ALEXIS Biochemicals: Tryptanthrin

Advanced Search

You are here: Product Lines > Natural Products / Antibiotics

Antibiotics

Natural Products

Toxins

ALX-270-112

Revised 16-Jun-08

Pentoxifylline
SYNONYMS	Trental 3,7-Dihydro-3,7-dimethyl-1-(5-oxohexyl)-1H-purine-2,6-dione
PRODUCT LINE	Natural Products / Antibiotics
PRODUCT CATEGORY	Natural Products - Other Signal Transduction Pathway Modulators

Ordering Information

Product Numbers:	Format:	Size:	Unit Price:	Quantity:	Add To Cart
ALX-270-112-G001		1 g	15.00 USD
ALX-270-112-G005		5 g	35.00 USD

Product Specification

FORMULA:	C₁₃H₁₈N₄O₃
MW:	278.3
CAS NUMBER:	6493-05-6
MERCK INDEX:	14: 7136
SOURCE/HOST:	Isolated from Penicillium expansum.
PURITY:	≥99%
APPEARANCE:	White solid.
SOLUBILITY:	Soluble in water.
SHIPPING:	AMBIENT
LONG TERM STORAGE:	+20°C

Product Description

Phosphodiesterase inhibitor. Blocks the synthesis of TNF-α. Improves blood flow by decreasing blood viscosity.

Product Specific Literature References

Pentoxifylline inhibits lipopolysaccharide-induced serum tumor necrosis factor and mortality: P. Noel, et al.; Life Sci. 47, 1023 (1990) Abstract
Pentoxifylline inhibits the expression of tissue factor mRNA in endotoxin-activated human monocytes: V. Ollivier, et al.; FEBS Lett. 322, 231 (1993) Abstract
Pentoxifylline: C.P. Samlaska & E.A. Winfield; J. Am. Acad. Dermatol. 30, 603 (1994), Review Abstract
Suppression of hypercholesterolemic atherosclerosis by pentoxifylline and its mechanism: K. Prasad & P. Lee; Atherosclerosis 192, 313 (2007) Abstract

Further Categories Containing This Product:

Phosphodiesterases / Related Products • TNF-alpha & TNF Receptors Other Products • Nitric Oxide Pathway Other Products

ALX-270-113

Revised 08-Apr-08

Phloretin
PRODUCT LINE	Natural Products / Antibiotics
PRODUCT CATEGORY	Natural Products - Protein Kinase Inhibitors

Ordering Information

Product Numbers:	Format:	Size:	Unit Price:	Quantity:	Add To Cart
ALX-270-113-M100		100 mg	37.00 USD

Product Specification

FORMULA:	C₁₅H₁₄O₅
MW:	274.3
CAS NUMBER:	60-82-2
MERCK INDEX:	14: 7326
PURITY:	≥98%
APPEARANCE:	Off-white to beige solid.
SOLUBILITY:	Soluble in acetone, DMSO, 100% ethanol or methanol.
SHIPPING:	AMBIENT
LONG TERM STORAGE:	-20°C

Product Description

Flavonoid. Protein kinase C (PKC) inhibitor. PGF_2a receptor antagonist. In astrocytes, these receptors are linked to phospholipase C, thus affecting phosphoinositide hydrolysis and intracellular Ca²⁺ levels. Inhibits myo-inositol uptake and 5’-iodothyronine deiodinase. Prevents TNF-α stimulated upregulation of VCAM-1, ICAM-1 and E-selectin. Enhances adiponectin expression.

Product Specific Literature References

Effects on water diffusion of inhibitors affecting various transport processes in human red blood cells: G. Benga, et al.; Eur. J. Cell Biol. 59, 219 (1992) Abstract
Phloretin as an antagonist of prostaglandin F2 alpha receptor in cultured rat astrocytes: J. Kitanaka, et al.; J. Neurochem. 60, 704 (1993) Abstract
Characterization of the inhibition by stilbene disulphonates and phloretin of lactate and pyruvate transport into rat and guinea-pig cardiac myocytes suggests the presence of two kinetically distinct carriers in heart cells: X. Wang, et al.; Biochem. J. 290, 249 (1993) Abstract
The effect of glucose and galactose toxicity on myo-inositol transport and metabolism in human skin fibroblasts in culture: G.T. Berry, et al.; Pediat. Res. 35, 141 (1994) Abstract
Activating effect of the flavonoid phloretin on Ca(2+)-activated K+ channels in myelinated nerve fibers of Xenopus laevis: D.S. Koh, et al.; Neurosci. Lett. 165, 167 (1994) Abstract
Thyroid hormones in tissues from fetal and adult rats: G. Morreale de Escobar; Endocrinology 134, 2410 (1994) Abstract
Gonadotropin-releasing hormone induced Ca2+ influx in nonsecreting pituitary adenoma cells: role of voltage-dependent Ca2+ channels and protein kinase C: N. Prevarskaya, et al.; Mol. Cell. Neurosci. 5, 699 (1994) Abstract
The flavonoid phloretin suppresses stimulated expression of endothelial adhesion molecules and reduces activation of human platelets: V. Stangl, et al.; J. Nutr. 135, 172 (2005) Abstract
Phloretin enhances adipocyte differentiation and adiponectin expression in 3T3-L1 cells: M. Hassan, et al.; BBRC 361, 208 (2007) Abstract

Further Categories Containing This Product:

Adiponectin [ACRP30] / Related Products • Adhesion Molecules & Receptors Other Products • PKC Inhibitors • Active Substances from Fruit and Vegetables

ALX-270-125

Revised 25-Apr-08

Resveratrol
SYNONYMS	trans-3,4’,5-Trihydroxystilbene
PRODUCT LINE	Natural Products / Antibiotics
PRODUCT CATEGORY	Natural Products - Antioxidants

Ordering Information

Product Numbers:	Format:	Size:	Unit Price:	Quantity:	Add To Cart
ALX-270-125-M050		50 mg	36.00 USD
ALX-270-125-M100		100 mg	50.00 USD
ALX-270-125-M250		250 mg	95.00 USD

Product Specification

FORMULA:	C₁₄H₁₂O₃
MW:	228.2
CAS NUMBER:	501-36-0
MERCK INDEX:	14: 8158
SOURCE/HOST:	Isolated from Polygonum cuspidatum.
PURITY:	≥98% (HPLC)
APPEARANCE:	White to off-white powder.
SOLUBILITY:	~65mg/ml soluble in DMSO, 100% ethanol or dimethyl formamide; slightly soluble in PBS, pH 7.2 (~100 µg/ml).
SHIPPING:	AMBIENT
LONG TERM STORAGE:	-20°C
HAZARD:	IRRITANT.

Product Description

Shows cancer chemopreventive activity. Specific inhibitor of cyclooxygenase-1 (COX-1). Inhibits the hydroperoxidase activity of COX-1. Antioxidant. Potent activator of human deacetylase SIRT1. Protects against 4-hydroxynonenal (4-HNE) induced oxidative stress and apoptosis.

Product Specific Literature References

Vasorelaxing activity of resveratrol and quercetin in isolated rat aorta: C.K. Chen, et al.; Gen. Pharmacol. 27, 363 (1996) Abstract
Cancer chemopreventive activity of resveratrol, a natural product derived from grapes: M. Jang, et al.; Science 275, 218 (1997) Abstract
Cancer chemopreventive activity of resveratrol: M. Jang & J.M. Pezzuto; Drugs Exp. Clin. Res. 25, 65 (1999) Abstract
Capillary electrophoresis determination, synthesis, and stability of resveratrol and related 3-O-beta-D-glucopyranosides: V. Brandolini, et al.; J. Agric. Food Chem. 50, 7407 (2002) Abstract
Small molecule activators of sirtuins extend Saccharomyces cerevisiae lifespan: K.T. Howitz, et al.; Nature 425, 191 (2003) Abstract
Resveratrol protects against 4-HNE induced oxidative stress and apoptosis in Swiss 3T3 fibroblasts: O. Kutuk, et al.; Biofactors 20, 1 (2004) Abstract
Resveratrol, a polyphenol found in grapes, suppresses oxidative damage and stimulates apoptosis during early colonic inflammation in rats: A.R. Martin, et al.; Biochem. Pharmacol. 67, 1399 (2004) Abstract
Resveratrol interferes with AKT activity and triggers apoptosis in human uterine cancer cells: E. Sexton, et al.; Mol. Cancer 5, 45 (2006) Abstract
Resveratrol and its analogs: Defense against cancer, coronary disease and neurodegenerative maladies or just a fad?: P. Saiko, et al.; Mutat. Res. 658, 68 (2008) Abstract

Related Products

ALX-385-034

Pterostilbene

Further Categories Containing This Product:

Natural Products - Chemopreventive Agents • Active Substances from Fruit and Vegetables • Stilbenoids • Sirtuins / Related Products • COX Inhibitors

ALX-270-157

Revised 03-Apr-08

Australine . hydrochloride
SYNONYMS	(1R,2R,3R,7S,7aR)-3-Hydroxymethyl-1,2,7-trihydroxypyrrolizidine . HCI
PRODUCT LINE	Natural Products / Antibiotics
PRODUCT CATEGORY	Natural Products - Other Signal Transduction Pathway Modulators

Ordering Information

Product Numbers:	Format:	Size:	Unit Price:	Quantity:	Add To Cart
ALX-270-157-M001		1 mg	180.00 USD

Product Specification

FORMULA:	C₈H₁₅NO₄. HCl
MW:	189.2 . 36.5
CAS NUMBER:	186766-07-4
SOURCE/HOST:	Isolated from Castanospermum australe seeds.
PURITY:	≥95%
APPEARANCE:	Crystalline solid.
SOLUBILITY:	Soluble in water, methanol and 100% ethanol.
SHIPPING:	AMBIENT
LONG TERM STORAGE:	+4°C
HANDLING:	After reconstitution, prepare aliquots and store at -20°C.
HAZARD:	HARMFUL.

Product Description

Alkaloid. Inhibitor of α-glucosidase, amyloglucosidase and glucosidase I. Does not inhibit glucosidase II, and is reported to be the first glucosidase inhibitor which differentiates glucosidase I from glucosidase II. Does not inhibit α-galactosidase, β-galactosidase, β-glucosidase, α-mannosidase and β-mannosidase.

Product Specific Literature References

Australine, a pyrrolizidine alkaloid that inhibits amyloglucosidase and glycoprotein processing: J.E. Tropea, et al.; Biochemistry 28, 2027 (1989) Abstract
Calystegins, a novel class of alkaloid glycosidase inhibitors: R.J. Molyneux, et al.; Arch. Biochem. Biophys. 304, 81 (1993) Abstract
Stereoselective synthesis of the glycosidase inhibitor australine through a one-pot, double-cyclization strategy: C. Ribes, et al.; Org. Lett. 9, 77 (2007) Abstract

Further Categories Containing This Product:

Glycosidases / Related Products • Alkaloids

ALX-270-160

Revised 27-Sep-07

Castanospermine
SYNONYMS	(1S,6S,7R,8R,8aR)-1,6,7,8-Tetrahydroxyoctahydroindolizine
PRODUCT LINE	Natural Products / Antibiotics
PRODUCT CATEGORY	Natural Products - Other Signal Transduction Pathway Modulators

Ordering Information

Product Numbers:	Format:	Size:	Unit Price:	Quantity:	Add To Cart
ALX-270-160-M010		10 mg	60.00 USD
ALX-270-160-M050		50 mg	180.00 USD

Product Specification

FORMULA:	C₈H₁₅NO₄
MW:	189.2
CAS NUMBER:	79831-76-8
MERCK INDEX:	14: 1896
SOURCE/HOST:	Isolated from Castanospermum australe seeds.
PURITY:	≥98%
APPEARANCE:	White to off-white solid.
SOLUBILITY:	Soluble in water.
SHIPPING:	AMBIENT
LONG TERM STORAGE:	+4°C
HANDLING:	Protect from moisture.

Product Description

Plant alkaloid. Potent inhibitor of α- and β-glucosidase activity in fibroblast extracts; inhibits the glycoprotein processing cycle. Exhibits antiviral properties. Prevents angiogenesis.

Product Specific Literature References

Castanospermine inhibits the processing of the oligosaccharide portion of the influenza viral hemagglutinin: Y.T. Pan, et al.; Biochemistry 22, 3975 (1983) Abstract
Glycoproteins: their structure, biosynthesis and possible clinical implications: H. Schachter; Clin. Biochem. 17, 3 (1984) Abstract
The effects of processing inhibitors of N-linked oligosaccharides on the intracellular migration of glycoprotein E2 of mouse hepatitis virus and the maturation of coronavirus particles: R. Repp, et al.; J. Biol. Chem. 260, 15873 (1985) Abstract; Full Text
Effects of the anti-inflammatory compounds castanospermine, mannose-6- phosphate and fucoidan on allograft rejection and elicited peritoneal exudates: M.R. Bartlett, et al.; Immunol. Cell Biol. 72, 367 (1994) Abstract
Antiviral activity and metabolism of the castanospermine derivative MDL 28,574, in cells infected with herpes simplex virus type 2: S.P. Ahmed, et al.; BBRC 208, 267 (1995) Abstract
The alpha-glucosidase I inhibitor castanospermine alters endothelial cell glycosylation, prevents angiogenesis, and inhibits tumor growth: R. Pili, et al.; Cancer Res. 55, 2920 (1995) Abstract
Perturbation of free oligosaccharide trafficking in endoplasmic reticulum glucosidase I-deficient and castanospermine-treated cells: C. Durrant & S.E. Moore; Biochem. J. 365, 239 (2002) Abstract

Further Categories Containing This Product:

Glycosidases / Related Products • Natural Products - Antiviral / anti-HIV Agents • Natural Products for Angiogenesis Research • Alkaloids

ALX-270-202

Revised 07-Oct-08

Piceatannol
SYNONYMS	3,4,3',5'-Tetrahydroxy-trans-stilbene
PRODUCT LINE	Natural Products / Antibiotics
PRODUCT CATEGORY	Natural Products - Protein Kinase Inhibitors

Ordering Information

Product Numbers:	Format:	Size:	Unit Price:	Quantity:	Add To Cart
ALX-270-202-M001		1 mg	22.00 USD
ALX-270-202-M005		5 mg	62.00 USD
ALX-270-202-M010		10 mg	105.00 USD
ALX-270-202-M050		50 mg	375.00 USD

Product Specification

FORMULA:	C₁₄H₁₂O₄
MW:	244.3
CAS NUMBER:	10083-24-6
SOURCE/HOST:	Synthetic.
PURITY:	≥98%
APPEARANCE:	Off-white to light pink crystalline solid.
SOLUBILITY:	Soluble in DMSO, dimethyl formamide, 100% ethanol, methanol, acetone or ethyl acetate; slightly soluble in water (1mg/ml).
SHIPPING:	AMBIENT
LONG TERM STORAGE:	+4°C
USE/STABILITY:	Unstable in sodium hydroxide.
HANDLING:	Protect from light and oxygen.

Product Description

Originally isolated from Euphorbia lagascae. Selective protein tyrosine kinase Syk inhibitor. Activator of human deacetylase SIRT1.

Product Specific Literature References

Synthesis and evaluation of stilbene and dihydrostilbene derivatives as potential anticancer agents that inhibit tubulin polymerization: M. Cushman, et al.; J. Med. Chem. 34, 2579 (1991) Abstract
Inhibition of mast cell Fc epsilon R1-mediated signaling and effector function by the Syk-selective inhibitor, piceatannol: J.M. Oliver, et al.; J. Biol. Chem. 269, 29697 (1994) Abstract; Full Text
The tyrosine phosphorylation of a p72syk-like protein in activated murine resident peritoneal macrophages: K.I. Abu-Lawi & B.M. Sultzer; Cell Mol. Biol. Res. 41, 49 (1995) Abstract
Calcium signaling in endothelial cells involves activation of tyrosine kinases and leads to activation of mitogen-activated protein kinases: I. Fleming, et al.; Circul. Res. 76, 522 (1995) Abstract
Coronary arteriolar flow-induced vasodilation signals through tyrosine kinase: J.M. Muller, et al.; Am. J. Physiol. 270, H1878 (1996) Abstract
Syk, activated by cross-linking the B-cell antigen receptor, localizes to the cytosol where it interacts with and phosphorylates alpha-tubulin on tyrosine: J.D. Peters, et al.; J. Biol. Chem. 271, 4755 (1996) Abstract; Full Text
Src-regulated extracellular signal-related kinase and Syk-regulated c-Jun N-terminal kinase pathways act in conjunction to induce IL-1 synthesis in response to microtubule disruption in HL60 cells: B. Cambien, et al.; J. Immunol. 163, 5079 (1999) Abstract; Full Text
FcepsilonRI-mediated antigen endocytosis turns interferon-gamma-treated mouse mast cells from inefficient into potent antigen-presenting cells: C .Tkaczyk, et al.; Immunology 97, 333 (1999) Abstract
Piceatannol, a stilbene phytochemical, inhibits mitochondrial F0F1-ATPase activity by targeting the F1 complex: J. Zheng & V.D. Ramirez; BBRC 261, 499 (1999) Abstract
Microarray analysis of piceatannol-induced changes in gene expression in human gastric cancer cells : D. Jeoung, et al.; Biotechnology Lett. 24, 463 (2002) Abstract; Full Text
Piceatannol, a Syk-selective tyrosine kinase inhibitor, attenuated antigen challenge of guinea pig airways in vitro: C.J. Seow, et al.; Eur. J. Pharmacol. 443, 189 (2002) Abstract
Small molecule activators of sirtuins extend Saccharomyces cerevisiae lifespan: K.T. Howitz, et al.; Nature 425, 191 (2003)

Further Categories Containing This Product:

Kinases in T Cell Signal Transduction / Related Products • B Cell Receptor [BCR] & Co-Receptors / Related Products • Tyrosine Kinase Inhibitors • Stilbenoids • Sirtuins / Related Products

ALX-270-209

Revised 05-Apr-08

Etoposide
SYNONYMS	4-Desmethylepipodophyllotoxin 9-(4,6-O-ethylidene)-β-D-glucopyranoside VP-16-213
PRODUCT LINE	Natural Products / Antibiotics
PRODUCT CATEGORY	Natural Products - Topoisomerase Inhibitors

Ordering Information

Product Numbers:	Format:	Size:	Unit Price:	Quantity:	Add To Cart
ALX-270-209-M025		25 mg	30.00 USD
ALX-270-209-M100		100 mg	65.00 USD
ALX-270-209-M500		500 mg	260.00 USD

Product Specification

FORMULA:	C₂₉H₃₂O₁₃
MW:	588.6
CAS NUMBER:	33419-42-0
MERCK INDEX:	14: 3886
RTECS:	KC0190000
SOURCE/HOST:	Semisynthetic derivative of podophyllotoxin.
PURITY:	≥99%
APPEARANCE:	White to off-white powder.
SOLUBILITY:	Soluble in DMSO, dimethyl formamide, ethyl ether or chloroform:methanol (1:1); slightly soluble in methanol or acetone; insoluble in water.
SHIPPING:	AMBIENT
LONG TERM STORAGE:	+20°C
USE/STABILITY:	Store solutions in DMSO at 4°C. For long term storage prepare aliquots and store at -20°C.
HANDLING:	Protect from light and moisture.
HAZARD:	MAY BE CARCINOGENIC. TOXIC.

Product Description

Antitumor reagent. Topoisomerase II inhibitor. Induces apoptosis by FasL. Activates p53 resulting in upregulated expression of TRAIL-R2 (DR5) and Bak to overcome TRAIL resistance in Bax-deficient human colon carcinoma cancer cells.

Product Specific Literature References

The podophyllotoxin derivatives VP16-213 and VM26: B.F. Issell; Cancer Chemother. Pharmacol. 7, 73 (1982) Abstract
Etoposide: four decades of development of a topoisomerase II inhibitor: K.R. Hande; Eur. J. Cancer 34, 1514 (1998) Abstract
Etoposide sensitivity of human prostatic cancer cell lines PC-3, DU 145 and LNCaP: M. Salido, et al.; Histol. Histopathol. 14, 125 (1999) Abstract
A systematic review of the role of etoposide and cisplatin in the chemotherapy of small cell lung cancer with methodology assessment and meta-analysis: C. Mascaux, et al.; Lung Cancer 30, 23 (2000) Abstract
Distinct pathways for stimulation of cytochrome c release by etoposide: J.D. Robertson, et al.; J. Biol. Chem. 275, 32438 (2000) Abstract; Full Text
Ordering of ceramide formation, caspase activation, and Bax/Bcl-2 expression during etoposide-induced apoptosis in C6 glioma cells: M. Sawada, et al.; Cell Death Differ. 7, 761 (2000) Abstract
Etoposide-induced apoptosis is not associated with the fas pathway in acute myeloblastic leukemia cells: T. Siitonen, et al.; Leuk. Res. 24, 281 (2000) Abstract
Early caspase activation in leukemic cells subject to etoposide-induced G2-M arrest: evidence of commitment to apoptosis rather than mitotic cell death: R.J. Sleiman & B.W. Stewart; Clin. Cancer Res. 6, 3756 (2000) Abstract; Full Text
Cell cycle phase specificity in the potentiation of etoposide-induced DNA damage and apoptosis by KN-62, an inhibitor of calcium-calmodulin- dependent enzymes: M. Aoyama, et al.; Biochem Pharmacol 61, 49 (2001) Abstract
Deacetylase activity associates with topoisomerase II and is necessary for etoposide-induced apoptosis: C.A. Johnson, et al.; J. Biol. Chem. 276, 4539 (2001) Abstract; Full Text
In vitro topo II-DNA complex accumulation and cytotoxicity of etoposide in leukaemic cells from patients with acute myelogenous and chronic lymphocytic leukaemia: Y. Wang, et al.; Leuk. Res. 25, 133 (2001) Abstract
Etoposide: discovery and medicinal chemistry: P. Meresse, et al.; Curr. Med. Chem. 11, 2443 (2004), Review Abstract
Etoposide, topoisomerase II and cancer: E.L. Baldwin & N. Osheroff; Curr. Med. Chem. Anticancer Agents 5, 363 (2005), Review Abstract

Further Categories Containing This Product:

Other Toxins • Natural Products - Apoptosis Inducers & Inhibitors • Natural Products - Antitumor Reagents • Antitumor Agents (Enzyme Inhibitors) • Antitumor Agents (Apoptosis Inducers)

ALX-270-231

Revised 28-Feb-08

Caffeic acid
SYNONYMS	3-(3,4-Dihydroxyphenyl)-2-propenoic acid
PRODUCT LINE	Natural Products / Antibiotics
PRODUCT CATEGORY	Natural Products - Anti-inflammatory Agents

Ordering Information

Product Numbers:	Format:	Size:	Unit Price:	Quantity:	Add To Cart
ALX-270-231-M250		250 mg	10.00 USD
ALX-270-231-G001		1 g	14.00 USD

Product Specification

FORMULA:	C₉H₈O₄
MW:	180.2
CAS NUMBER:	331-39-5
MERCK INDEX:	14: 1635
SOURCE/HOST:	Synthetic.
PURITY:	≥97%
APPEARANCE:	Off-white to brown crystalline solid.
SOLUBILITY:	Soluble in 100% ethanol, DMSO or dimethyl formamide; also soluble in PBS, pH 7.2.
SHIPPING:	AMBIENT
LONG TERM STORAGE:	+20°C
USE/STABILITY:	Stable for at least 2 years when stored at +20°C. Organic stock solutions are stable for at least 6 months when stored at –20 °C. Store aqueous solutions of the product on ice and use within 12 hours of preparation.

Product Description

Naturally occuring phenolic compound found in many fruits, vegetables and herbs, including coffee. Shows anti-tumor, antiviral, antioxidant and anti-inflammatory effects. Inhibitor of 5- and 12-lipoxygenase (LO).

Product Specific Literature References

Caffeic acid is a selective inhibitor for leukotriene biosynthesis: Y. Koshihara, et al.; Biochim. Biophys. Acta 792, 92 (1984) Abstract
Inhibitory effect of caffeic acid esters on azoxymethane-induced biochemical changes and aberrant crypt foci formation in rat colon: C.V. Rao, et al.; Cancer Res. 53, 4182 (1993) Abstract
Inhibition of arachidonate lipoxygenase activities by 2-(3,4-dihydroxyphenyl)ethanol, a phenolic compound from olives: N. Kohyama, et al.; Biosci. Biotech. Biochem. 61, 347 (1997) Abstract
Caffeic acid derivatives: in vitro and in vivo anti-inflammatory properties: F.M. da Cunha, et al.; Free Radic. Res. 38, 1241 (2004) Abstract
Novel and therapeutic effect of caffeic acid and caffeic acid phenyl ester on hepatocarcinoma cells: complete regression of hepatoma growth and metastasis by dual mechanism: T.W. Chung, et al.; FASEB J. 18, 1670 (2004) Abstract
Anti-HIV activities of natural antioxidant caffeic acid derivatives: t