possible biogenetic pathway from an akuammiline-type precursor is presented.

Four indole alkaloids all possessing the rare methyl chanofruticosinate skeletal system have been isolated from the leaves of Kopsia arborea , viz. methyl 11,12-methylenedioxychanofruticosinate, methyl- N 1 -decarbomethoxychanofruticosinate, methyl 11,12-methylenedioxy- N 1 -decarbomethoxychanofruticosinate and methyl 11,12-methylenedioxy- N 1 -decarbomethoxy-Δ 14,15 -chanofruticosinate. The last two are new alkaloids.

The phytochemistry of Kopsia arborea Blume has received considerable attention, which has resulted in the isolation of a number of new unusual indole alkaloids with intriguing structures. In this study, a new eburnane-type alkaloid, phutdonginin (1), together with eight known alkaloids: 19-OH-(-)-eburnamonine (2), melodinine E (3), kopsinine (4), kopsilongine (5), kopsamine (6), (-)-methylenedioxy-11,12-kopsinaline (7), decarbomethoxykopsiline (8), and vincadifformine (9), were isolated from the twigs of K. arborea. Their structures were characterized extensively by 1D and 2D NMR spectroscopy and HR-ESI-MS. All compounds were submitted to TLC screening for acetylcholinesterase inhibitory activities. Only kopsamine and decarbomethoxykopsiline showed AChE inhibition with MIR values of 12.5 and 6.25 μg, respectively, compared with galanthamine (positive control, 0.004 μg). In addition, compounds 1 and 2 inhibited moderate antibacterial activity against E. coli TISTR 780 with the MIC value of 32 μg/mL.

A new alkaloid, kopreasin A (1) was isolated from the leaves of Kopsia arborea (Apocynaceae) together with ten known indole alkaloids (2 - 11), and the structure was elucidated by NMR spectral analysis using 2D techniques. These indole alkaloids showed a moderate vasorelaxant activity on isolated rat aorta ring.