Terpenoid bio-transformations and applications via cell/organ cultures: a systematic review.

Structurally diverse natural products are valued for their targeted biological activity. The challenge of working with such metabolites is their low natural abundance and complex structure, often with multiple stereocenters, precludes large-scale or unsophisticated chemical synthesis. Since select plants contain the enzymatic machinery necessary to produce specialized compounds, tissue cultures can be used to achieve key transformations for large-scale chemical and/or pharmaceutical applications. In this context, plant tissue-culture bio-transformations have demonstrated great promise in the preparation of pharmaceutical products. This review describes the capacity of cultured plant cells to transform terpenoid natural products and the specific application of such transformations over the past three decades (1988-2019).

Microbial biotransformation as a tool for drug development based on natural products from mevalonic acid pathway: A review.

Natural products are structurally and biologically interesting metabolites, but they have been isolated in minute amounts. The syntheses of such natural products help in obtaining them in bulk amounts. The recognition of microbial biotransformation as important manufacturing tool has increased in chemical and pharmaceutical industries. In recent years, microbial transformation is increasing significantly from limited interest into highly active area in green chemistry including preparation of pharmaceutical products. This is the first review published on the usage of microbial biocatalysts for some natural product classes and natural product drugs.

The flavonoid constitunts of Leucaena leucocephala. Growing in Egypt, and their biological activity.

BACKGROUND: Leucaena leucocephala is native to Southern Mexico and Northern Central America, but is now naturalized throughout the tropics. The phyto-chemical data of L. leucocephala revealed the presence of terpenes, flavonoids, coumarins and sterols. Various parts of L. leucocephala have been reported to have medicinal properties. MATERIALS AND METHODS: Flavonoids were isolated from the aerial parts of L. leucocephala. Antioxidant activity of the extracts and the isolated compounds was evaluated using (DPPH), as well as their cytotoxic activity using a single tumor [Ehrlish ascites carcinoma cells]. RESULTS: The flavonoidal constituents isolated from chloroform, ethyl acetate and n-butanol fractions of the aqueous alcoholic extract of aerial parts of Leucaena leucocephala were identified as Caffeic acid, Isorhamnetin, Chrysoeriol, Isorhamnetin 3-O-galactoside, Kaempferol-3-O-rubinoside, Quercetin-3-O-rhamnoside and Luteolin-7-glucoside. Chemical structures of the isolated compounds were identified by TLC, PC and spectral techniques (UV, (1)H-NMR and MS). The ethyl acetate fraction and the isolated flavonoidal compounds showed high antioxidant activity compared to Trolox (standard antioxidant compound). The different fractions and isolated compounds of Leucaena leucocephala exhibited no cytotoxic activity against Ehrlich-ascitis carcinoma cell line at the tested concentrations. CONCLUSION: This is the first record of the flavonoids in the aerial parts of Leucaena leucocephala (L.) except Quercetin-3-O-rhamnoside.

Phytochemical and biological investigations of Atriplex semibacata R .BR. growing in Egypt.

The lipid content of Atriplex semibacata growing in Egypt was studied. The unsaponifiable fraction was identified by GLC. A series of hydrocarbons ranging from C(14)- C(28) in addition to cholesterol, stigmasterol and the triterpenoids α and ß - amyrin were identified. GLC analysis of fatty alcohols fraction revealed the presence of six fatty alcohols in which dotriacontanol (C(32)H(66)O) was the major (14.68%). Six compounds (five coumarins and one phenolic acid) were isolated for the first time from A. semibacata. The coumarin constituents isolated from the chloroform and the ethyl acetate fractions of the aqueous alcoholic extract of A. semibacata were identified as scopoletin, umbelliferorne, coumarin, scopolin, 7-methoxy coumarin in addition to a phenolic acid P-coumaric acid. Also, the flavonoidal compounds isolated from the n-butanol fraction of the plant revealed the presence of kaempferol 3-O glucoside and acacetin. Their identity was proved by m.p., TLC, PC, UV and MS analysis. The alcohol extract showed significant antimicrobial activity against G-ve bacteria, moderate activity against G+ve bacteria. On the other hand, the pet. Ether extract showed marked activity against G+ve bacteria and fungi, also the G-ve bacteria was greatly inhibited by the chloroform extract. The different extracts of the plant exhibited no cytotoxic activity against Erlich-ascites carcinoma cells line at the tested concentrations, also showed a strong antioxidant activity using DPPH.

Naphthaquinones of Alkanna orientalis (L.) Boiss.

The roots of Alkanna orientalis (L.) Boiss yielded alpha-methyl-n-butyl alkannin (compound 1) and alkannin acetate (compound 2). The compounds were identified by UV, MS, (1)H NMR and (13)C NMR. Quantitative determination of alpha-methyl-n-butyl alkannin and alkannin acetate in Alkanna orientalis (L) Boiss roots was established by TLC densitometry.