Bitter cucurbitaceae

Momordica charantia (bitter gourd) (Cucurbitaceae) [seed] BGIA (68 aa 7 kDa 2 Cys 1 S-S) Streptomyces griseus Glutamate Endopeptidase [70 nM], Subtilisin Carlsberg [465]... 

Cucurbitacin is a bitter-tasting principle that can be isolated from members of the family Cucurbitaceae, such as cucumber Cucumis sativus) and melon (Cucumis melo L.). In particular, cucurbitacin149 and momordicine,150 which have an intensely bitter taste, are contained abundantly in Momordica charantia (bitter melon in English, go-yaa in Okinawa, Japan), which people enjoy due to its bitterness. There are more than 18 kinds of cucurbitacin, and among them cucurbitacin B is a typical component. It has been reported that cucurbitacin exhibits anticancer activity.1 1 In addition, it is used for the treatment of hepatic disease in traditional Chinese medicine. It is also found in some herbal teas. 

Momordica balsamina L. [inkakha, bitter gourd] (Cucurbitaceae) aerial parts are eaten as a vegetable for hypertension and diabetes 18). The leaf contains alkaloids, flavonoids, glycosides and polyphenols 18). The seed oil contains two conjugated octadecatrienoic acids 19). The plant also possesses antiplasmodic, analgesic and sedative properties which have been demonstrated in rodents (20). 

Momordica Charanlia Linn (Cucurbitaceae) Fruits, Seeds (Asia, Africa, South America) Bitter melon, also known as balsam pear or karela, is widely cultivated in Asia, Africa and South America and has been used extensively in folk remedies for diabetes. The fresh juice of the unripe fruit, dried fruit or seeds has demonstrated oral hypoglycemic activity [5], Several compounds with hypoglycemic activity have been identified, including an insulin-like polypeptide known as p-insulin ( p-is for plant) [153],... 

CucurbHacins. Large group (>40) of tetracyclic tri-terpenes, mostly occurring in glycosidic form (exceptions C. A, C. C, and C. F) as poisonous bitter substances in cucumber and pumpkin plants (Cucurbitaceae) as well as in some craciferous plants (Brassicaceae) they have also been isolated from an agaric ( hebevino-... 

The name of about 50 naturally abundant cucurbitanes stems from Cucurbitaceae, the Latin term of cucurbitaceous plants such as cucumbers and pumpkins, known since antiquity for their beneficial and toxic properties. One of the most frequently isolated representatives is the bitter substance (+)-cucurbitacin B from Phormium tenax and Ecballium elaterium (Cucurbitaceae), also found in Iberis species (Cru-ciferae), Euphorbiaceae and Scrophulariaceae. (+)-Cucurbitacin F from Cucumis angolensis and C. dinteri is reported to inhibit the growth of human tumor cells. Toxic cucurbitacines shape the unpleasant bitter taste of salads prepared from spoiled cucumbers Cucumis sativus some representatives are reported to be antihypertonic, antirheumatic, and also active against HIV. 

Although cucurbitacins serve as allomones for most other insects, these compounds are kairomones, or attractants, for many insects associated with the Cucurbitaceae (Metcalf, 1985). For example, when cucumber beetles are offered a choice of nonbitter and bitter (cucurbitacin containing) fruits, they feed almost exclusively on the bitter fruits (11 1). When given the same choice, the honeybee. Apis mellif-era, will select food materials lacking the cucurbitacins (Har-bome, 1982). 

Cueurbitacins tetracyclic triterpenes found as their glycosides in the Cucurbitaceae and Cruciferae. These toxic, bitter compounds are structurally related to the parent hydrocarbon, cucurbitane [19(10-9P)-abeo-5p-lanostane], which differs from lanostane (see Lanosterol) in the formal shift of the 10-methyl group to the 9p-position. Cucurbitacin E was formerly known as elaterin. C. have a laxative action some serve as insect attractants, and a few have antineo-plastic and antigibberellin activity. 

Hopanoids are membrane stabilizers in certain procaryotes (E 2.2). Their hydrophilic, polyhydroxylated side-chain is directed towards the aqueous face the lipophilic ring system is integrated in the lipophilic core of the membranes. Lanosterol is used as emulsifier in the pharmaceutical industry. Cucurbitacins due to their bitter taste may discourage animal predators, but attract certain beetles, which use Cucurbitaceae as food plants (E 5.5.3). 

Cucurbitacins are the most oxygenated 30C triterpenoids with a dimethyl group at C4 and three methyl groups at C9, C13, and C14, respectively. About 50 species have been isolated and identified mainly from Cucurbitaceae species commonly in glycosides. Some of them are the most bitter substances known. Unlike common steroids, they are not methylated at C-10. Cucurbitacin D, a typical example of cucurbitacins, is a potential new therapeutic drug for treatment of T-cell leukemia. 

Cucurtbitacins are tetracyclic compounds produced by plants of Cucurbitaceae family and humans sense their taste as bitter. Some specialized cucumber leaf beetles of can efficiently detoxify these compounds. Limonoids are a large group of oxygenated triterpenoids produced by plants in Rutaceae and Meliaceae famihes. 

The lipid content of vegetables is generally low (0.1-0.9%). In addition to triacylglyce-rides, glyco- and phospholipids are present. Carotenoids are occasionally found in large amounts (cf. 18.1.2.3.2). Table 17.7 provides data on carotenoid compounds in green bell and paprika peppers, tomato and watermelon. For the occurrence of bitter cucurbitacins in Cucurbitaceae, see 18.1.2.3.3. 

Vegetables of the cucurbit family (Cucurbitaceae), which includes squashes, melons, pumpkins, cucumbers and gourds of the genera Benincasa, Citrullus, Cucumic, Cucurbita, Lagemria and Lujfa, occasionally show bitter taste in response to various... 

A special group of cucurbitacins are found in bitter melon, also known as bitter gourd or bitter squash Momordica charantia, Cucurbitaceae), which belongs to the most bitter of the edible fruits. The bitter taste of bitter melon is caused by a number of cucurbitane-type triterpenic glycosides called momordicosides, such as momordicosides K and L (8-239). Bitter melon originated in India and is now widely cultivated in Asia and Africa. The plant also contains other biologically active compounds for which it is used to treat a number of diseases, such as toothache, diarrhea, furuncle and diabetes. 

Marrow, pumpkin, squash, courgette (zucchini) are all Cucurbita species and members of the Cucurbitaceae, as are melons (Cucumis melo). Squashes were very important to early inhabitants of Southern and Central America, as important as corn and beans. Fossilized remains of squashes in Peru have been dated to 4000 bc. Originally the flowers, seeds and flesh were eaten. The seeds provided a source of sulphur-containing amino acids. Wild members of the family are thin-skinned and bitter. There are few data available on the phytochemical content of the flesh of squashes. Butternut squash has been found... 

---