Tylophora alkaloids isolation

Tylophorine (1) and its analogs, the phenanthroindolizidine alkaloids also referred to as tylophora alkaloids, have been isolated primarily from plants of the family Asclepiadaceae [13-16], Fig. (1), including members of the genus Tylophora, Vincetoxicum, Pergularia, Cynanchum, but also from Hypoestes verticillaris (Acanthaceae) [17], Cryptocarya phyllostemmon (Lauraceae) [18], Ficus hispida and F. septica (Moraceae) [2, 19]. TTie isolations of these alkaloids are summarized in Table 1. The most significant phenanthroindolizidine alkaloids are tylophorine (1), tylocrebrine (2), antofine (3), and tylophorinine (4), Fig. (2). 

Tylophora Alkaloids.—Administration of [2- C]tyrosine to Tylophora asthma-tica was followed by the isolation of radioactive tylophorine (51) and tylo-phorinine (52). Degradation of the former indicated an exclusive incorporation of the label at in (51). It is perhaps surprising that one rather than two tyrosine units is apparently involved in the biosynthesis of tylophorine, but on the other hand the tracer experiments on these alkaloids have only just begun. 

Most of the alkaloids isolated from Tylophora which have a phenanthro-indolizidine skeleton exhibit cytotoxic activity against HeLa cells, the position... 

ISOLATION OF TYLOPHORA ALKALOIDS FROM MEDICINAL PLANTS... 

Saraswati S, Kanaujia PK, Kumar S, Kumar R, Alhaider AA. Tylophorine, a phenan-thraindoUzidine alkaloid isolated from Tylophora indica exerts antiangiogenic and antitumor activity by targeting vascular endothelial growth factor receptor 2-mediated angiogenesis. Mol Cancer 2013 12 82. 

In addition to quinine and related alkaloids see Chapter 34), other quinoline alkaloids occur in Tylophora asthmatica (Asclepiadaceae) see Chapter 30). Two quinoline alkaloids have been reported from Melochia (Sterculiaceae) (Specialist Periodic Reports 1978, 1979). An alkaloid isolated from Broussonetia (Moraceae), 4-formyl-8-hydroxyquinoline, may not be closely related to other quinoline alkaloids. An... 

Few alkaloids have been found in this relatively large family. Those in Cryptolepis, Cynanchum, Pergularia, Tylophora, and Vm-cetoxicum have been characterized, some have been synthesized, others have yet to be isolated in pure form. 

Furoquinoline Alkaloids.—Well-known furoquinoline alkaloids have been identified for the first time in twelve species of the Rutaceae (see the Table 2.5.8,9,11—13,15,16 on p an(j rare trimethoxydictamnine halfordinine (1 R1 = R2 = R3 = OMe) has been obtained from Araliopsis tabouensis2 and from Teclea verdoorniana.12 The isolation of y-fagarine and skimmianine from Tylophora asthmatica (Asclepiadaceae)14 and skimmianine from Datura stramonium (Solanaceae)4 is of considerable taxonomic interest. 

Tylophora crebriflora S. T. Blake (T. floribunda Benth.) occurs in North Queensland. Extraction of the plant material with hot methanol afforded the crude mixture of alkaloids which was purified by chromatography on cellulose powder using propanol-2 N acetic acid as the eluent. Further purification by repeated chromatography yielded tylophorine (Bf 0.5 in butan-l-ol-acetic acid 97 3) and tylocrebrine (R 0.2 in the same solvent system) (mp 218°-220° [a] D — 45° + 2° (c 0.1, CHCI3). (+ )-Tylocrebrine isolated from Ficus septica Forst. f. was found (4) to have mp 220°-222° and [a] f + 20.5° + 2° (c 0.8, CHCI3). 

The objective of this review article is to provide comprehensive information about isolation, total synthesis, antitumor activity, and structure-activity relationship (SAR) correlations of tylophorinc-related alkaloids in order to facilitate the anticipated drug discovery and development of the tylophora class. 

Septicine (866), the prototypical alkaloid in this group, is a seco variant of the more populous phenanthroindolizidine class of alkaloids, of which tylophorine (867) and antofme (868) are commonly encountered examples. All fte known analogs of septicine are metabolites of the unrelated genera Cryptocarya (Lauraceae), Ficus (Moraceae), and Tylophora (Asclepiadaceae). In addition to Ihe previously described alkaloids 8a-hydroxysepticine (869) and hispidine (870) (7), seven new members of the family have been isolated (Table II and Fig. 16). 

In addition to benzylisoquinolines, the family Lauraceae furnishes phenanthro-quinolizidine alkaloids such as the previously mentioned cryptopleurine (31) [77], a highly cytotoxic and vesicant substance first isolated from Cryptocarya pleurosperma [78]. These alkaloids are closely related structurally to the phenanthroindolizidines, a group of bases found in the families Asclepidaceae and Moraceae that are likewise vesicant. An example is tylocrebrine (56), which is elaborated by a Queensland plant from each family, Tylophora crebriflora [79] and Ficus septica [80], respectively. In the latter it occurs along with the seco analogue septicine (57), its presumed biosynthetic precursor. Apart from phenanthroindolizidines, certain Ficus spp. produce some simple pyrrolidine bases such as ficine (58) that are noteworthy because of their flavonoid substituents [81],... 

The constituents of Tylophora crebriflora S. T. Blake have also been reexamined and, in addition to tylocrebrine (32) and tylophorine, a total of six alkaloids has been isolated.14 Of these, Alkaloid F is septicine,15 and the remainder (Alkaloids A—E) are new. 

Four alkaloids have been isolated from Tylophora crehriflora (Family Asclepiadaceae) by systematic fraetionation, namely Tylophorine Tylocrebrine, Tylophorinine, and Phenanthroindolizidine. 

An alkaloid, possibility identical with tylophorinidine, 7, which was isolated by Rao from Tylophora asthmatica 18) and from T. dalzellii 18), showed significant activity in murine leukemia (L-1210 system). 

Rathnagiriswaran AN, Venkatachalam K. The chemical examination of Tylophora asthmatica and isolation of the alkaloids tylophorine and tylophorinine. Indian J. Med. Res. 1935 22(3) 433 1. 

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