Nature which consists of so many variabilities of living components of the environment possesses useful, harmful and inactive chemical constituents. The classification based on these chemical constituents is known as chemotaxonomy. All the living components of the environment produce secondary metabolites that are derived from primary metabolites. The chemical structure of the secondary metabolites is often specific and restricted to taxonomically related organisms. The classification of plants on the basis of specific class of secondary metabolites and their biosynthetic pathways constitutes chemotaxonomy. Its study is helpful to taxonomist, phytochemists and pharmacologists to solve selected taxonomical problems

https://www.plantsjournal.com/archives/2016/vol4issue3/PartB/4-2-17.pdf

Chemotaxonomy: A Tool for Plant Classification

Nine new alkaloids, melodinines M-U (1-9), and 11 known alkaloids were isolated from Melodinus suaveolens. The new structures were elucidated by extensive NMR and mass spectroscopic analyses and comparison to known compounds. All compounds were evaluated for their cytotoxicity against five human cancer cell lines. Compounds 6, 11, and 16 showed significant cytotoxicity.

Melodinines M-U, cytotoxic alkaloids from Melodinus suaveolens.

Eight new monoterpenoid indole alkaloids, alstoyunines A-H (1-8), along with 17 known analogues, were isolated from Alstonia yunnanensis. The structures of. the new alkaloids were established by means of extensive spectroscopic methods. Alstoyunines C (3), E (5), and F (6) showed selective inhibition of Cox-2 (>75%). Alstoyunine F (6) showed weak cytotoxicity against the human myeloid leukemia HL-60 (IC(50) = 3.89 mu M) and hepatocellular carcinoma SMMC-7721 (IC(50) = 21.73 mu M) cell lines.

Monoterpenoid Indole Alkaloids from Alstonia yunnanensis

Rauwolfia is an important genus of the plant family Apocynaceae. There are nearly one hundred and twenty‐five species of Rauwolfia which are distributed all over the tropical regions of the world (1‐8). The most important member of the genus is R. serpentina Benth; the crude drug was known to the ancient Indians as a useful febrifuge (8), a remedy for snake bite, and as a cure for dysentery. In more recent times it has been used for insomnia, hypochondria and insanity.

The presence of alkaloidal principles in R. serpentina was first pointed out in 1890 by Greshoff (9). In 1933, Chopra, Gupta, and Mukherjee (10) reported the hypotensive activity of the material extracted from the plant and in 1931 Siddiqui and Siddiqui (11) isolated a series of crystalline alkaloids from R. serpentina. Active chemical and pharmacological interest in R. serpentina has resulted in the discovery of several new alkaloids (Table I). The isolation by Muller, Schlittler, and Bein (12) of reserpine, an alkaloid with pronounced hypotensive and sedative activity, has lent further impetus to the pharmacological and chemical study of the alkaloids of R. serpentha. A brief summary of the chemical aspects of R. serpentina will be presented in this review.

E. Schlittler

Papers

Rauwolfia Alkaloids. IX.1 Isolation of Yohimbine from Rauwolfia serpentina Benth.